Journal of Food Composition and Analysis

[[CONTENTSCONTENTS — continuedcontinued fromfrom outsideoutside backback cover]cover] Journal of Food Composition and Analysis Melatonin: A new bioactive compound in wine The Journal of Food Composition and Analysis publishes manuscripts on scientific aspects of data on the chemical composition of human foods, with particular emphasis on: M. Isabel Rodriguez-Naranjo, Angel Gil-Izquierdo, Ana M. Troncoso, Emma Cantos and M. Carmen Garcia-Parrilla 603 actual data on composition of foods; analytical methods; studies on the manipulation, storage, distribution and use of food composition data; and studies on the statistics, use and distribution of such data and data systems. The Journal’s basis is nutrient composition, with increasing emphasis on bioactive non-nutrient and anti-nutrient components. Assessment of 4-(5-)methylimidazole in soft drinks and dark beer Papers must provide sufficient description of the food samples, analytical methods, quality control procedures and statistical treatments of the data to permit the end users of the food composition data to evaluate the appropriateness of such data in their projects. S.C. Cunha, A.I. Barrado, M.A. Faria and J.O. Fernandes 609

The Journal does not publish papers on: microbiological compounds; sensory quality; aromatics/volatiles in food and wine; essential oils; organoleptic characteristics of food; Short communications physical properties; or clinical papers and pharmacology-related papers. Effect of extraction solvents on the phenolic compounds and antioxidant activities of bunga kantan (Etlingera CHIEF SCIENTIFIC EDITOR MANAGING EDITOR SPECIAL ISSUES AND SUPPLEMENTS EDITOR elatior Jack.) inﬂ orescence K. Phillips J. Crews C. Champagne M.M. Jeevani Osadee Wijekoon, Rajeev Bhat and Alias A. Karim 615 Blacksburg, VA, USA Rome, Italy Baton Rouge, LA, USA Inﬂ uence of ethylene on carotenoid biosynthesis during papaya postharvesting ripening Gisela P.M. Barreto, João P. Fabi, Veridiana V. De Rosso, Beatriz R. Cordenunsi, Franco M. Lajolo, João R.O. do CONSULTING EDITOR CONSULTING AND Nascimento and Adriana Z. Mercadante 620 N.S. Scrimshaw FOUNDING EDITOR Boston, MA, USA K.K. Stewart Austin, TX, USA Editorial 8th International Food Data Conference: Quality food composition data, key for health and trade

EDITORIAL BOARD Prapasri Puwastien 625 G.A. Annor C. Güler J. Klensin P. Puwastien Legon-Accra, Ghana Mersin, Turkey Cambridge, MA, USA Nakhon Pathom, Thailand Original research articles

E. Cantos-Villar J-F. Hausman C.P. Kouebou G.A. Reineccius Brazilian fl avonoid database: Application of quality evaluation system Jerez de la Frontera (Cadiz) Spain Belvaux, Luxembourg Garoua, Cameroon St Paul, MN, USA Elizabete Wenzel de Menezes, Nelaine Cardoso Santos, Eliana Bistriche Giuntini, Milana C.T. Dan, Maria Ines Genovese P.C.K. Cheung D.B. Haytowitz H.V. Kuhnlein F. Ribarova and Franco M. Lajolo 629 Hong Kong, China Beltsville, MD, USA Quebec, Canada Sofi a, Bulgaria Environmental implication of iodine in water, milk and other foods used in Saharawi refugees camps in Tindouf, H. Corke M. Heinonen N.B. Lutaladio H. Schönfeldt Algeria Hong Kong, China Helsinki, Finland Rome, Italy Pretoria, South Africa Ingrid Barikmo, Sigrun Henjum, Lisbeth Dahl, Arne Oshaug and Liv Elin Torheim 637 C. Díaz Romero J.M. Holden U. Lanfer Marquez M. Serafi ni Santa Cruz de Tenerife, Spain Beltsville, MD, USA São Paulo, Brazil Rome, Italy Investigation of Thai plants for potential sources of inulin-type fructans K.G. Duodu P.J.M. Hulshof A.Z. Mercadante R. Vannoort Kunchit Judprasong, Siriporn Tanjor, Prapasri Puwastien and Pongtorn Sungpuag 642 Pretoria, South Africa Wageningen, Netherlands Campinas, Brazil Christchurch, New Zealand Method performance study for total solids and total fat in coconut milk and products N.-E. Es-Safi N. Ismail R. Mokni W.R. Wolf Takaddoum, Morocco Penang, Malaysia Tunis, Tunisia Beltsville, MD, USA Niphaporn Lakshanasomya, Arunee Danudol and Tipawan Ningnoi 650 V. Gökmen G.V. Iyengar P.C. Onianwa Provision of profi ciency test (PT) scheme on proximate and mineral analyses: Philippine experience Ibadan, Nigeria Ankara, Turkey Bethesda, MD, USA Teresita R. Portugal, Mildred A. Udarbe, Julita G. Ardeña, Leah N. Castillo and Sheila T. Mendez 656 M. González J. Jakobsen K.Y. Patterson Tenerife, Spain Søborg, Denmark Beltsville, MD, USA The distance learning tool ‘Food Composition Study Guide’ contributes to global capacity development in food composition Cover Illustrations U. Ruth Charrondiere, Heinz Freisling and Ibrahim Elmadfa 663 Except where otherwise indicated, all images used on JFCA covers are from the Rare Book Collection of the the David Lubin Memorial Library of the Food and Agriculture Organization of the United Nations (FAO), whose collections include over a million volumes on agriculture, food and nutrition, rural development, fi sheries, forestry and other related topics. Included in this extraordinary collection are many ancient, Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits rare and valuable scientifi c books, papers and manuscripts. The Library is based on a historical core collection of over 360,000 books assembled by David Lubin beginning in 1905, the date of the founding of the International Institute of Agriculture (IIA), FAO’s predecessor in Rome. L.Y. Chew, K. Nagendra Prasad, I. Amin, A. Azrina and C.Y. Lau 670

Cattle: Mongolian (Halhïn Gol) of Dornod, the northeastern grasslands of Mongolia. This miniature to small-sized authentic breed of cattle serves for dairy, work and beef. Well-fed cows will yield 500–700 kg of milk with 4.6–6% fat. Cattle are the mainstay of the Mongolian economy, outnumbering people by two to one. Original watercolours by Marleen Felius, Cattle Breeds, An Encyclopedia, Misset, Doetinchem Reports (NL), p. 438, 1995. By kind permission of the author. Fish: Parapenaeus longirostris, Deep-water rose shrimp; Engraulis encrasicolus, anchovy; Eledone cirrhosa, Curled octopus. Three of the edible marine organisms of the Eastern Mediterranean Sea. Original Brazilian Network of Food Data Systems and LATINFOODS Regional Technical Compilation Committee: Food watercolours by Emanuela D’Antoni, FAO Fisheries Department. composition activities (2006–2009) Fruits and Vegetables: From top, and left to right: Fragaria sp. “Lehigh”, Strawberry. This fruit-bearing plant belongs to the rose family, Roseaceae, and the nutritious and edible fruits are widely consumed. National Agricultural Library, Agricultural Research Elizabete Wenzel de Menezes, Eliana Bistriche Giuntini, Milana C.T. Dan, Nelaine Cardoso Santos, Alexandra Tavares de Service, USDA. Melo and Franco M. Lajolo 678 Malva rosea (also known as Alcea rosea L.), Mallow plant, common in woodland gardens and along sunny roads. The young leaves can be eaten raw in salads, or cooked; the fl ower petals are used for making tea. Metal plate engraving, hand-coloured. Hortus Romanus juxta Systema Tournefortianum, 1772–1793. Distributed by Georgiia Bonelli. Engravings by M. Bouchard et Gravier, Rome. Food composition databases for nutrition labelling: Experience from Australia Pinus cembra, Swiss stone pine cone with pine nuts, found in the Alps and Carpathian Mountains across Central and Eastern Europe. The nuts of the pine are edible seeds. The Swiss stone pine is known for its high protein content (about 34%). The nuts can also be used to extract pine nut oil, highly valued for its mild and nutty fl avour. Hempel, Gustav & Karl Wilhelm. Die Bäume und Sträucher des Waldes in J. Cunningham and R. Sobolewski 682 botanischer und forstwirthschaftlicher Beziehung. II. Die Laubhölzer. Wien & Olmütz, Ed. Hölzel, 1889–1899, 3 volumes. Ficoides Africana humilis (Original image name), fi coide glaciale (Mesembryanthemum crystallinum). The leaves and stems are edible either raw or cooked, can be used as a spinach substitute, and can also Modes of handling Oxygen Radical Absorbance Capacity (ORAC) data and reporting values in product labelling be pickled like cucumbers or used as a garnish. The seeds may be used as a famine food when all else fails. Metal plate engraving, hand-coloured. Hortus Romanus juxta Systema Tournefortianum, 1772–1793. Distributed by Georgiia Bonelli. Engravings by M. Bouchard et Gravier, Rome. Katherine Stockham, Rohani Paimin, John D. Orbell, Paul Adorno and Saman Buddhadasa 686 Cucumis Sativus, common cucumber. This familiar plant belongs to the gourd family Cucurbitaceae, which also includes squash and melons. Cucumbers are scientifi cally classifi ed as fruits because they contain seeds within and the plant develops from a fl ower. Metal plate engraving, hand-coloured. Hortus Romanus juxta Systema Tournefortianum, 1772–1793. Distributed by Georgiia Bonelli. Engravings by Nutrition indicator for biodiversity on food composition—A report on the progress of data availability M. Bouchard et Gravier, Rome. Melopepo (Original fi le name), may be identifi ed as Cucurbita pepo. The species Cucurbita pepo is a cultivated plant of the genus Cucurbita, a genus in the gourd family Cucurbitaceae fi rst cultivated in the Barbara Stadlmayr, Emma Nilsson, Beatrice Mouille, Elinor Medhammar, Barbara Burlingame and U. Ruth Americas and now used in many parts of the world. The rind of this particular variety is naturally green. Fruits and fl owers are edible and highly nutritious. Metal plate engraving, hand-coloured. Hortus Romanus Charrondiere 692 juxta Systema Tournefortianum, 1772–1793. Distributed by Georgiia Bonelli. Engravings by M. Bouchard et Gravier, Rome. Solanum tuberosum, potato. Varieties pictured here include, beginning with the purple-fl eshed potato on the left, Vitelotte Noire, (top and bottom left) Bintje, (right, unpeeled) Ratte and (bottom right) Nutritional composition of freshly harvested and stored Latvian potato (Solanum tuberosum L.) varieties depending Bonnotte. In R. Diehl, 1938. La Pomme de Terre. Paris, Imprimerie Nationale. Background image: Wheat (Triticum aestivum L.) growing in Afghanistan, © FAO/Giulio Napolitano. on traditional cooking methods Irisa Murniece, Daina Karklina, Ruta Galoburda, Dace Santare, Ilze Skrabule and Helena S. Costa 699

(Contents continued on page VI)

YYJFCAJFCA IIFCFC 24(4-5).indd24(4-5).indd 1 66/2/11/2/11 33:37:15:37:15 PPMM Journal of Food Composition and Analysis 24 (2011) i–iii

Contents lists available at ScienceDirect

Journal of Food Composition and Analysis

journal homepage: www.elsevier.com/locate/jfca

Contents

Volume 24, Issues 4–5, 2011

Study review A review of composition studies of cultivated almonds: Macronutrients and micronutrients Sylvia Yada, Karen Lapsley and Guangwei Huang 469

Biodiversity Tocopherol content in fifteen grape varieties obtained using a rapid HPLC method Serpil Gök Tangolar, Fatih Özogul, Semih Tangolar and Cahide Yag˘mur 481 Preliminary assessment of the nutritional composition of underexploited wild legumes from semi-arid Caatinga and moist forest environments of northeastern Brazil Ana Fontenele Urano Carvalho, Davi Felipe Farias, Lady Clarissa Brito da Rocha-Bezerra, Nathanna Mateus de Sousa, Mariana Giovenardi Cavalheiro, Geórgia Sampaio Fernandes, Isabel Cristiane Façanha Brasil, Andréa Agaciana Bessa Maia, Daniele Oliveira Bezerra de Sousa, Ilka Maria Vasconcelos, Sandro Thomaz Gouveia and Olga Lima Tavares Machado 487

Food composition databases and dietary intake Food composition database harmonization for between-country comparisons of nutrient data in the TEDDY Study Ulla Uusitalo, Carina Kronberg-Kippilä, Carin Andren Aronsson, Sally Schakel, Stefanie Schoen, Irene Mattisson, Heli Reinivuo, Katherine Silvis, Wolfgang Sichert-Hellert, Mary Stevens, Jill M. Norris, Suvi M. Virtanen and The TEDDY Study Group 494

Analytical methods Effect of solvents in extracting polyphenols and antioxidants of selected raw vegetables Shaida Fariza Sulaiman, Azliana Abu Bakar Sajak, Kheng Leong Ooi, Supriatno and Eng Meng Seow 506 Rapid and effective evaluation of the antioxidant capacity of propolis extracts using DPPH bleaching kinetic profiles, FT-IR and UV–vis spectroscopic data Augustin Ca˘ta˘lin Mot¸, Radu Silaghi-Dumitrescu and Costel Saˆrbu 516

Nutrients and bioactive components in foods Fatty acid composition of beef from Nguni steers supplemented with Acacia karroo leaf-meal C. Mapiye, M. Chimonyo, K. Dzama, A. Hugo, P.E. Strydom and V. Muchenje 523 Fatty acid, amino acid and mineral composition of milk from Nguni and local crossbred cows in South Africa M. Mapekula, M. Chimonyo, C. Mapiye and K. Dzama 529 Phenolic and polysaccharidic composition of applesauce is close to that of apple flesh Carine Le Bourvellec, Karima Bouzerzour, Christian Ginies, Sylvaine Regis, Yves Plé and Catherine M.G.C. Renard 537

Amsterdam • Boston • London • New York • Oxford • Paris • Philadelphia • San Diego • St. Louis doi:10.1016/S0889-1575(11)00125-6 ii Cantents

Elemental analysis for categorization of wines and authentication of their certified brand of origin Sónia M. Rodrigues, Marta Otero, André A. Alves, Joana Coimbra, Manuel A. Coimbra, Eduarda Pereira and Armando C. Duarte 548 Influence of ionizing radiation and conventional food processing treatments on the status of free radicals in lotus seeds: An ESR study Rajeev Bhat and K.R. Sridhar 563 Effect of full-scale brewing process on polyphenols in Italian all-malt and maize adjunct lager beers Maria Daria Fumi, Roberta Galli, Milena Lambri, Gianluca Donadini and Dante Marco De Faveri 568 Total phenolic compounds and antioxidant potential of Hedychium spicatum Buch. Ham. ex D. Don in west Himalaya, India Sandeep Rawat, Indra Dutt Bhatt and Ranbeer Singh Rawal 574 Changes in phenolic antioxidants during chuño production (traditional Andean freeze and sun-dried potato) J. Mauricio Peñarrieta, Trinidad Salluca, Leslie Tejeda, J. Antonio Alvarado and Björn Bergenståhl 580 Antioxidant activity and bioactive compound changes during fruit ripening of high-lycopene tomato cultivars Riadh Ilahy, Chafik Hdider, Marcello S. Lenucci, Imen Tlili and Giuseppe Dalessandro 588 Influence of environment on seed soluble carbohydrates in selected lentil cultivars Mohammad Tahir, Albert Vandenberg and Ravindra N. Chibbar 596 Melatonin: A new bioactive compound in wine M. Isabel Rodriguez-Naranjo, Angel Gil-Izquierdo, Ana M. Troncoso, Emma Cantos and M. Carmen Garcia-Parrilla 603 Assessment of 4-(5-)methylimidazole in soft drinks and dark beer S.C. Cunha, A.I. Barrado, M.A. Faria and J.O. Fernandes 609

Short communications Effect of extraction solvents on the phenolic compounds and antioxidant activities of bunga kantan (Etlingera elatior Jack.) inflorescence M.M. Jeevani Osadee Wijekoon, Rajeev Bhat and Alias A. Karim 615 Influence of ethylene on carotenoid biosynthesis during papaya postharvesting ripening Gisela P.M. Barreto, João P. Fabi, Veridiana V. De Rosso, Beatriz R. Cordenunsi, Franco M. Lajolo, João R.O. do Nascimento and Adriana Z. Mercadante 620

Editorial 8th International Food Data Conference: Quality food composition data, key for health and trade Prapasri Puwastien 625

Original research articles Brazilian flavonoid database: Application of quality evaluation system Elizabete Wenzel de Menezes, Nelaine Cardoso Santos, Eliana Bistriche Giuntini, Milana C.T. Dan, Maria Ines Genovese and Franco M. Lajolo 629 Environmental implication of iodine in water, milk and other foods used in Saharawi refugees camps in Tindouf, Algeria Ingrid Barikmo, Sigrun Henjum, Lisbeth Dahl, Arne Oshaug and Liv Elin Torheim 637 Investigation of Thai plants for potential sources of inulin-type fructans Kunchit Judprasong, Siriporn Tanjor, Prapasri Puwastien and Pongtorn Sungpuag 642 Method performance study for total solids and total fat in coconut milk and products Niphaporn Lakshanasomya, Arunee Danudol and Tipawan Ningnoi 650 Provision of proficiency test (PT) scheme on proximate and mineral analyses: Philippine experience Teresita R. Portugal, Mildred A. Udarbe, Julita G. Ardeña, Leah N. Castillo and Sheila T. Mendez 656 The distance learning tool ‘Food Composition Study Guide’ contributes to global capacity development in food composition U. Ruth Charrondiere, Heinz Freisling and Ibrahim Elmadfa 663 Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits L.Y. Chew, K. Nagendra Prasad, I. Amin, A. Azrina and C.Y. Lau 670 Cantents iii

Reports Brazilian Network of Food Data Systems and LATINFOODS Regional Technical Compilation Committee: Food composition activities (2006–2009) Elizabete Wenzel de Menezes, Eliana Bistriche Giuntini, Milana C.T. Dan, Nelaine Cardoso Santos, Alexandra Tavares de Melo and Franco M. Lajolo 678 Food composition databases for nutrition labelling: Experience from Australia J. Cunningham and R. Sobolewski 682 Modes of handling Oxygen Radical Absorbance Capacity (ORAC) data and reporting values in product labelling Katherine Stockham, Rohani Paimin, John D. Orbell, Paul Adorno and Saman Buddhadasa 686 Nutrition indicator for biodiversity on food composition—A report on the progress of data availability Barbara Stadlmayr, Emma Nilsson, Beatrice Mouille, Elinor Medhammar, Barbara Burlingame and U. Ruth Charrondiere 692 Nutritional composition of freshly harvested and stored Latvian potato (Solanum tuberosum L.) varieties depending on traditional cooking methods Irisa Murniece, Daina Karklina, Ruta Galoburda, Dace Santare, Ilze Skrabule and Helena S. Costa 699 Report on the FAO/INFOODS Compilation Tool: A simple system to manage food composition data U. Ruth Charrondiere and Barbara Burlingame 711 Food composition activities in Argentina, Chile and Paraguay N. Sammán, L. Masson, S. de Pablo and E. Ovelar 716 The nutrient composition of South African mutton J. Sainsbury, H.C. Schönfeldt and S.M. Van Heerden 720 Food composition data: Identifying new uses, approaching new users Simone Bell, Paolo C. Colombani, Heikki Pakkala, Tue Christensen, Anders Møller and Paul M. Finglas 727

Review On the origins of food composition tables Paolo C. Colombani 732

Short communications Determining iron bio-availability with a constant heme iron value H.C. Schönfeldt and N.G. Hall 738 Management of food composition database harmonized with EuroFIR criteria using a web application Maria Glibetic, Agnes Kadvan, Jasna Tepsic, Jasmina Debeljak Martacic, Marija Djekic-Ivankovic and Mirjana Gurinovic 741 OQALI: A French database on processed foods C. Menard, C. Dumas, R. Goglia, M. Spiteri, N. Gillot, P. Combris, J. Ireland, L.G. Soler and J.L. Volatier 744 Development of a rapid assessment method for the prediction of the glycemic index Nicolette Gibson, Hettie C. Schönfeldt and Beulah Pretorius 750

Programme Programme of the 8th International Food Data Conference, “Quality Food Composition Data: Key for Health and Trade,” Bangkok, Thailand, 1–3 October 2009 755

Calendar I Note to Authors II This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright

Author's personal copy

Journal of Food Composition and Analysis 24 (2011) 506–515

Contents lists available at ScienceDirect

Journal of Food Composition and Analysis

jo urnal homepage: www.elsevier.com/locate/jfca

Original Article

Effect of solvents in extracting polyphenols and antioxidants of selected raw vegetables

a,b, a a

Shaida Fariza Sulaiman *, Azliana Abu Bakar Sajak , Kheng Leong Ooi ,

a,c a

Supriatno , Eng Meng Seow

School of Biological Sciences, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia

Centre For Marine and Coastal Studies, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia

Department of Biology, Faculty of Teacher Training and Education, Universitas Syiah Kuala, Darussalam-Banda Aceh 23111, Indonesia

A R T I C L E I N F O A B S T R A C T

Article history: Thirty-seven raw vegetables were extracted using four solvent systems: 70% acetone, 70% ethanol, 70%

Received 4 December 2009

methanol, and distilled water. The extracts were tested for their total phenolic content, total ﬂavonoid

Received in revised form 29 December 2010

content and antioxidant activities (using diphenylpicryl-hydrazyl (DPPH) and ferric reducing

Accepted 15 January 2011

antioxidant power (FRAP) assays). The results revealed the effect of different extracting solvents in

Available online 25 February 2011

altering the quantitative analyses of all vegetables and 70% acetone was identiﬁed as the most efﬁcient

solvent for extracting polyphenolic antioxidants from the vegetables. The highest total phenolic content

Keywords:

and total ﬂavonoid content were obtained from 70% acetone extract of Portulaca oleracea (138.2 2.1 mg

Total phenolic content

GAE/g dw basis) and 70% methanol extract of Cosmos caudatus (27.7 1.0 mg QE/g dw basis), respectively.

Total ﬂavonoid content

The 70% acetone extract of Etlingera elatior with moderate amount of total phenolic content exhibited the

Antioxidant activity

Radical scavenging activity highest antioxidant activity in both assays. The correlation analyses within 37 different extracts of each

Raw vegetables solvent extraction demonstrated weak to moderate relationships between all the studied parameters. The

Extraction solvent highest r value of 0.7139 (p < 0.001) was determined between total phenolic contents and FRAP values of the

Food analysis 70% methanol extracts. Meanwhile, a wide range of correlation coefﬁcients was derived from correlation

Food composition

analyses within four different extracts of each vegetable, with the highest relationship between total

phenolic contents and FRAP values for the extracts of Coriandrum sativum (r = 0.9998, p < 0.001).

1. Introduction free radical scavengers (Vattem et al., 2005; Zhou et al., 2009). In

vegetables, phenolic compounds were reported to be dominated

Consumption of raw vegetables is considered as a traditional by glycocidic ﬂavonols and hydroxycinnamic acids (Han et al.,

healthy diet (Ong, 2004). This diet is a rich source of antioxidant 2007).

contents such as phytochemicals, vitamins and enzymes, as well as Vegetables are often classiﬁed according to the edible plant

other minerals and fibers beneficial to health. Consistent intake of parts such as leaves, flowers or fruits (Grubben et al., 1994).

raw vegetables is believed to assist in preventing degenerative Vegetables that are edible in raw form are mostly derived from the

diseases (such as cancer, diabetes, hypertension and cardiovascu- less ﬁbrous, not pungent and non bitter plant parts. In Malaysia,

lar diseases), delaying the sign of aging, and improving physical this group of vegetables is locally known as fresh ulam. The soft and

ﬁtness (Mohamed et al., 2005). Among the phytochemicals, tender leaf, aerial or entire parts of herbal plants and the shoots of

phenolic compounds are reputed to be the main contributor of woody plants can be consumed individually by cutting or tearing

antioxidant activity in plant extracts due to their higher value in them into smaller pieces. They are often dipped in shrimp and chilli

total content (Hodzic et al., 2009), interaction and redox property paste or peanut sauce to enhance ﬂavors (Samy et al., 2005). The

of an individual or combination of their diverse chemical more ﬁbrous plant parts, such as inﬂorescences or unripe pods,

structures with assay used (Teixeira et al., 2005) and their must be sliced, diced, chopped, grated or shredded into different

synergistic effectiveness as hydrogen donors, reducing agents and shapes and sizes of tiny portions to make them easier to digest. All

the selected vegetables can be mixed with an assortment of

ingredients as a mixed salad preparation, locally known as kerabu

(Aman, 2002).

* Corresponding author at: School of Biological Sciences, Universiti Sains

Processed or cooked vegetables are lower in nutritional value

Malaysia, 11800 USM, Pulau Pinang, Malaysia. Tel.: +60 4 6534095;

than raw vegetables, because some of their phytochemicals and

fax: +60 4 6565125.

E-mail address: [email protected] (S.F. Sulaiman). enzymes tend to be degraded by heat or dissolved into the cooking

Author's personal copy

S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515 507

water environment (Samy et al., 2005). Several studies have higher antioxidant activity; and (iii) to determine possible

conﬁrmed the effect of thermal treatment in reducing antioxidant correlation between antioxidant activity, total phenolic and total

activity and total phenolic content of vegetables that were ﬂavonoid contents of the extracts.

subjected to blanching, boiling and freezing processes (Ismail

et al., 2004; Sikora et al., 2008). Thus, for accurate assessment of

2. Materials and methods

the antioxidant and polyphenolic contents of these raw edible

vegetables, this study was conducted using a matrix of the fresh

2.1. Plant materials

vegetables. We believe that this is the ﬁrst comprehensive report

on antioxidant evaluation of this group of vegetables. Most of the

Table 1 shows a list of 37 raw vegetables that were used in this

previous antioxidant studies utilized dried (Chanwitheesuk et al.,

study. They were classiﬁed into four major groups of plant parts,

2005; Abas et al., 2006; Wong et al., 2006) and freeze-dried

i.e. herb and leafy, ﬂower, fruit and bean sprout vegetables. Some of

samples (Zhou and Yu, 2006; Huang et al., 2009; Andarwulan et al.,

the vegetables such as Allium cepa, Apium graveolens, Coriandrum

2010; Isabelle et al., 2010; Kim et al., 2010) for total recovery of

sativum, Cucumis sativus and Lactuca sativa are well-known

compounds, neglecting the drying effect to the naturally occurring

worldwide. The selection of plant parts was made based on those

phytochemicals, and the freshness attribute to the antioxidant

that can be eaten raw. Different parts of fresh samples were

activity.

collected at Relau Agriculture Centre and Herbal garden at School

Dry sample matrix is susceptible to the formation of Maillard

of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang,

reaction product or non-enzymatic browning causes by the

Malaysia. The interval between harvesting and experimental work

activation of Maillard reaction. This product was reported to

was speciﬁed to be less than 3 h in order to sustain the freshness of

contain polyphenolics that might enhance antioxidant activity of

the sample. The identities were checked by morphological

processed foods. This may lead to overestimation of polyphenolics

examination and comparison with authentic herbarium speci-

and antioxidants of raw vegetables (Manzocco et al., 2001; Porter

mens.

et al., 2006). Meanwhile, disruption of freeze-dried and fresh

sample matrixes has been reported to activate polyphenol oxidase

2.2. Measurement of moisture content in raw vegetables

that is responsible for enzymatic browning or oxidation, degrada-

tion and structural modiﬁcation of polyphenolics at room

The moisture content of fresh plant material was determined

temperature. Hence, intense precaution must be taken to ensure

according to AOAC (1995), ofﬁcial method 964.22. Brieﬂy, in

reliable quantiﬁcation of antioxidant activity, total phenolic and

triplicate, each fresh vegetable sample (100 g) was sliced into tiny

ﬂavonoid contents of fresh matrix (Szeto et al., 2002; Robards,

pieces and was dried for approximately 24 h to a constant weight

2003).

at 70 8C in a vacuum oven (Memmert, Germany). The percentage of

To date, the published antioxidant evaluations of the selected

moisture content was calculated as follows:

vegetables are not comprehensive, as they have been made on an

individual basis and for a limited number of samples (Vimala et al.,

Moisture content ð%Þ

2000; Chanwitheesuk et al., 2005; Abas et al., 2006; Wong et al.,

2006; Maisuthisakul et al., 2008; Huda-Faujan et al., 2009; Ismail original sample weight final sample weight

¼ 100

et al., 2009; Andarwulan et al., 2010; Isabelle et al., 2010; Wan- original sample weight

Ibrahim et al., 2010). Comparative antioxidant information of

these vegetables is urgently needed for the public to rank the

healthier beneﬁts of raw vegetables, and to select only those with 2.3. Chemicals

higher antioxidant activity, which are better to eat from a health

point of view. Moreover, data from literature reports are All chemicals and reagents used in this study are of analytical

incomparable, due to the usage of different extraction and grade. Methanol, ethanol and acetone were purchased from R & M

quantiﬁcation procedures. Chemicals (Essex, England). Folin–Ciocalteu phenol reagent, 1,1-

Accumulating evidence has suggested that the recovery, yield diphenyl-2-picryhydrazyl radical (DPPH), 2,4,6-tri-(2-pyridyl)-s-

and type of polyphenolics in an extract are inﬂuenced by the type triozine (TPTZ), ferric chloride hexahydrate (FeCl36H2O), gallic

and polarity of extracting solvents, time and temperature of acid and quercetin were obtained from Sigma–Aldrich Chemicals

extractions as well as physical characteristic of the samples (St. Louis, MO). Anhydrous sodium carbonate (Na2CO3), potassium

(Naczk and Shahidi, 2006). Therefore, in this study, all those acetate (CH3COOK) and aluminium chloride (AlCl3) were pur-

factors were standardized, except for extraction solvent. Thus far, chased from Fluka (Switzerland).

no speciﬁc or appropriate extraction solvent is recommended for

optimal recovery of total phenolic content from fresh sample 2.4. Extraction of polyphenols

matrix owing to the diverse chemical structures of polyphenolics

ranging from simple and free to conjugated and polymerized The fresh sample (10 g fresh weight) was washed with distilled

forms (lipophilic) that might consequently affect their solubility water and the remaining water at the external surface of the

behavior (Prior et al., 2005). The selection of solvent systems for sample was dried out using blotting paper (Whatman 3MM Chr). It

this study was made on the basis of their reported efﬁciency in was later ground for 2 min using a grinder to yield a ﬁne paste (40

extracting polyphenols and other antioxidant compounds from mesh or 400 mm of particle size). The paste was then soaked in

fresh sample matrix (Luthria et al., 2006; Sun et al., 2007; 100 mL of solvent for 1 h at room temperature (27 1 8C). The

Alothman et al., 2009). extract was then ﬁltered using a clean muslin cloth and centrifuged

To our knowledge, most of the previous studies were restricted using Hittech EBA 20 Centrifuge (Japan) at 61,000 g for 15 min. For

to the usage of single solvent for extraction, and no comparative each sample, four different solvent mixtures were used for extrac-

study on the effect of solvent in extracting polyphenolics from tions that are 70% acetone (v/v), 70% ethanol (v/v), 70% methanol (v/v)

these vegetables has previously been conducted. Therefore, the and distilled water. The fresh extracts were stored at 4 8C in dark until

main objectives of this study were (i) to evaluate the efﬁciency of further analysis. The interval between extraction process and

four different solvents in extracting of polyphenols and antiox- experimental work was speciﬁed to be less than 2 h. The extraction

idants from fresh specimens; (ii) to identify raw vegetables with process was carried out in triplicate, for each sample–solvent

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508 S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515

Table 1

List of 37 raw vegetables used in this study, their tested plant parts and moisture content.

Scientiﬁc name Common name Local name Part tested Moisture

content (%)

Herb and leafy vegetables

Allium cepa L. Spring onion Daun bawang Leaf 91.5

Anacardium occidentale L. Cashew Gajus Shoot 79.4

Apium graveolens L. Leaf celery Saderi Aerial part 90.2

Ardisia crenata Sims Spiceberry Mata itik Shoot 86.0

Barringtonia racemosa (L.) Spreng. Barringtonia Putat Shoot 85.5

Centella asiatica (L.) Urb. Asiatic pennywort Pegaga nyonya Whole plant 84.0

Coriandrum sativum L. Coriander, cilantro Ketumbar Whole plant 87.3

Cosmos caudatus Kunth Cosmos Ulam raja Shoot 83.7

Curcuma longa L. Turmeric Kunyit Shoot 89.7

Hydrocotyle umbellata L. Water marshpennywort Pegaga besar Whole plant 87.0

Justicia gendarussa Burm. f. Willow-leaved justica Ganda rusa Shoot 65.3

Kaempferia galanga L. Chinese ginger Cekur Shoot 92.4

Lactuca sativa L. Lettuce Salad Leaf 93.3

Melicope pteleifolia (Champ. ex Benth) T.G. Hartley Thin Evodia Cabang tiga, Tenggek burung Shoot 70.0

Mentha arvensis L. Japanese mint Pudina Leaf 89.0

Micromelum minutum Wight & Arn. Lime berry Cemumar Shoot 65.1

Morinda elliptica (Hook. f.) Ridl. Indian mulberry Mengkudu Shoot 73.1

Murraya koenigii (L.) Spreng. Curry leaf Daun kari Shoot 62.9

Ocimum basilicum L. Basil Selasih hitam Shoot 83.7

Ocimum tenuiﬂorum L. Holy basil Kemangi Shoot 80.9

Oenanthe javanica (Blume) DC. Water dropwort Selom Aerial part 91.1

Oroxylum indicum (L.) Kurz Midnight horror Beka Shoot 73.9

Paederia diffusa (Britton) Standl. Lesser stinkwort, skunk-vine Sekuntut Shoot 78.5

Persicaria minor (Huds.) Opiz Small water Pepper Kesum Leaf 76.8

Piper sarmentosum Roxb. Pointed pepper Kaduk Shoot 81.8

Pluchea indica (L.) Less. Indian (marsh) ﬂeabane Beluntas Shoot 77.3

Portulaca oleracea L. Purslane Gelang pasir Aerial part 93.0

Premna cordifolia Roxb. Musk maple Bebuas Shoot 89.1

Spondias pinnata (L.f.) Kurz Wild mango Daun ambra Shoot 78.1

Vitex negundo L. Chaste Lemuni Shoot 68.4

Flower vegetables

Etlingera elatior (Jack) R.M. Sm. Torch ginger Kantan Inﬂorescence 89.4

Musa acuminata Colla Banana Jantung pisang Inﬂorescence 92.3

Fruit vegetables

Cucumis sativus L. Cucumber Timun Young fruit 95.7

Mangifera indica L. Mango Mangga muda Young ﬂesh 90.1

Psophocarpus tetragonolobus (L.) DC. Winged bean Kacang botol Young pod 92.7

Vigna sinensis Endl. Long bean Kacang panjang Young pod 91.5

Bean sprout vegetable

Vigna radiata (L.) R. Wilczek Mung Bean sprout Taugeh Bean sprout 92.0

combination. Concentration of obtained extracts was referred to fresh 95% ethanol, 10 mL of 10% aluminium chloride, 10 mL of 1.0 M

sample weight resulting in 100 mg/mL (w/v). potassium acetate and 140 mL of distilled water. Blank was

prepared for every sample without addition of aluminium chloride

2.5. Determination of total phenolic content and potassium acetate. After incubation at room temperature

(27 1 8C) for 40 min, absorbance of the reaction mixture was

Total phenolic contents from the extracts were quantiﬁed measured against blank at 415 nm using Multiskan EX microplate

using Folin–Ciocalteu’s method (Singleton et al., 1999) adapted to reader (Thermo Fisher Scientiﬁc, Finland). Quercetin (0–250 mg/mL)

the 96-well plate assay, as described by Dicko et al. (2002). Folin– was used as a reference to produce a standard curve. All tests were

Ciocalteu’s reagent (25 mL) was added to 10 mL of extract performed in triplicate. The data were expressed as milligram

(100 mg/mL) in a well of a 96-well plate. After 5 min of incubation quercetin equivalent per gram dry weight basis of fresh sample (mg

at room temperature (27 1 8C), 25 mL of 20% (w/v) sodium QE/g dw basis).

carbonate was added to the mixture followed by distilled water to a

ﬁnal volume of 200 mL per well. After 30 min of incubation at room 2.7. Ferric reducing antioxidant potential (FRAP) assay

temperature (27 1 8C), the absorbance was read at 760 nm against

blank (solvent used for extraction) using Multiskan EX microplate The FRAP assay was conducted according to Firuzi et al. (2005).

reader (Thermo Fisher Scientiﬁc, Finland). All assays were carried out FRAP solution was prepared by adding 10 mL of acetate buffer

at least in triplicate. A standard curve was plotted using gallic acid 300 mM (which was adjusted to a pH of 3.6 by the addition of

(0–250 mg/mL). The results were expressed as milligram gallic acid acetic acid) to 1.0 mL of ferric chloride hexahydrate 20 mM

equivalent per gram dry weight basis of fresh sample (mg GAE/g dw (dissolved in distilled water) and 1.0 mL of 2,4,6-tri-(2-pyridyl)-s-

basis). triozine (TPTZ) 10 mM (dissolved in HCl 40 mM). In a well of a 96-

well plate, an aliquot (10 mL) of extract (at four different

2.6. Determination of total ﬂavonoid content concentrations: 100, 50, 25 and 12.5 mg/mL) was added to

190 mL of the FRAP solution. After 30 min of incubation at 37 8C,

Total ﬂavonoid contents were determined using method absorbance of the reaction mixture was measured at 593 nm using

described by Lin and Tang (2007). In a well of a 96-well plate, Multiskan EX microplate reader (Thermo Fisher Scientiﬁc,

an aliquot (25 mL) of extract (100 mg/mL) was mixed with 75 mL of Finland). All tests were run in triplicate. Gallic acid (0–125 mg/

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S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515 509

mL) was used as a reference to produce a standard curve. The considered as the most efﬁcient solvent system for extracting

absorbance of the extract was compared to that of the gallic acid phenolic compounds from the fresh matrixes of these vegetables

standard and all results were expressed as milligram gallic acid except for Anacardium occidentale, Premna cordifolia, Barringtonia

equivalent per gram dry weight basis of fresh sample (mg GAE/g racemosa, Centella asiatica, C. sativum, Cosmos caudatus, Justicia

dw basis). gendarussa, L. sativa, Musa acuminata, C. sativus, Psophocarpus

tetragonolobus, Kaempferia galanga and Vigna radiata. The best

2.8. DPPH free radical scavenging assay solvent system for extracting TPC from the ﬁrst and last two species

are respectively 70% methanol and distilled water, while the rest is

Radical scavenging activity of extracts was measured by the 70% ethanol. Several studies have also revealed the efﬁciency of 70%

slightly modiﬁed method of Brand-Williams et al. (1995), as acetone in extracting phenolic from the dry-ground samples of plant

described below. Brieﬂy, a 0.3 mM solution of DPPH in ethanol was materials (Rocha-Guzma´n et al., 2007; Demiray et al., 2009). With

prepared. An aliquot (50 mL) of extract (at four different concentra- the exception to samples of A. cepa, Ardisia crenata, Portulaca

tions: 100, 50, 25 and 12.5 mg/mL) was added to 150 mL of the DPPH oleracea, and Etlingera elatior, distilled water was found as the most

solution in each well of a 96-well plate. For blank, only 50 mL of inefﬁcient solvent in extracting phenolic compounds.

extraction solvent was added to the DPPH solution. The decrease in The apparent variation of TPC in four different extracts of most

absorbance was measured at 515 nm after 30 min of incubation at species revealed the effect of extracting solvent in altering the

37 8C using the Multiskan EX microplate reader (Thermo Fisher analytical estimation of TPC from the same fresh sample matrix. A

Scientiﬁc, Finland). All tests were performed in triplicate. Gallic acid TPC qualiﬁcation by Andarwulan et al. (2010) that relied only on

was also used as a reference in this assay. A standard curve was an extracting solvent (95% ethanol) of several freeze-dried samples

obtained using gallic acid standard solution at concentration 0– found a very poor recovery of TPC in P. oleracea and the result was

1 mg/mL. The absorbance of the extract was compared to that of the almost conformed with the low value obtained from the 70%

gallic acid standard and all results were expressed as milligram gallic ethanol extract of its aerial part (Table 2). In contrast, among all the

acid equivalent per gram dry weight basis of fresh sample (mg GAE/g extracts tested in this study, its 70% acetone extract had the highest

dw basis). TPC. This may indicate that 70% acetone is more appropriate to be

used for extraction of phenolic compounds from this vegetable.

2.9. Statistical analysis The 70% ethanol extracts of the leaf of L. sativa and the young pod of

P. tetragonolobus ranked next with no signiﬁcant difference

Data were analyzed using SPSS 11.5 for Window software (SPSS between their values. Of the distilled water extracts, the highest

Inc., Chicago, IL). Values were expressed as means standard value was also indicated by the extract of P. oleracea, while among

deviations. Tukey’s honestly signiﬁcant different (HSD) test was used the 70% methanol extracts, the highest value was obtained from

to assess differences between means. Correlation between the the extract of P. tetragonolobus. Other TPC values above 70 mg GAE/

studied parameters (total phenolic and ﬂavonoid contents, and FRAP g dw basis were also quantiﬁed from the 70% acetone extracts of

and DPPH inhibition values) was established by regression analysis different plant parts of vegetables, i.e. the aerial part of A. cepa, the

computed using Prism 3.02 statistical software of GraphPadPrism shoot of A. crenata, the leaf of M. arvensis, the inﬂorescence of E.

(San Diego, CA). The p-value less than 0.05 (p < 0.05) was considered elatior and the young ﬂesh of M. indica. All of these vegetables

as statistically signiﬁcant. have been measured for their TPC in several earlier studies

(Wong et al., 2006; Andarwulan et al., 2010; Kim et al., 2010;

3. Results and discussion Newell et al., 2010). However, due to the application of different

sample matrixes, extracting procedures and solvent systems,

3.1. Total phenolic and ﬂavonoid contents there were discrepancies in comparing our results with the

literature data.

In this study, fresh samples of vegetables were used in order to Moreover, a TPC determination by Chanwitheesuk et al. (2005)

retain their original edible quality for the accurate quantiﬁcation. on dried leaves extracted using acetone:methanol:water (7:7:6)

Each fresh vegetable was extracted using four different polarities found a moderate value of TPC ranging from 123 0.12 to

of solvent systems that are acetone, ethanol and methanol with 31.1 0.14 mg pyrocatechol equivalents/g dw of P. sarmentosum

speciﬁc proportion of distilled water (7:3), and distilled water. The extract followed by C. asiatica, Ocimum basilicum, M. arvensis, C.

effects of these solvent systems in extracting polyphenolics and sativum and A. graveolens. With the exception of P. sarmentosum, our

antioxidants from these vegetables were quantitatively measured results were within the range of the reported values. As indicated in

and compared. Table 2 shows a list of the total phenolic content Table 2, low TPC values ranging from 5.3 0.6 to 2.8 0.9 mg GAE/g

(TPC) and total ﬂavonoid content (TFC) of the four solvent dw basis were detected in the four extracts of P. sarmentosum. The

extractions from the vegetables. When the vegetables were difference may be resulted from the inefﬁciency of four solvents used

classiﬁed according to plant parts used, herbal and leafy vegetables in this study to extract TPC from the fresh sample matrix or the drying

are by far the most frequent with 30 representatives; whereas process of this sample that facilitates increasing the recovery of TPC in

ﬂower, fruit and bean sprout vegetables account for 2, 4 and 1 dried matrix. Thus, a comparative study on the different matrixes of

samples, respectively. The difference in polarities of extracting this vegetable is required.

solvents might inﬂuence the solubility of chemical constituents in Another important factor which makes the result obtained from

a sample and its extraction yield. Therefore, the selection of an this study incompatible with the literature data is related to the

appropriate solvent system is one of the most relevant steps in use of different edible plant parts of the same vegetables in each

optimizing the recovery of TPC, TFC and other antioxidant experiment. For instance, three vegetables used in this study, i.e. C.

compounds from a sample (Zhao et al., 2006). Although the asiatica, O. basilicum and Spondias pinnata were previously

analysis was conducted using fresh sample matrix, the results were analyzed for their TPC by Maisuthisakul et al. (2008) using 95%

expressed as mg GAE/g dw basis, in order to rule out the effect of ethanol extracts of fresh leaves. When the results of the two

moisture content to the quantiﬁcation. The percentages of studies were compared, we determined a higher TPC value in the

moisture contents in the vegetables are indicated in Table 1. 70% acetone and 70% ethanol extracts of the entire plant part of C.

From 148 extracts of 37 vegetables, 70% acetone extracts of 24 asiatica, and a lower TPC in all extracts of the shoots of O. basilicum

species of vegetables exhibited the highest value of TPC, hence it is and S. pinnata.

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510 S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515

Moreover, all extracts of the following vegetables consisted of extracts of C. caudatus, Oenanthe javanica, Pluchea indica and S. pinnata

TPC less than 10 mg GAE/g dw basis: the shoots of Curcuma longa, J. and distilled water extract of Persicaria minor. Several phytochemical

gendarussa, K. galanga, Morinda elliptica, Micromelum minutum and studies have indicated the presence of ﬂavonoids in the leaf extracts

P. sarmentosum; unripe fruit of C. sativus; and bean sprouts of V. of these species: A. occidentale (Arya et al., 1989), C. caudatus (Faridah

radiata. The lower values of TPC in C. sativus and V. radiata are in et al., 2003), O. javanica (Miean and Mohamed, 2001; Ma et al., 2010),

agreement with that reported by Isabelle et al. (2010), while a O. indicum (Subramanian and Nair, 1972), P. indica (Ohtsuki et al.,

study by Chan et al. (2008) on fresh leaves of several ginger species 2008), P. minor (Urones et al., 1990), S. pinnata (Maisuthisakul et al.,

also reported a lower TPC in C. longa and K. galanga. The results also 2008) and V. negundo (Banerji et al., 1969; Basudeb et al., 1984).

revealed that the variation in TPC of the vegetables was not As comparisons were made between the four solvent extractions

inﬂuenced by the plant part used as the higher and lower values of every species, 70% acetone extracts of 22 species gave the highest

were not determined from a similar group of edible part. score of TFC whereas 70% ethanol extract of 20 species gave the

Most of the extracts contain a lower amount of TFC than of TPC lowest score. Thus, 70% acetone may also be considered as the most

(Table 2). Flavonoids are considered as being restricted in efﬁcient solvent for extraction of ﬂavonoids from the fresh

distribution and composition in these vegetables in comparison vegetables. This solvent system was often used as an extraction

with the overall phenolics. The 70% methanol extract of the shoot solvent for ﬂavonoids in many studies (Belboukhari and Cheriti,

of C. caudatus contained statistically the highest TFC, followed by 2007).

its distilled water extract and the 70% acetone extract of the shoot

of Vitex negundo. The higher content (which ranged from 3.2. Antioxidant activity

13.46 0.42 to 22.33 1.93 mg QE/g dw) was also determined

mostly from the group of herbal and leafy vegetables, i.e. in the 70% The antioxidant activities of the extracts were evaluated using

acetone, 70% methanol and distilled water extracts of A. occidentale, ferric reducing power (FRAP) and DPPH free radical scavenging

70% acetone and 70% methanol extracts of Oroxylum indicum, 70% assays. Although the 70% acetone extract of P. oleracea and the 70%

ethanol and 70% methanol extracts of V. negundo, 70% acetone methanol extract of C. caudatus, respectively contained the highest

Table 2

Total phenolic content (TPC) and total ﬂavonoid content (TFC) in 37 raw vegetables extracted using four different solvents.

Sample TPC (mg GAE/g dw basis) TFC (mg QE/g dw basis)

70% acetone 70% ethanol 70% methanol Distilled water 70% acetone 70% ethanol 70% methanol Distilled water

Herb and leafy vegetables

b mnopq j b jklm hijkl ghi ghijkl

Allium cepa 110.4 0.3 7.4 0.2 1.1 0.5 62.9 5.0 3.8 1.6 1.7 0.3 5.3 0.4 3.0 0.1

hi ef b ghi b c b b

Anacardium occidentale 29.2 2.4 43.6 1.4 44.8 1.8 10.2 2.6 21.7 1.1 9.3 0.6 18.3 1.2 19.9 1.0

d pqr j hijklmno klmn kl klmno fghijk

Apium graveolens 69.5 1.6 3.8 0.9 0.2 0.2 6.1 0.9 2.9 0.3 0.8 0.1 2.2 0.4 3.8 0.3

d gh b d fg fghi fgh d

Ardisia crenata 70.6 2.6 26.6 1.1 53.3 3.3 46.8 2.8 9.4 1.5 3.2 0.2 5.7 0.3 7.2 1.1

jk b j klmno klmno fghij klmno lmn

Barringtonia racemosa 25.6 2.6 61.9 1.4 1.7 0.6 2.3 0.5 2.2 0.2 3.1 0.0 2.0 0.1 1.4 0.1

jkl cd j no jklm ijkl klmno jklmn

Centella asiatica 22.4 2.1 52.5 0.7 1.4 0.7 0.3 0.1 3.5 0.4 1.2 0.3 1.8 0.5 1.8 0.1

mnopq bc j jklmno klmn fgh klmno hijklm

Coriandrum sativum 11.7 1.7 55.7 1.2 0.1 0.1 3.5 0.6 2.8 0.3 3.5 0.8 1.9 0.4 2.9 0.2

klmno de j no b c a a

Cosmos caudatus 17.2 1.0 48.8 2.0 1.7 0.8 0.3 0.1 22.3 1.9 9.3 0.3 27.7 1.0 25.1 0.6

opqrs opqr ij hijklmno gh ef ghi defg

Curcuma longa 7.9 2.7 4.9 1.0 4.1 1.4 4.7 0.2 8.5 1.5 4.3 0.5 5.0 0.5 5.0 0.6

fgh jklm ghij mno ef d d jklmn

Hydrocotyle umbellata 38.5 0.4 13.4 2.0 9.6 0.4 0.9 0.1 11.7 0.9 6.6 0.4 9.3 0.6 1.8 0.2

s qr j no mno ghijkl lmno n

Justicia gendarussa 0.4 0.1 1.8 1.2 0.2 0.1 0.1 0.1 1.2 0.0 2.1 0.3 1.1 0.1 0.1 0.0

rs qr j ijklmno klmn hijkl klmno lmn

Kaempferia galanga 0.9 0.1 2.6 0.5 2.0 0.4 3.7 0.2 2.8 0.2 1.4 0.4 1.4 0.4 0.6 0.1

e a j klmno klmno hijkl jklmn lmn

Lactuca sativa 53.8 3.4 120.5 6.6 2.6 0.6 2.0 0.5 2.3 0.6 1.5 0.3 2.6 0.7 1.4 0.2

jklm ijk cdef jklmno hij hijkl de lmn

Melicope pteleifolia 21.2 0.5 18.7 0.4 20.8 1.9 3.4 0.5 6.0 0.6 1.8 0.1 8.1 0.5 1.4 0.5

c nopqr hij fg gh fghijk efgh def

Mentha arvensis 95.7 5.1 5.7 1.4 6.1 1.2 14.3 1.2 7.2 0.6 2.8 0.2 6.3 0.8 5.7 0.4

opqrs pqr j mno lmno ijkl no lmn

Micromelum minutum 7.9 0.7 3.8 1.1 1.6 0.2 0.9 0.1 1.3 0.4 1.2 0.3 0.6 0.3 0.8 0.1

qrs qr j klmno ijkl hijkl mno ghijkl

Morinda elliptica 4.8 0.5 2.2 0.3 1.7 0.1 2.3 0.1 3.9 0.3 1.7 0.2 0.8 0.1 3.0 0.1

klmn lmnop efghij gh jklm fgh hij efgh

Murraya koenigii 18.3 1.7 9.2 0.7 11.1 0.3 11.2 0.3 3.8 0.6 3.6 0.6 4.5 0.6 4.7 0.4

efg pqr fghij e de jkl jkl efghi

Ocimum basilicum 45.2 3.5 3.8 0.6 10.8 0.3 25.5 3.0 12.3 0.8 1.0 0.3 2.9 0.1 4.6 0.9

hi lmno defgh jklmno hi fghijk ijk jklmn

Ocimum tenuiﬂorum 30.8 0.9 11.1 0.4 16.5 0.3 2.8 0.5 6.5 0.8 2.9 0.0 3.3 0.6 2.1 0.3

ef f cd lmno de l d de

Oenanthe javanica 46.2 3.8 42.1 1.0 25.4 3.7 1.4 0.1 13.5 0.4 0.7 0.1 8.8 0.3 6.2 0.3

gh r j gh d ijkl c d

Oroxylum indicum 35.6 1.2 0.3 0.1 0.8 0.1 11.2 0.5 14.8 1.1 1.1 0.2 14.2 0.4 7.4 0.4

klmno jklm defghi gh gh de fgh efghij

Paederia diffusa 16.6 0.4 13.5 0.8 14.4 1.3 10.4 0.3 7.1 1.0 6.2 0.4 5.8 0.8 4.0 0.4

lmnopq qr j klmno de efg def c

Persicaria minor 12.9 2.8 2.8 0.2 0.9 0.3 2.0 0.4 12.4 0.2 4.2 0.4 7.5 0.5 13.5 0.4

qrs opqr j hijklmno ijklm def klmno hijklm

Piper sarmentosum 5.3 0.6 5.1 0.2 2.8 0.9 5.1 0.3 3.8 0.3 4.9 1.1 2.2 0.2 3.0 0.2

hi ij defg hijklmno c b efg hijklm

Pluchea indica 28.8 1.7 19.3 0.5 17.7 7.6 5.2 0.2 18.1 0.8 11.5 1.1 6.7 0.9 2.9 0.3

a hi ij a ijk l jklm ijklmn

Portulaca oleracea 138.2 2.1 23.8 1.5 5.1 0.9 98.6 2.1 4.3 0.6 0.6 0.1 2.7 0.6 2.3 0.2

jklm klm cde ghijk gh ijkl efgh de

Premna cordifolia 21.4 0.2 13.0 0.3 21.9 0.4 8.1 0.6 7.6 0.7 1.1 0.3 6.1 0.3 6.2 0.6

e g c f de d fgh d

Spondias pinnata 54.6 0.9 32.8 1.8 30.8 2.0 18.6 0.4 14.4 0.4 6.7 0.4 6.0 0.4 7.2 1.0

jk jkl defghi hijklmn a a c defg

Vitex negundo 24.7 1.1 15.2 0.3 14.4 0.8 6.6 0.5 25.1 0.4 18.9 0.7 15.2 0.7 5.4 0.5

Flower vegetables

c lmn j c klmno ijkl klmno klmn

Etlingera elatior 89.3 1.1 11.5 0.6 2.0 0.2 53.4 4.2 1.7 0.3 1.3 0.0 1.8 0.2 1.5 0.1

klmnop hi defghi klmno no l lmno n

Musa acuminata 15.7 4.4 22.9 3.2 14.9 1.5 1.5 0.3 0.5 0.2 0.2 0.1 1.2 0.2 0.3 0.1

Fruit vegetables

pqrs lmnop ghij ghijkl o l klmno n

Cucumis sativus 5.9 1.3 9.8 0.3 8.2 1.4 7.9 1.4 0.1 0.1 0.2 0.0 1.7 0.2 0.1 0.1

c nopqr ij ghij no l o n

Mangifera indica 91.1 5.2 5.8 1.5 4.8 1.0 8.9 0.6 0.4 0.1 0.1 0.0 0.3 0.1 0.4 0.1

d a a hijklm mno l mno lmn

Psophocarpus 69.7 0.9 118.0 0.2 80.5 2.3 7.1 1.1 1.1 0.4 0.1 0.0 0.8 0.4 0.8 0.1 tetragonolobus

nopqr qr ij jklmno klmno kl lmno lmn

Vigna sinensis 10.5 2.9 1.2 0.2 3.8 0.5 2.4 0.6 1.6 0.2 0.8 0.2 1.0 0.1 1.2 0.1

Bean sprout vegetable

s r j klmno no l lmno mn

Vigna radiata 0.4 0.0 0.3 0.1 1.1 0.5 2.2 0.3 0.3 0.1 0.4 0.1 1.1 0.2 0.6 0.2

Values are mean standard deviation of triplicate analyses. Results of each solvent extraction were analyzed separately. Values per each solvent extraction followed by the same

letter (a, b, c, etc.) in the same column are not signiﬁcantly different (p < 0.05) as measured by Tukey’s HSD Test.

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S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515 511

Table 3

Antioxidant activities (obtained from FRAP and DPPH assays) of 37 raw vegetables extracted using four different solvents.

Sample FRAP (mg GAE/g dw basis) DPPH (mg GAE/ g dw basis)

70% acetone 70% ethanol 70% methanol Distilled water 70% acetone 70% ethanol 70% methanol Distilled water

Herb and leafy vegetables

efg klmno lmno cd q mn qr fghij

Allium cepa 24.4 0.2 3.5 0.3 0.6 0.0 12.6 0.8 1.4 0.2 0.8 0.1 2.1 0.0 1.3 0.1

b a a a fghi efg fghij b

Anacardium occidentale 54.2 1.5 43.4 4.2 52.1 1.0 27.6 0.5 15.4 0.9 13.1 0.1 16.2 1.2 27.1 0.8

ijkl klmno klmno ghij q mn pqr hij

Apium graveolens 12.0 0.8 2.5 0.2 1.0 0.1 3.6 0.3 1.3 0.2 1.6 0.3 2.5 0.5 0.7 0.1

c c b c efgh cd b a

Ardisia crenata 37.1 3.4 27.4 1.7 29.9 1.2 14.5 0.8 16.7 0.9 19.6 0.6 38.8 0.4 45.2 1.6

klmn b lmno ijkl bcd b c efg

Barringtonia racemosa 7.6 0.5 31.4 0.8 0.8 0.1 1.3 0.1 26.0 1.8 29.0 0.4 29.1 2.0 4.1 1.2

lmno fgh lmno kl nopq ijklmn mnop j

Centella asiatica 6.3 0.5 12.7 0.1 0.8 0.1 0.7 0.0 4.0 1.3 5.1 2.1 8.1 0.2 0.2 0.0

nop hi mno jkl nopq mn mnopq ij

Coriandrum sativum 2.4 0.1 10.5 0.2 0.4 0.0 0.8 0.0 2.6 0.6 0.9 0.1 6.8 1.1 0.6 0.1

ijk efgh c d defg cd de ghij

Cosmos caudatus 12.6 5.9 13.9 4.7 14.8 0.3 11.0 3.6 19.4 1.3 19.6 1.8 23.2 1.0 0.9 0.2

nop mno jkl hijkl pq mn opqr efgh

Curcuma longa 3.7 0.1 2.0 0.1 2.0 0.0 2.1 0.0 2.0 0.1 1.7 0.5 3.7 0.8 3.8 0.4

defg jklm gh ijkl b bc cd efghij

Hydrocotyle umbellata 26.8 0.5 5.1 0.2 4.7 0.5 1.2 0.1 30.2 0.7 25.1 1.4 27.8 4.4 2.2 0.2

op no no l q mn r j

Justicia gendarussa 0.4 0.0 0.4 0.0 0.3 0.0 0.1 0.0 0.7 0.1 0.4 0.1 0.1 0.0 0.3 0.0

nop no ijk kl q mn r fghij

Kaempferia galanga 2.7 0.2 0.9 0.0 2.5 0.3 0.6 0.1 1.1 0.0 0.7 0.0 0.8 0.0 1.5 0.1

hij d klmno hijkl jklmnop klmn nopqr ij

Lactuca sativa 16.3 0.8 20.5 0.0 1.3 0.2 2.7 0.1 8.3 1.6 3.5 0.4 4.9 1.3 0.6 0.1

ijkl klmn gh kl lmnopq klmn ijklm ij

Melicope pteleifolia 12.0 1.7 3.8 0.2 4.5 0.2 0.4 0.0 6.8 0.4 3.4 0.9 12.1 0.2 0.3 0.1

a klmno klmn efgh bcd e ef ij

Mentha arvensis 70.1 0.6 2.8 0.1 1.7 0.1 4.7 0.4 25.5 7.3 18.5 1.7 21.1 1.3 0.3 0.1

nop mno klmno ijkl hijklm n klmn hij

Micromelum minutum 3.0 0.1 1.4 0.1 1.3 0.2 1.3 0.1 11.2 0.2 0.1 0.0 10.1 0.4 0.6 0.0

op no klmno ijkl klmnopq jklmn r efghij

Morinda elliptica 1.5 0.1 1.0 0.1 1.0 0.0 1.3 0.0 7.2 1.5 4.0 0.3 0.7 0.0 2.6 0.3

klmn jkl e e ijklmn fghij mnopq d

Murraya koenigii 7.9 1.1 5.8 0.2 8.4 0.3 7.4 0.4 9.2 1.2 10.2 0.6 7.0 0.3 9.8 1.1

de ef f hijk fghij def efghi ghij

Ocimum basilicum 27.7 2.0 15.6 0.1 6.4 0.2 3.2 0.2 14.5 2.0 15.8 0.1 17.5 0.2 1.0 0.2

gh klmn f ijkl fghijk fghi klmn j

Ocimum tenuiﬂorum 20.9 2.6 4.0 0.3 6.3 0.1 1.1 0.0 13.7 0.2 11.1 0.5 9.5 0.5 0.2 0.0

nop klmno hij jkl cde fghi ab efghij

Oenanthe javanica 3.7 0.3 3.6 0.3 3.4 0.2 0.8 0.1 23.1 7.2 10.7 1.3 40.4 2.6 2.5 0.3

jklm no o hijk klmnopq ghijk efghi fghij

Oroxylum indicum 10.9 3.3 0.3 0.0 0.1 0.0 3.1 0.2 6.9 0.9 9.0 0.4 17.5 0.1 1.4 0.4

mnop jk f efg def mn efgh c

Paederia diffusa 6.0 0.4 6.2 0.1 6.3 0.0 6.2 0.1 20.6 0.4 1.7 0.5 18.8 0.3 15.4 0.3

nop no lmno ijkl jklmno efgh ghijk ij

Persicaria minor 2.9 0.0 0.5 0.0 0.6 0.0 1.0 0.0 8.9 0.2 12.1 1.4 15.0 0.6 0.4 0.0

nop mno klmno ijkl nopq klmn qr hij

Piper sarmentosum 2.3 0.0 1.8 0.1 1.3 0.6 1.0 0.0 3.0 0.1 2.6 0.5 2.0 0.4 0.7 0.1

de fgh fg ijkl fghij def klmn ghij

Pluchea indica 27.7 0.7 12.7 1.2 5.3 0.1 1.8 0.0 14.5 0.0 16.3 0.9 10.2 3.6 1.0 0.2

cd ij klm b mnopq hijklm lmno hij

Portulaca oleracea 31.5 0.3 7.7 0.6 1.8 0.2 18.5 1.1 5.2 0.2 6.7 2.1 8.8 0.5 0.8 0.1

nop lmno hi kl bc b b efghij

Premna cordifolia 2.6 0.2 2.2 0.1 3.6 0.2 0.7 0.0 27.5 4.2 26.0 6.1 35.8 0.2 2.1 0.3

fgh efg c ef defg def efg e

Spondias pinnata 21.1 0.2 14.9 0.7 14.1 1.4 6.4 0.3 19.4 0.9 16.3 0.7 20.1 1.9 4.9 1.0

def efgh d hijk mnopq ghijkl jklmn ef

Vitex negundo 27.1 3.6 14.1 0.4 10.8 0.3 3.0 0.1 6.3 0.1 8.6 0.1 10.5 0.4 4.4 0.1

Flower vegetables

a jklmn lmno a a a a c

Etlingera elatior 66.5 5.3 4.1 0.1 1.0 0.0 26.1 3.3 52.3 0.5 38.2 8.3 45.0 4.9 14.6 5.3

ijk gh e kl hijklm klmn mnop efghij

Musa acuminata 13.3 2.3 11.8 1.5 8.5 1.1 0.7 0.0 10.9 2.3 3.4 0.4 8.2 0.9 1.7 0.1

Fruit vegetables

q o o l q mn r efghij

Cucumis sativus 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.6 0.0 0.8 0.1 1.7 0.0

gh klmno klmn fghi lmnopq klmn hijkl efghi

Mangifera indica 20.9 0.1 3.1 0.3 1.7 0.1 3.8 0.2 6.9 1.2 3.6 0.4 14.2 1.6 3.5 0.1

hi de c hijkl opq lmn qr ghij

Psophocarpus tetragonolobus 18.0 0.7 16.8 1.3 14.9 0.9 2.0 0.1 2.2 0.2 2.4 0.4 1.9 0.2 1.0 0.0

nop mno klmn jkl ghijkl b b efghij

Vigna sinensis 2.6 0.3 1.5 0.2 1.7 0.2 0.9 0.0 13.6 3.3 28.4 3.0 38.1 5.4 2.3 0.6

Bean sprout vegetable

p o o l q mn r ghij

Vigna radiata 0.1 0.0 0.1 0.0 0.0 0.0 0.1 0.0 0.9 0.0 0.4 0.0 0.7 0.0 0.9 0.0

Values are mean standard deviation of triplicate analyses. Results of each solvent extraction were analyzed separately. Values per each solvent extraction followed by the same

letter (a, b, c, etc.) in the same column are not signiﬁcantly different (p < 0.05) as measured by Tukey’s HSD Test.

TPC and TFC (Table 2), they however do not exhibit the highest strongly highlighted the efﬁciency of 70% acetone in increasing the

antioxidant activity. As indicated in Table 3, 70% acetone extract of total recovery of antioxidant content in its fresh sample matrix.

the inﬂorescence of E. elatior exhibited the greatest activity in both Meanwhile, all the shoot extracts of A. occidentale extracts were

assays. No signiﬁcant difference was observed between the FRAP consistently and signiﬁcantly ranked higher in FRAP activity. Its

value of this extract than that of the leaf of M. arvensis. Their higher distilled water extract showed no signiﬁcant difference in the

activities are in line with their TPC. Caffeic, ferulic and p-coumaric activity from that of E. elatior. Abas et al. (2006) reported similar

acids are phenolic compounds that had been identiﬁed from M. results showing the methanol extract of air-dried leaves of A.

arvensis (Majak and Neil Towers, 1973). In addition, the 70% occidentale possessed the highest antioxidant capacity in compari-

methanol extracts of E. elatior and the aerial part of O. javanica and son with 12 extracts of different medicinal plants. Its equally

the 70% methanol and distilled water extracts of the shoot of A. higher in TFC might be accountable in enhancing the FRAP activity

crenata were also ranked among the top ﬁve when analyzed by the of the extracts. To date only () epicatechin was isolated from A.

DPPH assay. Flavonol derivatives such as persicarin (isorhamnetin occidentale leaves by Swarnalakshni et al. (1981). Therefore,

3-O-sulfate) in O. javanica (Ma et al., 2010) and quercitrin and rutin further bioactivity guided fractionation and isolation of bioactive

in A. crenata (Newell et al., 2010) seem to be their major compounds from the fresh inﬂorescence of E. elatior and the shoot

constituents that may be responsible for the activity. of A. occidentale are highly needed. Other extracts that gave the

To date, the phytochemical and antioxidant evaluations of E. FRAP values more than 30 mg GAE/g dw basis are the 70% acetone

elatior were mainly focused on the rhizome and leaf extracts extracts of the shoot of A. crenata and the aerial part of P. oleracea,

(Mohamad et al., 2005; Chan et al., 2009). Moreover, the and 70% ethanol extract of the shoot of B. racemosa. Their higher

comparative antioxidant studies by Andarwulan et al. (2010) activities can be correlated with their higher in TPC.

and Wetwitayaklung et al. (2008), respectively revealed a very Furthermore, the remaining extracts with DPPH inhibition

poor antioxidant activity of its 95% ethanol extract of freeze-dried values above 30 mg GAE/g dw basis are the 70% acetone extract of

inﬂorescence and methanol extract of dried inﬂorescence. Thus, the whole plant of Hydrocotyle umbellata, 70% ethanol extract of

the prominent antioxidant activity of the 70% acetone extract of the inﬂorescence of E. elatior, and 70% methanol extracts of the

fresh inﬂorescence of E. elatior (as obtained from this study), aerial part of P. cordifolia and the young pod of Vigna sinensis. The

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512 S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515

present study apparently is the ﬁrst comparative report highlight- maximum plateau of absorbance. Gallic acid can scavenge up to 90%

ing the signiﬁcant antioxidant activity of these vegetables. of DPPH radical and its EC50 value is 7.8 mg/mL.

Moreover, neither TPC nor TFC was found to be involved in Only a very low concentration of gallic acid in the 70% methanol

enhancing the activities of these extracts. The effectiveness of extract of B. racemosa is adequate to enhance its antioxidant

phenolics and ﬂavonoids as antioxidants is not only attributed by activity. Thus, with a low value of TPC (1.7 0.6 mg GAE/g dw basis;

their composition or relative amount but also by the degree of Table 2), the extract exhibited a high DPPH inhibition (29.1 2.0 mg

polymerization, concentration and interaction of their diverse GAE/g dw basis; Table 3). On the other hand, there was a parallel

chemical structures to the colorimetric assays. Thus, the higher correlation between FRAP assay and TPC analysis for B. racemosa as its

levels of TPC and TFC do not necessarily correspond to the higher 70% methanol extract gave the lowest FRAP value (0.8 0.1 mg GAE/g

antioxidant responses (Parejo et al., 2002). dw basis) and its 70% ethanol extract with the highest in TPC

For instance, the radical scavenging activity of B. racemosa might (61.9 1.4 mg GAE/g dw basis) also exhibited the highest FRAP value

be elicited by the occurrence of an effective radical scavenger (31.4 0.8 mg GAE/g dw basis). In accordance with our ﬁndings, Kaur

compound in the extract. According to Hussin et al. (2009), the 60% and Kapoor (2001) found that FRAP assay may give a true picture of

methanol extract of the leaf of B. racemosa contained a free gallic total antioxidant capacity as compared to DPPH. This is due to the less

acid. Gallic acid was used as a standard for this evaluation and sensitiveness of DPPH towards hydrophilic antioxidants and its

positive control in many studies. Based on the standard curve graph interaction with antioxidant constituents is entirely dependent on

of different concentrations of gallic acid (graph not shown), only a structural conformation.

little amount of gallic acid (concentration less than 125 mg/mL for Twenty-seven of the 70% acetone extracts and 17 of the 70%

FRAP assay and 1 mg/mL for DPPH assay) is required to reach the methanol extracts showed the highest values of FRAP and DPPH

a b

75 75

50 50

25 25 DPPH (mg GAE/g dw basis) FRAP (mg GAE/g dw basis)

0 0

0 25 50 75 100 125 150 0 25 50 75 100 125 150

TPC (mg GAE/g dw basis) TPC (mg GAE/g dw basis)

70% Acetone (r = 0.6424***) 70% Aceton e (r = 0.2496)

70% Ethanol (r = 0.5948***) 70% Ethano l (r = -0.0116)

70% Methanol (r = 0.7139***) 70% Methano l (r = 0.2200)

Distilled water (r = 0.7092***) Distill ed water (r = 0.2624)

c d

75 75

50 50

25 25 DPPH (mg GAE/g dw basis) FRAP (mg GAE/g dw basis) 0

0102030

0 10 20 30

TFC (mg QE/g dw basis) TFC (mg QE/g dw basis)

70% Aceton e (r = 0.2204)

70% Ace tone (r = 0.2894)

70% Ethano l (r = 0.1692)

70% Ethano l (r = 0.3552*)

70% Methano l (r = 0.4994**) 70% Methanol (r = 0.2617)

Distilled water (r = 0.4439**) Distill ed water (r = 0.3135)

Fig. 1. Correlation between total phenolic content (TPC) and FRAP (a), total phenolic content (TPC) and DPPH (b), total ﬂavonoid content (TFC) and FRAP (c), and total ﬂavonoid

content (TFC) and DPPH (d) of four different solvent extractions.

Signiﬁcant at p < 0.05, 0.01 and 0.001 are indicated by *, ** and ***, respectively.

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S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515 513

Table 4

inhibition, respectively, whereas 19 and 25 of the distilled water

Pearson’s correlation coefﬁcients (r) between antioxidant activities (obtained from

extracts, respectively showed the lowest values (Table 3). Yet

(a) FRAP and (b) DPPH assays) with (i) total phenolic content (TPC) and (ii) total

again, distilled water could be considered as the least efﬁcient

ﬂavonoid content (TFC) of 37 different raw vegetables.

solvent for extraction of antioxidant compounds for these

Sample (a) FRAP (b) DPPH

vegetables. Many antioxidant evaluations have reported a signiﬁ-

cant activity of 70% acetone extracts in their FRAP analysis (i) TPC (ii) TFC (i) TPC (ii) TFC

(Siddhuraju and Manian, 2007) and 70% methanol extracts in their

Herb and leafy vegetables

** *

DPPH assay (Zhou and Yu, 2004). In both tests, all extracts of C. Allium cepa 0.9948 0.0443 0.1205 0.9876

Anacardium occidentale 0.7273 0.0757 0.8969 0.4810

longa, J. gendarussa, K. galanga, P. sarmentosum, C. sativus and V.

Apium graveolens 0.9896 0.3396 0.2706 0.5556

radiata gave values less than 4 mg GAE/g dw. The FRAP value of C.

Ardisia crenata 0.4841 0.2309 0.0652 0.0056

sativus could not be quantiﬁed due to its low activity. The results *

Barringtonia racemosa 0.9823 0.9221 0.4907 0.7543

can be associated with their low amount of TPC and TFC. Several Centella asiatica 0.9987 0.1506 0.1484 0.1077

***

comparative studies of these vegetables excluding J. gendarussa, Coriandrum sativum 0.9998 0.7924 0.4990 0.9119

Cosmos caudatus 0.3079 0.1783 0.3777 0.2078

also reported poor antioxidant activities of these vegetables (Chan

* *

Curcuma longa 0.9814 0.9881 0.5890 0.0323

et al., 2008; Isabelle et al., 2010; Song et al., 2010; Wan-Ibrahim et *

Hydrocotyle umbellata 0.9828 0.7734 0.6990 0.9391

al., 2010). The results also revealed that the higher and/or lower

Justicia gendarussa 0.2643 0.8932 0.1891 0.2160

values of antioxidant activities (evaluated using both assays) were Kaempferia galanga 0.9044 0.7757 0.4205 0.2788

Lactuca sativa 0.9447 0.2432 0.2017 0.7373 detected from different plant parts and were not restricted

Melicope pteleifolia 0.7124 0.5495 0.7637 0.9617

towards certain part. **

Mentha arvensis 0.9983 0.5950 0.4733 0.1643

Micromelum minutum 0.9400 0.6950 0.4866 0.0389

3.3. Correlation between total phenolic and ﬂavonoids content and Morinda elliptica 0.8703 0.9619 0.9313 0.8124

antioxidant activity Murraya koenigii 0.5003 0.5864 0.0600 0.4344

Ocimum basilicum 0.5534 0.7008 0.2664 0.0379

* ***

Ocimum tenuiﬂorum 0.9674 0.9994 0.8415 0.7444

The results in Tables 2 and 3 clearly indicated that the

Oenanthe javanica 0.9326 0.1529 0.3381 0.4941

quantitative estimation of TPC, TFC, FRAP and DPPH values is **

Oroxylum indicum 0.9990 0.5208 0.4184 0.3446

greatly inﬂuenced by two variables that are extracting solvent and Paederia diffusa 0.5229 0.5340 0.3079 0.0345

Persicaria minor 0.9689 0.6210 0.0596 0.7678

species of plant. Therefore, the correlation analyses between the

Piper sarmentosum 0.4078 0.5969 0.0999 0.5173

studied parameters were analyzed within the extracts of each *

Pluchea indica 0.9066 0.9853 0.8679 0.8152

variable. Different reports are found from the literatures, whereby *

Portulaca oleracea 0.9851 0.6753 0.6696 0.0798

some authors suggested correlation between all these parameters, Premna cordifolia 0.9169 0.0685 0.8768 0.0876

while others found no such relationship (Demiray et al., 2009; Spondias pinnata 0.9669 0.7047 0.7206 0.2894

** *

Vitex negundo 0.9923 0.9609 0.2174 0.3456

Sulaiman et al., 2011). Moderate to weak correlations were

Flower vegetables

observed between the studied parameters, when four different *

Etlingera elatior 0.9779 0.2715 0.0598 0.4660

solvent extractions of the 37 species of vegetables were separately

Musa acuminata 0.8980 0.0730 0.3604 0.5519

analyzed. The relationships between TPC (mg GAE/g dw basis) and Fruit vegetables

FRAP (mg GAE/g dw basis) of four different solvent extractions Cucumis sativus – – 0.6036 0.4533

Mangifera indica 0.9980 0.4814 0.0485 0.1502

were separately plotted as shown in Fig. 1a, the correlation

Psophocarpus tetragonolobus 0.8734 0.1264 0.9408 0.3430

coefﬁcients (r), calculated from linear regression analysis, between

Vigna sinensis 0.8816 0.6029 0.2107 0.581

these two parameters were in a range of 0.5948–0.7139 (p < 0.001) Bean sprout vegetable

indicating that there are signiﬁcant and moderate correlations Vigna radiata 0.0761 0.9366 0.5317 0.0001

between the TPC and FRAP of the solvent extractions. *

Signiﬁcant at p < 0.05.

The correlations between TPC and DPPH inhibition (mg GAE/g Signiﬁcant at p < 0.01.

***

Signiﬁcant at p < 0.001.

dw basis) are shown in Fig. 1b, and the correlation coefﬁcients

were lower than that of TPC and FRAP (r = 0.0116 to 0.2624) and

statistically not signiﬁcant (p > 0.05). The highest correlation FRAP than that of DPPH inhibition. As indicated in Table 4, 16

between TPC and FRAP was observed from the 70% methanol species, including E. elatior (a species with the highest antioxidant

extracts followed by the distilled water extracts. Thus, 70% activity), exhibited signiﬁcant correlations (r > 0.9000, p < 0.05)

methanol could be considered as the most appropriate solvent between TPC and FRAP values and the highest linear correlation

for extracting of phenolic compounds with FRAP property from (r = 0.9998, p < 0.001) was determined within the extracts of C.

these vegetables. Thaipong et al. (2006) also suggested the highest sativum. Meanwhile, the values of TFC in extracts of Ocimum

correlation between TPC and FRAP of polar extracts as compared to tenuiﬂorum were signiﬁcantly correlated with their FRAP

other extracts and antioxidant assays. In comparison with TPC, TFC (r = 0.9994, p < 0.001). These ﬁndings convincingly suggested

(mg QE/g dw basis) was less correlated with FRAP (r = 0.2894– the major contribution of the respective TPC and TFC in these

0.4994, 0.05 < p < 0.01; Fig. 1c) but was more correlated to DPPH two vegetables to their FRAP activity. Moreover, correlation

inhibition (r = 0.1692–0.3135, p > 0.05; Fig. 1d). In agreement analysis within the extracts of P. tetragonolobus demonstrated

with our ﬁndings, Feliciano and Bravo (2009) also found less the highest correlation between TPC and DPPH inhibition with a

correlation of TPC and TFC with DPPH inhibition than that of FRAP. lower and not statistically signiﬁcant r value of 0.9408 (p > 0.05),

The highest r was also demonstrated by the 70% methanol extracts, while the highest correlation between TFC and DPPH inhibition

for the correlation analysis between TFC and FRAP (Fig. 1c), and by was derived from the extracts of A. cepa with r value of 0.9876

distilled water extracts for other correlation analyses (Fig. 1b and (p < 0.05).

d). With exception for the correlation between TFC and FRAP, the Many inverse correlations between TPC and TFC with DPPH

lowest r was mostly indicated by the 70% ethanol extracts. inhibition were observed, however the highest inverse correlation

Furthermore, a wide range of correlations between the studied was determined between the TFC and FRAP values of V. radiata

parameters was observed, when correlation analyses were (r = 0.9366). Moreover, a consistent relationship between TPC and

performed within four different extracts of each vegetable. The TFC with antioxidant activities was found within the extracts of M.

results also revealed higher correlation between TPC and TFC, with elliptica (with r values ranging from 0.8124 to 0.9619), O. tenuiﬂorum

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514 S.F. Sulaiman et al. / Journal of Food Composition and Analysis 24 (2011) 506–515

leaves and Polygonum bistorta roots. World Academy of Science, Engineering

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