DOCSLIB.ORG

Total Phenolic Contents and Phenolic Acid Constituents in 4 Varieties Of

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Total Phenolic Contents and Phenolic Acid Constituents in 4 Varieties Of JFS C: Food Chemistry and Toxicology Total Phenolic Contents and Phenolic Acid Constituents in 4 Varieties of Bitter Melons (Momordica charantia) and Antioxidant Activities of their Extracts RONNY HORAX, NAVAM HETTIARACHCHY, AND SHAHIDUL ISLAM ABSTRACT: Four varieties of bitter melon (Momordica charantia), India green (IG), India white (IW), China green (CG), and China white (CW) were analyzed for total phenolics, phenolic acid constituents, and antioxidant activities of their methanolic extracts. Phenolic contents of the oven-dried and freeze-dried tissues ranged from 5.39 to 8.94 and 4.64 to 8.90 mg chlorogenic acid equivalent (CAE)/g on dry weight basis, respectively. Phenolic contents of bitter melon seed, inner tissues, and flesh ranged from 4.67 to 8.02, 4.64 to 8.94, and 5.36 to 8.90 mg CAE/g, respectively. The total phenolic contents of IG, IW, CG, and CW were 4.64 to 6.84, 6.03 to 8.94, 5.39 to 7.81, and 6.07 to 8.90 mg CAE/g, respectively. The main phenolic acids in flesh were gallic acid, gentisic acid, catechin, C: Food Chemistry & Toxicology chlorogenic acid, and epicatechin, which ranged from 8.04 to 39.76, 16.99 to 32.39, 23.06 to 82.45, 4.55 to 15.83, and 16.14 to 44.28 mg/100 g on dry weight basis, respectively, while in inner tissues were gallic acid, gentisic acid, catechin, and epicatechin, which ranged from 2.57 to 18.05, 5.39 to 32.61, 13.54 to 39.74, and 2.96 to 40.91 mg/ 100 g, respectively. The main phenolic acids contained in seeds were gallic acid, catechin, and epicatechin, which ranged from 4.61 to 18.9, 13.2 to 57.61, and 6.00 to 40.08 mg/100 g, respectively. There was no significant difference in the antioxidant activities of the extracts among varieties (P = 0.2556) and between drying methods (P = 0.1444). The antioxidant activities of flesh, inner tissue, and seed ranged from 81.7% to 86.5%, 78.8% to 88.4%, and 78.5% to 85.4% inhibition, respectively. Bitter melon is a rich source of phenolic compounds. These natural plant phenolics can be a good source of antioxidants for application in food system. Keywords: bitter melon, phenolics, extract, antioxidant Introduction Many preservatives are added to foods as antioxidant agents. Phe- lants contain a large variety of phenolic derivatives including nolic compounds are known to possess this property. Antioxidants Psimple phenols, benzoic acid derivatives, flavonoids, phenyl- markedly delay or prevent oxidation of the substrate, when they are propanoids, tannins, lignans, and lignins. These various substanc- present in foods or in the body at low concentrations. Furthermore, es are essential for the growth and reproduction of plants as well as beneficial effects of consuming plant foods that have been ascribed contribute to plant tissue’s defense mechanism against infections to the presence of phenolics are achieved by preventing lipid oxida- or injuries caused by insects and microbial pathogens and environ- tion, protein cross-linking, and DNA mutation and tissue damage. mental stresses such as UV irradiation, fungicide treatment, tem- Antioxidants can be classified as free radical terminators, chelators of perature, or air pollution (Beier and Oertli 1983; Dercks and others metal ions, or oxygen scavengers that react with oxygen in closed sys- 1990; Babic and others 1993; Friedman 1997; Nigg and others 1997). tem. Phenolic antioxidants are included in the category of free radical Many properties of plant products are associated with the presence, terminators. Synthetic food antioxidants currently permitted for use type, and content of their phenolic compounds. The beneficial health in foods are butylated hydroxytoluene, butylated hydroxyanisole, effects of certain phenolics are significant to producers and consumers propyl gallate, dodecyl gallate, and tertiary butylhydroquinone. How- of foods. Fruits and vegetables are excellent sources of phenolics. Many ever, people are concerned to consume foods that contain synthetic studies showed that these phenolic compounds exhibit health-promot- compounds as ingredients. Natural antioxidants are primarily plant ing effects such as reducing blood pressure and lowering incidences of phenolics and polyphenolic compounds that may occur in all parts of cancer and cardiovascular diseases (Huang and Ferraro 1992; Tanaka the plant. Exploration of natural phenolic compounds from plants is and others 1993; Balentine and others 1997; Bravo 1998; Surh 1999; an alternative to replace synthetic antioxidants to maintain the quality Gorinstein and other 2002; Wang and Mazza 2002; Hannum 2004). How- of the foods from oxidative deterioration. ever, published data on the content of phenolics in fruit and vegetables Bitter melon (Momordica charantia) or bitter gourd is an impor- are still incomplete and restrictive to a few cultivars. tant cultivated food crop and widely used as vegetable in Asia. Fruit pulp, seed, and whole plant of bitter gourd have been investigat- ed for their hypoglycemic effects (Ali and others 1993; Srivastava MS 20040607 Submitted 9/8/04, Revised 10/20/04, Accepted 1/3/05. Authors Horax and Hettiarachchy are with Dept. of Food Science, Univ. of Arkan- and others 1993; Jayasooriya and others 2000). Bitter melon also has sas, 2650 North Young Ave., Fayetteville, AR 72704. Author Islam is with been reported to have other medicinal properties such as anticar- Dept. of Agriculture, Univ. of Arkansas at Pine Bluff, Ark. Direct inquiries to cinogenic and hypocholesterolemic (Ganguly and others 2000; author Hettiarachchy (E-mail: [email protected]). Ahmed and others 2001). Like many plants, bitter melon may be a © 2005 Institute of Food Technologists Vol. 70, Nr. 4, 2005—JOURNAL OF FOOD SCIENCE C275 Further reproduction without permission is prohibited Published on Web 4/28/2005 Phenolic acids of bitter melon . source of phenolic compounds. Although the value of bitter melon to cool at room temperature. To 1 mL of the clear solution in a screw-cap is realized, information on its phenolic constituents is limited. More test tube, 1.0 mL of 0.25 N Folin-Ciocalteau’s reagent, 1.0 mL of 1 N detailed investigation on bitter melon phenolics is needed to pro- sodium carbonate, and 7 mL of deionized water were added. The vide information for their nutraceutical values. tubes were vortexed and held for 2 h at room temperature. Absorption The objectives of this research were to determine the total phe- of the solution at 726 nm was measured using a spectrophotometer nolic contents and phenolic acid constituents of bitter melon tis- (Shimadzu Model UV-1601, Kyoto, Japan). The total phenolic content sues from 4 varieties and evaluate the antioxidant activities of their was expressed as chlorogenic acid equivalents (CAE) in milligram per phenolic extracts. gram dry material and calculated as follows: total phenolics (mg/g dry weight) = (A × 222.57)/10, where A was absorbance at 726 nm. Materials and Methods Methanolic extraction of phenolics Materials Phenolics of the fine ground flesh, inner tissue, and seed of the C: Food Chemistry & Toxicology Four varieties of bitter melon, India white, India green, China white, bitter melon samples were extracted by methanol. Five hundred and China green, were provided by the Univ. of Arkansas at Pine Bluff milligrams of the fine ground sample were weighed into a test tube (Pine Bluff, Ark., U.S.A.). Fourteen standard phenolic acids were used for and 5 mL methanol was added. The tube was then heated for 2 h in phenolic acid constituent determination using HPLC. Eleven phenolic a 65°C water bath. During heating, the dispersion was vortexed acids including gallic acid, protocatechuic acid, gentistic acid, (+)-cat- every 30 min. After extraction, the dispersion was cooled at room echin, vanillic acid, syringic acid, (–)-epicatchin, p-coumaric acid, ben- temperature and centrifuged (centrifuge model J2-21, Beckman, zoic acid, sinapinic acid, and o-coumaric acid were purchased from Sig- Fullerton, Calif., U.S.A.) at 3000 × g for 10 min. The residue was ma Chemical Co. (St. Louis, Mo., U.S.A.). Chlorogenic acid, t-cinnamic rinsed with 1 mL methanol, and the clear solution was combined acid, and t-ferulic acid (trans-4-hydroxy-3-methoxycinnamic acid) were with the previous supernatant. The combined methanolic extract purchased from Aldrich Chemical Co. (Milwaukee, Wis., U.S.A.). Triflu- was then evaporated to dryness under a stream of nitrogen at 60°C. oroacetic acid, methanol, acetonitrile, and water used for high-perfor- The dried methanolic extract was stored at 4°C for analysis. mance liquid chromatography (HPLC) analysis were HPLC grade. Phenolic acid constituent determination Sample preparation The phenolic acid constituents of the methanolic extracts were Flesh, seed coat tissue or inner tissue (IT), and seed (Figure 1) of determined using HPLC by the method of Cai and others (2003) with bitter melons var. India white, India green, China white, and Chi- some modification. Twenty milligrams of the extracts were dissolved na green were separated soon after the samples were received. The in 0.2 mL of methanol, and the solution was filtered through a 0.2-␮m flesh was chopped into approximately 1 to 2 mm thickness using a PVDF Target Syringe Filter (Natl. Scientific, Duluth, Ga., U.S.A.). Phe- food processor (Model FP1200, The Black & Decker Corp., Towson, nolics were quantified by a Hewlett-Packard Liquid Chromatograph Md., U.S.A.). The separated tissues were then dried in either a model 1090 equipped with UV detector (Agilent Technologies, Inc., freeze-drier (Model 25LE, The Virtis Co., Inc., Gardiner, N.Y., U.S.A.) Palo Alto, Calif., U.S.A.), and absorbance was monitored at 254 nm. A or an oven (at 60°C for 18 h, about 1 to 1.5 cm thickness of layer on TSK-GEL Super-ODS (Supelco, Bellefonte, Pa., U.S.A.) column was a stainless steel tray), ground using a coffee grinder model KSM 2B used.
Load more

Recommended publications
  • Dietary Plant Polyphenols: Effects of Food Processing on Their Content and Bioavailability
    molecules Review Dietary Plant Polyphenols: Effects of Food Processing on Their Content and Bioavailability Leila Arfaoui Department of Clinical Nutrition, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80324, Jeddah 21589, Saudi Arabia; [email protected]; Tel.: +966-0126401000 (ext. 41612) Abstract: Dietary plant polyphenols are natural bioactive compounds that are increasingly attracting the attention of food scientists and nutritionists because of their nutraceutical properties. In fact, many studies have shown that polyphenol-rich diets have protective effects against most chronic diseases. However, these health benefits are strongly related to both polyphenol content and bioavailability, which in turn depend on their origin, food matrix, processing, digestion, and cellular metabolism. Although most fruits and vegetables are valuable sources of polyphenols, they are not usually con- sumed raw. Instead, they go through some processing steps, either industrially or domestically (e.g., cooling, heating, drying, fermentation, etc.), that affect their content, bioaccessibility, and bioavail- ability. This review summarizes the status of knowledge on the possible (positive or negative) effects of commonly used food-processing techniques on phenolic compound content and bioavailability in fruits and vegetables. These effects depend on the plant type and applied processing parameters (type, duration, media, and intensity). This review attempts to shed light on the importance of more comprehensive dietary guidelines that consider the recommendations of processing parameters to take full advantage of phenolic compounds toward healthier foods. Citation: Arfaoui, L. Dietary Plant Keywords: plant polyphenols; food processing; phenolic content; bioavailability; bioaccessibility Polyphenols: Effects of Food Processing on Their Content and Bioavailability. Molecules 2021, 26, 2959.
    [Show full text]
  • Saurashtra University Re – Accredited Grade ‘B’ by NAAC (CGPA 2.93)
    Saurashtra University Re – Accredited Grade ‘B’ by NAAC (CGPA 2.93) Odedra, Nathabhai K., 2009, “Ethnobotany of Maher Tribe In Porbandar District, Gujarat, India”, thesis PhD, Saurashtra University http://etheses.saurashtrauniversity.edu/id/eprint/604 Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author. The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given. Saurashtra University Theses Service http://etheses.saurashtrauniversity.edu [email protected] © The Author ETHNOBOTANY OF MAHER TRIBE IN PORBANDAR DISTRICT, GUJARAT, INDIA A thesis submitted to the SAURASHTRA UNIVERSITY In partial fulfillment for the requirement For the degree of DDDoDoooccccttttoooorrrr ooofofff PPPhPhhhiiiilllloooossssoooopppphhhhyyyy In BBBoBooottttaaaannnnyyyy In faculty of science By NATHABHAI K. ODEDRA Under Supervision of Dr. B. A. JADEJA Lecturer Department of Botany M D Science College, Porbandar - 360575 January + 2009 ETHNOBOTANY OF MAHER TRIBE IN PORBANDAR DISTRICT, GUJARAT, INDIA A thesis submitted to the SAURASHTRA UNIVERSITY In partial fulfillment for the requirement For the degree of DDooooccccttttoooorrrr ooofofff PPPhPhhhiiiilllloooossssoooopppphhhhyyyy In BBoooottttaaaannnnyyyy In faculty of science By NATHABHAI K. ODEDRA Under Supervision of Dr. B. A. JADEJA Lecturer Department of Botany M D Science College, Porbandar - 360575 January + 2009 College Code.
    [Show full text]
  • Monocyclic Phenolic Acids; Hydroxy- and Polyhydroxybenzoic Acids: Occurrence and Recent Bioactivity Studies
    Molecules 2010, 15, 7985-8005; doi:10.3390/molecules15117985 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Review Monocyclic Phenolic Acids; Hydroxy- and Polyhydroxybenzoic Acids: Occurrence and Recent Bioactivity Studies Shahriar Khadem * and Robin J. Marles Natural Health Products Directorate, Health Products and Food Branch, Health Canada, 2936 Baseline Road, Ottawa, Ontario K1A 0K9, Canada * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +1-613-954-7526; Fax: +1-613-954-1617. Received: 19 October 2010; in revised form: 3 November 2010 / Accepted: 4 November 2010 / Published: 8 November 2010 Abstract: Among the wide diversity of naturally occurring phenolic acids, at least 30 hydroxy- and polyhydroxybenzoic acids have been reported in the last 10 years to have biological activities. The chemical structures, natural occurrence throughout the plant, algal, bacterial, fungal and animal kingdoms, and recently described bioactivities of these phenolic and polyphenolic acids are reviewed to illustrate their wide distribution, biological and ecological importance, and potential as new leads for the development of pharmaceutical and agricultural products to improve human health and nutrition. Keywords: polyphenols; phenolic acids; hydroxybenzoic acids; natural occurrence; bioactivities 1. Introduction Phenolic compounds exist in most plant tissues as secondary metabolites, i.e. they are not essential for growth, development or reproduction but may play roles as antioxidants and in interactions between the plant and its biological environment. Phenolics are also important components of the human diet due to their potential antioxidant activity [1], their capacity to diminish oxidative stress- induced tissue damage resulted from chronic diseases [2], and their potentially important properties such as anticancer activities [3-5].
    [Show full text]
  • NINDS Custom Collection II
    ACACETIN ACEBUTOLOL HYDROCHLORIDE ACECLIDINE HYDROCHLORIDE ACEMETACIN ACETAMINOPHEN ACETAMINOSALOL ACETANILIDE ACETARSOL ACETAZOLAMIDE ACETOHYDROXAMIC ACID ACETRIAZOIC ACID ACETYL TYROSINE ETHYL ESTER ACETYLCARNITINE ACETYLCHOLINE ACETYLCYSTEINE ACETYLGLUCOSAMINE ACETYLGLUTAMIC ACID ACETYL-L-LEUCINE ACETYLPHENYLALANINE ACETYLSEROTONIN ACETYLTRYPTOPHAN ACEXAMIC ACID ACIVICIN ACLACINOMYCIN A1 ACONITINE ACRIFLAVINIUM HYDROCHLORIDE ACRISORCIN ACTINONIN ACYCLOVIR ADENOSINE PHOSPHATE ADENOSINE ADRENALINE BITARTRATE AESCULIN AJMALINE AKLAVINE HYDROCHLORIDE ALANYL-dl-LEUCINE ALANYL-dl-PHENYLALANINE ALAPROCLATE ALBENDAZOLE ALBUTEROL ALEXIDINE HYDROCHLORIDE ALLANTOIN ALLOPURINOL ALMOTRIPTAN ALOIN ALPRENOLOL ALTRETAMINE ALVERINE CITRATE AMANTADINE HYDROCHLORIDE AMBROXOL HYDROCHLORIDE AMCINONIDE AMIKACIN SULFATE AMILORIDE HYDROCHLORIDE 3-AMINOBENZAMIDE gamma-AMINOBUTYRIC ACID AMINOCAPROIC ACID N- (2-AMINOETHYL)-4-CHLOROBENZAMIDE (RO-16-6491) AMINOGLUTETHIMIDE AMINOHIPPURIC ACID AMINOHYDROXYBUTYRIC ACID AMINOLEVULINIC ACID HYDROCHLORIDE AMINOPHENAZONE 3-AMINOPROPANESULPHONIC ACID AMINOPYRIDINE 9-AMINO-1,2,3,4-TETRAHYDROACRIDINE HYDROCHLORIDE AMINOTHIAZOLE AMIODARONE HYDROCHLORIDE AMIPRILOSE AMITRIPTYLINE HYDROCHLORIDE AMLODIPINE BESYLATE AMODIAQUINE DIHYDROCHLORIDE AMOXEPINE AMOXICILLIN AMPICILLIN SODIUM AMPROLIUM AMRINONE AMYGDALIN ANABASAMINE HYDROCHLORIDE ANABASINE HYDROCHLORIDE ANCITABINE HYDROCHLORIDE ANDROSTERONE SODIUM SULFATE ANIRACETAM ANISINDIONE ANISODAMINE ANISOMYCIN ANTAZOLINE PHOSPHATE ANTHRALIN ANTIMYCIN A (A1 shown) ANTIPYRINE APHYLLIC
    [Show full text]
  • Xanthones. Part I V.* a New Synthesis of Hydroxyxanthones and Hydrozybenzophenones
    3982 Grover, Shah, agad Shah : Xanthones. Part I V.* A New Synthesis of Hydroxyxanthones and Hydrozybenzophenones. By P. I<. GROVER,G. D. SHAH,and R. C. SHAH. [Reprint Order No. 6470.1 Hydroxy-santhones and -benzophenones are conveniently obtained from hydroxybenzoic acids and phenols in presence of zinc chloride and phosphorus oxychloride. DISTILLATIONof a mixture of a phenol, a phenolic acid, and acetic anhydride is the earliest and simplest method for the synthesis of hydroxyxanthones (Michael, Amer. Chsm. J., 1883, 5, 81; Kostanecki and his co-workers, Ber., 1891, 24, 1896, 3981, etc.; Lund, Robertson, and Whalley, J., 1953, 2438), but yields are often poor, experimental conditions are rather drastic, and there is a possibility of decarboxylation, autocondensation, and other side reactions (Lespegnol, Bertrand, and Dupas, BUZZ. SOC.chim. France, 1939, 6, 1925; Lund et aZ., Zoc. cit.). There are numerous other routes, but none is of general application and some require uncommon starting materials or involve a number of steps. In continuation of the work on naturally occurring xanthones (J. Indian Chem. SOC., 1953,30,457,463; J. Sci. Id.Res., India, 1954,13, B, 175; 1955,14, B, 153) the known methods for the synthesis of 1 : 3 : 7 : 8-tetrahydroxyxanthone or its tetramethyl ether * Part 111, J. Sci. Ind. Res., India, 1954, 13, B, 175. [ 19551 Xanthones. Part IV. 3953 were found unsuitable. Condensation under mild conditions of a phenolcarboxylic acid with a reactive phenol in presence of condensing agents such as anhydrous aluminium chloride, phosphorus oxychloride, phosphoric oxide, or sulphuric acid was not promising ; but a mixture of phosphorus oxychloride and fused zinc chloride, which had previously been found effective for the preparation of 2 : 4dihydroxybenzophenone (Shah and Mehta, J.
    [Show full text]
  • Phenolics in Human Health
    International Journal of Chemical Engineering and Applications, Vol. 5, No. 5, October 2014 Phenolics in Human Health T. Ozcan, A. Akpinar-Bayizit, L. Yilmaz-Ersan, and B. Delikanli with proteins. The high antioxidant capacity makes Abstract—Recent research focuses on health benefits of polyphenols as an important key factor which is involved in phytochemicals, especially antioxidant and antimicrobial the chemical defense of plants against pathogens and properties of phenolic compounds, which is known to exert predators and in plant-plant interferences [9]. preventive activity against infectious and degenerative diseases, inflammation and allergies via antioxidant, antimicrobial and proteins/enzymes neutralization/modulation mechanisms. Phenolic compounds are reactive metabolites in a wide range of plant-derived foods and mainly divided in four groups: phenolic acids, flavonoids, stilbenes and tannins. They work as terminators of free radicals and chelators of metal ions that are capable of catalyzing lipid oxidation. Therefore, this review examines the functional properties of phenolics. Index Terms—Health, functional, phenolic compounds. I. INTRODUCTION In recent years, fruits and vegetables receive considerable interest depending on type, number, and mode of action of the different components, so called as “phytochemicals”, for their presumed role in the prevention of various chronic diseases including cancers and cardiovascular diseases. Plants are rich sources of functional dietary micronutrients, fibers and phytochemicals, such
    [Show full text]
  • A Critical Study on Chemistry and Distribution of Phenolic Compounds in Plants, and Their Role in Human Health
    IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) e-ISSN: 2319-2402,p- ISSN: 2319-2399. Volume. 1 Issue. 3, PP 57-60 www.iosrjournals.org A Critical Study on Chemistry and Distribution of Phenolic Compounds in Plants, and Their Role in Human Health Nisreen Husain1, Sunita Gupta2 1 (Department of Zoology, Govt. Dr. W.W. Patankar Girls’ PG. College, Durg (C.G.) 491001,India) email - [email protected] 2 (Department of Chemistry, Govt. Dr. W.W. Patankar Girls’ PG. College, Durg (C.G.) 491001,India) email - [email protected] Abstract: Phytochemicals are the secondary metabolites synthesized in different parts of the plants. They have the remarkable ability to influence various body processes and functions. So they are taken in the form of food supplements, tonics, dietary plants and medicines. Such natural products of the plants attribute to their therapeutic and medicinal values. Phenolic compounds are the most important group of bioactive constituents of the medicinal plants and human diet. Some of the important ones are simple phenols, phenolic acids, flavonoids and phenyl-propanoids. They act as antioxidants and free radical scavengers, and hence function to decrease oxidative stress and their harmful effects. Thus, phenols help in prevention and control of many dreadful diseases and early ageing. Phenols are also responsible for anti-inflammatory, anti-biotic and anti- septic properties. The unique molecular structure of these phytochemicals, with specific position of hydroxyl groups, owes to their powerful bioactivities. The present work reviews the critical study on the chemistry, distribution and role of some phenolic compounds in promoting health-benefits.
    [Show full text]
  • Hydroxybenzoic Acid Isomers and the Cardiovascular System Bernhard HJ Juurlink1,2, Haya J Azouz1, Alaa MZ Aldalati1, Basmah MH Altinawi1 and Paul Ganguly1,3*
    Juurlink et al. Nutrition Journal 2014, 13:63 http://www.nutritionj.com/content/13/1/63 REVIEW Open Access Hydroxybenzoic acid isomers and the cardiovascular system Bernhard HJ Juurlink1,2, Haya J Azouz1, Alaa MZ Aldalati1, Basmah MH AlTinawi1 and Paul Ganguly1,3* Abstract Today we are beginning to understand how phytochemicals can influence metabolism, cellular signaling and gene expression. The hydroxybenzoic acids are related to salicylic acid and salicin, the first compounds isolated that have a pharmacological activity. In this review we examine how a number of hydroxyphenolics have the potential to ameliorate cardiovascular problems related to aging such as hypertension, atherosclerosis and dyslipidemia. The compounds focused upon include 2,3-dihydroxybenzoic acid (Pyrocatechuic acid), 2,5-dihydroxybenzoic acid (Gentisic acid), 3,4-dihydroxybenzoic acid (Protocatechuic acid), 3,5-dihydroxybenzoic acid (α-Resorcylic acid) and 3-monohydroxybenzoic acid. The latter two compounds activate the hydroxycarboxylic acid receptors with a consequence there is a reduction in adipocyte lipolysis with potential improvements of blood lipid profiles. Several of the other compounds can activate the Nrf2 signaling pathway that increases the expression of antioxidant enzymes, thereby decreasing oxidative stress and associated problems such as endothelial dysfunction that leads to hypertension as well as decreasing generalized inflammation that can lead to problems such as atherosclerosis. It has been known for many years that increased consumption of fruits and vegetables promotes health. We are beginning to understand how specific phytochemicals are responsible for such therapeutic effects. Hippocrates’ dictum of ‘Let food be your medicine and medicine your food’ can now be experimentally tested and the results of such experiments will enhance the ability of nutritionists to devise specific health-promoting diets.
    [Show full text]
  • Sensory and Physico-Chemical Analyses of Roasted Marama Beans [Tylosema Esculentum (Burchell) A
    Sensory and physico-chemical analyses of roasted marama beans [Tylosema esculentum (Burchell) A. Schreiber] with specific focus on compounds that may contribute to bitterness Patricia Nyembwe , Amanda Minnaar , Kwaku G. Duodu, Henriette L. de Kock* Department of Food Science, University of Pretoria, Private Bag X20, Hatfield, Pretoria 0028, South Africa *Corresponding author: [email protected] Tel: +27 12 420 3238; Fax: +27 12 420 2839 ABSTRACT The role of phenolics and saponins in contributing to bitterness in marama beans, an underutilized legume, especially when roasted, was investigated. Marama beans were roasted at 150 °C for 20, 25 or 30 min, dehulled to separate cotyledons, and pastes were prepared from these. Water extracts were prepared from full fat and defatted flours from roasted and unroasted marama cotyledons. A sensory panel evaluated the sensory attributes of marama pastes and water extracts. Marama water extracts were analysed for total phenolic content, phenolic composition and saponin content. Roasting marama beans for more than 20 min resulted in negative properties such as bitterness. The major extractable phenolic acids present in marama water extracts were gallic and protocatechuic acids which increased as a function of roasting time. Saponin content of the water extracts was in the range of 55 to 63 mg/L. The identified phenolic acids, saponins and other as yet unidentified compounds may contribute to the perceived bitterness. KEYWORDS: Tylosema esculentum; marama bean water extracts; roasting; descriptive sensory evaluation; bitterness; phenolic compounds; saponins. 1 1. INTRODUCTION There is a search worldwide for food sources to alleviate malnutrition in developing countries due to a shortage of protein-rich foods.
    [Show full text]
  • Betalains and Phenolics in Red Beetroot (Beta Vulgaris)
    Betalains and Phenolics in Red Beetroot (Beta vulgaris) Peel Extracts: Extraction and Characterisation Tytti Kujala*, Jyrki Loponen and Kalevi Pihlaja Department of Chemistry, Vatselankatu 2, FIN-20014 University of Turku, Finland. Fax: +3582-333 67 00. E-mail: [email protected] * Author for correspondence and reprint requests Z. Naturforsch. 56 c, 343-348 (2001); received January 9/February 12, 2001 Beta vulgaris , Betalains, Phenolics The extraction of red beetroot (Beta vulgaris ) peel betalains and phenolics was compared with two extraction methods and solvents. The content of total phenolics in the extracts was determined according to a modification of the Folin-Ciocalteu method and expressed as gallic acid equivalents (GAE). The profiles of extracts were analysed by high-performance liquid chromatography (HPLC). The compounds of beetroot peel extracted with 80% aqueous methanol were characterised from separated fractions using HPLC- diode array detection (HPLC-DAD) and HPLC- electrospray ionisation-mass spectrometry (HPLC-ESI-MS) tech­ niques. The extraction methods and the choice of solvent affected noticeably the content of individual compounds in the extract. The betalains found in beetroot peel extract were vulgaxanthin I, vulgaxanthin II, indicaxanthin, betanin, prebetanin, isobetanin and neobe- tanin. Also cyclodopa glucoside, /V-formylcyclodopa glucoside, glucoside of dihydroxyindol- carboxylic acid, betalamic acid, L-tryptophan, p-coumaric acid, ferulic acid and traces of un­ identified flavonoids were detected. Introduction acid in their cell walls (Jackman and Smith, 1996). Phenolic compounds are ubiquitous in the plant Except ferulic acid, also other phenolic acids and kingdom and they have been reported to possess phenolic acid conjugates have been reported in many biological effects.
    [Show full text]
  • Phenolic Compounds in Cereal Grains and Their Health Benefits
    and antioxidant activity are reported in the Phenolic Compounds in Cereal literature. Unfortunately, it is difficult to make comparisons of phenol and anti- Grains and Their Health Benefits oxidant activity levels in cereals since different methods have been used. The ➤ Whole grain cereals are a good source of phenolics. purpose of this article is to give an overview ➤ Black sorghums contain high levels of the unique 3-deoxyanthocyanidins. of phenolic compounds reported in whole ➤ Oats are the only source of avenanthramides. grain cereals and to compare their phenol and antioxidant activity levels. ➤ Among cereal grains, tannin sorghum and black rice contain the highest antioxidant activity in vitro. Phenolic Acids Phenolic acids are derivatives of benzoic and cinnamic acids (Fig. 1) and are present in all cereals (Table I). There are two Most of the literature on plant phenolics classes of phenolic acids: hydroxybenzoic L. DYKES AND L. W. ROONEY focuses mainly on those in fruits, acids and hydroxycinnamic acids. Hy- TEXAS A&M UNIVERSITY vegetables, wines, and teas (33,50,53,58, droxybenzoic acids include gallic, p- College Station, TX 74). However, many phenolic compounds hydroxybenzoic, vanillic, syringic, and in fruits and vegetables (i.e., phenolic acids protocatechuic acids. The hydroxycinna- esearch has shown that whole grain and flavonoids) are also reported in cereals. mic acids have a C6-C3 structure and Rconsumption helps lower the risk of The different species of grains have a great include coumaric, caffeic, ferulic, and cardiovascular disease, ischemic stroke, deal of diversity in their germplasm sinapic acids. The phenolic acids reported type II diabetes, metabolic syndrome, and resources, which can be exploited.
    [Show full text]
  • Evaluation of Anticancer Activities of Phenolic Compounds In
    EVALUATION OF ANTICANCER ACTIVITIES OF PHENOLIC COMPOUNDS IN BLUEBERRIES AND MUSCADINE GRAPES by WEIGUANG YI (Under the Direction of CASIMIR C. AKOH) ABSTRACT Research has shown that diets rich in phenolic compounds may be associated with lower risk of several chronic diseases including cancer. This study systematically evaluated the bioactivities of phenolic compounds in blueberries and muscadine grapes, and assessed their potential cell growth inhibition and apoptosis induction effects using two colon cancer cell lines (HT-29 and Caco-2), and one liver cancer cell line (HepG2). In addition, the absorption of blueberry anthocyanin extracts was evaluated using Caco-2 human intestinal cell monolayers. Polyphenols in three blueberry cultivars (Briteblue, Tifblue and Powderblue), and four cultivars of muscadine (Carlos, Ison, Noble, and Supreme) were extracted and freeze dried. The extracts were further separated into phenolic acids, tannins, flavonols, and anthocyanins using a HLB cartridge and LH20 column. In both blueberries and muscadine grapes, some individual phenolic acids and flavonoids were identified by HPLC with more than 90% purity in anthocyanin fractions. The dried extracts and fractions were added to the cell culture medium to test for cell growth inhibition and induction of apoptosis. Polyphenols from both blueberries and muscadine grapes had significant inhibitory effects on cancer cell growth. The phenolic acid fraction showed relatively lower bioactivities with 50% inhibition at 0.5-3 µg/mL. The intermediate bioactivities were observed in the flavonol and tannin fractions. The greatest inhibitory effect among all four fractions was from the anthocyanin fractions in the three cell lines. Cell growth was significantly inhibited more than 50% by the anthocyanin fractions at concentrations of 15-300 µg/mL.
    [Show full text]