Variation of Quality Characteristics in Greek and Turkish Carob Pods During Fruit Development

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Procedia Social and Behavioral Sciences 19 (2011) 750–755

The 2nd International Geography Symposium GEOMED2010 Variation of quality characteristics in Greek and Turkish carob pods during fruit development

Stavroula A.Vekiaria, Georgia Ouzounidoua, Münir Ozturkb*, Güven Görkc

aNational Agric. Res.Foundation, Institute of Technology of Agricultural Products, Athens, Greece bEge University, Botany Department, Bornova, Izmir, Turkey cUniversity of Mugla, Biology Department, Mugla, Turkey

Abstract

The carob tree (Ceratonia siliqua L.) is widely cultivated in Mediterranean countries including Greece and Turkey. Carob pod is the fruit of carob tree. The present study reports the changes of chemical characteristics of two types (fleshy and wild) Greek and one type (fleshy) of Turkish carob pods during one period harvesting. The content of protein, total polyphenols, fatty acids and sugars, which are substances of vital importance for the evaluation of their food and medicine quality were determined at three growth stages. Sucrose, glucose and fructose were the major sugars identified and quantified in the fruit. In the first growth stage the predominant fatty acid in Turkish carobs was oleic followed by linoleic, palmitic and linolenic fatty acids while in Greek carobs the major acid was linoleic (n-6). During maturation an increase in oleic acid and a sharply decrease in linoleic and linolenic (n-3) fatty acids were noticed in both Greek and Turkish samples. Turkish carobs appeared higher level of total sugars, fructose and sucrose content than the Greek ones in the first growth stage. A higher ratio of total unsaturated / saturated fatty acids was found in Greek than in Turkish mature fleshy carob pods. Our results could aid in the assessment of adequate compositional information for further studies.

©© 20112011 Published Published by by Elsevier Elsevier Ltd. Ltd. Selection Selection and/or and/or peer-review peer-review under under responsibility responsibility of The of 2nd Recep International Efe and GeographyMunir Ozturk Symposium-Mediterranean Environment

Keywords: Ceratonia siliqua, Carob pods, Greece, Turkey, protein, fatty acids, total polyphenols, sugars

1. Introduction

The Mediterranean basin is a conservation sanctuary, a historical area of ecotony, a refuge and a baseline for life, representing a rich heritage both for the exploration of new resources (food, medicines, energy etc.) as well as the traditional culture of the inhabitants in the basin [1,2,3,4]. The region offers researchers with a good insight into the plant diversity, utilitarian value of natural resources, harmonious relationship of the individuals, traditions of stewardship with the environment, the biodynamics of the nature and the fragile ecological balances. It is an area with a rich plant diversity and approximately 25000 species of plants are distributed here which comes to about 10 percent of the world’s higher plants [ 5,6,7]. One of these is the

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1877–0428 © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of The 2nd International Geography Symposium- Mediterranean Environment doi:10.1016/j.sbspro.2011.05.194 Stavroula A.Vekiari et al. / Procedia Social and Behavioral Sciences 19 (2011) 750–755 751 carob tree Ceratonia siliqua; a native tree of the East Mediterranean; which is flourishing in this area since antiquity, usually in mild and dry places with poor soils, and has great economic importance from both industrial as well as nutritional point of view [8, 9, 10, 11,12, 13,14,15,16, 17, 18]. Lot of work has been done on its physiological behaviour [19,20,21,22]. Its value was recognized by the ancient Greeks, who brought it from Middle East to Greece and Italy, and by the Arabs, who disseminated it along the North African coast and north into Spain and Portugal. It has spread to other Mediterranean-like regions such as California, Arizona, Mexico, Chile and Argentina, to parts of Australia and to South Africa and India. The carob tree is an important component of the Mediterranean vegetation and its cultivation in marginal and prevailing calcareous soils of the Mediterranean region is important environmentally and economically. Traditionally, grafted carob trees have been interplanted with olives, grapes, almonds and barley in low- intensity farming systems in most producing countries. Carob pods with their sugary pulp are a staple in the diet of farm animals and are eaten by children as snacks or by people in times of famine. However, currently the main interest is seed production for gum extraction. Because of low orchard management requirements the carob tree is suitable for part-time farming and shows potential for planting in semi-arid Mediterranean or subtropical regions. The trees are also useful as ornamentals and for landscaping, windbreaks and afforestation. World production is estimated at about 310 000 t/year produced from some 200 000 ha with very variable yields depending on cultivar, region and farming practice. Spain is the leading carob producer, producing on average 135 000 t/year, followed by Italy, Portugal, Morocco, Greece, Cyprus, Turkey, Algeria and some other countries [8, 9, 23]. The carob Carob pods are very important economically and medicinally [24, 25, 26, 27, 28, 29, 30], rich in sucrose and protein but poor in fat. They contain vitamins A and B and several minerals. Due to their chemical composition, the carobs are used in food and in the medicine as well. The main use of economical importance of carob is as a cocoa substitute and for foodstuff as well. They are used to obtain a high quality, nutritious, and superb tasting fodder for horses, cattle, and goats. The most important use of the pods lies in the production of gum, taken from the seeds after shuttering and separation, and used in many commercial food products as a thickening agent as well as textile industry [24]. The pulp is the main constituent of the pod ranging between 73 to 95 percent [25], with corresponding seed contents. The pods have a high content of soluble sugars and a low content of fats and proteins [26, 27]. As carobs are also rich in insoluble fibers they might improve cholesterol profile [27, 28]. Carob pods have demonstrated interesting anti- cardiovascular and antioxidant properties, apparently related to phenolic compounds contains[29, 30]. Carob pods can actually be regarded as a by-product in the carob processing procedure, because the seeds are considered the most valuable part of the fruit, containing polysaccharides, which are widely used in the food industry. They are, therefore, a cheap source of natural polyphenolic phytochemicals, whose nature and importance has not been investigated at length. This study seeks to evaluate the importance of carobs as part of other aspects of the overall study conducted within the framework of the Greece-Turkey bilateral Project. The aim being coordination and collection of comprarative data from carob dominated localities selected by the research groups from Greece and Turkey. These studies have an urgency because both the countries are industrializing at a fast speed and demographic developments, urbanisation, tourism and other impacts are altering the physical and biological environment resulting in an accelerated loss of diversity. This study presents a preliminary investigation on variation of health beneficial compounds such as polyphenols, proteins, sugars and fatty acids (including Ȧ -3 and Ȧ-6) of two types (fleshy and wild) Greek and one type (fleshy) Turkish carob pods (Ceratonia siliqua L.) during fruit developing.

2. Materials and methods

The samples were harvested in three growth stages (at the beginning of May, at the end of June and at the end of October) from different localities of Crete and Mugla. The content of moisture (%) [31], protein (%) by Kjelhdahl method, total polyphenols by UV / VIS (as mg/kg of caffeic acid) [ 32], fatty acids (%) by GC content [33], total sugars and analysis of non reducing type sugars by HPLC [34, 35, 36], substances of vital importance for the evaluation of their food and medicine quality were determined during one period harvesting. 752 Stavroula A.Vekiari et al. / Procedia Social and Behavioral Sciences 19 (2011) 750–755

3. Results and discussion

The results obtained are presented in the tables 1-3. - Both types possess moisture content much greater than 50% in the first stage, which diminishes sharply from the first stage to the second (by more than 85 and 89% in wild and fleshy type, respectively) and more wildly in the next samplings. - Protein followed a similar pattern showing a significant drop during ripening. This is in accordance with the findings of [8]. - There were noticed significant differences between the carob of the different areas in phenolics, proteins, fatty acids and sugars content in the majority of cases. - Sucrose, one of the most important parameter for assessment of the commercial carob quality, was the principal sugar identified and quantified in the fruit following by glucose and fructose. This is in agreement with the findings of [23, 37, 38, 39]. -Turkish carobs appeared higher level of total sugars, fructose and sucrose content than the Greek ones in the first growth stage. -In the first growth stage the predominant fatty acid in Turkish carobs was oleic followed by linoleic, palmitic and linolenic fatty acids while in Greek carobs the major acid was linoleic acid (n-6). -During maturation an increase in oleic acid and a sharply decrease in linoleic and linolenic (n-3) fatty acids were noticed in both Greek and Turkish samples. -A higher ratio of total unsaturated / saturated fatty acids, that was increased in all cases during ripening, was found in Greek than in Turkish mature fleshy carob pods.

Table 1. Sugar content (% on the basis of dry matter) of two types of Greek and one type of Turkish carob pods during the three growth stages.

Greek Greek Sugars Growth Stage Turkish Fleshy Fleshy Wild 1st 6.8a 6.7a 5.9a Glucose 2nd 7.0a 9.2b ----- 3rd 7.1a 3.0b 5.4c 1st 10.6a 7.9b 10.7a Fructose 2nd 4.2a 3.3a ----- 3rd 3.8a 9.5b 2.2c 1st 5.4a 3.3b 10.0c Sucrose 2nd 44.6a 26.3b ----- 3rd 26.9a 32.6b 29.9c 1st 23.1a 18.1b 27.0c Total 2nd 56.4a 39.2b ----- 3rd 38.0a 45.6b 37.7a

4. Conclusions

As the carob fruit has a high level of sugars it could be a significant cheap source for industry of sugars and fatty acids (n-6 and n-3) as well and its natural phenolics, whose nature and importance is as yet poorly investigated, could also be evaluated for its antioxidant capacity. Our results may aid in the assessment of adequate compositional information for further studies concerning carobs of Greek and Turkish origin. Stavroula A.Vekiari et al. / Procedia Social and Behavioral Sciences 19 (2011) 750–755 753

5. Acknowledgements

The present study was founded by GSRT and TUBITAK in the frame of Bilateral S&T Cooperation between Greece and Turkey.

Table 2. Fatty acid composition (% on the basis of dry matter) of two types of Greek carob and one type of Turkish pods during the three growth stages.

Greek Fleshy Greek Wild Turkish Fleshy Fatty acids 1st 2nd 3rd 1st 2nd 3rd 1st 3rd Caproic acid (C6:0) 1.0 3.3 1.4 4.0 1.0 2.5 2.3 2.0 Caprylic acid (C8:0) 0.1 0.4 0.5 0.2 0.5 0.4 0.2 0.8 Capric acid (C10:0) 4.3 8.1 3.1 1.9 4.0 8.9 5.2 4.4 Lauric acid (C12:0) 0.1 0.2 0.2 0.1 0.2 0.1 0.1 0.3 Tridecanoic acid (C13:0) 0.2 0.1 0.1 0.4 0.2 0.1 0.1 0.2 Myristic acid (C14:0) 0.5 0.3 0.5 0.5 0.4 0.3 0.3 0.8 Pentadecanoic acid (C15:0) 0.3 0.1 0.1 0.3 0.1 0.1 0.2 0.3 Pentadecanoic acid (C15:1) 0.2 0.2 0.4 0.2 0.2 0.4 0.1 0.7 Palmitic acid (C16:0) 21.9 17.0 15.9 17.8 16.2 16.8 17.0 19.0 Palmitoleic acid (C16:1) 0.2 0.9 1.3 0.3 0.9 0.9 0.6 0.3 Margaric acid /C17:0) 0.9 0.9 0.4 0.6 0.5 0.4 0.9 0.4 Stearic acid (C18:0) 3.7 2.7 2.3 1.9 2.3 2.2 1.9 2.9 Oleic acid (C18:1) 16.2 57.1 56.0 19.2 56.9 56.7 37.5 44.8 Linoleic acid (C18:2 n6) 29.1 7.9 8.8 24.0 12.3 9.3 22.2 6.0 ĮLinolenic acid (C18:3 n3) 8.9 2.6 2.2 13.8 3.8 2.5 9.0 2.4 arachidic acid (C20:0) 0.1 1.1 0.5 0.4 0.1 0.7 0.4 1.0 n-6/n-3 3.2 3.0 4.0 1.7 3.2 3.7 2.4 2.5 Unsaturated/Saturated 1.6 1.9 2.7 2.0 2.9 2.1 1.4 1.6 Values represent the means of trplicate analysis.

Table 3. Moisture, total sugars, polyphenols and protein content (% on the basis of dry matter) of two types of Greek and one type of Turkish carob pods during the three growth stages. (The values represent the means of triplicate analyses. Mean values in the same row followed by different letter differ significantly at P0.05.)

Growth Stage Greek Fleshy Greek Wild Turkish Fleshy Moisture 1st 80.6 a 75.8b 74.2c 2nd 22.3a 13.3b --- 3rd 10.9a 12.8b 11.0a Total polyphenols 1st 10.0a 24.8b 17.5c 2nd 1.6a 7.0b --- 3rd 3.3a 2.4b 1.6c Proteins 1st 9.5a 10.1a 5.6b 2nd 4.7a 4.2a --- 3rd 4.8a 4.8a 3.6b 754 Stavroula A.Vekiari et al. / Procedia Social and Behavioral Sciences 19 (2011) 750–755

References

[1] Myers, N., Mittermeier, R.A., Mittermeier, C.G., da Fonseca, G.A.B., Kent, J., 2000. Biodiversity hotspots for conservation priorities. Nature 403, 853–858. [2] Pineda, F.D., de Miguel, J.M., Casado, A., Montalvo, J., 2002a. La Diversidad Biológica de España. Prentice Hall, Madrid, pp. XV. [3] Pineda, F.D., de Miguel, J.M., Casado, A., Montalvo, J., 2002b. Claves para comprender la “diversidad biológica” y conservar la “biodiversidad”. In:Pineda, F.D., de Miguel, J.M., Casado, A., Montalvo, J. (Eds.), La Diversidad Biológica de España. Prentice Hall, Madrid, pp. 7–30. [4] Ozturk,M., Gucel,S., Sakcali,S., Gork,C., Yarci,C., Gork,G.2008. An overview of plant diversity and land degradation interactions in the eastern Mediterranean. Chapter 15, In: Nature & Environment in the Mediterranean (Eds. R.Efe et al). Cambridge Scholars Press, UK. [5] Heywood, V.H., 1999. The Mediterranean region a major centre of plant diversity. In: Heywood V.H., Skoula M. (Eds.), Wild food and non-food plants: Information networking. Chania: CIHEAM-IAMC: 5–13. Cahiers Options Méditerranéennes, v. 38. [6] Medail, F., Quézel, P., 1999. Biodiversity hotspots in the Mediterranean Basin: setting global conservation priorities. Conservation Biology 13 (6),1510–1513. [7] Feoli, E., Giacomich, P., Mignozzi, K., Ozturk, M., Scimone, M., 2003. Monitoring desertification risk with an index integrating climatic and remotely-sensed data: An example from the coastal area of Turkey. Management of Environmental Quality: An Intern. Journal, Vol. 14, No.1, pp. 10-21. [8] Batlle, I. and Tous, J. 1997. Carob tree: Ceratonia siliqua L. IPGRI, Rome, p.78. [9] Gork,G., Ozturk,M., Sakcali,S. 2009. Biomonitoring of Desertification in the Mediterranean Using Carob (Ceratonia siliqua L.). Turkey (TUBITAK) and Greece (NAGREF) Bilateral Project Report , pp:30. [10] Nunes , M.A., Ramalho, J. D. C., Rijo, P. da S. 1992. Seasonal changes in some photosynthetic properties of Ceratonia siliqua (carob tree) leaves under natural conditions. Physiologia Plantarum,86,3,381-387. [11] Custódio,L., Serra, H., José Manuel F. Nogueira, Sandra Gonçalves and Anabela Romano. Analysis of the Volatiles Emitted by Whole Flowers and Isolated Flower Organs of the Carob Tree Using HS-SPME-GC/MS. Journal of Chemical Ecology , Volume 32, Number 5, 929-942, 2006. [12] Vardar, Y., Secmen, O., Ozturk, M., 1980.Some distributional problems and biological characteristics of Ceratonia in Turkey. Acta Biologica, Portugaliae, 16, 75-86. [13] Ozturk, M., Secmen, O., Guvensen, A.1995. Carob (Ceratonia siliqua L.) as a secondary forest product. Forest Engineers Jour.,Ankara,Turkey, 32, 3, 5-8. [15] Kumazawa, S., Taniguchi, M., Suzuki, Y., Shimura, M., Kwon, M.- S. and Nakayama, T., 2002. “Antioxidant activity of polyphenols in Carob pods”, J. Agric. Food Chem. 50, 373-377. [16] Makris, D.P. and Kefalas, P. 2004. Carob pods (Ceratonia siliqua L.) as a source of polyphenolic antioxidants. Food Technol. Biotechnol. 42, 105-108. [17]. Marakis, S., Marakis, G. and Lambraki, M. 1997. Tannins of eight carob varieties from the island of Lefkada, Greece, Chimica Chronika, New Series, 26, 57-66. [18] Morton, J.F. 1987. Carob. In fruits of warm climates (C.F.Dowling, ed.), Morton, Miami, FL. [19] Manso T, Nunes C, Raposo S, Lima-Costa ME. 2010. Carob pulp as raw material for production of the biocontrol agent P. agglomerans PBC-1. J Ind Microbiol Biotechnol. 2010 Nov;37(11):1145-55. [20]. Vertovec, M., Sakcali, S., Ozturk, M., Salleo, S., Giacomich, P., Feoli,E., Nardini, A., 2001. Diagonosing plant water status as a tool for quantifying water stress on a regional basis in Mediterranean drylands. Ann. For. Sci. 58, 113-125. [21] Sakcali MS, Ozturk M. 2004. Eco-physiological behaviour of some Mediterranean plants as suitable candidates for reclamation of degraded areas. Journal of Arid Environments , 57, 141-153. [22] Correia, P.J., Martins-Loucão, M. A. 2001. Seasonal variations of leaf water potential and growth in fertigated carob-trees (Ceratonia siliqua L.) Plant and Soil , Volume 172, Number 2, 199-206, DOI: 10.1007/BF00011322 [23] Ramalho, J.C., Lauriano, J.A., Nunes,M.A. 2010. Changes in Photosynthetic Performance of Ceratonia Siliqua in Summer . Photosynthetica 38, 3, 393-396, DOI: 10.1023/A:1010921504033 [24] Ayaz, F.A., Torun, H., Ayaz, S., Correia, P.J., Alaiz, M., Sanz, C., Gruz, J. and Strnad, M. 2007. Determination of chemical composition of Anatolian carob pod (CERATONIA SILIQUA L.): Sugars, amino and organic acids, minerals and phenolic compounds, Journal of Food Quality, 30, 1040-1055. [25] Ahmed,M. and Vardar, Y. 1975. Chemical composition of carob seed. ĭȊȉȅȃ, 33 (1), 63-64. [26] Vourdoubas, J., Makris, D., Kefalas, P., Kaliakatsos, J. 2002: 12th European Conference and Technology Exhibition on Biomass for Energy, Industry and Climate Protection, Proceedings, Amsterdam, pp. 489-493. [27] Vardar, Y., Secmen, O., Ahmed, M. 1972. Preliminary results on the chemical composition of the Turkish carob beans. Qual. Plant. Mater. Veg. 21/4: 367-379. [28] Ouarda, H. E.F., Naghmouchi, S., Walker, D.J., Correal, E., Boussaïd, M., Khouja, M. L. 2008. Variability in the pod and seed parameters and nuclear DNA content of Tunisian populations of Ceratonia siliqua L. Agroforestry Systems , 74, 1, 73-81. [29] Calixto, F.S. and Canellas, J. 1982. Components of nutritional interest in carob pods (Ceratonia siliqua L.),J. Sci. Food Agric., 33, 1319-1323. [30] Stacey, G., Burris, R.H., Evans, H.J. 1992. Biological Nitrogen Fixation. Routlege, Chapman & Hall Inc., USA, 945 pp. [31] Arts, I.C.W., Hollman, P.C.H. 2005. Dietary Polyphenols & Health: Proc. Of the Ist. Internat. Conf. On Polyphenols & Health. Am. Soc. For Clinical Nutrition,81,1,317S-325S. Stavroula A.Vekiari et al. / Procedia Social and Behavioral Sciences 19 (2011) 750–755 755

[32] AOACS (1990). Official methods of analysis, 15th cd. Association of Official Analytical Chemists, Washington, DC. [33] Vekiari, S.A., Koutsaftakis, A. “The effect of different processing stages of olive fruit on the extracted olive oil polyphenol content”, Grasas Y Aceites, vol. 53 (3), 304-308, 2002. [34] EUC 1991. Analytical methods described in The Regulation EEC/2568/91 of the European Union Commission. [35] Perez, A.G., Rios, J.J., Sanz, C. and Oleas, J.M. 1997. Rapid determination of sugars, non-volatile acids, and ascorbic acid in strawberry and other fruits. J. Agric. Food Chem. 45, 3545-3549. [36] Silanikove, N., Landau, S., Or D., Kababya, D., Bruckental, I., Nitsan, Z. 2006. Analytical approach and effects of condensed tannins in carob pods (Ceratonia siliqua) on feed intake, digestive and metabolic responses of kids, Livestock Science 99, 29-38. [37] Avallone, R., Plessi, M., Baraldi, M. and Monzani, A. 1997. Determination of chemical composition of carob (Ceratonia Siliqua L): Protein, Fat, Carbohydrates and Tannins. Journal of Food Composition and Analysis, 10, 166-172. [38] Ayaz, F.A., Torun, H., Glew, R.H., Bak, Z.D., Chuang, L.T., Presley, J. M., Andrews, R. 2009. Nutrient Content of Carob Pod (Ceratonia siliqua L.) Flour Prepared Commercially and Domestically. Plant Foods for Human Nutrition (Formerly Qualitas Plantarum) Volume 64, Number 4, 286-292. [39] Dubois, V., Breton, S., Linder, M., Fanni, J. and Parmentier, M. 2007. “Fatty acid profiles of 80 vegetable oils with regard to their nutritional potential”, Eur. J. Lipid Sci. Technol. 109, 710-732.