Abstract

The present study compares Water-soluble Phenolic Content (WPC) and antioxidant activities in eggplant, kidney bean, bitter gourd and spinachprior to and after subjecting to boiling, microwaving and pressure cooking. The total antioxidant activity was increased in cooked spinach, eggplant and bitter gourd, estimated based on the ferric reducing antioxidant power, the Troloxequivalent antioxidant capacity and 2, 2-diphenyl-1-picryl-hydrazyl radical scavenging activity. Pressure cooking did not cause any significant decline in the antioxidant property. Boiling generally improved the overall antioxidant activity in all the vegetables. Correlation analysis suggests that WPC contributed to significant antioxidant activities in these vegetables. Thus, prudence in selecting an appropriate cooking method for different vegetables may improve or preserve their nutritional value.

Keywords:

Antioxidant activity, cooking methods, phenolics, vegetables,

References

1. Adams, A.K., E.O. Wermuth and P.E. Mcbride, 1999. Antioxidant vitamins and the prevention of coronary heart disease [J]. Am. Fam. Physician, 60(3): 895-904.
   PMid:10498115    Direct Link
2. Apak, R., K. Guclu, B. Demirata, M. Ozyurek, S.E. Celik, B. Bektasoglu, K.I. Berker and D. Ozyurt, 2007. Comparative evaluation of various total antioxidant capacity assays applied to phenolic compounds with the CUPRAC assay [J]. Molecules, 12(7): 1496-1547.
   CrossRef    PMid:17909504    
3. Benzie, I.F. and J.J. Strain, 1996. The Ferric Reducing Ability of Plasma (FRAP) as a measure of ‘antioxidant power’: The FRAP assay [J]. Ann. Biochem., 239(1): 70-76.
   CrossRef    PMid:8660627    Direct Link
4. Chuah, A.M., Y.C. Lee, T. Yamaguchi, H. Takamura, L.J. Yin and T. Matoba, 2008. Effect of cooking on the antioxidant properties of coloured peppers [J]. Food Chem., 111(1): 20-28.
   CrossRef    Direct Link
5. Faller, A.L.K. and E. Fialho, 2009. The antioxidant capacity and polyphenol content of organic and conventional retail vegetables after domestic cooking [J]. Food Res. Int., 42(1): 210-215.
   CrossRef    
6. Hamidi, M. and H. Tajerzadeh, 2003. Carrier erythrocytes: An overview [J]. Drug Deliv., 10(1): 9-20.
   CrossRef    PMid:12554359    Direct Link
7. Hunter, K.J. and J.M. Fletcher, 2002. The antioxidant activity and composition of fresh, frozen, jarred and canned vegetables [J]. Innov. Food. Sci. Emerg., 3(4): 399-406.
   CrossRef    Direct Link
8. Jimenez-Monreal, A.M., L. Garcia-Diz, M. Martinez-Tome, M. Mariscal and M.A. Murcia, 2009. Influence of cooking methods on antioxidant activity of vegetables [J]. J. Food. Sci., 74(3): H97-H103.
   CrossRef    PMid:19397724    
9. Miglio, C., E. Chiavaro, A. Visconti, V. Fogliano and N. Pellegrini, 2008. Effects of different cooking methods on nutritional and physicochemical characteristics of selected vegetables [J]. J. Agr. Food. Chem., 56(1): 139-147.
   CrossRef    PMid:18069785    
10. Munyaka, A.W., E.E. Makule, I. Oey, A. Van Loey and M. Hendrickx, 2010. Thermal stability of L-ascorbic acid and ascorbic acid oxidase in broccoli (Brassica oleracea var. italica) [J]. J. Food. Sci., 75(4): C336-C340.
    CrossRef    PMid:20546391    
11. Nicoli, M.C., M. Anese and M. Parpinel, 1999. Influence of processing on the antioxidant properties of fruit and vegetables [J]. Trends Food. Sci. Tech., 10(3): 94-100.
    CrossRef    Direct Link
12. Podsedek, A., 2007. Natural antioxidants and antioxidant capacity of Brassica vegetables: A review [J]. LWT-Food. Sci. Technol., 40(1): 1-11.
    CrossRef    
13. Re, R., N. Pellegrini, A. Proteggente, A. Pannala, M. Yang and C. Rice-Evans, 1999. Antioxidant activity applying an improved ABTS radical cation decolorization assay [J]. Free Radical Bio. Med., 26(9-10): 1231-1237.
    CrossRef    
14. Sahlin, E., G.P. Savage and C.E. Lister, 2004. Investigation of the antioxidant properties of tomatoes after processing [J]. J. Food Compos. Anal., 17(5): 635-647.
    CrossRef    Direct Link
15. Szeto, Y.T., B. Tomlinson and I.F. Benzie, 2002. Total antioxidant and ascorbic acid content of fresh fruits and vegetables: Implications for dietary planning and food preservation [J]. Brit. J. Nutr., 87(1): 55-59.
    CrossRef    PMid:11898770    Direct Link
16. Turkmen, N., F. Sari and Y. Sedat Velioglu, 2005. The effect of cooking methods on total phenolics and antioxidant activity of selected green vegetables [J]. Food Chem., 93(4): 713-718.
    CrossRef    
17. Valko, M., D. Leibfritz, J. Moncol, M.T. Cronin, M. Mazur and J. Telser, 2007. Free radicals and antioxidants in normal physiological functions and human disease [J]. Int. J. Biochem. Cell. B., 39(1): 44-84.
    CrossRef    PMid:16978905    
18. Wachtel-Galor, S., K.W. Won and I.F.F. Benzie, 2008. The effect of cooking on brassica vegetables [J]. Food Chem., 110(3): 706-710.
    CrossRef    
19. Xu, B.J. and S.K. Chang, 2007. A comparative study on phenolic profiles and antioxidant activities of legumes as affected by extraction solvents [J]. J. Food Sci., 72(2): S159-S166.
    CrossRef    PMid:17995858    
20. Yang, J., J. Guo and J. Yuan, 2008. In vitro antioxidant properties of rutin [J]. LWT-Food Sci. Technol., 41(6): 1060-1066.
    Direct Link
21. Zhang, D.L. and Y. Hamauzu, 2004. Phenolics, ascorbic acid, carotenoids and antioxidant activity of broccoli and their changes during conventional and microwave cooking [J]. Food Chem., 88(4): 503-509.
    CrossRef    

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