| Analysis of Food-based Natural Antioxidants |
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Raspberries have 42 mg of the anthocyanidin, cyanidin and 8 mg of the flavan-3-ol, epicatechin per 100 grams | |
Walnuts contain 20 mg gamma tocopherol and are high in omega-3 fatty acids. Their TAC value is 13,540, second only to pecans among the common edible nuts. |
| Index of Relative Antioxidant Capacity |
| Introduction The chemical methods employed for Total Antioxidant Capacity (TAC) analysis all measure reactions involving different hydrogen atom and electron transfer processes, making correlation of data very difficult. The idea of a statistical method based on the integrated analysis of TAC data from all the analytical methods has merit at this time in the development of the subject. Relative Antioxidant Capacity Index (RACI) 7 TAC methods, including the ORAC method favoured here, are integrated to obtain a relative antioxidant capacity index for 20 foods. In this first paper, the authors chose common vegetable foods which as they aver have different classes and different quantities of individual antioxidants, however, the range will be substantially greater when fruits, grains, nuts, and spices are added. Reference: T. Sun and S.A. Tanumihardjo, J. Food Sci., 72, (9) R159-R165, 2007 Permission is being sought to report the preliminary findings here, for discussion. Comparative antioxidant capacities of phenolics In a recent article in press, Tarbart, J. et al., Food Chem., (2008), doi:10.1016/j.foodchem.2008.08.013 describe a similar approach to the above (without reference to it), in which over 20 common phenolic compounds are compared using five methods (TEAC, DPPH, ORAC, Haemolysis and ESR. They then go on to compare the TAC of six beverages (iced green tea, wine and apple, orange, vegetable and grape juices). They concluded that a method using a weighted mean of the four different methodologies (DPPH, ORAC, haemolysis and ESR) could be used to standardise TAC results. Back to >>>> Site map |