58-2 |
Evaluation of almond seed, skin and shell cover as sources of natural antioxidants |
S. S. K. W. SIRIWARDHANA and F. Shahidi. Department of Biochemistry, Memorial University of Newfoundland, St. John's, NF A1B 3X9, Canada
Almond is the seventh largest food exported from the United States and Canada is a major importer of it. While antioxidant properties of several nuts and their hull constituents have been studied, little is known about the antioxidant activity of almond and their constituents. The objective of this research was to evaluate the antioxidant properties of defatted almonds, as such, its brown skin and the cover on the hard shells. Extracts were prepared in 80% ethanol. After removal of ethanol at 40° C under vacuum the concentrated solutions were lyophilized for 72 h at -46° C and 46 ´ 10-3 mbar. The antioxidant properties of the ethanolic crude extracts of the seed, skin and the cover on the hard shell were evaluated using hydrogen peroxide- and superoxide radical-scavenging assays. The total phenolic compounds (as mg catechin equivalents/g of ethanolic extract) were 8.05 ± 0.37, 87.76 ± 0.75 and 71.03 ± 0.74 for seed, skin and shell cover, respectively. The corresponding scavenging activity of the superoxide radical by 100 and 200ppm was 75.5, 88.9 and 97.4% (100ppm), and 85.1, 95.3 and 99.2% (200ppm). The reduction of hydrogen peroxide concentration by 100 and 200ppm of seed, skin and shell cover was 59.8, 62.6 and 65.6% (100ppm), and 85.9, 90.8 and 90.6% (200ppm), respectively. Thus, almond, as such and specially its skin and shell cover serve as good sources of natural antioxidants. This indicates the neutraceutical potential of almond and its components in different food and specialty applications.
Session 58, Food Chemistry: Lipids, Emulsions and Antioxidants
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