Effects of addition of egg ovotransferrin-derived peptides on the oxygen radical absorbance capacity of different teas

• Published in: Food chemistry 2012-12, Vol.135 (3), p.1600-1607
• Main Authors: Huang, Wuyang, Shen, Shengwen, Nimalaratne, Chamila, Li, Sen, Majumder, Kaustav, Wu, Jianping
• Format: Article
• Language: English
• Subjects: absorbance; antioxidant activity; Antioxidants - chemistry; ascorbic acid; Biological and medical sciences; black tea; caffeic acid; Coffee, tea and other stimulative beverage industries; Conalbumin - chemistry; eggs; Food industries; Food Storage; Free Radical Scavengers - chemistry; functional foods; Fundamental and applied biological sciences. Psychology; human health; Hydrolysate; hydrolysates; IRW; methanol; Ovotransferrin; oxygen; Oxygen radical absorbance capacity (ORAC); peptides; Peptides - chemistry; Reactive Oxygen Species - chemistry; Tea; Tea - chemistry; Temperature
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.05.093

► No significant difference existed in ORAC values among green, oolong, black teas. ► Eighty percentage methanol extracts possessed better antioxidant capacity than hot water extracts. ► ORAC values of teas were improved by adding either egg hydrolysate or peptide IRW. ► Adding hydrolysate did not improve antioxidant stability of tea samples. ► Teas stored at 4°C showed higher ORAC values than those stored at room temperature. Ovotransferrin-derived peptides showed synergistic effects with vitamin C, epigallocatechin gallate (EGCG), and caffeic acid, but not quercetin in our previous report. In this study, we further investigated the interactions between ovotransferrin-derived peptides and teas, based on the oxygen radical absorbance capacity (ORAC) assay. Our results showed that there was no significant difference in ORAC values among green, oolong, and black teas. For all the samples, 80% methanol extracts possessed better antioxidant capacity than hot water extracts. The antioxidant capacity of teas were improved by adding either ovotransferrin hydrolysate or its purified peptide IRW; however, adding hydrolysate did not improve antioxidant stability of teas. ORAC values of both teas and hydrolysate added teas were decreased during 22weeks of storage, while samples stored at 4°C exhibited higher antioxidant capacity than those stored at room temperature. This suggested that ovotransferrin hydrolysate could be used as functional food ingredients in enhancing antioxidant capacities of foods, which would benefit human nutrition and health.