Abstract
Duck albumen hydrolysates (DAH) conjugated with epigallocatechin gallate(EGCG) at various levels (2–5%, w/w) were prepared and characterized. FTIR analysis showed that the conjugation between DAH and EGCG induced the change of secondary structure and modified functional groups of DAH. Furthermore, surface hydrophobicity of DAH was increased, while total sulfhydryl group and total carbonyl contents were decreased when EGCG was conjugated, especially when EGCG at higher levels was used (P < 0.05).Antioxidant activities and emulsifying properties of DAH-EGCG conjugates were enhanced, particularly when DAH conjugated with 4% EGCG (P < 0.05). Storage stability of fish oil emulsion (FOE) stabilized by DAH or DAH-EGCG conjugate was also investigated up to 15 days at 26–28 °C. Emulsion stabilized by DAH-EGCG conjugate had higher magnitude of ζ-potential (negative charge), smaller oil droplets size (d43), as well as lower flocculation andcoalescence of oil droplets as compared to those of emulsion prepared using DAH throughout the storage. Moreover, oxidative stability of FOE was improved when DAH-EGCG conjugate was incorporated as evidenced by lowered thiobarbituric acid-reactive substances and peroxide value. Thus, the conjugate between DAH and 4% EGCG could serve as an antioxidantemulsifier for enhancement of physical and oxidative stability of FOE.
… obtained from Sigma Chemical Co. (St. Louis, MO, USA). EGCG was purchased from Chengdu Biopurify Phytochemicals Ltd. (Sichuan, China). 2.2. Preparation of duck albumen hydrolysate. Duck albumen hydrolysate (DAH) was …
