Effects ofin vitrosimulated digestion on the flavonoid content and antioxidant activity of aged and fresh dried tangerine peel

Abstract

The effects of digestion in vitro on the flavonoid content and antioxidant activities of aged and fresh dried tangerine peel were investigated by treating with simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) compared with organic solvent or deionized water. The total phenolic content of both aged and fresh dried tangerine peel were significantly decreased by SGF and SIF treatments, with the exception of the SIF-treated fresh dried peel. The total flavonoid content of both the aged and fresh dried tangerine peel were also reduced by SGF, but not by SIF, compared with deionized water. FRAP values were markedly improved by SGF and reduced by SIF treatments compared with deionized water. Conversely, the ABTS value of SIF-treated fresh dried peel was significantly higher than that of SGF-treated peel. The antioxidant activities of tangerine peel were altered by simulated digestion in vitro. Practical applications Citrus peel is the main byproduct of the citrus industry. Tangerine is one of the most important citrus widely planted in Southeast Asia. Dried tangerine peel which called “Chenpi” in Chinese traditional medicine was used for indigestion and inflammatory treatments. Dried tangerine peel can be developed as functional foods. To investigate the simulated gastric and intestinal fluid digestion on the contents of active component and antioxidant activities of aged dried tangerine peel and fresh dried tangerine peel could provide a theoretical basis for the commercial development and utilization of dried tangerine peel.