Changes in the phenolic contents and antioxidant activities of citrus peels from different cultivars after in vitro digestion

Abstract

The aim of this study was to investigate the effects of in vitro digestion on the phenolic contents and antioxidant activities of citrus peels. Three different varieties of citrus peels (mandarin, ponkan and red tangerine) were treated with simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The results showed that the SGF or SIF treatments of the citrus peels did not significantly increase the total phenolic content (TPC) or total flavonoid content (TFC), except for that of the TFC of ponkan peel treated with SGF. However, simulated in vitro digestion did improve the antioxidant activities measured with FRAP and ABTS methods. The effect of SGF was more positive than those of SIF for the FRAP assay, but the opposite was true for ABTS. Notably, both simulated digestion techniques decreased the DPPH free radical scavenging abilities. Simulated digestion in vitro changed the antioxidant activities of the citrus peels.

Evaluation of antioxidant properties of extractable and nonextractable polyphenols in peel and flesh tissue of different peach varieties

“…Natural antioxidants such as vitamins, carotenes, minerals, or fiber are not supposed to be the only components responsible for the antioxidant properties of fruit (Chuyen, Roach, Golding, Parks, & Nguyen, 2017;Sungsinchai, Niamnuy, Jaree, & Devahasti, 2017). In previous research, the significant correlations have been reported between phenolic contents and antioxidant capacities (Su et al, 2017;Zhuang, Ma, Guo, & Sun, 2017). There is strong evidence that the phenolic compounds could be significantly bioavailable and even more powerful than antioxidants as vitamin C, E in vitro (Scalbert, Manach, Morand, R em esy, & Jim enez, 2005).…”

Effects of in vitro digestion on the composition of flavonoids and antioxidant activities of the lotus leaf at different growth stages

“…Digestion and absorption of the lotus leaf will be affected by pH, digestive enzymes, inorganic salts and other physiological factors (Bouayed et al, 2011). The in vitro simulated gastric and intestinal digestions are widely used for a preliminary assessment of the effect of digestion (Moomand & Lim, 2015;Kamiloglu et al, 2017;Su et al, 2017). Researchers have provided contradictory information that the phenolic content and antioxidant activity of fruits, vegetables and cereals may either be increased (Tagliazucchi et al, 2010) or reduced after digestion (Bao et al, 2016).…”

The effect of simulated digestion on the composition of phenolic compounds and antioxidant activities in lychee pulp of different cultivars

“…The ABTS value was detected using the method reported previously (Su et al, 2017). The absorbance values were measured on an ultraviolet spectrophotometer at 734 nm.…”

“…Several researchers have studied the changes of the content of active components and antioxidant properties after the simulated digestion of fruits, vegetables and agro-industrial co-products. For instance, Su et al investigated the effects of simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) on the phenolic contents and antioxidant activities of three different varieties of citrus peels and found that in vitro simulated digestion did not significantly increased the total phenolic content or total flavonoid content but did improve antioxidant activities (Su et al, 2017). Similarly other research has shown that the SGF and SIF digestions could significantly increase the total phenolic content of lotus leaf, but had different effects on the FRAP and ABTS antioxidant activities (Su et al, 2018).…”