Background Lychee pericarp is rich in phenolic and has good antioxidant activity. The effects of simulated gastric (SGF) and intestinal fluid (SIF) digestion on the contents, composition, and antioxidant activities of the phenolic substances in the pericarp of different lychee cultivars (cv Jizui , Lizhiwang , Guiwei , Yuhe , Nuomici and Guihong ) were investigated. Results Compared with distilled water (DW) treatment, the total phenolic content (TPC) and total flavonoid content (TFC) in the pericarp of different lychee cultivars decreased after SGF digestion; especially, the TFC in “ Lizhiwang ” decreased by 41.5%. The TPC and TFC of lychee pericarp also decreased after SIF digestion. However, the TPC in “ Jizui ”, “ Guiwei ” and “ Yuhe ” increased. The SGF and SIF also had different effects on the FRAP and ABTS antioxidant activities of different lychee cultivars. The SGF digestion decreased the ABTS antioxidant capacity of lychee pericarp but enhanced the FRAP value of some lychee cultivars. However, the SIF digestion decreased the FRAP antioxidant activity of different lychee cultivar pericarps but enhanced the ABTS antioxidant capacity of lychee. The HPLC results showed that lychee pericarp had relatively high contents of procyanidin B2 and procyanidin A2. After SIF digestion, caffeic acid and isoquercitrin could not be detected in any of the lychee varieties. However, quercetin-3-rutinose-7-rhamnoside and isoquercitrin were increased after SGF digestion. Conclusions Lychee pericarp could be used as an inexpensive functional food ingredient.

BACKGROUND To evaluate their fat reduction effect, common carp fish protein hydrolysates (FPH) were made using four methods: the conventional enzymatic process, a microwave‐intensified enzymatic process, the conventional alkaline hydrolysis process, and a microwave‐intensified alkaline hydrolysis process. RESULTS The efficiency of protein extraction was significantly enhanced by microwave intensification. The oil‐holding capacities of FPH produced by these four processes were all lower than that of raw fish protein. The water‐holding capacities of FPH produced by these four processes were all higher than that of raw fish protein. The FPH from the four processes and raw fish protein were used in the preparation of deep‐fried kamaboko. The fat content of deep‐fried kamaboko was drastically reduced from approximately 160 g kg−1 to about 50 g kg−1 by replacing 20 g kg−1 fish mince with FPH, regardless of the process. Texture profile analysis (TPA) of deep‐fried kamaboko found no significant difference in hardness and brittleness among all the deep‐fried kamaboko samples. The similar interior protein cross‐linking micro‐structure of all these samples further explained the TPA finding. CONCLUSION With the involvement of FPH in the formulation, the fat content of deep‐fried kamaboko can be significantly reduced from approximately 160 to 50 g kg−1, without a change in its texture. © 2018 Society of Chemical Industry