Abstract This study aims to develop a batter system with natural purple and functional quality for vacuum fried breaded shrimp. Purple sweet potato flour (PSPF), soy protein isolate (SPI), and xanthan gum were used as coating materials. The effect of the ratio of SPI and xanthan gum on the rheological properties, coating pick-up, color, moisture content, oil content, texture, anthocyanin content and antioxidant activity were investigated. Compared with the control group, it was observed that the batter system with PSPF, SPI and xanthan gum had better rheological properties. The result showed that a ratio of 2:1 for SPI to xanthan gum had the highest coating pick-up value (49.83%), the more attractive purple (a* = 3.07), less oil content (20.55%) and retained higher anthocyanin content (51.71 mg/100 g). Based on the results of anthocyanin content, vacuum fried shrimps were analyzed for antioxidant activity. In the 2,2-diphenyl-1-picrylhydrazyl (•DPPH), hydroxyl (•OH) radical-scavenging assay test, PSPF vacuum fried shrimps showed high free-radical scavenging activity (60.19% for •DPPH and 35.97% for •OH). Therefore, the batter system with PSPF, SPI and xanthan gum is a promising coating material, which is widely used for vacuum fried breaded products, such as pork chop, steak, chicken nuggets and fish fingers.

Abstract Aroma attributes are one of the most important criteria that affect the flavor quality of dried shrimp, but the dynamic changes of aroma attributes remain largely unknown during the drying process. The present study investigated aroma attributes change during the hot-air-drying process of shrimp using gas chromatography-mass spectrometry (GC-MS), electronic nose (E-nose) and sensory analysis. The potential correlations among volatile compounds, sensory attributes and E-nose data were analyzed by partial-least-squares regression (PLSR). Results showed that the aroma characteristic of shrimps changed significantly during processing. The odor in the fresh shrimp was very light, and the key aroma compounds mainly consisted of trimethylamine and three aldehydes. The aroma characteristics mainly consisted of roasted and meat-like odors had come into being gradually with the decrease of water activity (Aw), and the aroma attributes were the most acceptable at about Aw 0.274 (hot-air drying for 7 h). Four kinds of aroma-active compounds (pyrazines, amines, aldehydes and heterocyclic compounds) made important contributions to the formation of aroma characteristics. The PLSR result showed a good correlation between most variables of volatile compounds, E-nose data and sensory attributes.

Abstract In order to promote the development and application of small molecule oligopeptides from tilapia (SMOT), its anti-fatigue effect was evaluated by using exhaustive swimming in mice. The results showed that compared with the negative control group, SMOT could significantly prolong the exhausted swimming time of mice, reduce blood lactic acid, blood urea nitrogen and malondialdehyde content, and could significantly improve liver glycogen storage status. Meanwhile, the activities of superoxide dismutase and glutathione peroxidase of the mice gavaged with SMOT were significantly higher than those in the negative control group. In addition, SMOT could increase the activity of immune factor IL-2, stimulate the secretion of sIgA and regulate the level of inflammatory factors. So SMOT had significant anti-fatigue effect. Its anti-fatigue effect was exerted by increasing energy reserves, eliminating the accumulation of metabolites, reducing oxidative stress, and improving the body’s immune function.

Abstract Auxis thazard meat was hydrolyzed by alkaline protease. Auxis thazard hydrolysate (ATH) obtained was isolated by ultrafiltration, size exclusion chromatography and reversed-phase high-performance liquid chromatography. Two peptides with high XOD inhibitory activity purified from ATH were identified as Pro-Asp-Leu (PDL, 344.87 Da) and Ser-Val-Gly-Gly-Ala-Leu (SVGGAL, 504.26 Da) by UPLC-MS/MS, which possessed high in vitro XOD inhibitory activity with the IC50 values of 4.37 ± 0.11 mg mL-1 and 5.59 ± 0.09 mg mL-1, respectively. Molecular simulation indicated that PDL and SVGGAL binded to XOD mainly through hydrogen bond and hydrophobic interaction, thereby inhibiting XOD activity. The research results suggested that the two peptides had potential application prospects as a safe XOD inhibitor substance for hyperuricemia treatment.