In-vitro digestibility,protein digestibility corrected amino acid,and sensory properties of banana-cassava gluten-free pasta with soy protein isolate and egg white protein addition

Soy protein isolate and egg white protein were added to cassava-banana gluten-free pasta and the effects on the nutritional quality,digestibility properties,protein digestibility corrected amino acid(PDCAA),and sensory acceptance of the pasta was observed.Banana-cassava composite flour(75:25)was blended with soy protein isolate or egg white protein at the following rates:0,5,10,and 15 g/100 g flour.Cooked pasta samples were analysed for total phenolic content(TPC),antioxidant activity,amino acid profiles,protein content,starch digestibility,protein digestibility and protein digestibility corrected amino acid score(PDCAAS).Addition of both proteins decreased starch digestibility,increased protein digestibility,improved the balance of the amino acid profile,and PDCAAS whereas only soy protein isolate enhanced the TPC and antioxidant capacity of the banana-cassava pasta.An egg white protein-fortified banana-cassava pasta had better customer acceptance and purchase intent than soy protein isolate inclusion.

Changes of visceral properties and digestive enzymes in the herbivorous marine teleost Siganus canaliculatus fed on different diets

The rabbitfish Siganus canaliculatus is one of the few cultured herbivorous marine teleosts. To better understand the digestive physiology of this fish and provide data for designing formulated feed using macroalgae as an ingredient, the changes of visceral properties and digestive enzyme activities were investigated after the juveniles were fed on different types of food including raw fish（RF）, formulated diet（FD） or macroalgae Enteromorpha prolifra（EP） and Gracilaria lemaneiformis（GL） for eight weeks. The results showed that the hepatosomatic and viscerosomatic indices in the RF and FD groups, as well as the relative intestine length（RIL） in the EP and GL groups, were significantly higher than those in other groups. Additionally, differences in the histological structure of the liver and anterior intestine were also observed among different dietary groups. The hepatic nuclei were displaced to the periphery by lipid inclusions in fish fed RF. The highest levels of mucosal folds were found in the anterior intestines of fish fed macroalgae. Digestive enzyme activity profiles showed obvious fluctuations in the first three weeks, and then leveled off in the following weeks. The levels of protease, lipase and α-amylase in the alimentary tract showed changes related to the levels of dietary protein, lipid and carbohydrate, respectively.Although macroalgae significantly inhibited the activity of protease in the stomach, it increased RIL and the number of mucosal folds in the anterior intestine so as to compensate for the influences on protease activities in the stomach. This study suggests that the digestive tract of rabbitfish can well adapt to different diets, and needs about three weeks to physiologically acclimatize to the nutritional status, thus implying that rabbitfish are somewhat omnivorous.

Digestion performance improvement of tributyrin through nano-emulsion preparation technology

The current research aimed to optimize the preparation technology of tributyrin nano-emulsion(TBNE)to improve its digestion properties, which were investigated through digestion models in vitro and in vivo. The content of each component of TBNE was optimized by response surface methodology(RSM) to improve the z-average particle size and stability of TBNE. The optimized TBNE was evaluated for its digestion properties by in vitro and in vivo models. The preparation conditions of TBNE optimized by RSM were as follows: 61.3% of sorbitol, 32.7% of tributyrin, and 6.0% of modified phospholipid(MP). The predicted z-average particle size of TBNE was(246.02 ± 18.10) nm. The results of the verification test showed that the z-average particle size, zeta potential, conductivity, emulsification activity index, and emulsification stability index of TBNE were(250.02 ± 7.18) nm,(-40.23 ± 0.76) m V,(31.80 ± 2.09) μS/cm,(848.00 ± 84.53) min and(1.14 ± 0.02) m^(2)/g, respectively. The in vitro digestion experiment results showed that the TBNE remained stable in the stomach and was released in the intestine, while the size of TBNE in the gastrointestinal tact was significantly smaller than that of tributyrin(P < 0.05), which made it easier to be digested and absorbed. Compared with tributyrin treatment, TBNE significantly promoted the average body weight at the 7th day, average daily feed intake,average daily gain, feed/gain, ileum weight, and organ index of ileum of Hy-Line BROWN chicks(P < 0.05), and the butyric acid content in the ileal chyme from TBNE and tributyrin treatment were172.18 mg/m L and 100.85 mg/m L(P < 0.01). Therefore, the established TBNE technology in this study could be supposed to improve the digestion properties of tributyrin.