Effects Of Feruloy Esterase On The Nutrient Digestibilities And Enzymatic Degradation Of Cell Wall Components Of Rice Bran

The protocol of this research was based on the recognized information in chemical co-mposition and structural aspect of rice bran cell wall. It was aimed to get the detail inform-ation on phenolic acids content and composition of rice bran and attempted to evaluate the possible synergetic effects between feruloy esterase and phytase, and non-starch polysacch-arides enzyme cocktails in degradation of cell wall constitutes nutrient digestibilities of rice bran, both in vitro and in vivo.Experiment1. The study of phenolic composition and content of rice branThe rice bran from two different company were degraded to release phenolic acid by alkali-alcohol solutions which joined sodium sulfite to prevent the phenolic acid from being oxidized. The alkali-alcohol degradation liquid were detected by high-perormance liquid chromatography with protocatechuic acid, hydroxybenzoic acid, caffeic acid, syringic acid, coumaric acid, ferulic acid, salicylic acid, cinnamic acid, vanillic acid as the standard material. The results show caffeic acid, syringic acid, vanillic acid were not detected and other six phenolic acids were detected in the two kinds of rice bran. In both rice bran, the content of six phenolic acids in per100g rice bran are:ferulic acid,214,189mg; coumaric acid,74.72,79.78mg; salicylic acid74.28,56.55mg; cinnamic acid42.47,51.12mg, protocatechuic acid30.93,43.71mg, hydroxybenzoic acid8.62,12.04mg. From the above results, the phenolic acid of rice bran based mainly ferulic acid, coumaric acid and salicylic acid followed consistent with the similar foreign coverage.Experiment2. Enzymatic hydrolysis rice bran in vitroThe experiment is divided into two parts with defatted rice bran for the research object. The first part is that feruloyl esterase directly hydrolyze defatted rice bran to study the effects of feruloyl esterase on release rate of ferulic acid of rice bran. The seconed part is that defatted rice bran are first hydrolyzed by amylase glucosidase and protease to remove fatty and protein, and then are hydrolyzed by different enzyme combination which be composed of feruloy esterase, phytase and non-starch polysaccharides enzymes. The results show that:①Only a small of free ferulic acid exist in rice bran, and most of ferulic acid exist in the non-starch polysaccharides of rice bran.②Synergy between feruloy esterase and non-starch polysaccharides enzyme is observed in the degradation of non-starch polysaccharides, the release rate of ferulic and the yields of reducing sugar(P<0.05).③There is a certain antagonism between phytase and feruloy esterase or non-starch polysaccharides enzyme. The combination of phytase, feruloy esterase and non-starch polysaccharides enzyme compared with the combination of feruloy esterase and non-starch polysaccharides enzyme reduce degradation rate of non-starch polysaccharides, release rate of ferulic acid and the yields of reducing sugar(P<0.05).Experiment3:Effect of multi-enzyme combinations on degradation of rice bran in vivoA scheme of single factor test was used in this experiment.30major cocks were randomly divided into5groups each with6replications to study effects of supply amount of phytase, feruloy esterase and non-starch polysaccharides enzyme on digestibility and retention of nutrientions of rice bran. Treatment I was rice bran, treatment II suppled with non-starch polysaccharides enzymes, treatment III suppled with feruloy esterase and non-starch polysaccharides enzymes, treatment IV suppled with phytase, treatment V suppled with phytase, feruloy esterase and non-starch polysaccharides enzymes. The results show that:Multi-enzyme combinations can significantly increase digestibility of crude fat, energy, dry matter, crude fiber, neutral detergent fiber and non-starch polysaccharides(P<0.05), and can not improve digestibility of amino acids and crude ash. However, phytase and feruoly esterase have different effects on digestibility of ether extract, non-starch polysaccharides and crude fiber. Group fed ferulic acid esterase and non-starch polysaccharides enzymes is superior to group fed phytase, feruloy esterase and non-starch polysaccharides enzymes in digestibility of ether extract and non-starch polysaccharides. Group fed phytase, feruloy esterase and non-starch polysaccharides enzymes is superior to group fed ferulic acid esterase and non-starch polysaccharides enzymes in digestibility of crude fiber. Synergy between feruloy esterase and phytase is observed in the digestibility of neutral detergent fiber.