三种苦瓜多糖的体外发酵特性比较研究

Comparative Study on in Vitro Fermentation Characteristics of Three Fractions of Momordica charantial Polysaccharides

采用体外发酵技术评价分段醇沉提取的3种苦瓜多糖(MCP1、MCP2和MCP3,乙醇终浓度分别为45%、60%和75%)对三元猪盲肠食糜的发酵特性和发酵产物的影响。于不同发酵时间点记录产气量,48 h后检测发酵液pH值、NH3和短链脂肪酸(SCFA)含量。结果表明,MCP1和MCP2发酵动力学参数最优,显著优于葡萄糖和空白对照组(P<0.05);MCP2和葡萄糖组pH值最低,MCP1和葡萄糖组的NH3含量最低;葡萄糖组的丙酸、异丁酸和SCFA总量显著高于其它各组(P<0.05);MCP2的乙酸、异丁酸和SCFA总量显著高于其它多糖组(P<0.05)。结果提示,MCP1和MCP2是2种理想的可被盲肠微生物利用的碳源,并可改变微生物发酵产生的SCFA含量与组成。

This study was conducted to determine the effects of 3 fractions of Momordica charantial polysaccharides （MCP） on fermentation characteristics and fermentation productions of cecal digesta collected from Duroc × Landrace × Yorkshire pig in an anaerobic in vitro system.MCP1,MCP2 and MCP3 were extracted with water-extracting-ethanolprecipitation method,when the final concentrations of ethanol were 45%,60% and 75%,respectively.After a 48 h period of fermentation,and the kinetic parameters,pH value,NH3 content,production and composition of short-chain fatty acids （SCFA） in the fermentation broth were determined.Results showed that the kinetic parameters in MCP1-and MCP2-supplemented groups were better（P0.05） compared with the glucose-and free-supplemented groups.The pH values in MCP2-and glucose-supplemented groups and NH3 contents in MCP1-and glucose-supplemented groups were lower（P0.05） compared with the other groups.The contents of propanoic acid,isobutyric acid and total SCFA in the glucose-supplemented group were higher（P0.05） compared with the other groups,as well as the contents of acetic acid,isobutyric acid and total SCFA in MCP2-supplemented group compared with the other 2 polysaccharide-supplemented groups.These findings suggested that MCP1 and MCP2 may be good sources of origin of carbon,and therefore modulate SCFA production patterns of microorganism in hindgut.