发酵时间对青贮凤梨渣pH·亚硝酸盐·氨态氮·可溶性糖和有机酸含量的影响

Effects of Fermentation Time on pH,Contents of Nitrite,Ammonia Nitrogen,Soluble Sugar and Organic Acid in Silage Pineapple Residue

[目的]探讨不同发酵时间对青贮凤梨渣pH、亚硝酸盐、氨态氮、可溶性糖和有机酸含量的影响。[方法]将含水量65%~75%的新鲜凤梨渣置于体积2.0 L的密封塑料青贮容器中,分别于发酵7、14、21、28、35 d取样,测定其pH、氨态氮、亚硝酸盐、可溶性糖和有机酸等指标。[结果]青贮凤梨渣的pH均显著低于新鲜凤梨渣(P<0.05),青贮21、28和35 d显著高于7和14 d(P<0.05);青贮凤梨渣的亚硝酸盐含量为3.50~11.13 mg/kg;青贮凤梨渣的可溶性糖含量均显著低于新鲜凤梨渣(P<0.05),青贮28 d时显著高于其他青贮时间(P<0.05);青贮28、35 d时青贮凤梨渣氨态氮浓度显著高于21 d(P<0.05);青贮凤梨渣的乙酸、丙酸和乳酸含量均显著高于新鲜凤梨渣(P<0.05),28 d时乙酸、丙酸和乳酸含量均最高,且显著高于7 d(P<0.05),14 d后乳酸、丙酸和乳酸含量逐步稳定(P<0.05);青贮凤梨渣的丁酸含量均显著低于新鲜凤梨渣(P<0.05),35 d时丁酸含量最低(P<0.05)。[结论]青贮凤梨渣的最佳青贮利用时间为28 d。

[Objective]To discuss the effects of different fermentation time on pH,contents of nitrite,ammonia nitrogen,soluble sugar and organic acid in silage pineapple residue.[Method]The fresh pineapple residue with water content of 65%-75%was filled in a sealed plastic silage container with the volume of 2.0 L,samples were collected on the 7 th,14 th,21 st,28 th,and 35 th days after the fermentation.And pH,nitrite,ammonia nitrogen,soluble sugar and organic acid were determined.[Result]pH of silage pineapple residue was significantly lower than that of fresh pineapple residue(P<0.05),that on the 21 st,28 th and 35 th days after the fermentation was significantly higher than that on the 7 th and 14 th days(P<0.05).The nitrite content of silage pineapple residue was 3.50-11.13 mg/kg.The soluble sugar content of silage pineapple residue was significantly lower than that of fresh pineapple residue(P<0.05),the soluble sugar content on the 28 th day of silage was significantly higher than that on other silage time(P<0.05).Ammol/Lonia nitrogen concentration in silage pineapple residue on the 28 th and 35 th days was significantly higher than that on the 21 st day(P<0.05).The contents of acetic acid,propionic acid and lactic acid in silage pineapple residue was significantly higher than that in fresh pineapple residue(P<0.05).And the contents of acetic acid,propionic acid and lactic acid on the 28 th day was the highest,which was significantly higher than that on the 7 th day(P<0.05).After 14 days,the contents of lactic acid,propionic acid and lactic acid were gradually stabilized(P>0.05).The content of butyric acid in silage pineapple residue was lower than that in fresh pineapple residue(P<0.05)and that was the lowest on the 35 th day(P<0.05).[Conclusion]The optimal silage utilization time for silage pineapple residue was 28 days.