水分含量和发酵时间对带轴高湿玉米发酵品质和有氧稳定性的影响

Impact of moisture content and fermentation duration on the fermentation quality and aerobic stability of high-moisture ear corn

为探讨不同水分含量和发酵时间对带轴高湿玉米(Zea mays)发酵品质及有氧稳定性的影响,确定带轴高湿玉米(HMEC)的最佳发酵时间及理想水分含量,选用完熟期的带轴玉米为主要原料,将添加剂溶于蒸馏水添加至粉碎后的玉米中,调整水分含量至32.5%、37.5%、42.5%和47.5%,装袋、密封保存(每组10个重复,每个重复1000 g),分别于发酵60和180 d取样,评定其物理感官指标,并测定其发酵品质和有氧稳定性。结果表明:1)青贮180 d的HMEC感官评分优于发酵60 d。2)发酵时间与HMEC水分含量的交互作用对中性洗涤纤维、酸性洗涤纤维、灰分和淀粉含量有显著影响(P<0.05)。随着发酵时间的延长HMEC中性洗涤纤维、酸性洗涤纤维含量显著升高(P<0.05),干物质、木质素和淀粉含量显著降低(P<0.05)。3)发酵时间与HMEC含水量的交互作用对pH、乳酸、氨态氮以及可溶蛋白含量均有显著影响(P<0.05)。37.5%组HMEC发酵180 d后pH显著低于其他3个水分处理组(P<0.05),发酵180 d的HMEC对比发酵60 d,其pH显著降低(P<0.05),乳酸、乙酸、氨态氮以及可溶蛋白含量均显著升高(P<0.05)。4)发酵时间与HMEC含水量的交互作用对总可消化养分、维持净能、生长净能、泌乳净能以及7 h淀粉消化率指标均有显著影响。37.5%组HMEC发酵180 d后7 h淀粉消化率显著高于其余3个水分组(P<0.05);且随着发酵时间的延长,总可消化养分、泌乳净能以及7 h淀粉消化率的值均显著提升(P<0.05)。5)发酵180 d的HMEC有氧稳定性显著高于发酵60 d(P<0.05)。综合考虑感官评分、营养成分、发酵品质以及有氧稳定性等几个方面,37.5%含水量发酵180 d的HMEC发酵品质最好。

This study investigated the effects of water content and fermentation duration on the fermentation quality and aerobic stability of high moisture ear corn(HMEC)to determine the optimal fermentation time and water content for HMEC.Corn at full maturity was used as the raw material.The fermentation additives were dissolved in distilled water and mixed with ground corn.The water content was adjusted to 32.5%,37.5%,42.5%,and 47.5%.The mixture was bagged and sealed(10 replicates per group,1000 g per replicate).Samples were taken on the 60th and 180th days of fermentation to evaluate the organoleptic and physical parameters and determine the fermentation quality and nutrient composition.The results showed that:1)The organoleptic and physical parameters of HMEC on the 180th day of silage were better than those on the 60th day.2)The interaction between fermentation time and water content had significant effects on neutral detergent fiber(NDF),acid detergent fiber(ADF),ash,and starch content(P<0.05).The NDF and ADF contents of HMEC increased significantly(P<0.05),while the dry matter,lignin,and starch contents decreased significantly(P<0.05)with increasing fermentation time.3)The interaction between fermentation time and water content had significant effects on pH,lactic acid,NH3-N,and soluble protein content(P<0.05).The pH of the 37.5%water content group of HMEC after 180 days of silage was significantly lower than that of the other three moisture treatment groups(P<0.05).The pH was significantly lower(P<0.05),and the lactic acid,acetic acid,ammonia nitrogen,and soluble protein content were significantly higher(P<0.05)in HMEC on the 180th day compared to those on the 60th day of fermentation.4)The interaction of fermentation time and HMEC water content had significant effects on total digestible nutrients,net energy for maintenance,net energy for growth,net energy for lactation,and 7 h starch digestibility indexes.The 7 h starch digestibility after 180 days of HMEC fermentation in the 37.5%group was significantly higher than that in the remaining three moisture groups(P<0.05).Additionally,the values of total digestible nutrients,net lactation energy,and 7 h starch digestibility were significantly higher with increasing fermentation time(P<0.05).5)The aerobic stability of HMEC was significantly higher after 180 days of fermentation compared to 60 days of fermentation(P<0.05).In conclusion,HMEC with 37.5%water content for 180 days had the best quality in terms of organoleptic and physical parameters,nutrient composition,fermentation quality,and aerobic stability.