不同原料对发酵参数的影响

Effects of Different Substrates on Fermentation Parameters

试验采用3个菌种(乳酸菌、酵母菌、枯草芽孢杆菌)分别固态发酵相同水分的3种原料(玉米、豆粕、棉籽粕),以感官评价、原料pH变化和发酵后益生菌存留量作为评价指标,探讨不同饲料原料品质随发酵时间变化的规律,优化发酵饲料生产工艺。结果显示,不同饲料原料达到稳定pH所需的时间不同,相同发酵菌种达到pH稳定所需的时间为:玉米<豆粕<棉籽粕;玉米、豆粕和棉籽粕的种类对初始pH无影响;在pH达到稳定时,3种原料发酵后颜色和气味各呈现相应的特性,而黏度强度表现为:棉籽粕>豆粕>玉米;益生菌存留数量为:玉米>豆粕>棉籽粕。由此可知,玉米作为微生物发酵底物,发酵率高,益生菌存留量多,优于豆粕和棉籽粕。

Fermenting different raw materials（corn,soybean meal and cottonseed meal）with three kinds of strains（Lactobacillus,yeast and Bacillus subtilis）were employed to optimize the fermentation parameter with sensory evaluation,pH and amount of probiotics retention.The results showed that the time to reach stable pH of materials with different substrates was different.Cottonseed meal had the longest time to reach stable pH followed by soybean meal,while corn had the shortest time under the condition of same water content.Different substrates had no effect on initial pH of corn,soybean meal and cottonseed meal.The count of the probiotics was also influenced by different substrates.When pH reached steady state,corn had the largest number of the probiotics followed by soybean meal and cottonseed meal.The color and smell of three materials after fermented had distinctive features.But cottonseed meal had the highest viscosity followed by soybean meal and corn.Because of shorter time and more microorganisms,corn was better than soybean meal and cottonseed meal to be fermenting medium.