【摘要】：苜蓿是一種優(yōu)質(zhì)的豆科牧草,富含蛋白質(zhì)、脂肪、維生素及多種礦物元素,營(yíng)養(yǎng)成分均衡,是具有潛力的蛋白飼料資源。本研究以降低苜蓿纖維素含量,提高蛋白質(zhì)和酸溶性肽含量為目的,采用固態(tài)發(fā)酵方法,選擇合適的菌種進(jìn)行發(fā)酵,制備苜蓿蛋白,并進(jìn)一步以酶解法制備苜蓿肽,同時(shí)對(duì)苜蓿肽的理化性質(zhì)進(jìn)行研究。1.通過優(yōu)化白腐菌固態(tài)發(fā)酵苜蓿草粉工藝參數(shù),確定最佳的發(fā)酵條件為:料水比1:1.2,發(fā)酵時(shí)間為72 h,接種量為108 cfu/g,發(fā)酵溫度是28℃。發(fā)酵后,粗纖維含量為11.90%,比未發(fā)酵時(shí)降低了38.34%;粗蛋白質(zhì)和真蛋白質(zhì)含量為29.62%、22.97%,分別比未發(fā)酵時(shí)提高了42.41%,28.97%;酸溶性小肽的含量升高了12.59%;必需氨基酸和總氨基酸含量均有所增加;2.以啤酒酵母為發(fā)酵菌種,固態(tài)發(fā)酵苜蓿草粉,確定工藝參數(shù)。在單因素試驗(yàn)的基礎(chǔ)上進(jìn)行響應(yīng)面分析設(shè)計(jì),得到回歸方程為:Y=4.276667+0.165X1+0.73X2+0.2475X3-0.417083X12-0.3025X1X2+0.0025X1X3-0.842083X22-0.3225X2X3-0.577083X32(X1表示料水比,X2表示發(fā)酵時(shí)間,X3表示發(fā)酵溫度)。對(duì)回歸方程求導(dǎo)得知最優(yōu)條件為:料水比:1:1.52,發(fā)酵時(shí)間為122.6 h,發(fā)酵溫度為28.3℃。此時(shí),粗蛋白質(zhì)的含量為26.81%。通過驗(yàn)證試驗(yàn)可知,實(shí)際發(fā)酵苜蓿粉的粗蛋白質(zhì)含量為26.65%,與理論預(yù)測(cè)值相比,相對(duì)誤差為0.60%,發(fā)酵后的苜蓿粉纖維素含量為15.73%,比未經(jīng)發(fā)酵的苜蓿纖維素含量降低了18.50%,酸溶性小肽的含量提高了69.58%。3.對(duì)所獲得的發(fā)酵苜蓿粉提取苜蓿蛋白,提取條件為料水比1:8,堿提pH為9.0,浸提時(shí)間為30 min,浸提溫度為45℃,酸沉pH為4.0,得到提取效率為41.25%;4.采用酶解法提取苜蓿肽產(chǎn)品,將發(fā)酵樣品提取的苜蓿肽與未經(jīng)發(fā)酵的樣品提取的苜蓿肽相比,兩種產(chǎn)品的起泡性和起泡穩(wěn)定性沒有顯著的差別,但是經(jīng)過發(fā)酵的樣品提取的苜蓿肽的吸油性和吸水性明顯優(yōu)于未經(jīng)發(fā)酵的樣品提取的苜蓿肽;發(fā)酵后樣品提取的苜蓿肽含有4種多肽,其中在保留時(shí)間為6.37 min時(shí)的肽含量最高。結(jié)果表明經(jīng)過微生物發(fā)酵能夠使苜蓿粉的粗蛋白質(zhì)含量相對(duì)增加,降低纖維素含量,提高酸溶性肽含量,從而改善苜蓿粉的飼用品質(zhì)。
[Abstract]:Alfalfa is a kind of high quality legume forage, which is rich in protein, fat, vitamins and many mineral elements. In order to reduce the content of cellulose and increase the content of protein and acid soluble peptide in alfalfa, alfalfa protein was prepared by solid state fermentation, and alfalfa protein was prepared by enzyme hydrolysis. At the same time, the physicochemical properties of alfalfa peptide were studied. By optimizing the technological parameters of solid state fermentation of alfalfa meal with white rot fungus, the optimum fermentation conditions were determined as follows: the ratio of material to water was 1: 1.2, the fermentation time was 72 h, the inoculation amount was 108 cfur / g, and the fermentation temperature was 28 鈩，

本文編號(hào)：2155950