本文關(guān)鍵詞：優(yōu)質(zhì)奶啤乳源酵母菌的篩選及其活性干粉制備的研究　出處：《江蘇大學(xué)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 奶啤 乳源酵母菌 增殖培養(yǎng) 真空冷凍干燥

【摘要】：奶啤是一種經(jīng)乳酸菌、酵母菌兩步發(fā)酵制成的有益于人類健康的新型乳飲料,屬國內(nèi)外首創(chuàng)。酵母菌是奶啤發(fā)酵的關(guān)鍵菌種,能為奶啤提供醇、酸和酯等主要風(fēng)味物質(zhì)。但目前采用市售釀酒酵母生產(chǎn)的奶啤產(chǎn)品,無論是在風(fēng)味上還是在口感上,都不足以滿足消費者多樣性的需求;部分企業(yè)采用篩選后的優(yōu)質(zhì)奶啤酵母菌發(fā)酵,改善了奶啤的質(zhì)量,卻缺乏此類酵母菌的活性干粉,不利于奶啤產(chǎn)業(yè)的長期發(fā)展。因此,近年來,奶啤飲料的研究熱點逐漸轉(zhuǎn)為優(yōu)質(zhì)酵母菌的篩選及其活性干粉的制備問題。本課題首先從開菲爾粒中分離篩選出了一株優(yōu)質(zhì)的奶啤發(fā)酵乳源酵母菌,并對其種屬進行了鑒定,為活性菌粉的制備提供了優(yōu)質(zhì)的菌種。然后以搖瓶發(fā)酵為基礎(chǔ),采用單因素、BBD(Box-Behnken Design)和正交試驗的方法,研究了該酵母菌的最佳培養(yǎng)基組成和最適培養(yǎng)條件,為活性干粉的制備提供高濃度的菌體。最后對真空冷凍干燥法制備活性干粉進行了研究,為優(yōu)質(zhì)奶啤乳源活性干酵母的工業(yè)化應(yīng)用提供了基礎(chǔ)。論文主要實驗結(jié)果歸納如下:1.篩選到了一株優(yōu)質(zhì)的奶啤發(fā)酵乳源酵母菌。以西藏、新疆、黑龍江等地區(qū)的新鮮開菲爾粒作為菌種分離源,分離得到了17株純種乳源酵母菌。分別從發(fā)酵樣品的理化數(shù)據(jù)、微生物數(shù);酵母菌的遺傳穩(wěn)定性;發(fā)酵樣品的感官風(fēng)味;發(fā)酵樣品的理化、感官和風(fēng)味結(jié)果的主成分分析這4個方面,逐步進行酵母菌的篩選。結(jié)果表明MJ1菌株發(fā)酵的樣品整體風(fēng)味最佳,適于奶啤發(fā)酵,經(jīng)5.8S rDNA分子生物學(xué)鑒定為馬克思克魯維酵母(Kluyveromyces marxianus)。2.優(yōu)化了馬克斯克魯維酵母菌MJ1的增殖培養(yǎng)基組成和培養(yǎng)條件。通過單因素和響應(yīng)面設(shè)計對培養(yǎng)基成分進行了優(yōu)化,得到增殖培養(yǎng)基最佳成份是蔗糖66.37 g/L,酵母粉28.3 g/L,玉米漿15.61 g/L,KH2PO4 4.13 g/L,MgSO40.3 g/L;利用正交設(shè)計得到MJ1的培養(yǎng)條件為30℃、160 r/min、初始pH 6.0。3.確定了真空冷凍干燥法制備MJ1活性干粉的條件,得到了真空冷凍干燥保護劑的最佳配方。在真空冷凍干燥過程中,通過比較MJ1菌體的離心收得率,得到了離心的最佳條件6000 r/min,15 min;真空冷凍干燥24 h時,MJ1凍干粉的含水率為2.9±0.08%;單因素和正交試驗確定的最佳保護劑組合為5%蔗糖,5%甘露醇,7.5%脫脂乳粉,此條件下所得干粉凍干存活率為74.63±1.17%;-20℃比4℃條件更適宜存放馬克斯克魯維酵母菌活性干粉;活性干粉的發(fā)酵活性穩(wěn)定,發(fā)酵產(chǎn)生的奶啤樣品在風(fēng)味和口感上都能得到很好的保證。
[Abstract]:Milk beer is a new type of milk beverage, which is made by two steps of lactic acid bacteria and yeast, which is beneficial to human health. It is the first creation at home and abroad. Yeast is the key strain of milk beer fermentation. It can provide the main flavor substances such as alcohol, acid and ester for milk beer. But the present commercially available yeast production of milk beer products, either in flavor or taste, are not enough to meet consumer diversity demand; some enterprises with high-quality milk beer yeast fermentation after screening, to improve the quality of milk beer, but the lack of such active dry powder yeast, is not conducive to long-term the development of dairy industry. Therefore, in recent years, the research hotspot of milk beer has gradually changed to the selection of high quality yeast and the preparation of active powder. In this project, we first isolated and screened a high quality Ruyuan beer yeast from Phil seed and identified its species, which provided excellent strains for the preparation of active bacteria powder. Then, based on shake flask fermentation, single factor, BBD (Box-Behnken Design) and orthogonal test methods were used to study the optimum medium composition and optimal culture conditions of this yeast, providing high concentration of bacteria for the preparation of active dry powder. Finally, the preparation of active dry powder by vacuum freeze drying was studied, which provided a basis for the industrial application of high quality milk beer Ruyuan active dry yeast. The main results of this paper are summarized as follows: 1. a high quality milk beer fermented Ruyuan yeast was screened. 17 strains of pure Ruyuan yeast were isolated from fresh Phil particles in Tibet, Xinjiang, Heilongjiang and other regions. Yeast selection was gradually done from 4 aspects: physical and chemical data, microbial number, genetic stability of yeast, sensory flavor of fermented samples, physicochemical, physical and sensory analysis results, and principal component analysis. The results showed that the MJ1 strain fermented samples had the best overall flavor, suitable for milk beer fermentation, and identified by Max Clewett M rDNA molecular biology as Kluyveromyces (Kluyveromyces marxianus). 2. optimization Marx Kluyveromyces MJ1 proliferation culture medium and culture condition. Through the single factor and response surface design to optimize the composition of culture medium, get the best multiplication medium ingredient is 66.37 sucrose g/L, yeast powder 28.3 g/L, corn syrup 15.61 g/L, KH2PO4 4.13 g/L, MgSO40.3 g/L; using orthogonal design culture conditions of MJ1 is 30 DEG C, 160 R /min, initial pH 6. 3. the conditions for the preparation of MJ1 active powder by vacuum freeze drying were determined, and the best formula of the vacuum freeze-drying agent was obtained. In the vacuum freeze drying process, through the comparison of MJ1 centrifugal cell yield, the optimal conditions of centrifugation 6000 r/min, 15 min; 24 h vacuum freeze drying, water MJ1 freeze-dried powder rate was 2.9 + 0.08%; the optimum combination of protective agent to determine the single factor and the orthogonal experiment of 5% sucrose, 5% mannitol 7.5%, skim milk powder, the powder obtained under this condition, the survival rate of freeze-dried was 74.63 + 1.17%; -20 C is more suitable for storing Marx Kluyveromyces active powder than 4 DEG C; fermentation activity stable active dry powder, produced by fermentation of milk beer samples in flavor and mouth feeling can get a good guarantee.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TS201.3

【參考文獻】

相關(guān)期刊論文 前10條

1 王振斌;王晴;劉加友;陳兵兵;;葛根汁發(fā)酵前后營養(yǎng)及風(fēng)味成分變化研究[J];中國釀造;2016年07期

2 張U，

本文編號：1347046