【作者】 汤高奇；

【导师】 岳田利；

【作者基本信息】 西北农林科技大学 ， 食品科学， 2007， 硕士

【摘要】 本试验以经过选育的一株猕猴桃酒酵母为供试菌种,麦芽汁为基础培养基,利用JMP、Box-Behnken响应曲面和正交等试验设计方法,通过研究确定了酵母增殖培养基,优化了增殖培养条件和胞内海藻糖积累条件,确定了冻干保护剂配方,最后研制了符合国家相关标准的高活性猕猴桃干酵母,旨在为猕猴桃酒的工业化生产提供依据。研究结果表明:1.增殖培养基及培养条件JMP试验结果表明:在试验所选的13个影响因素中,葡萄糖、(NH4)2HPO4、MgSO4、维生素B1、维生素B2、泛酸、温度、初始pH、装液量、转速和时间等对酵母增殖均有极显著的影响,FeSO4和生物素对酵母增殖无影响。2.通过增殖培养基Box-Behnken响应曲面试验优化的酵母细胞增殖培养基为葡萄糖8.39g/L,(NH4)2HPO40.53g/L,MgSO40.07g/L,维生素B11.75mg/L,维生素B20.60mg/L和泛酸0.57ml/L,生物量的预测值可达到3.01785×108。3.通过增殖培养条件Box-Behnken响应曲面试验优化的酵母细胞增殖培养条件为温度28.5℃、初始pH4.5、转速175r/min、装液量65mL和时间30h,生物量的预测值可达3.06352×108。4.供试酵母在最佳培养基和培养条件的生长曲线表明:0h～10h为酵母生长延迟期,10h～22h为对数生长期,22h后转入稳定期。5.胞内海藻糖积累条件L 9(3 4)正交试验结果表明:温度、时间、pH和转速四个因素对海藻糖积累的影响主次为温度>时间>pH>转速,优化后的条件组合为温度37℃,pH5,时间5h和转速50r/min。6.以无菌生理盐水为冻干悬浮液,研究了蔗糖、海藻糖、脱脂乳粉和抗坏血酸四种保护剂的保护效果。JMP试验结果表明:四种保护剂对酵母冻干都有显著的保护作用。7.通过保护剂配方Box-Behnken响应曲面试验优化的酵母冻干保护剂配方为蔗糖121.1g/L,海藻糖93.9g/L,脱脂乳粉145.4g/L和抗坏血酸10.5g/L,活菌率的预测值可达92.2075%。8.研制的猕猴桃活性干酵母在感官和理化指标上均符合酿酒活性干酵母行业标准(QB2074-1995)。更多还原

【Abstract】 One kiwifruit wine yeast stain which has been breeded was selected as experimental strain and malt wort was selected as basal medium in this study. Making use of JMP,Box-Behnken response surface quadratic and orthogonal design , fertile medium and freeze-drying protestant formula were definited,fertile cultivation and trehalose accumulative conditions were optimized. At last a kind of kiwifruit wine active dry yeast matching to standard was developmented.The result of study is aimed to provide experimental basis for industrialized production of kiwifruit wine. The result indicated:1.The result of JMP design of fertile medium and fertile cultivation conditions indicated:glucose,(NH4)2HPO4,MgSO4,vitamin B1,vitamin B2,pantothenic acid,temperature,initial pH, volume of medium,rotated speed and time have significant influence on cell proliferation,FeSO4 and biotin have no influence.2.The result of Box-Behnken response surface quadratic design of fertile medium indicated: optimum fertile medium formula of cell proliferation is glucose8.39g/L ,(NH4)2HPO40.53g/L , MgSO40.07g/L , vitamin B11.75mg/L , vitamin B20.60mg/L , pantothenic acid0.57ml/L,the prediction value of biomass reach to 3.01785×108.3.The result of Box-Behnken response surface quadratic design of fertile cultivation conditions indicated : optimum cultivated conditions of cell proliferation are temperature28.5℃,initial pH4.5,rotated speed 175r/min,volume of medium65mL and time30h,the prediction value of biomass reach to 3.06352×108.4.The growth curve of experimental strain under optimum fertile medium and optimum cultivated conditions indicated:lag phase of yeast growth is from 0h～10hexponential growth phase is from 10h～22h,after 22h it reach to stabilization period.5.The result of orthogonal design of trehalose accumulative conditions inside cell indicated:. The importation of temperature time pH and rotated speed factors is temperature>time>pH>rotated speed,optimum conditions are temperature37℃,pH5,time5h,rotated speed50r/min.6.Using normal saline as suspended,the protective effects of sugar,trehalose,skim milk powder and ascorbic acid were studied. The result of JMP design indicated:All of protestants have significant influence on freeze-drying of yeast. 7.The result of Box-Behnken response surface quadratic design of freeze-drying protestant formula indicated: optimum freeze-drying protestant formula is sugar121.1g/L,trehalose93.9g/L,skim milk powder145.4g/L and ascorbic acid10.5g/L,the prediction value of living yeast rate can reach to 92.2075%.8.The kiwifruit wine active dry yeast obtained from this study matched to trade standard of brewing active dry yeast(QB 2074-1995) in both sensory and physical-chemical characteristics.更多还原