嗜酸乳杆菌冻干影响因子的研究

传统的乳酸菌发酵剂因活化过程复杂,极易引起污染而影响发酵乳的质量。目前,多采用冷冻干燥技术制备直投式粉末状乳酸发酵剂。然而,菌种冻干时机的把握和冻干保护剂的选择,将直接影响乳酸菌在冷冻干燥前后的存活率以及存活期。本文研究了嗜酸乳杆菌的生长曲线,选用蔗糖、乳糖、甘油、VC、谷氨酸钠、麦芽糊精、脱脂乳粉等为嗜酸乳杆菌冻干保护剂进行了冻干研究。结果表明:①嗜酸乳杆菌发酵液培养至酸度为100°T、pH值4.8时,OD410nm=0.511为最大,是最佳发酵终止时间;②嗜酸乳杆菌冻干保护剂配方以5%麦芽糊精、2%VC、5%甘油为最佳冻干保护剂组合,此时嗜酸乳杆菌冻干菌粉活菌数为2.34×109cfu/g。

Research of lactobacillus acidophilus freeze-dride impact factor

Traditional lactic acid bacteria fermentation process is complicated and easy to be polluted.At present,the freeze drying techniquewas used to prepare DVS powder of lactic acid fermentationagent.However,Bacteria lyophilization’s time and freeze-drying protectiveagent selection directly affected the survivalrate and survival time of lactic acid bacteria in freeze drying.The growth curve of lactobacillus acidophilus was studied,sucrose,lactose,glycerin,vitamin C,sodium glutamate,maltodextrin,skim milk were used as freeze-dried agents.The results showed:①the test termination condition of fermentation was when OD410nm was up to its biggest 0.511at 100°Tand pH 4.8.The best freeze-driedprotective agent was the composition of 5% dextrine、2% VC、5% glycerol.Under the above conditions,the living bacterium numberof lactobacil lus acidophilus in freeze-driedpowder was 2.34×1010cfu/g.