Safety,Freeze Andapplication Of I4 Cholesterol-removal Lactobacillus Bacteria

Cholesterol,also known as cholesterol,is a multi-cyclopentane hydrogen phenanthrene derivatives,is one of the important substances that make up the intracyto-plasmic membrane.However,excessive intake of cholesterol,easy to induce atherosclerosis,coronary heart disease,stroke,high blood pressure and other cardiovascular diseases,serious threat to human health,so how to reduce serum cholesterol isso important tocardiovascular patients.Lactobacillus is a kind of widely present in the human and animal probiotics,have promote the growth of the body,maintaining micro-ecological balance,thereby improving gastrointestinal function,inhibiting the growth of abnormal colonies in the gastrointestinal tract,improvethe immune force and many other important physiological functions.Experiments have shown that some lactic acid bacteria have a cholesterol-lowering effect,which provides a new way to reduce the concentration of cholesterol in the serum.At the same time,it is important to note that some lactic acid bacteria are also pathogenic bacteria,which must ensure the safety of lactic acid bacteria before applying.This paper studies the safety of Lactobacillus plantarum I4,optimized of freeze-dried protectant,apply to yogurt.It laid the foundation for the development and application of Lactobacillus plantarum I4.The paper studies from three aspects.1.Safety of Cholesterol-removal lactobacillus BacteriaI4Because of the metabolic product of lactobacillus havepotential adverse effects on the health of the body,so the safety of Lactobacillus plantarum I4 bacteria stored in our laboratory was tested.By adding the histidine and tyrosine to the medium,theninduction of 5'-phosphate pyridoxal,According to the preliminary examination of culture medium,Lactobacillus plantarum I4 did not show the histidine and tyrosine decarboxylase activity.Lactobacillus plantarum P8 has tyrosine decarboxylase activity,Lactobacillus plantarum H21 has both histidine decarboxylase activity and tyrosine decarboxylase activity.Using the primer PHDC1 / PHDC2 and P1-rev/P2-for,5 strains of lactic acid bacteria genomic DNA as a template,by PCR amplification,electrophoresis.The results showed that the PCR test was consistent with the results of the medium test.Lactobacillus plantarum I4 did not have histidine and tyrosine decarboxylase activity.At the same time,all the lactic acid bacteria tested by the culture medium were not metabolized nitro reductase and azo reductase.2.I4 cholesterol Lactobacillus bacteria preparationsIn order to improve the direct investment type of I4cholesterol-lowering plant lactobacillus bacteria starter cultures of biological activity.Experimentthe five kinds of protective agent of vacuum freeze-drying protective effect of I4 bacteria,Study on optimization of four protective agent with better effect using response surface method.The result shows that the optimal freeze-drying protective material contains 4.04% trehalose,2.9% sodium glutamate,10.38% ssucrose,14.84% driedskim milk,the survivalrate reaches 83.32%.The test of the cholesterol-lowering ability of zhe formula indicates a degrading rate of 36.2�1.75?%,n=3?.3.I4 cholesterol Lactobacillus probiotics used in the fermentation of kimchiI4 Cholesterol-lowering plant Lactobacillus bacteriahas good functional properties,in order to better play a role of prebiotics,to compound with I4 bacteria and commercial probiotic bacteria of yogurt,Using response surface methodology to optimalthe composited parameters.We also measured the microbial content,physical and chemical index and the rate of cholesterol-lowering of yogurt within 21 days.The result shows that the optimal sensory properties of fermentation yogurt with commercial probiotics bacteria and I4 bacteria ratio of 1:1,fermentation time 10.6h,fermentation temperature 40.9?,sucrose concentration 8.1%,after fermentation 16 h.4? refrigerated within 21 days,the number of lactic acid bacteria is 4.01�10⁷ cfu ml^-1-4.45�10⁷ cfu ml^-1,pH is4-4.28,titratable acidity is 72 oT-88 oT,water-holding power is 73.3%-80%,whey separation rate is 2.1%-8.3%,viscosity is 407mPa�s-434mPa�s,hardness is 129.96g-221.34 g.The test of the cholesterol-lowering ability of fermented yogurt of optimal compositedparametersindicates rate of 43.6�0.82?%,n=3?.