| This test by probiotic tablets to study as the main content,Lactobacillus planetarum Zhang-LL were chosen as research objects in this paper.The results were showed as following:(1)Viable count was firstly used in this study to detect the tolerance characteristics under simulated gastrointestinal tract environment.O-phthalaldehyde was used to detect its cholesterol-lowering capability.Under the condition of different pH maintained for 3h,the viable count of Lactobacillus strain reaches more than106 CFU/mL,and being cultured for 8h in the MRS-broth(less than 0.5%bile salt),the viable count reach more than 105 CFU/mL,it exhibited a strong tolerance to low pH and bile salt.A cholesterol removal rate ranging from 20.69%to 35.68%was observed under varying conditions.(2)The single factor experiments were carried out to determinate the optimal nitrogen sources of fermentation medium,according to the results,in the MRS culture medium,the carbon source were composed of 501 rapeseed peptone.And then,the single factor experiments and orthogonal experiment were employed combinedly to optimize fermentation conditions based on the optimized medium,the optimum fermentation conditions were determined as follows:the content of nitrogen source was 3.0%,temperature 34?,pH 6.5,inoculation 7%.Experiment results by the 5L automatic fermenter under the optimal conditions demonstrated:The highest bacterial counts of Lactobacillus plantarum was 1.07×1010 CFU/mL,while on the condition that the initial liquid volume was 2L,fermentation process was stuffied and stirring speed is 150 r/min.And the pH value controlled at 6.5 by chemical neutralization with 15%Na2CO3.(3)In the study of the effect of centrifugal time and rotational speed on the survival,yield and loss rates of Lactobacillus in the course of centrifugation,the optimum centrifugal conditions were decided.The optimum conditions were 8000r/min centrifugation for 10min at 4?.In this case,the highest survival rate of living cells was 109.25%,the centrifugal yield of Lactobacillus could reach 109.20%,and the centrifugal loss rate is only 0.052%.What's more,through the study on the effect of freeze-drying protectants on survival rate of Lactobacillus,the single-factor-experiment results showed:the optimum freeze-drying protectants were 15%skim milk,in this condition,the freeze-dried survival rate could reach 64.20%and the living bacterial counts of the fungus powder was 3.51×1011 CFU/g.(4)The culture substrates and fermentation conditions were optimized by means of orthogonal experiments.The optimized fermentation conditions were studied and concluded:initial moisture content 50%,material thickness 4 cm and fermentation time 13 days.Using rice as substrate,the maximum yield of monacolin K was 2.50 mg/g in the optimized conditions.Using glutinousrice as substrate,the maximum yield of monacolin K was 2.71 mg/g in the optimized conditions.(5)To obtain the optimized formula of probiotics tablets.An orthogonal experiment was conducted to optimize the formula of probiotic tablet based on 15 trained sensory evaluations' score.The optimized fonnula was as follows:microcrystalline cellulose/red yeast rice powder was 1:1.5,15%powdered milk,7%sugar,0.5%citric acid,10%low poly fructose content,10%xylitol,1%fungus powder.Probiotic tablet was developed by direct powder compression method with 1%Magnesium Stearate as lubricant,The production with good appearance and suitable rigidity was got.The viable cell numbers was 3.41 ×109 CFU/g.And the HPLC determination results shows that the probiotic tablet content of lovastatin is 1.18mg/g.After 90 d preservation at 4?,then the total number of lactic acid bacteria in probiotic tablet,survival rate can reach 68.62%,The probiotic tablet is satisfied to the market and requirement and have a good health care function. |
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