Research On The Application Of Lactobacillus Acidophilus In Probiotic Cheese

In recent years, food security and nutrition are more and more concerned by consumers, especiallythe food which is helpful with the human health. Thus probiotic cheese appeared as a new type of cheeseat the historic moment, and become the most potential food. For the research of cheese, probiotics andcheese are banded together by more and more scholars, and all kinds of probiotics are added to thevarious types of cheese. In the fermentation dairy products, excellent matrix is provided by cheese forprobiotics entering into human gastrointestinal tract, especially the fresh cheese. Therefore the interactionrelationship among all kinds of strains are observed taking Lactobacillus acidophilus (which had theconfirmed resistant to acid, bile salt and pathogenic bacteria) and Lactococcus lactis preserved inlaboratory as the research object in the present experiment, the optimum inoculation quantity andproportion were determined under the condition of a certain addition of Lactobacillus acidophilus, andthe best identification medium of Lactobacillus acidophilus was selected, then cottage cheese productswere prepared under the above condition, and the physical and chemical indicators, TPA and sensoryquality were measured and evaluated, the survival situation of Lactobacillus acidophilus was observed inthe simulated human stomach and intestinal environment which made a foundation for the developmentof probiotic cheese and attached starter. The control function of Lactobacillus acidophilus for Listeriamonocytogenes in cottage cheese was studied, meanwhile the identified Enterococcus faecalis(KLDS6.0610) by the laboratory was as a control.Findings by the interaction between the various strains, we can observe that there is no inhibitionzone around Oxford cup and per strain did not inhibit to each other after cultured24h.So we can carry outthe follow-up test. Through the result of choice of for the best ratio of starter, we can see whenLactobacillus acidophilus inoculation quantity of108cfu/ml, starter inoculation quantity was4%,inoculation ratio1:1, curd has good flavors and best organization. Addition, MRS-1%clindamycin(concentration0.005%) as medium aureus inhibitory effect is best, we can use it as a differential medium.The Lactobacillus acidophilus added to cottage cheese production with starter, and compared withcommercial starter cultures. Experimental results show that the experimental group of cheese moisture,protein, ash significant difference. In addition, adding Lactobacillus acidophilus will also affect thephysical and chemical indicators, cheese products indicators higher than the control group, the saltcontent of no significant difference in the four groups of cheese; The four groups cheeses’s Lactococcuslactis number is on the decline during storage, Lactobacillus acidophilus in the experimental group theprobiotics on the number of living bacterium decreased during storage is different, but the number of living bacterium can be maintained at more than107cfu/g; The lower pH, titratable acidity increased canbe seen in the four groups during20d storage at4℃. The addition of Lactobacillus acidophilus canfurther promote a decrease in pH and titratable acidity of cheese; With the extension of storage time, thecheese water-soluble nitrogen and trichloroacetic acid soluble nitrogen content increased; By simulatedgastrointestinal condition, the cheese of Lactobacillus acidophilus on low acid high bile salt environmentin vivo has better tolerance; Research on four groups of cheese quality and structure, the adding ofLactobacillus acidophilus and has no effect on cheese quality constructed as negative, and lab startercultures make cheese elasticity, cohesion and adhesion degrees higher than commercial starter cultures.Lactobacillus acidophilus supernatant that cultured in MRS and skim milk for48h has antibacterialeffect on L. monocytogenes, but the inhibition effect of supernatant in MRS supernatant is better than inskim milk; Lactobacillus acidophilus and L.monocytogenes mixed cultured in skim milk thatLactobacillus acidophilus in the acidic conditions of L.monocytogenes growth inhibition. Lactobacillusacidophilus and KLDS6.0610respectively added to cottage cheese with L.monocytogenes. Two lacticacid bacteria all have inhibitory effect on L.monocytogenes, and the Inhibitory effect of Lactobacillusacidophilus on L.monocytogenes is greater than the adds KLDS6.0610cheese, so Lactobacillusacidophilus can be used as a biological preservative of the cottage cheese.