Studies On The Processing Technology Of Low Fat Probiotic Cream Cheese And Its Functional Propetries

This experiment based on the researches of low fat cream cheese in civil andabroad, explored the key processing parameters of fat substitutes, homogeneouspressure and stabilizer by the single factor and orthogonal experiment, andestablished the optimal process of low fat cream. It studied the effect of probiotic onlow fat cream cheese made by optimal process. Finally, it verified that the low fatprobiotics cream cheese had cholesterol-lowering and antioxidant functionalcharacteristics by the animal experiments. The main experiments and the results are asfollows:1. Fat substitutes for the variety and dosage, which were whey proteinconcentrate（WPC）, beta-cyclodextrin（sβ-CD）and insulin, added40g/kg mixture and80g/kg mixture respectively， were researched by single factor experiment.Experiments based on good quality of low fat cream cheese, elected the beta-cyclodextrins (β-CD) as a fat substitute of low fat cream cheese, and added4%.2. Homogeneous pressures,which were10MP,20MP,30MP,40MP and50MP，were researched by single factor experiment. Experiments based on good qualityof low fat cream cheese, elected20MP as homogeneous pressure of low fat creamcheese.3. Stabilizers, which were locust beans gum, xanthan gum, guar gum and themixtures of the three gums, were researched by single factor experiment. Experimentsbased on good quality of low fat cream cheese, elected the mixtures of the three gumsas a stabilizer of low fat cream cheese, and added0.6%.4. On the basis of the single factor experiments，optimized the processingparameters of low fat cream cheese by orthogonal test. the optimized combinationwas A2B1C3, namely20MP of homogeneous pressure, the additive amount of β-CDwas56g/kg mixture, mixed-stabilizer was0.7%. It indicated that low fat cream cheese made by optimal process had a better quality than control low fat cream cheese，andthe sensory evaluation closed to control full fat cream cheese and commercial full fatcream cheese in the verifying test. So, the optimal process of make low fat creamcheese was feasible.5. Added1%、0.2%and0.02%C88in low fat cream cheese to make low fatprobiotic cream cheese， and make cheese with no C88as a control groupsimultaneously. The changes of their microorganism situation and physical chemicalproperties have been studied during cold storage. We achieved blow results in thisstudy. Adding C88reduced the pH of low fat cream cheese, the more volume, thelower of pH; C88didn’t affect the texture of low fat cream cheeses. Compared withthe blank group, sensory evaluation of added groups have no significant difference;Probiotic C88significantly influenced the compose of the free amino acid, and thecontent was higher than the blank group; the fatty acids of all the groups have nosignificant differences. In the storage, C88could grow in low fat cream cheese andthe growth in the21th day to achieve maximum. Then the living bacterium number isreduced, and the declines of living bacterium number were decreased along with theincrease of adding amount of probiotic; probiotic could enhance the survival rate ofstarter. Compared with blank group, the pH of added groups in the storage were lower,the decline was lower with the increase of C88; water solubility nitrogen contents ofadded groups were higher. C88had no negative impact on low fat cream cheese, andhad better activity in low fat cream cheese. Low fat cream cheese with C88wasfeasible.6. In order to investigate the hypolipidemic effects and antioxidant activities oflow fat probiotic cream cheese, the hyperlipidemic rat model induced from high-fatfeed was used as experimental material. The low fat cream cheese with differentamounts of C88were gave to rats, then hypolipidemic effect and changes of SOD，GSH-Px，T-AOC，MDA were observed. The results showed that high-fat diet couldresult in the levels of TC、TG and LDL-C were increased, HDL-C were decreased ascompared to normal energy diets, and reduced antioxidation capability of rat significantly. Giving the low fat cream cheese with C88could decrease the levels ofTC, TG, LDL-C and AI significantly. It also enhanced the activities of SOD, GSH-Px,increase the level of T-AOC, and decrease the content of MDA in serum and livereffectively. The result indicated that low fat probiotic cream cheese had hypolipidenicand antioxidant effects.