Research On The Preparation Technologies Of Three Probiotic Products From Centenarians

In this paper,the probiotics isolated from the centenarians in Bama,Guangxi,were used to develop three probiotics products with high viable count and quality.The first is pure culture of probiotics.Based on the composition of MRS medium,food grade nitrogen source,carbon source,buffer salt and growth factor are selected as the culture,and single factor test and response surface test are used to optimize the pure culture formula;The second is probiotic fermentation compound fruit and vegetable juice.Papaya,guava,pumpkin,skimmed milk powder and sugar are the main materials.According to the results of single factor test and response surface test,the preparation process of fermentation fruit and vegetable juice is optimized;The third is Cheddar type probiotic buffalo milk cheese.With buffalo milk as material,the single factor tests were carried out on the amount of starter,rennet,probiotics,salt and the time of probiotics addition,cheese ripening time,cheese ripeningtemperature,etc.response surface test was used to optimize,and the optimized product quality was comprehensively analyzed.The main results are as follows:1.The most technological choice of pure culture of Lactobacillus casei L614With Lactobacillus casei L614 as the culture object,the suitable and edible carbon sources,nitrogen sources and prebiotic species and their addition amount were selected with single factor method.By response surface methodology(RSM),an optimal medium was obtained: peanut protein powder 1.5%,high fructose corn syrup 12.0%,fructooligosaccharide 1.0%,sodium citrate 0.1%,probiotics 3.0%,spirulina 5.0% and fermentation temperature 39? for 24 hours,Lactobacillus casei L614 9.41±0.02log(cfu/mL).The number of probiotics was 8.94±0.05 log(cfu / mL)after 21 days storage at 4?.2.Probiotics fermentation compound fruit and vegetable juiceWith Lactobacillus casei L614 as the culture object.According to the single factor experiment,the proportion of raw materials,compound fruit and vegetable juice,skimmed milk powder,white granulated sugar,probiotics,sodium citrate and oligofructose were selected.Response surface methodology was used to optimize the formula: the proportion of raw materials(volume ratio)was 1:2:2(papaya: pumpkin: guava),the amount of compound fruit and vegetable juice was 72%,the amount ofnitrogen source was 1.5%,the amount of sucrose was 9.0%,the amount of probiotics was 5.0%,the amount of sodium citrate was 0.2%,the amount of fructooligosaccharide was 0.6%,and the fermentation temperature was 39? for 24 hours.The number of probiotics in fermentation compound fruit and vegetable juice was9.60±0.05log(cfu/mL),and the sensory score was 84.50±2.07.When stored at 4? for 21 days,the number of probiotics was9.03±0.03log(cfu/mL),and the acidity was 119.04±2.69°T.The viscosity of fermented compound fruit and vegetable juice did not change significantly during storage.The results showed that the aroma induction of fermented fruit and vegetable juice increased.Compared with the fermented yam juice by Lactobacillus casei,the number of Lactobacillus casei in the compound fruit and vegetable juice fermented by Lactobacillus casei L614 in this study is 10.6 times higher.3.Cheddar probiotic cheeseLactobacillus casei L614 was used as the additive.According to the single factor experiment,the amount of starter,rennet,probiotics,salt,probiotics adding time,cheese ripening temperature and cheese ripening time were determined.The optimum technological parameters were determined by response interview : 0.03% of starter,2953 SU/ Kg of rennet,2.3% of salt,and 90 days of maturity at 8?.At this time,the number of probiotics in the product was 9.26±0.06log(cfu/g)and thesensory score was 88.0±1.69.Based on the best technology of Lactobacillus casei L614,the cheese containing Lactobacillus casei L614,Lactobacillus reuteri LT018 and the control cheese(without probiotics)were produced.The results of physical and chemical indexes showed that there was no significant difference in the content of water,fat,protein and salt among the three groups(P > 0.05),and the pH value of L614 cheese was significantly higher than that of the other two groups(P < 0.05);There was no significant difference in the degree of protein proteolysis and texture among the three groups(P > 0.05).The electronic nose was used to measure the cheese flavor of three groups.The flavor components of the control group were similar to those of L614 cheese,but slightly different from that of LT018 cheese.During ripening,the number of viable bacteria in L614 and LT018 cheese decreased from 9.45±0.03log(cfu / g)and 8.98±0.04log(cfu/ g)to 9.26±0.02log(cfu / g)and 8.49±0.03log(cfu / g),respectively.Compared with the probiotic cheddar cheese reported in the study,the number of Lactobacillus casei L614 in this sample is about 10 times higher than that reported by others,and the number of Lactobacillus reuteri LT018 is 10.21 times higher.