Study On The Influencing Factors Of Lily Fermentation By Probiotics And The Development Of Lily Probiotic Drink

Lily is the first batch of medicine and food homologues in the country.It is divided into medicinal and edible.Among them,Lanzhou lily,which is eaten as a vegetable,is famous for its whiteness like jade,sweet and delicious,both medicine and food,high protein content and good functionality.It is very popular among consumers,but lilies are not resistant to storage,and are prone to spoilage during processing,which seriously hinders the deep processing of lily products.At present,the research of lily products is mainly based on non-fermented products,and there are few reports on fermented products,and Adding more auxiliary materials,so as to solve the problem of spoilage and deterioration of lily processing,research and development of new lily fermentation products is an urgent problem in the development of the lily industry.This paper uses Lanzhou lily as the raw material.During the sterilization process,it was found that a large number of endophytic bacteria in the lily are difficult to kill.Therefore,Illumina high-throughput sequencing technology and separation and identification were used to analyze the endophytic bacteria in the lily,and then probiotics The biological control method inhibits endophytic bacteria,and optimizes the conditions of probiotics fermentation of lily by response surface method,uses the best fermentation conditions to ferment lily,and determines the content of polysaccharides and saponins during fermentation.In the end,a lily plant-based dairy product with nutrients and good functionality was developed to provide a basis for the development of lily probiotic plant-based dairy products.The experimental research results are as follows:Study on sterilization conditions of lily:The test results showed that the total number of colonies before sterilization was 1.86×109 CFU/mL;the total number of bactericidal colonies at 100? and below was 7.94×107?5.13×108 CFU/mL;the total number of colonies after sterilization at 115? and 121?was 1×103 CFU,respectively./mL and 0 CFU/mL,the bactericidal effect is good,but the browning and odor are serious.Therefore,the endogenous bacterial flora of the lily needs to be studied.Endophytic bacterial communities in lily bulbs:Illumina high-throughput sequencing test results showed that the main dominant bacteria of Lily before sterilization were Enterobacteriaceae and Bacillus,and the main dominant bacteria after sterilization Bacillus and Paenibacillus polymyxa.After isolation,5 strains of dominant bacteria were obtained,of which 4 strains had spores and 1 strain had no spores.They were identified as Leuconostoc mesenteroides subsp.,Bacillus proteolyticus,Bacillus mojavensis,Bacillus tequilensis,Paenibacillus polymyxa.Inhibition of probiotics on dominant endophytic bacteria in lily bulbs:After separating and identifying the dominant bacteria,probiotic biological control methods are used to suppress the dominant bacteria.The results of the Oxford Cup test showed that Streptococcus thermophilus and Lactobacillus rhamnosus had better effects on CGJ and YB4(p<0.05),and Lactobacillus plantarum had better inhibitory effects on YB1,YB2 and YB3.During co-cultivation,the inhibition rate of Streptococcus thermophilus,Lactobacillus rhamnosus,Lactobacillus plantarum,Lactobacillus paracasei,Lactobacillus casei on YB1 and YB3 in MRS broth can reach 100%(p<0.05),LP,LGG,ST has good inhibition on CGJ,YB2,YB4 The rate is 99%.Therefore,the ST+LGG+LP probiotic combination was used to ferment the lily.After 72 hours of fermentation,the pH was 4.17,the acidity was 93.37 T°,and the number of viable probiotic bacteria was 3.80×109CFU/mL.The inhibition rate of probiotics on endophytes in lily is 99%.Probiotic fermentation lily conditions:After obtaining a better combination of fermentation strains,the fermentation conditions were optimized.The results showed that the combination of bacteria ST+LGG+LP,temperature 37?,inoculation volume 1.5%,charging volume 80%,feed water ratio 1:3,62?After 30 minutes of sterilization,the results of pH,acidity and viable cells were the best after fermentation for 4 hours,respectively 5.11,42.37 T0,1.95×108 CFU/mL,and the overall score was 0.889,which was basically consistent with the predicted value.The 7-week fermented lily expansion test was carried out under better fermentation conditions and reached the national standard for fermented milk at 1 d;the single-bacteria expansion test with better conditions and 121? sterilization expansion test under better conditions,the results were not as good as the expanded culture test,Indicating that the combination of strains and sterilization temperature are reasonable.Effects of probiotic fermentation on Lily functional components:The lily was fermented under better conditions,and the changes of polysaccharide and saponin content during fermentation were studied.The polysaccharide content first decreased and then increased,and it gradually stabilized after 7 days,at 3.18 g/100g;the saponin content continued to decrease,and gradually stabilized after 7 days,at 0.19 mg/g.Preliminary preparation of probiotic fermented lily plant-based milk:Based on the above experiments,the best conditions for fermenting lily were obtained.The lily plant-based yoghurt was initially prepared,and its acidity,viable count,and senses met the national standard for yoghurt.The probiotic lily yoghurt powder has a protein content of 9.22 g/100g.After storage at 4? for 20 days,the polysaccharide content in the yoghurt powder is 9.61 g/100g,the saponin content is 1.15 mg/g,and the number of live probiotic bacteria is 9.77×107 CFU/mL.