The Production Technology And Nutrient Substance’s Change Of Probiotic Fermented Quinoa Powder

Quinoa,rich in protein and unsaturated fatty acids and lactose-free and gluten-free,has a lower allergy probability.Probiotics can improve the balance of the gastrointestinal flora and have a beneficial effect on the host.The use of quinoa as a probiotic carrier is not only rich in nutritive value,but also provides a new way for lactose and gluten intolerant people to ingest probiotic products,and is the development trend of new functional foods in the future.This study was to optimize the conditions for the fermentation of quinoa-based beverage by screening probiotics which were suitable for fermenting quinoa-based beverage with acid-resistant and bile-salt,and then dynamically monitor the dynamic changes of nutrients during the fermentation of quinoa-based beverage.Finally,vacuum freeze-drying technology was used to prepare quinoa granules with high activity probiotics.The research results were as follows:(1)Lactobacillus plantarum 21805 and Lactobacillus acidophilus 20250 selected from the eight strains,which had good acid and bile salt resistance,was selected to ferment quinoa milk.The optimal fermentation conditions which were used by single factor and the response surface analysis were as follows: Lactobacillus acidophilus 20250 and Lactobacillus plantarum 21805 ratio 3:1,inoculum 4%,fermentation time 8 h and fermentation temperature 33°C.Under these conditions,the viable count in the quinoa-based beverage reached to 9.37 Log CFU/m L,and the acidity reached to 56.08 °T.(2)Using the optimal fermentation conditions to ferment the quinoa-based beverage,analyzed the dynamic changes of the viable count,organic acids and polyphenols in the fermentation process of quinoa-based beverage.The results showd that the viable count continued to rise in the 0～7.5 hours and tended to be stable in 7.5～30 hours.During the fermentation of quinoa-based beverage,the content of organic acids and polyphenols were affected by the fermentation process.The content of oxalic acid,tartaric acid and acetic acid increased significantly after fermentation.Besides,the content of total phenolic and total flavonoids increased significantly.Free phenolics and conjugated phenols are both significantly increased after fermentation.Gallic acid,p-hydroxybenzoic acid,vanillic acid,epicatechin,vanillin,phlorizin,cinnamic acid,chlorogenic acid,ferulic acid,isoferulic acid,rutin,p-coumaric acid,protocatechuic acid,quercetin and kaempferol changed significantly after fermentation.The gallic acid,quercetin and kaempferol increased the most significantly after fermentation.(3)The centrifugal conditions and vacuum freeze-drying optimization test of the fermented quinoa-based beverage were carried out.Optimized the conditions of the centrifugally of the quinoa-based beverage before the vacuum freeze-drying and selected the centrifugal parameters of 4000 r/min(10 min).The protective agent and its concentration optimized by orthogonal test were: the glucose concentration 8%,the trehalose concentration12% and the sucrose concentration 8%.Under this condition,the viable count in the granule reached to 9.58 Log CFU/g.