Study On Process Of Kombucha Industrial Fermentation

Kombucha is a kind of folk acid health drink with many beneficial effects to human health, which have a variety of benefits for health, such as clean up stomach, strengthens immunity, prevent and treat hypertension, cancer prevention and anti-cancer, suggesting a wide application field and good prospect.Traditionally the microbial mat/colony is added the sweetened tea with a previous Kombucha in family. This fermentation generally takes about10days, a lot of carbon source is used to generate a homogeneous thick BC, and the production rate of Kombucha is severely affected. But ferment Kombucha with pure strains in the fermenter will greatly improve the efficiency, the fermentation time can be shortened to3d, and Ferment Kombucha with pure strains can avoid contaminating by other bacteria. The pure strain fermentation can also prevent the the production of a large amount of bacteria cellulose, reducing the loss of carbon source and energy substances and improving the production rate of the Kombucha fermentation. The pure strain fermentation can also provide a theoretical basis for industrial production.This paper studied changes of total acid in the fermentation when seed Kombucha with different acid were inoculated. Experiments showed that the total acid increased fast at first6d when inoculum with total acid of5.14g/L was used, but the total acid increased fast at first7d when inoculum with total acid of3.02g/L. At first6d, the increase of total acid had little difference between inoculum with acid of5.14g/L and acid of3.02g/L. So the optimum total acid of inoculum for Kombucha fermentation was3.02g/L.This paper studied the effects of the stirring speed of ferment on pH, gross sugar and total acid in5L fermenter, and experiments showed that as the fermentation carried on, total acid kept increase, pH value decreased continuously, gross sugar also decreased continuously, when the stirring speed reach200r/min; the total acid of Kombucha was growing fastest, when the stirring speed reach150r/min, the Kombucha yield (total acid/glucose consumption) was highest. When the stirring speed was150r/min, less sugar could be consumed and more total acid was obtained. So the stirring speed of150r/min was more suitable for Kombucha fermentation.In order to obtain high quality Kombucha, our research optimized the conditions to clarify Kombucha. After24h natural clarification, transmittance of Kombucha reached to 79.61%. When the dosage of bentonite reach4g/L transmittance of Kombucha could reach to90.78%after2h. When the dosage of diatomite was3g/L, transmittance of Kombucha reached to87.67%after10h. when the dosage of gelatin was4g/L, transmittance of Kombucha reached to82.80%after16h. So the optimal conditions of Kombucha clarification were as follows:pH value of5.0, temperature of40℃, dosage of bentonite of4g/L, clarification of2h.As the operation of spray-drying is simple, low cost, conducive in large-scale and continuous productions, so spray-drying is widely applied in medicine and food industry. This test mainly focused on two process parameters:protective agents and outlet temperature. Taking the survival rate of strain Gluconacetobacter xylinum RST as main index the optimum conditions of process parameters were as following:dry skim milk as the protective agent, the recovery rate of milk was51.6%, the optimum outlet temperature was70℃, and the survival rate of Gluconacetobacter xylinum RST could reach58.8%.