Preliminary Exploration Of Kombucha Fermentation Technology And Research On Cellulose Modification Of Kombucha

Kombucha is a tea beverage fermented by microorganisms,which is rich in nutrients.In recent years,the health care efficacy of Kombucha has attracted more and more attention of scholars,especially the research on the antioxidation of Kombucha.In addition,Kombucha cellulose will be produced during the fermentation of Kombucha,causing waste of resources and not conforming to the sustainable development strategy of the health industry.In this study,the fermentation process of Kombucha was explored,and a fruit Kombucha with good antioxidant effect and suitable taste was prepared by scientific compatibility.By product Kombucha cellulose were respectively modified with Compound enzyme method and Vortex fluidic device(VFD)to obtain soluble dietary fibers or functional materials with high added value,in order to expand the applications of Kombucha cellulose in food,textile materials,and energy storage devices.The main findings of this paper are as follows:(1)Using the antioxidative property as an indicator,optimized fermentation process of Kombucha,compared the antioxidant effects of six fruit Kombucha under secondary fermentation.After taste deployment and product quality detection,a fruit Kombucha with good antioxidant effect and suitable taste was prepared.The results showed that the highest antioxidative activity was observed in kombucha fermented from green tea at 25?30?for 6?7days.Among the six fruits,grape is more dominant in the fermentation of Kombucha.The Grape Kombucha exhibited a total phenolic content of 422.43?g GAE/m L,ABTS clearance54.33%,FRAP content m MFe²⁺.The sensory test for the grape kombucha based on two age groups of participants suggested that this grape kombucha(40%grape kombucha,5%sugar,60%bubble water)is more acceptable by young generation aged less than 30 years old.The physicochemical indexes,heavy metals and microbial detection indexes of the products were in accordance with the national standards.(2)Using the purified Kombucha cellulose for raw materials,treated with a complex hydrolase with a neutral cellulase:xylanase=4:1 ratio to extract soluble dietary fiber.Its soluble dietary fiber(SDF)extraction process was optimized by single factor and response surface methods,and the extracted SDF was tested for FT-IR,TGA,SEM,cellulose water holding,swelling,oil holding,and cholesterol/cholate adsorption capacities.The results showed that the optimal extraction yield was 13.41%when the compound enzyme addition amount was added to 2.5%,the enzymatic hydrolysis time was 2.6 h,and the enzymatic hydrolysis temperature was 50?.Through 3 parallel validation tests,the extraction rate of cellulose SDF of Kombucha after enzymatic hydrolysis was 13.41%,which was 0.014%lower than the theoretical value.It shows that the model is reliable and the optimal enzymatic hydrolysis process parameters obtained based on response surface method have reference value.Therefore,enzymatic digestion improved the water retention,oil retention,swelling force,cholesterol adsorption rate and cholate adsorption rate of fibers.It is known from structural characterization that soluble dietary fiber extracted by the cellulase method has characteristic absorption peaks of polysaccharides.(3)Using the purified Kombucha cellulose for raw materials,treated with Vortex fluidic device.FTIR,XRD,SEM,TEM,BET and TGA were used to evaluate the application potential of VFD modified Kombucha biofilm.The results show that the microfibers are arranged in an orderly manner,rough and easy to interweaving after VFD treatment,and the VFD treatment at6kmp and 8kmp can reduce the fiber diameter and improve the crystallinity and thermal stability of the fibers,and the sample adsorption force is stronger,the energy storage is larger and the hardness is higher at VFD 6kmp speed.In the word,VFD treatment worked better than homogeneous treatment.After the VFD secondary treatment,the fibers are more likely to break and accumulate,and the fiber diameter is further reduced.The crystallinity of the fiber does not increase with the increase in the number of VFD processing,and the VFD secondary treatment does not improve the thermal stability of the fiber.Therefore,a simple one-time VFD treatment is more suitable for the processing applications of Kombucha cellulose.