Study On Lactic Acid Bacteria Fermented Beverage Of Coconut Water

Cocos nucifera L.is a treasure of the whole body.It is known as the "life tree" and"universal tree".It is mainly grown in tropical and subtropical environments,such as Philippines,Indonesia,India,Tanzania,Papua New Guinea,Sri Lanka,and Hainan,Guangxi?Yunnan Xishuangbanna.Coconut water is the liquid endosperm of coconut(white coconut meat is its solid endosperm),a pure natural plant source with high nutritional value drinking water,tender coconut water taste fresh and sweet,old coconut water is less sweet,but the aroma is slightly rich.In short,it can replenish the water,electrolytes and vitamins after the body loses water.At present,domestic coconuts mainly use copra to process coconut juice,coconut milk,shredded desiccated coconut,coconut oil and other products,coconut water is a by-product of its processing.At present,due to the disappearance of the domestic nata de coco fermentation industry,coconut water is used as a soup in addition to the“original coconut chicken”food in restaurant,and there is no effective way for large-scale utilization.Being dumped and abandoned is a waste of resources and pollutes the environment.It is an urgent problem to be solved in the current coconut industry in Hainan.This study focused on the advantages of natural coconut water has comprehensive and balanced nutrition,and is the natural medium of microbial culture,combined with various health characteristics of lactic acid bacteria,research on coconut water lactic acid bacteria fermented beverage,based on the first screening of suitable strains or strain combinations,focusing on research their health characteristics and unique flavor characteristics of the product.This study explored a useful way to solve the problem of waste of resources and high value-added utilization of coconut water,which has important theoretical and practical significance.The main results were as follows:1.Through the study of antibacterial activity and tolerance,preliminary screening of lactic acid strains with strong performance was used to further study fermented coconut water:Lactobacillus fermentum L20,Lactobacillus casei 32-2-2,Lactobacillus brevis 64-1,Lactobacillus plantarum A33,Streptococcus thermophilus IFFI6038 and Lactobacillus delbrueckii Bulgaria Subspecies CICC6045.In this study,the single-layer agar diffusion plate method was used to measure the diameter of the bacteria circle to evaluate the antibacterial activity,and the tolerance of the strain was evaluated from four aspects:acid resistance,bile salt resistance,salt tolerance and optimum growth temperature.2.Using coconut water as raw material,using six strains of lactic acid bacteria to ferment coconut water,evaluate the fermentation characteristics of different lactic acid bacteria on coconut water,analyzed and determined the viable counts,total acid.pH value,reducing sugar content of fermented coconut water in the fermentation process.The results showed that at 48h,the total acid content of32-2-2 fermented coconut water was the highest,reaching 10.85g/L;the lowest pH value of A33 fermented coconut water was 3.1;CICC6045 fermented coconut water has a minimum reducing sugar content of 0.03 g/L.The effects of different strains on the organic acid and sensory evaluation of coconut water were analyzed.The A33,IFFI6038 and CICC6045 fermented coconut water have higher sensory scores.3.At present,a small number of similar studies were carried out by single bacteria fermentation.This study is devoted to the synergy between different strains and preliminary evaluation of the activity of the mixed fermentation broth.The combination of A33,IFFI6038 and CICC6045 strain,which were screened for bacteriostatic activity,tolerance and fermentation performance,and three mixed fermentations were compared.The acid-producing ability and sugar-consuming ability of the mixed lactic acid bacteria fermented coconut water and the growth ability and sensory evaluation of the strain showed that the combination of A33 and CICC6045 had the strongest fermentation performance in coconut water,and the two had potential synergistic fermentation,for further process research.The single-factor-response surface optimization of the mixed fermentation process was carried out,and the optimal process for preparing the mixed strains fermented coconut water was 1:1,the inoculum was 4%,and the fermentation time was 51 h.4.The organic acids,total phenolic content,antioxidant activity and amino acid composition of the A33+CICC6045 mixed strains fermented coconut water and the single bacteria fermented coconut water were compared.The total amount of amino acids decreased after the fermentation of coconut water by lactic acid bacteria,but some functional amino acids such as glycine,cysteine,arginine and phenylalanine increased after fermentation,and the species of amino acid in the mixed strains fermented coconut water was richer than single bacteria fermentation.The results showed that citric acid and amber acid was the main organic acid in fermented coconut water.The content of citric acid and amber acid increased significantly after coconut water fermentation(P<0.05),and the total amount of organic acid in the fermented coconut water of the mixed strains was higher than that of single bacteria fermentation.During the fermentation of coconut water,the total phenolic content increased significantly(P<0.05)and then decreased.It was found that the total phenolic content in the fermented coconut water of the mixed strains was higher than that of single bacteria fermentation;The scavenging rate of DPPH· was significantly enhanced,and the DPPH·free radical scavenging rate of the fermented coconut water of the mixed strains was higher than that of single bacteria fermentation;the ABTS+free radical scavenging rate was different after different lactic acid bacteria fermented coconut water,and the ABTS·free radical scavenging rate of the mixed strains fermented coconut water was the highest;the hydroxyl radical scavenging rate decreased,there was no significant difference between different strains.5.In order to obtain the coconut water lactic acid bacteria fermented beverage which takes into consideration the fermentation characteristics of lactic acid bacteria and the flavor of coconut water,the A33+CICC6045 mixed strains fermented coconut water in the above experiment and new coconut water were proportioned,and the best ratio was 1:1,the coconut water lactic acid bacteria fermented beverage has a pH value of 3.90,a soluble solid content of 8° Brix.Suitable and necessary sterilization conditions are sterilized at 115 0 C for 10 min.,the beverage is pale yellow,rich in nutrients,unique in flavor,and healthy and safe.