Analysis Of Compositions,Functionalities Of Different Chinese Tamarind Indica L. And Study On The Processing Method Of Tamarind Probiotic Beverage

Tamarind(Tamarindus indica L.),also known as Suan Jiao and Suan Dou,is an evergreen large tree of Leguminosae,Rosaceae.It is widely distributed in the tropics and subtropics,and is planted in Chinese southern provinces.The fruit is used to treat dysentery,abdominal pain and other diseases in Africa,and its antibacterial,anticancer,antioxidant and other functions have also been found in previous studies.There are two types of tamarind,acid type and sweet type.However,the distribution of tamarind in China is not clear,and each type of fruit has not been clearly studied.In view of this phenomenon,7 kinds of tamarind fruits were selected from Hainan,Fujian,Yunnan and Sichuan,including 3 kinds of acid fruits and 4 kinds of sweet fruits.High performance liquid chromatography(HPLC)and mass spectrometer(MS)were used to analyze the conponents in the pulp.In addition,in order to improve the utilization value of Hainan tamarind fruit,probiotics and prebiotics were used in the production of tamarind beverage.Through sensory evaluation and analysis by fuzzy mathematics analysis,we got a unique flavor of tamarind and a delicious probiotic beverage.Then,the period of fermentation and storage of tamarind beverage were studied.(1)Analysis of sugars,acids,phenols,antioxidant and antibacterial activities of different types of tamarind pulpIt was found that the main sugars components were glucose,fructose and sucrose,the main acids were tartaric acid and oxalic acid,the main phenolic substances were neochlorogenic acid,gallic acid and syringic acid,the free polyphenol content was much higher than the combined polyphenol content,and the total phenol content was about 20 times of the total flavone content.The correlation analysis of the sugar,acid,total phenol and antioxidant capacity of all the fruit pulp showed that there was a significant negative correlation between the total acid content and the reducing sugar content(p<0.05),a significant positive correlation between the reducing sugar content and the antioxidant capacity(p<0.05),and a significant negative correlation between the total acid content and the antioxidant capacity(p<0.05).The contents of tartaric acid and oxalic acid were negatively correlated with the contents of glucose,fructose and sweetness of pulp,but negatively correlated with the contents of sucrose(p<0.05).There are significant differences in the content of raw sugar and total acid in the pulp of various kinds of tamarind,from 26.18%to 41.58%and from 3.05%to 22.96%,indicating that the metabolism of tartaric acid,oxalic acid,the main components of total acid and glucose and fructose,the main components of reducing sugar,may determine the type of tamarind.There were significant differences in the total phenol content of the pulp(free polyphenolics),from 977.13?g GAE/g DW to 1936.83?g GAE/g DW,and in the antioxidant capacity(p<0.05),from 254.39?mol Trolox/100g DW to 372.10?mol Trolox/100g DW.The results showed that the inhibitory effect of juice was higher than that of free extract(MIC and MBC),but that of combined extract was not found.In different fruit juices,the inhibition ability of acid type juice to various pathogens(Salmonella paratyphoid,Pseudomonas aeruginosa,Escherichia coli,Staphylococus aureus,Bacillus subtilis and Listeria monocytogenes)is stronger than that of sweet type juice.This shows that the main substance of antibacterial activity is not polyphenols,but organic acids with tartaric acid as the main one,which makes the p H of the juice lower.(2)Study on the production of fermented beverage by probioticsUsing sodium carbonate to reduce the acid content of the juice can improve the sensory quality and the number of viable bacteria in the beverage;adding fructooligosaccharide can significantly improve the number of viable counts in the beverage,and also can provide the appropriate taste for the beverage;the fermentation time is closely related to the sensory score and the number of viable counts in the beverage.Using the above three factors,the sensory quality and the number of viable counts of the beverage were optimized by the Box Behnken response surface methodology.Through the model prediction and validation experiments,when the amount of oligofructose was 11%,the amount of sodium carbonate was 0.3%,inoculation content was 2%and the fermentation time was36 h,the sensory score of the beverage was the highest,which was 66.42,and the number of viable bacteria was also high,which was 9.61(lg CFU/m L).(3)Changes during fermentation and storageDuring the fermentation process,oligofructose was decomposed by lactic acid bacteria to produce new sugar,which led to the increase of total sugar content and total acid content with the fermentation time,while the number of viable bacteria reached the maximum of 9.59(lg CFU/m L)at 36h of fermentation.In the process of fermentation,the content of organic acids in beverages is mainly tartaric acid,and the content of oxalic acid is relatively high,about 14mg/m L and 3mg/m L,respectively,but the change is not obvious;In the fermentation process,adding FOS significantly increased the acid production capacity of Lactobacillus plantarum A33,among which the maximum production of lactic acid and acetic acid was 3.12 g/L and 0.34 g/L,respectively,which were 2.5 times and 9 times of that of the blank group;meanwhile,adding FOS significantly increased the number of viable bacteria in the juice,up to 9.59(lg CFU/m L),about 4.3 times higher than that of the control group;Fos significantly increased the total polyphenol content and antioxidant capacity of the juice to156.75 mg GAE/100m L and 37.96?mol Trolox/100m L,respectively.To sum up,11%FOS and 0.3%sodium carbonate were added into the beverage.The beverage fermented by probiotics has the best sensory quality,high viable counts number and antioxidant capacity.It was found that fructooligosaccharide had no significant protective effect on Lactobacillus plantarum A₃₃in cold storage(p>0.05),but the number of viable lactobacillus was above 10⁶(CFU/m L)in 28days,which met the recommended value of FAO/WHO.Using SPME-GC-MS to analyze the volatile components of tamarind juice and fermented beverages.After36 hours of fermentation,one ester,three alcohols,two ketones,two aldehydes and two other kinds of volatile components were added compared to tamrind juice.The main volatile components after fermentation were acetic acid,alcohol and ethyl acetate.The content of ethyl acetate increased significantly after fermentation,from 62.87?g/L to 248.08?g/L,and continued to increase to 48.0?g/L after refrigeration The content of acetic acid increased from 91.02?g/L to349.60?g/L,and decreased to 287.56?g/L after refrigeration.Furfural,5-methyl-2(3H)-furanone,ethyl hexanoate,5-hydroxymethylfurfural,CIS linolenic acid,furan,linalool,nonanal,acetic acid and terpineol were also found in fermented tamarind beverages and tamarind juice,which may provide a unique aroma for tamarind.