Study On The Fermentation Technology,antioxidant Activity And Aroma Components Of Functional Fermented Fruit Beverage

With the change of people’s lifestyles,people are increasingly concerned about the nutrition and health of food,and beverage market also will change,and the proportion of fermented beverage is also growing.The functional beverage with low alcohol,low sugar and pleasant flavor was obtained by adding cereals,fruits and multiple bacteria compound fermentation.It can not only provide micronutrients,prevention and treatment of chronic diseases,but also to meet the needs of the people.And it also can provide theoretical and practical guidance for the development of functional beverages.In the present study,the vitamin C contents and total phenolic contents of peel,flesh,whole fruit and fruit juice of eight fruits were determined.And phenolic profiles of eight fruits were determined by high performance liquid chromatography(HPLC),and its antioxidant activity was evaluated.The results showed that the vitamin C contents of eight fruits were in the order of guava> navel orange> pineapple 、 papaya> green apple 、 crown pear 、 kumquat 、 mango.Mango had the highest total phenolic content.Sixteen phenolic compounds were identified in eight fruits.The contents of chlorogenic acid,catechins,epicatechin,rutin,myricetin and phloridzin were higher in eight fruits.Eight fruits were divided into four categories in terms of the phenolic profiles:(1)navel orange;(2)mango;(3)kumquat;(4)green apple,crown pear,guava,pineapple and papaya.DPPH radical scavenging activities were in a descending order as follow: mango> guava> green apple> crown pear 、 kumquat 、 navel orange 、 pineapple 、 papaya.Oxygen radical absorbance capacities decreased in the order of navel orange> guava> crown pear、 mango> green apple 、 kumquat 、 pineapple 、 papaya.On this basis,total phenolic contents and antioxidant activity of mixed fruit juice(green apple,guava,navel orange and mango)were determined,and after sensory evaluation,the proportion of green apple,guava,navel orange and mango was determined to be 2: 2: 4: 2.With glutinous rice,brown rice and mixed fruit as raw material,the fermented beverage was produced by multiple bacteria compound fermentation.This experiment was studied on the effects of the addition amount,fermentation temperature and fermentation time on the total sugar,alcohol,titratable acidity and pH value of the distiller’s yeast,yeast and acetic acid bacteria.The results showed that the optimum fermentation conditions of the fermented fruit beverage were as followed: ratio of brown rice and glutinous rice was 1:1 by adding 0.80 % distiller’s yeast at 30 ℃ for 3 d;then,the mixture was treatment with 0.06 % yeast at 28 ℃ for 7 d;the mixed fruits were added into rice wine at the ratio of 2:1;the mixture was fermented by adding 0.30 % acetic acid bacteria at 33 ℃ for 4 d.The total sugar,alcohol and titratable acidity contents and pH value of the fermented fruit beverage were 4.62 %,4.41 %,3.00 % and 3.49,respectively.On this basis,the fruit wine,fruit vinegar and mixed fruit juice were prepared according to the same proportion of fruit.The total phenolic contents,antioxidant activity and aroma composition of fermented fruit beverage,fruit wine,fruit vinegar and mixed fruit juice were determined.The results showed that total phenolic contents of mixed fruit juice was the highest,followed by the fruit wine,the third fruit vinegar,and the fermentation fruit beverage was the lowest.DPPH free radical scavenging ability and the oxygen free radical absorption ability were in a descending order as follow: fruit wine> fruit vinegar> fermentation fruit beverage > mixed fruit juice.The dissolution rate of the total phenol,DPPH free radical scavengers and oxygen free radical absorbers was the highest,up to 2130.22 mg/kg,15.21 mM Trolox equiv/kg and 24.97 mM Trolox equiv/kg,respectively,which were 1.5-2 times of fruit wine and fruit vinegar.Under the conditions of fermentation,the utilization rate of polyphenols and antioxidants was the highest.The sensory characteristics of fermented fruit beverages are uniform texture,delicate texture,smooth taste,moderate sweet and sour taste,weak bitter taste and strong fruity smell,accompanied by wine bouquet.The volatile components of fermented fruit beverage,fruit wine,fruit vinegar and mixed fruit juice were analyzed by headspace solid phase microextraction(HS-SPME)and gas chromatography mass spectrometry.A total of 120 volatiles were identified,including alcohols(33),esters(24),aldehydes(17),acids(9),alkyl hydrocarbons(26),ketones(6),phenols(2)and furans(3).The main volatile substances in fermented fruit beverages were alkyl hydrocarbons,alcohols,esters and acids,accounting for 54.13 %,36.15 %,6.38 % and 1.80 % of the total volatile substances,respectively.The relative contents of alkyl hydrocarbons were 0.62,6.16 and 0.56 times of that of fruit wine,fruit vinegar and mixed fruit juice respectively.The relative contents of alcohols were 4.20,0.47 and 43.55 times of that of fruit wine,fruit vinegar and mixed fruit juice respectively.The relative content of esters were 2.01,0.64,18.23 times of that of fruit wine,fruit vinegar and mixed fruit juice respectively.The relative content of acids were 4.19,0.95,12.86 times.that of fruit wine,fruit vinegar and mixed fruit juice respectively.The relative higher contents of volatile substances in fermented fruit beverages were cinene,phenethyl alcohol,terpinen-4-alcohol,3-methyl-1-butanol,1-isopropyl-2-methylbenzene,ethyl benzoate,2,4-dimethyl styrene,ethyl caprylate,1-hexanol,1-octanol,2-methyl-1-butanol,acetic acid glacial,β-myrcene and linalool,accounting for 90.39% of the total volatile substances.