The Effect of Enzymatic Hydrolysis on Flavor of Banana Wine Before and After Fermentation

Due to the high viscosity of banana pulp and the difficulty of extracting juice, banana pulp was pectinase-treated or supplemented with water to prepare enzymatic hydrolysis banana juice and non-enzymatic hydrolysis banana juice, respectively. The changes of physicochemical parameters and volatile components of banana wine with different treatments were compared before and after fermentation. The results showed that the total soluble solids (TSS) and total acid (TA) of the banana juice (fruit wine) treated with pectinase were 24.91 ^oBrix (8.40 ^oBrix) and 4.70 g/L (5.67 g/L), respectively, which were higher than those of the banana juice (fruit wine) without pectinase treatment. While a lower pH value was found in pectinase treatment groups. Meanwhile, the alcohol content of pectinase-treated samples was 11.5% vol, which was higher than that of the non-enzymolysis samples. Then headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze the volatile components of different samples. A total of 87 volatile components were detected in the four samples, including 43 esters, 13 alcohols, and relatively few other types of substances. Combined with odor activity value (OAV) and principal component analysis (PCA), a total of 15 aroma substances with OAV>1 were found. Ten substances such as 1-hexyl alcohol, ethyl acetate, isobutyl acetate, butyl acetate, isoamyl butyrate, trans-2-hexenal, and hexal were the main volatile components in banana juice. These substances were mainly related to sweet aroma, banana aroma, raspberry aroma, pear aroma, peach aroma and grass aroma. Compared with untreated banana juice, the content of hexal in banana juice treated with pectinase was less, which was mainly related to grass aroma. Seven aroma components such as phenylethanol, ethyl isovalerate, ethyl caprylate, ethyl caprylic acid and isoamyl acetate had a great contribution to the aroma of banana wine. These substances mainly provided apple, rose, banana, apricot and cream aroma for banana wine. The aroma concentration of banana wine treated with pectinase was higher, and its overall aroma is more balance and rich. In conclusion, the overall aroma of banana wine fermented from pectinase-treated banana pulp was richer and more harmonious, which provided scientific basis for the production of banana wine.