Fermentation of Fruit Vinegar from Hovenia acerba

Hovenia acerba is a nutritional food material for fermentation due to its high sugar content. Fruit vinegar was produced from the peduncles by pulping with water, alcoholic fermentation and acetic fermentation. The applicable two-step fermentation method and technological parameters were investigated. Skin-on fermentation was carried out in the alcoholic fermentation stage with technological parameters as addition of water to 1.5 times, inoculation with 0.1% Angel fruit wine yeast, fermentation at 16 ℃ for 80 h. The alcohol concentration of wine reached 8.13%(m/V). Semicontinuous submerged fermentation was conducted in the acetic fermentation stage with a 5 L laboratory-scale fermenter for fruit vinegar production. The technological parameters of the acetic fermentation were as follows: inoculum size of acetic acid bacteria 10%, and fermentation temperature 34 ℃. It took 72 h to finish the first cycle of acetification with the titratable acidity of 5.42%(m/V), and 30 h to finish the second cycle. The optimized processing method and technological parameters could be applied directly in the industrialized production of Hovenia acerba vinegar.