Abstract:

Two fermentation methods, i.e., static liquid-state fermentation and static solid-state fermentation, were applied
to make persimmon vinegar from ‘Lanxi Red’ persimmon for the purpose of investigating the effects of fermentation
methods on sensory quality, nutrient components, volatile compounds and antioxidant capability in vitro of persimmon
vinegar. Results indicated that persimmon vinegar had rich fragrance, and soft and mellow sourness, and the sensory quality
of vinegar made by static solid-state fermentation was better. Furthermore, the total acidity was up to 6.551 g/100 mL, and
flavones, polyphenol and protein contents were significantly higher than those in static liquid state fermented vinegar and
even persimmon pulp (P < 0.05). The total amino acid content in solid-state fermented persimmon vinegar was 0.778%,
with essential amino acids accounting for 44.47% of the total amino acids, the contents of all amino acids except arginine
were significantly higher than those in liquid-state fermentation. The same tendency was found for volatile components.
The content of ester compounds in solid state fermented samples was higher, especially for ethyl acetate (which showed
an increase of about 10%). The new occurrence of γ-nonanolactone, phenethyl benzoate, β-damascenone and eugenol,
which contributed to special aroma characteristics, was only found in solid-state fermented persimmon vinegar, and these
compounds were together responsible for its unique aroma and flavor. A higher antioxidant capability in vitro was also
found in persimmon vinegar prepared by solid state fermentation, and it was slightly but not significantly lower when
compared with that in the pulp (P > 0.05). From the perspective of both sensory and nutritional quality, the solid static state
fermentation method is more suitable for traditional vinegar manufacturers to produce fruit vinegar.

Key words: persimmon vinegar, fermentation methods, sensory quality, nutritional quality, antioxidant activity