The invention relates to a low-
sugar fully fermented health-care purple sweet potato red vinegar and a
processing technique thereof, which belong to the technical field of health-care food. The invention is characterized in that with fresh purple sweet potatoes as material, the health-care purple sweet potato vinegar beverage is prepared by cooking, double
enzyme saccharification, alcoholic
fermentation, acetic
fermentation, blending, sterilization and packaging. A liquid method is adopted by material
processing and acetic
fermentation, i.e., water is adopted to isolate
oxygen to prevent the oxidation and
browning of
anthocyanin; saccharification temperature is less than 60DEG C, the finished product is pasteurized, and thereby the thermal degradation loss of
anthocyanin is prevented; the growing states and
inoculation amounts of saccharomycete and
acetic acid bacteria are optimized, the
ethanol concentration of the alcoholic
fermentation broth is decreased, and as a result, the whole fermentation period is shortened to less than 100h. The
anthocyanin content in the final product is 15 plus or minus 1mg / 100mL (by
cyanidin-3-glycosid), the anthocyanin preservation rate is greater than 80 percent in the
processing process, the
sugar content is less than 3.0 percent, the
total acid content is 3.0g / 100mL (by
acetic acid), and therefore the low-
sugar fully fermented health-care purple sweet potato red vinegar meets the requirement on the acidity of health-care vinegar beverages, and can be drunk directly.