Lactic acid fermentation of onions

Lactic acid fermentation was conducted on sweet, white, and yellow storage onions to produce souronion. The onions were sliced to 0.3 cm thick, salt was added at 1.5, 2.0, and 2.5 g/100 g without or with sugar at 1.0 and 2.0 g/100 g, and the fermentation temperature was 18°C. Since onions do not have the necessary lactic acid bacteria for the anaerobic fermentation, onions were inoculated using either brine from sauerkraut or slices of cabbage. The fermentation produced souronion with pH between 3.25-3.35 and 1.2-1.5 g lactic acid/100 ml, which is in the range as that of sauerkraut. Sensory evaluation showed that the yellow storage souronion was a favorable product with respect to color, texture and flavor. The souronion had a tart acidic taste, characteristic of sauerkraut, with onion flavor but without the pungency of raw onions.