Lactic acid fermentation of Radish for shelf-stability and pickling

Abstract

Lactic acid fermentation of radish as one of the alternatives to preserve this vegetable besides providing consumers healthful product was examined and reported here. The physicochemical characteristics of radish (TSS 6^o B, total sugars 2.04% and ascorbic acid 12.8mg/100g) showed its suitability for lactic acid fermentation. The grated radish was fermented after addition of 2.5% salt at a temperature of 25±1^oC. With the natural microflora, the fermentation was completed in 16-18 days, giving a titratable acidity of 1.80% as lactic acid. It was observed that the fermented radish could be stored up for a period of 15 days under refrigerated conditions without any spoilage. Consequently, study on preservation of fermented radish with permitted preservatives was undertaken. Differences in the amount of different volatiles produced in the lactic acid fermented radish were recorded during storage. Addition of sodium benzoate in combination with sorbic acid prevented degradation of sugars in the fermented radish with production of reduced quantity of methyl propanol. With the addition of sodium benzoate @ 500 ppm lowest total microbial count was recorded, whereas, fungal count was the lowest in radish treated with 500 ppm of sorbic acid. No yeast count was observed in the treatments where 500 ppm of sodium benzoate was added while the titratable acidity was the lowest in the shreds where no preservative was added; correspondingly it had the highest pH. Higher TSS (°B) was retained in the shreds to which sorbic acid+sodium benzoate @ 250ppm was added and thus, had highest titrable acidity. It is concluded that combination of sodium benzoate and sorbic acid @ 250 ppm each was found effective in preventing the spoilage of fermented radish and maintaining its better sensory appeal.