The effect of salt concentration and fermentation time on pH value, total acidity and microbial characteristic of pickled ginger (Zingiber officinale Rosc.)

Abstract

Spontaneous fermentation of ginger are very popular in China and Japan and the product are known as pickled ginger, in Indonesia its popularity is still limited in certain society, but more increasing with the present of more japanese cuisine restaurants especially in metropolitan cities. Hence a study on the effect of salt concentration and fermentation time on pH value, total acidity number and microbial characteristic of pickled ginger (Zingiber officinale Rosc.) was conducted. Completely Randomized Design was used in this study with two factors namely salt (NaCl) concentrations (2.5, 5.0 and 7.5 % w/w) and fermentation time : 5 and 10 days, and this experiment was replicated three times, while the parameters observed were pH value, total acidity , Lactic Acid Bacteria total counts and characterisation and identification of lactic acid bacteria of selected pickled ginger sample using index de Garmo was carried out by 16SrRNA gene sequencing analysis. The selected sample was the one prepared using 2.5% w/w salt and 5 days fermentation at 26o

C with pH value of 3.40, total acidity 0.92% and lactic Acid

bacteria total counts of 7.56 x 106

CFU/ml. Based on 16S rRNA gene sequencing analysis and similarity by Neighbor Joining (NJ) method with phylogenic tree construction, the lactic acid bacteria of selected pickled ginger identified were Lactobacillus plantarum strain BM4 and Lactobacillus plantarum LOCK 0991 with similarity of 86% .