Effect of chemical factors and clove oil to decrease the growth of film yeast on fermented bamboo shoots

This research examined the effect of chemical factors (pH, sodium chloride, sugars (glucose and sucrose), preservatives (benzoic acid and sorbic acid)) and clove oil to decrease the growth of film yeasts (Saccharomyces cerevisiae J1, Candida krusei J2 and Candida krusei J3) on fermented bamboo shoots. All yeasts grew at pH 3.0-7.0 and did not grow greater than 7.5%(w/v) of sodium chloride concentration. The ability to grow in the presence of sodium chloride decreased at low pH. Both Candida krusei strains were more tolerant to sodium chloride concentration than S. cerevisiae J1. All strains grew well in the presence of 7.5%(w/v) sodium chloride at pH 4.0-7.0, whereas, Saccharomyces cerevisiae was only tolerant to 7.5%(w/v) sodium chloride at pH 6.0. All yeasts grew well at 60-70%(w/v) sugar concentration at pH 3.07.0. The effect of benzoic and sorbic acids found that all yeasts were tolerant at 1000 mg/l and pH range 6.0-7.0. No strains grew in the presence of preservatives at pH 2.0-4.0. Clove oil (Syzygium aromaticum L.) inhibited completely all yeast film strains at 2%(v/v). However, clove oil treatment reduced the organoleptic properties of fermented bamboo shoots with their strong flavour.