Journal of Pure and Applied MicrobiologyVol. 9 No. Special Edition Nov. 2015

Microbial Population and Degradation on Rice Granules during Fermentation of Bedak sejuk

Mohd Alif Afife Dzulfakar*, Noorhisham Tan Kofli and Siti Masrinda Tasirin

Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia.

Received on 14 September 2015 and accepted on 15 November 2015

 

ABSTRACT

Bedak sejuk is a traditional fermented rice based cosmetic used by women in Malaysia. To date, the production of both homemade and commercial bedak sejuk depends on natural fermentation without using starter cultures. Here, we monitored the microbial population and evaluate the degradation of rice starch in the initial batch fermentation of bedak sejuk. Bedak sejuk sample was prepared by natural fermentation of local rice grains (5% broken). The microbial population changes and degradation of rice starch were analysed for two weeks. Within two weeks, the total microbial, anaerobic bacteria, yeast and mould count increased while coliforms count decreased. The total microbial, anaerobic bacteria, yeast, mould and coliform counts were 11.44?0.54, 6.14?0.27, 2.78?0.22, 1.31?0.19 and 1.24?0.13 log CFU/mL, respectively. The liquefaction activity of a-amylase was higher on the second day (42.3?0.6 ?g/min/g) but after that it declined. Total carbohydrate decreased from 80.8 to 80.1 % while reducing sugar of the rice granules and in fermented supernatant increased from 0.02 to 0.15 % and 0.03 to 0.92 g/L, respectively. While the degree of hydrolysis shows an increase but the increment was low. From the scanning electron microscope pictures, the rice grains still retained their whole figures but the fermented starch lost their surface smoothness. Taken together, our results suggest that the changes of microbial population affected the rice starch during the natural fermentation.

Keywords : Lactic acid bacteria (LAB), Yeast, Natural Fermentation, Rice Starch, Bedak sejuk.