PENURUNAN KADAR AFLATOKSIN B1 PADA SARI KEDELAI OLEH SEL HIDUP DAN SEL MATI Lactobacillus acidophilus SNP-2 [Reduction of Aflatoxin B1 in Soymilk by Viable and Heat-killed Lactobacillus acidophilus SNP-2]

Abstract

Aflatoxins are carcinogenic mycotoxins that commonly contaminate foods and feed. There are many different forms of aflatoxin and its metabolites. Of these, aflatoxin B₁ (AFB₁) is the most prevalent and toxic. Lactobacillus acidophilus SNP-2 has previously been shown to remove AFB₁ from liquid solution of phosphate saline buffer. However, the ability of lactic acid bacteria to reduce AFB₁ content in soymilk has not been studied yet. The objective of this study was to investigate the ability of viable and heat-killed cells of L. acidophilus SNP-2 to reduce AFB₁ in soymilk and fermented soymilk. Soymilk contaminated with Aspergillus flavus was inoculated with culture of L. acidophilus SNP-2, and incubated at 37°C for 12 hours. Fermented soymilk, then, was heat sterilized and stored at cool room (4°C). Heat-killed cells were introduced to soy milk and then kept at cool room for 3 days. During soymilk fermentation, there was reduction of AFB₁ content in soymilk related to the growth of lactic acid bacteria and the reduction of pH. The initial concentration of AFB₁ in the soymilk was 4.9 ppb. Lactobacillus acidophilus SNP-2 reduced 67.58% of AFB₁ in the soymilk after 12 hoursof fermentation. In cool environment, the binding of AFB₁ to heat-killed cell after soymilk fermentation was relatively more stable than that of soymilk without fermentation.