SCREENING FOR GMO IN FERMENTED SOY SAUCE

Abstract

Soy sauce is worldwide popular condiment of Asian origin. With the advent of GM soybean production, soy sauce drew the interest of food safety control. Samples collected for inspection are generally of industrial grade soy sauce type, which is produced from hydrolyzed soybean and grain. Following the failure to perform RealTime PCR based GMO screening on a number of submitted samples we tested our screening system on soy sauce produced following traditional method based on fermentation. Four batches of soy sauce were produced and DNA extracted. DNA concentration ranged from 32,68 to 65,36 ng/μl. Amplification of taxon specific target was successful with rather high Ct ( > 30). Promoter P-35S sequence was not detected, but T-NOS was detected in three samples with values reaching or exceeding LOD of the method. The results show that it is possible to detect transgenic elements in traditionally produced soy sauce while DNA extraction from industrial grade soy sauce is not possible.