The effect of rice and edible starch compound ratios, starch type, and rice nutrients on Burkholderia gladioli pathovar cocovenenans growth and bongkrekic acid production in wet rice noodles and starch products.

Abstract

Bongkrekic acid (BA) toxin, produced by Burkholderia gladioli pathovar cocovenenans bacteria, has been implicated in foodborne illness outbreaks. BA poisoning is associated with rice noodle consumption; hence, this study investigated B. cocovenenans growth and BA production in wet rice noodles comprising varying starch ratios, starch types, rice nutrients, and saccharides. Noodles with 100% rice flour had BA concentrations 47.7 times higher than that of 100% starch samples (30.53 ± 1.08 mg∙kg-1 vs 0.65 ± 0.03 mg∙kg-1). Moreover, protein powder and glucose significantly promoted BA production (P < 0.05). Corn starch with 120 μl∙100 ml-1 rice oil had a BA concentration of 0.23 ± 0.01 mg∙kg-1, which was 31% lower than those without rice oil. Acid-treated starch had a BA concentration 7.24 times higher than that of other natural starch and no BA was detected in acetate starch. Of the carbohydrates tested, only hexacarbon sugars stimulated BA production. Overall, the degree of carbohydrate hydrolysis critically influenced BA formation. Increasing the use of edible starch and reducing the amount of polysaccharides hydrolyzed into monosaccharides during production will mitigate the risk of B. cocovenenans-related food poisoning in rice noodles and starch products. Rice oil serves as a possible additive to hinder BA production.