Food Hygienic Investigation on Japanese Apricot Extract

Benzoic acids of natural origin were found at high concentrations (262.8-635.7ppm) in four samples of Japanese apricot extracts being introduced in the health food market. In view of data from experiments based on the general production method of Japanese apricot extracts, the above benzoic acids were considered to have been derived from amygdalin (a cyanogen glucoside) in the apricot kernel. During the production of Japanese apricot extracts, amygdalin is hydrolyzed even in acidic juice (about pH 3) by β-glucosidase present in the kernel. Amygdalin is transformed to a benzaldehyde when the acidic juice is being obtained by squeezing and filtration. The benzaldehyde is then oxidized to benzoic acid. Cyanic acids were also generated in the hydrolysis, but were easily volatilized and were not present in final juice. All those reactions were completed within the first four hours during processing. The benzaldehyde in the viscid final juice was determined by reverse-phase liquid chromatography after pretreatment. In order to eliminate cyanic and benzoic acids from the final extracts, kernels should not be allowed to remain in contact with the fruit juice during the production process.