식품 중의 엽산함량 측정을 위한 Trienzyme 처리 방법

Trienzyme Treatment for Folate Determination in Foods

Food folate assay after trienzyme treatment (a-amylase, protease, folate conjugase) has been reported to be more effective than the assay after conjugase treatment alone. We evaluated the conditions of pH and incubation time for the treatment with trienzyme, and compared folate contents in selected Korean foods by applying two extraction methods (trienzyme treatment vs. conjugase treatment alone). Folate contents were measured by a microbiological method using L. easel after one of the extraction procedures. Optimal pHs for trienzyme treatment of black bean were found to be 5.0 and then 7.0. while those for Korean cabbage was 7.0. Therefore, a pH of 7.0 was selected for the buffer during trienzyme treatment. Since samples treated with low concentrations of a-amylase and protease for 16 hours yielded lower values than those with high concentrations of enzymes for 4 hours, the incubation with high concentrations for short period was chosen. The recovery of folate after trienzyme treatment was 96.4%, and the coefficient of variation between days in the microbiological assay was 9.0%. Folate values after trienzyme treatment were higher in most foods except Korean cabbage, beef and milk than those after conjugase treatment alone. In addition, folate values obtained in this study were generally higher than the database published in 2000. Therefore it is necessary to determine folate in Korean foods using the trienzyme treatment we suggested here as well as conjugase treatment alone in order to estimate folate intake of Koreans more accurately.