Evaluation of an Analytical Method for Cyanogenic Compounds in Beans and Surveillance of Cyanogenic Compounds in Beans

Abstract

The performance characteristics of an analytical method for cyanogenic compounds were evaluated. Specifically, we tested the trueness, repeatability and intermediate precision of the method using a spectrophotometric-based detection system for 4-pyridinecarboxylic acid and pyrazolone after steam distillation. The pH adjustment of the distillate was revealed to a#ect the trueness of the measurements. A pH of approximately 6 was found to be optimal. The targeted quantitation limit of the cyanide ion was set to 5 mg/kg. The performance of the method was evaluated using beans spiked with cyanide ion at one to two times the quantitation limit (5ῌ10 mg/kg). The trueness of the method was between 78ῌ90̮, and the repeatability and intermediate precision were between RSD 1.2̮ to 6.0̮. A surveillance of cyanogenic compounds in beans retailed in Japan was then carried out. All the results were below the quantitation limit of 5 mg/ kg.

Determination of Cyanide and Cyanoglycosides in Sweetened Bean Paste by HPLC with Fluorescence Detection

“…The free cyanide ion was extracted from samples with 0.01 M NaOH, whereas cyanoglycoside was extracted using 0.1 M citrate buffer (pH 5.9) since the pH 5.9 is the optimum pH for linamarase. 6) We considered to be determined the cyanide derived from only cyanoglycoside in cyanoglycoside analysis in sweetened bean sample because we little detected free cyanide in the sample. When both free cyanide and cyanoglycoside are contained in the sample such as the raw beans, they may be detected as their total amount.…”

“…In the analysis methods for cyanide and cyanoglycosides in the specifications and standards of the Japanese Food Sanitation Act (based on Article 13 of the Food Sanitation Act), it is stipulated that detection of cyanide and cyanoglycosides in beans and bean paste [2][3][4][5][6] as the final food products are not allowed. The official methods include the Japanese official notification test method "hydrogen cyanide test method (agricultural product)" and "cyanide test method in tapioca starch"; [7][8][9][10][11][12] however, there are some drawbacks such as the complexity of operation using steam distillation and time-consuming steps.…”