[Development of Analytical Method and Surveillance ofGibberellic Acid in Banana, Cherry, and Kiwi Fruit]

Gibberellic acid (GA₃) is commonly used as a plant growth regulator in many food crops owing to its essential signaling functions during plant growth and development. In Japan, a threshold for administrative action for GA₃ content of 0.3 mg/kg applies in produce in which maximum residue limits have not been established. Although the threshold is based on previous studies, the GA₃ concentrations in individual foods are still unknown. Thus, we surveyed the concentrations of GA₃ in banana, cherry, and kiwi fruit on the Japanese market. We developed and validated a method for the analysis of GA₃ using solid-phase extraction and LC-MS/MS in accordance with accepted criteria of trueness, repeatability, and selectivity. The limits of detection and of quantification were determined as 0.005 and 0.05 mg/kg, respectively, in all fruits. Concentrations of GA₃ did not exceed 0.3 mg/kg regardless of ripeness, suggesting the reasonability of the current regulation of GA₃ in banana, cherry, and kiwi fruit. These findings can support prompt administrative action on these fruits, contributing to the regulation of GA₃ in Japan.