Abstract: The effects of hot water treatment and/or β-aminobutyric acid (BABA) treatment on the incidence of blue mold rot disease in postharvest apple fruits were studied. Combined hot water and BABA treatment conditions were also optimized by orthogonal array design. The results showed that hot water and BABA treatment alone could effectively reduce lesion diameter of apple inoculated with Penicillium expansum. The lesion diameters of apple fruits treated with 45 ℃ hot water alone for 8 min and with 50 mmol/L BABA alone for 5 min were 82.86% and 80.76%, respectively, when compared with the control. In addition, the combined order of hot water and BABA had no significant effect on disease control; however, the interval time had an obvious effect on disease control. The optimal conditions for combined hot water and BABA treatment were hot water treatment at 45 ℃ for 6 min and then 50 mmol/L BABA treatment for 5 min with an interval of 10 min. Validation experiments also indicated that combined treatment with hot water and BABA can effectively shorten duration time of heat treatment and significantly improve disease control capability for blue mold rot in postharvest apple fruits.

Key words: apples, blue mold, heat treatment, β-aminobutyric acid