A regression model of electron-beam generated X-ray irradiation on postharvest quality of kiwifruit based on electrical properties

Abstract

This study aimed to investigate the effect of the X-ray on the postharvest quality of kiwifruit and to develop a mathematical model based on electrical properties. Xuxiang kiwifruit was irradiated at different doses (0, 0.2 and 0.4 kGy) by electron-beam generated X-ray to determine physiological and biochemical indexes, relative gene expression of enzymes, and 12 electrical parameters of kiwifruit at frequencies from 100 to 3,980,000 Hz. Results revealed that both irradiation groups significantly inhibited the decline in hardness, vitamin C (VC), and titratable acidity (TA) while reducing weight loss and malondialdehyde (MDA) accumulation. The 0.4 kGy irradiation group also maintained higher antioxidant enzyme gene expression and activity, and lower cell wall degrading enzyme gene expression and activity. Correlation and principal component analyses were used to identify eigenfrequencies of 3,980,000 Hz for the control and 0.2 kGy irradiation groups and 2,510,000 Hz for the 0.4 kGy irradiation group. A linear regression mathematical model was established using these eigenfrequencies and the common sensitive electrical parameter, yielding a 72.33 % accuracy rate for determining soft rot in kiwifruit. Overall, this study provides theoretical and technical support for the use of X-ray irradiation in kiwifruit preservation, storage, and future quality testing of fruits.