Abstract:A detection method that combined hyperspectral imaging and multiple optimization strategies was proposed to effectively detect early decay of oranges, addressing the issue of low detection accuracy in traditional methods. Traditional detection approaches, such as visual inspection and manual sorting, were highly subjective and fail to identify subtle changes in early decayed oranges, leading to substantial post-harvest losses in the citrus industry. To solve this problem, the hyperspectral data in the 450 ~ 1 050 nm wavelength range were collected by using a professional hyperspectral imaging system, covering the visible and near-infrared regions closely related to fruit internal quality. Then, enhanced data were synthesized by the Borderline-SMOTE algorithm with Kullback-Leibler (KL) divergence of 0. 02 and Wasserstein distance of 3. 4, which effectively alleviated the sample imbalance problem between healthy and early decayed oranges. Subsequently, totally 24 key characteristic wavelengths were screened out by the ReliefF algorithm to eliminate redundant information and reduce computational complexity. Machine learning based classification models and CNN model were constructed in combination with Bayesian optimization, which optimized key hyper parameters to improve model performance. A systematic evaluation was carried out on their classification performance and computational efficiency. After Bayesian optimization and feature selection, the classification error of the CNN model was reduced to 0. 008. The running time was significantly decreased from 910. 4 s to 177. 9 s, representing a reduction of 80. 5% . The accuracy rate on the test set reached 99. 0% . The research result can not only provide a reliable technical solution for early decay detection of oranges, but also lay a theoretical foundation for the development of rapid and intelligent detection equipment, which was of great significance for promoting the high-quality development of the citrus industry.