• Low-cost RGB imaging supports non-destructive beef quality monitoring. • Reconstructed spectra effectively capture carbonyl and sulfhydryl features. • Quantitative monitoring of sulfhydryl loss in beef under freeze–thaw stress. • MST and MST++ preserve spatial and spectral details. Protein oxidation is a critical factor affecting meat quality during cold-chain storage, particularly under repeated freeze–thaw cycles. Carbonyl formation and sulfhydryl loss are widely recognized indicators of protein structural damage and functional deterioration. In this study, a low-cost RGB-based hyperspectral reconstruction and prediction framework (ReSpec-RGB) is proposed to enable non-destructive monitoring of protein oxidation without reliance on expensive hyperspectral instrumentation. The results demonstrate that reconstructed spectra in the visible–near infrared range reliably capture continuous carbonyl accumulation and progressive sulfhydryl loss during freeze–thaw cycles, accurately reflecting oxidative dynamics in beef. Accelerated oxidation under repeated freeze–thaw conditions is primarily attributed to ice crystal–induced muscle fiber disruption, leakage of intracellular components, and sustained reactive oxygen species activity. Quantitative prediction models developed using reconstructed spectra exhibit stable and accurate performance, showing strong consistency with models established from original hyperspectral data. This ReSpec-RGB framework substantially reduces data acquisition costs while preserving key spectral information related to protein oxidation, providing a practical, non-destructive, and scalable solution for protein oxidation monitoring in beef, with strong potential for rapid quality evaluation and risk management in meat cold-chain systems.
Cui et al. (Sun,) studied this question.