Nondestructive quality detection of characteristic fruits is essential for ensuring nutritional value, economic viability, and consumer safety in global supply chains, yet traditional destructive methods compromise sample integrity and scalability. Visible and near-infrared (Vis/NIR) spectroscopy offers a transformative solution by enabling rapid, non-invasive multi-attribute quantification through molecular overtone vibrations. This review examines recent advancements in Vis/NIR-based fruit quality detection, encompassing fundamental principles, system configurations, and detection strategies calibrated to fruit biophysical properties. Firstly, optical mechanisms and system architectures (portable, online, vehicle-mounted) are compared, emphasizing their compatibility with fruit structural complexity. Then, critical challenges arising from fruit-specific characteristics—such as rind thickness, pit interference, and spatial heterogeneity—are analyzed, highlighting their impact on spectral accuracy. Applications across diverse fruit categories (pitted, thin-rinded, and thick-rinded) are systematically reviewed, with case studies demonstrating the robust prediction of key quality indices. Subsequently, considerations in model development and validation are presented. Finally, persistent limitations in model transferability and environmental adaptability are discussed, proposing future research directions centered on integrating hyperspectral imaging, AI-driven calibration transfer, standardized spectral databases, and miniaturized, field-deployable sensors. Collectively, these methodological breakthroughs will pave the way for autonomous, next-generation quality assessment platforms, revolutionizing postharvest management for characteristic fruits.

Light influences fruit development and quality through two primary pathways: its effect on vegetative organs, which subsequently impacts the fruit, and its direct effect on the fruit itself. While the mechanism of the former pathway is well-documented, the direct impact of light on fruit has been less studied due to limitations in applying controlled light exposure to preharvest fruit. This study addresses this gap by developing a novel device that delivers fruit-specific light treatment, enabling precise light exposure without altering the light conditions of vegetative tissues. The integration of metabolomics and transcriptomics reveals that light can directly affect the growth and development of fruits and the formation of quality, independent of the vegetative organs. Our findings reveal distinct regulatory patterns for primary and secondary metabolites during maturation. Direct light exposure activates primary metabolites and photosynthetic gene expression, though this effect diminishes as the fruit matures. Conversely, light enhances secondary metabolites, such as flavonoids, and their associated gene expressions, maintaining consistent activation throughout development and leading to higher accumulation during maturation. This study provides the first transcriptomic and metabolomic characterization of grape berries exposed to fruit-specific light treatment, advancing our understanding of light-dependent fruit development and quality formation mechanisms.