Assessment of commercial maturity in small berries with special emphasis on haskap ( Lonicera caerulea L.)

Timing and management after harvest are optimized when the maturity stage is known. This paper provides an in-depth review of common destructive and nondestructive methods used for evaluating berry maturity. Destructive methods such as total soluble solids (TSS), acidity, firmness, phenolic compounds, amino acids, aromatic compounds, sensory characteristics, and molecular profiling offer precise measurements. Nonetheless, these methods require sample preparation, which damages the fruit and is often impractical for large-scale monitoring. Conversely, we explore advanced nondestructive methods such as near-infrared spectroscopy (NIRS), hyperspectral imaging (HSI), red-green-blue (RGB) color imaging, and multispectral imaging (MSI), which enable rapid evaluation without compromising fruit integrity. Most of these methods are investigated in strawberries, raspberries, blueberries, gooseberries, and blackberries. However, emerging haskap berries remain unexplored despite their growing commercial importance, for which an overview and current maturity indicators have been discussed to enhance their assessment efficiency.