A Novel Hyperspectral Microscope Imaging Technology for the Evaluation of Physicochemical Properties and Heterogeneity in 'Xia Hui 6' Peaches.

Hyperspectral microscope imaging (HMI) was employed to evaluate the physiochemical properties of and the large intra-variability in individual fruit of 'Xia Hui 6' peaches during storage, which gave insights into the heterogeneity of peach fruits at the microscale. The physicochemical characteristics such as firmness (FI), soluble sugar content (SSC), and * value of peaches showed significant changes, while the microstructure of the tissues broke down. Principal component analysis (PCA) was applied to peach tissues from the sunny side and shady side at different storage stages, which allowed us to clearly visualize the distribution of sugars, water, and pigments at the cellular scale. Single-feature variables were constructed to clarify the correlation between the characteristic bands and physicochemical parameters based on Pearson correlation analysis, with an R of 0.99 for firmness at 588 nm, 0.98 for titratable acidity (TA) at 432 nm, 0.88 for the * value at 430 nm and 0.83 for the * value at 426 nm. This work demonstrated that HMI technology as an accurate and highly effective tool in evaluating the quality of 'Xia Hui 6' peaches and targeting, allowing us to visualize the spatial heterogeneity within peach fruit tissues.