Characteristics and oleocellosis sensitivity of citrus fruits

The effects of variety, growth phase, and water loss on development of oleocellosis, and relationships between chromatism and Vis/NIR spectra were studied in ‘EarlyGold’ sweet orange (Citrus sinensis Osbeck), ‘Fukumoto’ navel (Citrus sinensis Osbeck), and ‘Cara Cara’ navel (Citrus sinensis Osbeck) oranges. The varieties showed significant differences in the rate (RO) and degree (DO) of oleocellosis development. The sensitivity of varieties (from most to least sensitive) was ‘EarlyGold’ > ‘Fukumoto’ > ‘Cara Cara.’ Growth phase and water loss had a significant influence on fruit sensitivity to oleocellosis. The order of sensitivity to oleocellosis was dependent on harvest time (i.e., at normal period > at delayed period > at uncolored period), and RO and DO decreased significantly with water loss. The RO and DO models for fruit water loss were established as y = 0.75 − 3.94x − 271.33x2 (R2 = 0.77) and y = 1.70 − 7.29x − 1025.83x2 (R2 = 0.583). The sensitivity of ‘EarlyGold’ to oleocellosis was significantly correlated with dL and dC of fruit chromatism. At the same time, there were significant differences at 480–575 nm, 650–720 nm, and 925–965 nm between varieties with low and high sensitivity to oleocellosis, and ‘EarlyGolds’ with a low RO and DO had a higher reflectance than those with a high RO and DO.