Changes in 'Mosambi' orange (Citrus sinensis Osbeck) fruit during maturation under a sub-humid tropical climate

Changes in physical, biochemical, physiological, and sensory characteristics of monsoon-blossom crop fruit of 'Mosambi' orange (Citrus sinensis Osbeck) grown under sub-humid tropical climate of Central India were studied during maturation. Rapid increase in fruit diameter, volume, and weight was recorded from 180 to 220 days, however, the growth was slow thereafter up to 250 days. Maximum diameter was 8.42 cm while maximum weight was 253.28 g after 240 and 250 days, respectively. Fruit firmness, peel thickness, and peel and rag percentage decreased while peel colour, TSS (total soluble solid): acid ratio, and juice content increased from 180 to 250 days. Vitamin C content was 56.60 mg 100 mL(-1) after 180 days and decreased to 52 mg 100 mL(-1) as fruit matured. After 240 days, TSS:acid ratio was 16.63 with 12.82% TSS and 0.78% titratable acids. Juice pH increased with fruit maturity. Fruits had acceptable flavour and appearance after 240 days. L* and chroma rose and h(0) declined with maturation and fruit colour turned yellow after 250 days. Chlorophyll ('a', 'b', and total) content dropped and total carotenoides in rind flavedo increased significantly. Reducing and total sugars in juice increased. Total phenols in flavedo increased up to 210 days and then declined. Fructose, glucose, and sucrose increased in juice with fruit maturity and were in the ratio of 1:2:2 at 240 days. Xylose and maltose were present in trace amounts, ribose was not detected. Respiratory rate declined with fruit maturity and ripening confirming non-climacteric nature of 'Mosambi' fruit. Findings indicated that monsoon-blossom crop of 'Mosambi' orange grown under the sub-humid climate of Central India was ripe for harvest after 240 days from fruit set.