Primary and Secondary Metabolite Changes of Kinnow Mandarin Fruits During Different Stages of Maturity

The study conducted during 1999 and 2000 revealed that the total soluble solids (TSS), °Brix, acid ratio, sugars and ascorbic acid contents of fruit juice increased while acidity decreased with advancement of fruit maturation. Non-reducing sugars content was higher than reducing sugars; total phenols and pectin content in peel tissue decreased and increased in juice tissue. The secondary metabolites viz, hesperidin and naringin content did not show definite pattern of changes till fruits matured. However, juice tissue accumulated higher amount of hesperidin in mature fruits than in green fruits. The trend was reverse in case of naringin content. Reduced protein synthesis due to their increased utilization was observed during advancement of fruit maturation. The flavedo oil content followed the decreasing trend throughout the investigation period. The oil quantitative variation in 2 years of sampling was influenced by the variation in climatic factors in fruits attached to the plants. Thus, it can be concluded that the primary and secondary metabolite changes in kinnow fruit at different maturity stages could be exploited further for physiological advancement and industrial purposes.