Interactive Effects of Chemical Ripening and Moisture Management on Physicochemical Quality of Raja Banana (Musa spp.)

Raja banana (Musa spp.) is a climacteric fruit whose postharvest quality is strongly influenced by ripening-induced physicochemical changes, particularly in sugar and acid metabolism. Effective ripening management is therefore essential to balance fruit quality, shelf life, and market readiness. This study evaluated the effects of calcium carbide and silica gel treatments, combined with storage duration, on the physicochemical quality of Raja banana. Mature-green fruits were subjected to calcium carbide (1 g and 2 g) and silica gel (2 g and 4 g) treatments and stored at ambient temperature for up to six days. Total Dissolved Solids (TDS), relative TDS increase, total titratable acidity, and sugar–acid ratio were analyzed to assess ripening progression. The results showed that all treatments exhibited significant physicochemical changes during storage (p < 0.05), although the magnitude varied substantially. Calcium carbide significantly accelerated ripening, as indicated by higher TDS accumulation; the 2 g treatment reached 26.33 ± 3.78 °Brix, with the highest relative TDS increase (777.7%) and the highest sugar–acid ratio (26.84 ± 7.77) by day 6. In contrast, silica gel treatments delayed ripening, particularly at 4 g, maintaining the lowest final TDS (18.00 ± 1.00 °Brix) and a lower sugar–acid ratio while preserving relatively stable acidity. These findings demonstrate that calcium carbide promotes rapid ripening by accelerating carbohydrate metabolism, whereas silica gel delays physiological maturation by altering the storage microenvironment. This study provides cultivar-specific evidence for Raja banana and offers practical implications for optimizing postharvest ripening strategies according to supply chain requirements.