Postharvest ripening of noni fruit (Morinda citrifolia) and the microbial and chemical properties of its fermented juice.
The physiology of noni (Morinda citrifolia) fruit ripening, as well as the chemical and microbial properties of its fermented juice, were determined. The ripening fruit had a nonclimacteric respiratory pattern (34 mg CO2.kg-1h-1) and no detectable ethylene production. The fungus, Mucor circinelloides, was consistently isolated from fermented juice, with peak populations at 14 d coincident with an increase in headspace CO2 and a decline in pH and soluble solids. Bacterial populations were greatest at 42 d, with Erwinia pyrifoliae and Gluconobacter frateurii isolated from fermented juice. Sugar concentration (64.8 mg.mL-1) decreased by 37% after 7 d, while organic acids (26.6 mg.mL-1) were the highest at 28 d. Major non-volatile acids present in the fermented juice included acetic, ascorbic, dehydroascorbic, galacturonic, malonic, succinic, and tartaric acids.