Antioxidant Capacity and Total Phenolic Content Variations against Morinda citrifolia L. Fruit Juice Production Methods

Variations of antioxidant capacity (AC) and total phenolic content (TPC) of noni juice (Morinda citrifolia L) under different production methods and production time were studied. AC and TPC of noni juice were determined by DPPH (2-diphenyl-1-picrylhydrazyl) scavenging activity, and Folin-Ciocalteu reagent assay respectively. Traditional fermentation method resulted maximum AC (83.84% of DPPH scavenging activity) and maximum TPC (2698.89 mg gallic acid equivalent/L of noni juice) within two weeks of fermentation. Fresh juice had AC (77.06% of DPPH scavenging activity) and TPC (2898.89 mg gallic acid equivalent/L of noni juice). When fermenting the extracted fresh juice, AC (29% loss) and TPC (95% loss) were drastically reduced within one month of fermentation. Both traditional fermentation and fresh juice extraction had satisfactory levels of AC & TPC but allowing fresh noni juice for fermentation is not recommended.