Processing Quality of Noni Juice (Morinda Citrifolia)
Tropical Crop and Commodity Protection Research
2011 Annual Report
1a.Objectives (from AD-416)
1. Quantify the compositional and microbial changes of noni juice during the fermentation period.
2. Develop a standard method for processing fermented noni juice.
1b.Approach (from AD-416)
Physiologically mature, ripe noni fruit will be harvested from commercial orchards on the island of Hawaii. Fruit will be washed and placed into sterilized glass jars with sealed lids and allowed to age for 10-14 days at 25°C. A second batch will be aged for up to 30 days. Juice will be pasteurized at 85°C in a water bath, cooled, and frozen. Subsamples of juice will be collected throughout the fermentation process to conduct compositional and microbial analyses. Prominent yeast, bacteria, and fungi will be isolated and identified using standard microbiological techniques. Ascorbic acid, malic acid, lactic acid, and sugar concentrations will be analyzed using high performance liquid chromatography (HPLC). Total antioxidant activity will be determined using a photochemical luminescence method. Collaborators at the University of Hawaii, College of Pharmacy will test samples of noni juice for bioactivity and toxicity in various cell culture assays.
Research was conducted to determine the physiology of noni fruit ripening, as well as the chemical and microbial changes that occur during noni fermentation. Ripening noni fruit had a non-climacteric respiratory pattern with an average rate of 34 mg CO2/kg/hr and no detectable ethylene production. Chemical and microbial profiles differed for fresh and fermented juice. Bacterial populations remained low from 0 to 35 days of fermentation. However the fungus, Mucor circinelloides f. circinelloides was consistently isolated from noni juice produced from fruit collected in arid and high-rainfall districts of Hawaii island. M. circinelloides was confirmed as a wound pathogen of noni fruit for the first time. Mucor populations peaked after 14 days of fermentation, coincident with an increase in head space CO2 to 25% and a decline in pH and total soluble solids. These changes preceded the highest juice yield at 21 days. Large volumes of noni juice were partitioned into aqueous, n-butanol, and ethyl acetate fractions to assess antitumor activity in animal studies conducted by collaborators. The results confirmed an earlier report that fermented noni juice has antitumor activity, and also demonstrated that the n-butanol fraction contained the active components. The lead scientist monitors progress through regular meetings with cooperators, and through direct supervision of the research project and participation in research activities.