Effort to explore the potential use of palmyrah fruit for functional food

Abstract

PurposeThe purposes of this paper are to determine the nutritional composition of the pulp and its antioxidant activity; study the effect of drying and storage on the nutritional composition and antioxidant of the pulp; investigate the effect of de-bittering using fermentative microbes, sodium carbonate and polyethylene glycol (PEG) on antioxidant of the pulp, and to study the shelf-life and sensory evaluation of de-bittered pulp products.Design/methodology/approachThe ripe fruits of palmyra (Borassus flabellifer L) were collected around Kupang city, Indonesia. The pulp was extracted with different techniques. The fresh pulp was directly analyzed for its nutritional and antioxidant properties. The rest of the pulp was de-bittered, dried and used for further treatments and products development. The de-bittered pulp was used to make chips, stick cracker, and jelly sweet. Fresh products were sensory evaluated by 30 semi-trained panelists. For shelf-life analysis, products were wrapped and/or packed with different thickness of food grade plastic, plastic-alumina foil, or mica stopples and kept at different temperatures (30, 40 and 50oC) for one month.FindingsThe fresh pulp contains carotenoids (609.10 mg per kg of pulp), vitamin C (461.40 mg per kg of pulp), polyphenols (270 mg per kg of pulp) and anthocyanin (53.90 mg per kg of pulp). Free radical scavenging activity of the dried pulp (water content of 11.60 percent) was 93.4 percent. Several techniques including fermentation, sodium carbonate, and PEG treatment have been successfully developed to reduce the bitterness of the pulp without significantly reducing its antioxidant activities. Food products (chips, stick cracker, and jelly sweet) have then been developed and have got positive response from panelist.Research limitations/implicationsPulp of fruit is a potential source of antioxidants, i.e. carotenoids (pro vitamin A), vitamin C, and polyphenols. The pulp potentially can be used in fresh and dried form for functional food. The bitterness of the pulp can be significantly reduced using fermentation, sodium carbonate or PEG treatment. The pulp can be utilized for producing chips, crackers, and semi moist food products.Practical implicationsFirst, pulp of the palmyrah fruit can be easily extracted using water. Second, the bitterness of the pulp can be reduced by using traditional fermentation starter. Third, many type of food products can be developed using the palmyrah pulp.Social implicationsThis effort offers opportunity for farmers to optimize the use of palmyrah pulp for functional food. It will provide new jobs and increase the income of farmer at East Nusa Tenggara Province.Originality/valueThe study has revealed that pulp of palmyrah fruit is a source of antioxidants: carotenoids (pro vitamin A), vitamin C, and polyphenols. The pulp potentially can be used in fresh and dried form for functional food. The bitterness of the pulp can be significantly reduced using fermentation, sodium carbonate, and PEG. The pulp can be utilized for producing chips, crackers, and semi moist food products.