Preparation and evaluation of food grade copra

Abstract

Copra (dried coconut meat) meal after oil extraction is not used for human food because of microbial contamination during drying and storage. The objective of this research is to investigate the possibility of producing food grade copra by dipping coconut meat in an antimicrobial solution of propionic acid before drying. Coconut meat appeared spoiled when total plate count was 10 ⁷/g . High moisture content at the inner surface of coconut meat made it more susceptible to contamination. Effective propionic concentration and dipping time of antimicrobial treatment and drying were studied. Six percent propionic acid and one minute dipping time was sufficient for protecting during drying. Maximum permissible time delay before treating was 12 hours after shelling. About 99% of the microorganisms were destroyed by the propionic acid treatment. Treated coconut meat could be dried successfully indoors, inside a Lent, and outdoors. General standards for food grade copra were established in terms of chemical properties, oil, free fatty acid and moisture; color; and microbiological properties. Storage experiment at 20-60% relative humidity and 10-30°C for 26 weeks showed that untreated copra could be kept safely at initial moisture contents up to 6.8%. Treated copras could be kept at higher initial moisture up to 16%..