Nutritive Evaluation of Pineapple Peel Fermented by Cellulolytic Microbe and Lactic Acid Bacteria by In Vitro Gas Production Technique

ABSTRACT: The research was conducted to evaluate the nutritive value of pineapple peel fermented by rumen cellulolytic microbes and followed by addition of lactic acid bacteria (LAB) at the 4th, 8th, 12nd and 16th days of fermentation. Cellulolytic microbes was added as much as 5% of dry matter (DM) into 300 g of pineapple peel with three replicates for each treatment. Fermentation without addition of cellulolytic microbes and LAB was carried out as control . Fermentation was done up to 21 d and the sample of fermented pineapple peel were taken out for physical quality measurements including odor, color, the presence of fungi, as well as the lactic acid content. The sample was dried at 55°C, and then prepared for chemical composition analysis including dry matter (DM), organic matter (OM), crude fibre (CF), crude protein (CP), extract ether (EE) and nitrogen free extract (NFE). The samples were also prepared for evaluation of kinetic fermentation by in vitro gas production technique proposed by Menke and Steingass. The data obtained were analyzed by analysis of variance using one way design and continued by Duncan’s new multiple range test to examine the differences among the mean values. The result showed that pineapple peel fermented by cellulolytic microbes with addition of LAB in all treatment as well as the control had brown colour, and without fungus. The more acidic odor were found in fermented pineapple added with cellulolytic microbes and LAB, due to lactic acid content which increased significantly. Cellulolytic microbes and LAB addition didn’t affect DM and OM content, while the content of CF tended to decrease. The treatments increased NFE as well as CP content, and decreased EE content significantly. Gas production, and the values of a, b, c fractions were not affected by addition of cellulolytic microbes and LAB. It could be concluded that lactic acid bacteria which was added after 12 days of cellulolytic fermentation) gave the best nutritive quality of fermented pineapple peel. Keywords: Pineapple peel, Cellulolytic microbes, Lactic acid bacteria, Fermentation, In vitro gas production