LIGNOCELLULOSE MODIFICATION AND NUTRITIONAL ENRICHMENT OF PALM OIL FRONDS: A STUDY ON OPTIMIZED PRETREATMENT AND MICROBIAL FERMENTATION FOR RUMINANT FEED

Abstract

Palm oil fronds are a plantation waste with potential as ruminant feed, but their high lignocellulose content limits widespread use. This study aimed to improve the nutritional quality of palm oil fronds through pretreatment and fermentation, including their amino acid and fatty acid profiles. Three pretreatment methods (steaming, pressure cooking, and eco-enzyme) were combined with fermentation using Bacillus subtilis, Lactobacillus acidophilus, Aspergillus niger, and Saccharomyces cerevisiae. Fiber fractions, proximate composition, and amino and fatty acid profiles were analyzed using ANOVA and Duncan's Multiple Range Test. Pretreatment reduced lignin content by up to 52.07±2.58% (30-minute steaming with 100% eco-enzyme) relative to the untreated control (17.76±0.306%), with longer treatment durations giving greater lignin degradation. Fermentation raised crude protein from 4.99% to 16.50% in the T2M2 treatment (pretreatment with A. niger + L. acidophilus), which also had the most favorable amino acid profile. The T2M1 treatment (pretreatment with B. subtilis + L. acidophilus) showed the lowest fiber fraction content and the greatest improvement in fatty acid profile. Because both treatments combined pretreatment and fermentation, the improvements reflect their combined effect rather than the microbial consortium alone. These findings suggest that pretreated and fermented palm oil fronds have potential as a ruminant feed ingredient based on their improved chemical and nutritional profile. However, as the study was limited to laboratory analyses, in vivo feeding trials are needed to validate feed intake, growth performance, and productive efficiency.