Abstract

Traditional fermentation of noni (Morinda citrifolia) juice is a spontaneous process driven by indigenous microflora. This study is aimed at examining the proximate composition and sensory qualities of naturally fermented noni juice. Fully ripened fruits (300g) from Dilomat Farm, Rivers State University, were processed: for Day 0, 30 g were ground, and the juice was carefully strained through sterile muslin cloth to obtain fresh extract; 270 g was fermented in a sterile airtight container at 25–30 °C for 63 days. Samples collected on Days 14, 35, and 63 were first filtered through a sterile muslin cloth for proximate analysis. The remaining samples were then thermally treated at 90 °C for 60 seconds prior to sensory evaluation. Fermentation significantly increased crude protein (6.31 → 8.05 %), crude fibre (2.22 → 2.51 %), ash (2.06 → 2.27 %), and moisture (63.30 → 66.82 %), while carbohydrate content decreased (18.01 → 11.93 %), reflecting microbial utilization of fermentable substrates. Sensory evaluation using a nine-point hedonic scale showed a decline in all attributes at Day 14 relative to the control, followed by peak acceptability at Day 35 (appearance 7.6±0.9, aroma 7.7±0.5, taste 7.8±0.8, texture of mouth feel 7.6±0.7, overall acceptability 7.5±0.9), with scores remaining favourable through Day 63. Extended natural fermentation improved the nutritional and sensory quality of noni juice, offering baseline data for commercial Nigerian noni juice development.Further optimization of fermentation conditions is recommended to enhance the proximate and sensory quality of noni juice for potential commercial applications.