Abstract

Post-harvest microbial infection is a major constraint to the nutritional quality and marketability of indigenous tropical fruits. This study evaluated the proximate composition of Maesobotrya barteri (bush berry) fruits infected by Fusarium equiseti, Penicillium vickeryae and Bacillus pumilus relative to uninfected controls harvested from Oduoha-Emohua Forest, Rivers State, Nigeria. Fruits were surface-sterilised, incubated to allow expression of spoilage symptoms, and analysed for moisture, ash, crude protein, crude lipid, crude fibre and carbohydrate using Standard Official Methods of Analysis procedures. Significant differences (p < 0.05) were observed across all parameters. Uninfected control fruits retained the highest crude protein (34.98 ± 0.01%) and crude lipid (16.81 ± 0.02%), while infected fruits showed marked reductions protein 23.69–29.23%; lipid 9.23–13.52%. Carbohydrate content increased proportionally in infected samples with P. vickeryae up to 42.69 ± 0.04% and crude fibre was highest under F. equiseti infection (12.50 ± 0.02%). Moisture content declined sharply in F. equiseti-infected fruits (8.60 ± 0.02%). These changes reflect pathogen-driven enzymatic degradation of macromolecules and consequent shifts in the relative contribution of proximate fractions. The results demonstrate that microbial colonisation substantially impairs the nutritional value of M. barteri fruits and underscore the need for improved post-harvest handling to preserve this under-utilised indigenous resource.