Proximate and microbial quality of processed grubs of African palm weevil (<i>Rhynchophorus phoenicis</i> F., Coleoptera: Curculionidae) sold at Toru-Orua, Bayelsa State, Southern Nigeria

Abstract

The African palm weevil, Rhynchophorus phoenicis F. (Coleoptera: Curculionidae) constitutes a significant component in diets of the Niger Delta of Nigeria. This study aimed to determine the proximate composition and microbiological quality of processed grubs (steamed, dried, fried and fresh which served as control) purchased from food vendors in Toru-Orua community. Proximate composition determinations followed official methods recommended by the Association of Official and Analytical Chemicals (AOAC), while microbial load was determined by total plate count. Steamed grubs had the highest moisture content of 15% while fresh had the least moisture content of 9.3%. Steamed grubs had the highest ash content of 11.47% while fresh had the least ash content of 4.73%. Fresh grubs had the highest crude protein of 41.75% while fresh had the least crude protein of 30.13%. Steamed grubs had the highest crude fibre content of 18.07% while fresh had the least crude fibre of 13.7%. Steamed and fried grubs had the highest crude fat content of 10.93% while fresh had the least crude fat content of 2.8%. Steamed grubs had the highest moisture content of 28.35% while dried grubs had the least moisture content of 20.66%. The total heterotrophic bacteria count ranged from 8.5 x 10² CFU/g – 3.7 x 10⁶ CFU/g. Fungal count ranged from 2.2 x 10² - 3.4 x 10³ CFU/g. The microbial investigations showed Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the common microorganisms on the grubs. Frequent microbiological quality checks on such ready-to-eat foods, along with public enlightenment campaigns for food vendors is recommended, to guarantee food safety for consumers during processing/handling, storage and consumption.