Entomophagy — An evaluation of quality and acceptability of Raphia palm weevil larvae (<i>Rhynchophorus phoenicis</i>) as influenced by thermal processing methods

Abstract

In this study, the quality and acceptability factor of Raphia palm weevil larvae (Rhynchophorus phoenicis) as influenced by different thermal processing methods were investigated. Raphia palm weevil larvae (n=1000) were randomly distributed into four groups of 250 larvae per group according to a treatment, namely: T1 = boiling (100 °C), T2 = roasting (120 °C) T3 = frying (160 °C) and T4 = oven-drying (180 °C). All treatments lasted 20 minutes. Analyses were carried out to determine the physical, chemical, vitamin and mineral composition, and microbial load. In addition, sensory characteristics were evaluated. Weevil larvae processed by the boiling method had the highest cooking yield (97.59%), water holding capacity (21.78%) and the lowest cooking loss (2.41%). The protein and fat content was higher in weevil larvae processed by frying (37.63% and 17.70%, respectively), while moisture was lowest (18.68%) in oven-dried larvae. The calcium, magnesium and phosphorus content was higher in oven-dried larvae, while there were no significant differences in iron, manganese, zinc and vitamins in the processed larvae irrespective of the methods. Boiled larvae had a higher microbial load, while fried and oven-dried larvae had the lowest microbial load. Fried larvae elicited highest sensory characteristics except tenderness, which was higher in boiled larvae, but fried larvae had higher overall acceptability than those processed by other methods. Therefore, it has been shown that the frying method is an appropriate method of processing Raphia palm weevil larvae for enhanced quality and acceptability.