Nutrient composition, mineral content and the solubility of the proteins of palm weevil, Rhynchophorus phoenicis f. (Coleoptera: Curculionidae)

Abstract

Adult (ADS) and larva stages of palm weevil Rhynchophorus phoenicis were analyzed for their nutritional potentials using proximate and mineral contents as indices. The early larva stage (ELS) contains the highest moisture content of 11.94% while ADS has the least value of 4.79%. The late larva stage (LLS) has the highest protein content of 10.51% while ADS contains 8.43%. Ash content is highest in ELS with a value of 2.37% and lowest in ADS with a value of 1.43%. ELS and LLS have the highest (22.14%) and lowest (17.22%) fibre contents respectively. The values of potassium, magnesium and iron in ELS were (455.00+/-21.21), (60.69+/-2.57) and (6.50+/-3.40) mg/kg while LLS recorded (457.50+/-10.61), (43.52+/-1.37) and (6.00+/-1.10) mg/kg and ADS recorded (372.50+/-24.75), (53.31+/-1.88) and (22.90+/-3.70) mg/kg. Chromium, phosphorus, nickel, calcium, lead, manganese and zinc were also detected. Copper was not detected in any of the samples. In all the developmental stages the protein solubilities were pH dependent with the minimum protein solubilities occurring at acidic pH while the maximum protein solubilities occurred at alkaline pH.