Effects of NaCl and pH on the functional properties of edible crickets (Acheta domesticus) protein concentrate

Abstract

For a long time whole edible insects have been consumed in developing countries as part of food. With the aim of promoting food and nutrition security there is a focus on the industrial value addition of edible insects. The industrial utilization is hampered by limited information regarding the functionality of cricket proteins in food matrixes. Therefore this study aims at determining the NaCl and pH at which the functional properties of edible crickets protein concentrates is optimum. Reared edible crickets were acquired from JKUAT farm in Kenya, freeze dried and ground to powder. Two methods were used to extract the proteins namely; hexane and aqueous extraction. The protein solubility, water holding capacity, emulsion capacity and stability, foaming capacity and stability and least gelation concentration of the protein concentrates were determined separately using NaCl at concentrations of 2%, 4%, 6%, 8% and 12% and pH regimes of 2, 4, 6, 8 and 12 respectively. Protein solubility of the protein concentrates decreased from pH 2 to pH 8 followed by a significant increase at pH 12. Increase of NaCl concentration to 4% increased the water holding capacity followed by a decline towards 12%. pH had significant effect on the water holding capacity of the protein concentrates (p = 0.0246). Emulsion capacity decreased with increase in NaCl concentration up to 6% followed by an increase with continuous increase in NaCl concentration. NaCl and pH considerably influenced the foaming capacity of the protein concentrates. The least gelation concentration of the protein concentrates was 30%.