Effect of pH and Salt Concentration on Extractability and Functional Properties of Microtermes Nigeriensis Soluble Proteins:- Onyemuchara Chinedu T

ABSTRACT The meat crisis is prompting us to look for alternative protein sources. Insects represent a rich source of protein and a more sustainable alternative to conventional animal sources. The potential of edible termite (Af. nigeriensis) as an alternative protein source for food applications was investigated by studying the effect of NaCl and pH at which the extraction and functional properties the protein concentrates is optimum. Edible termites were obtained using traditional methods of exposure to light, oven dried and ground to powder. The powder was defatted using hexane extraction. The proximate and colour changes were determined using kjedahl methods and colorimeter respectively. Protein extractability, emulsion capacity and stability, foaming capacity and stability of protein concentrates were determined at NaCl concentrations of 2%, 4%, 6%, 8% and 10% and pH regimes of 2, 4, 6, 8 and 10 respectively. After acid precipitation an isolate with a protein content of 80.29% (yield of 24.82% oftotal protein) was obtained while Nacl extraction and yielded 91.68% protein (29.04% yield). A color change from 9.9 to 20.1 was recorded for Salt and acid extract respectively. Minimum protein solubility (10.2%) was at pH 4 and maximum (65.6%) at pH 10. Increase of NaCl concentration to 0.5M Nacl increased the protein extractability from 16 to 45% followed by a decline towards IM NaCl. pH had significant effect on the foaming capacity and stability ranging from 15-40% of the protein concentrates (P<0.05). Emulsion capacity decreased significantly (P<0.05) with increase in NaCl concentration up to 6%. NaCl and pH considerably influenced the solubility, foaming and emulsion capacity ofthe protein concentrates with pH 10 and 0.5M NaCl recording the best in all protein functionalities assayed. The results showed that M. nigeriensis proteins behave more or less the same as proteins from meat and fish with respect to functionality. These properties could be helpful for better use ofinsect products in the food industry