Study On Extraction Of Protein From Tenebrio Molitor And Preparation Of Protein Powder

Tenebrio moliror is an available resource of animal protein feed with high nutritional value and various healthy function, also is an underutilized protein source. The extracting techniques of protein from Tenebrio molitor and producing techniques of protein powder were investigated in this paper.First, oil extraction from Tenebrio molitor with different methods was studied. The optimum conditions of organic solvent extraction chosen by orthogonal experiment were as follows: anhydrous ether of extraction solvent, ratio of Tenebrio molitor and extraction solvent of 1:6, extracting solution heated for 3h at 40℃, and the extracting rate was 31.76%; The supercritical CO2 extraction's optimum conditions were confirmed as follows: extraction pressure 30MPa, flow rate of carbon dioxide 20 L/h, temperature 35℃and time 2.5 h. Under these conditions, the extracting rate was 30.45%. In this paper, the method of supercritical CO2 extraction was chosen, because of its better quality.Tenebrio molitor protein was extracted from the fat-free materials with three kinds of extracting methods. Through all those processing methods of alkali extracting, salt extracting and Enzymatic Hydrolysis, the method of trypsin was adopted in the experiment. The optimized conditions of the method of extracting protein with alkali solution were 1.0%NaOH, with the ratio of solid and liquid (w/v)1:15, at 50℃,stirring for 2h, the extraction yield was 77.8%. The best condition of method with salt was that the concentration being 1.0%, temperature being 40℃, time being 3 h, the ratio of solid and liquid was 1:20. Under these conditions, the extraction yield was 52.5%. The trypsin hydrolysis'optimum process conditions were as follow: amount of enzyme added 1.5%, the solid to liquid ratio is 1:10, pH value is 8.0 and takes 5 hours at 55℃. Under which, the extraction yield was 73.8%.Based on the crude Tenebrio molitor protein, the technology of purification and isolation were studied. Under 30℃, with 3% active carbon for 2 hours, the color of hydrolyzing liquid looked better. After decoloring, the protein was precipitated by salt, and then desalted by dialysis. The result of separation by Sephadex-G75 chromatography wasn't well. Many fractions of proteins were found after DEAE-32 ion-exchange chromatography. The effect on the property of Tenebrio molitor protein powder with three different methods such as hot-air drying, vacuum freeze-drying and spray drying was researched. Spray drying process was adopted, the optimum conditions were: solution condition was 30 %~40 %, solution temperature was 45℃, the inlet and outlet temperature was 180-73℃, the inlet quantity was 20mL/min.