Tenebrio molitor protein contains 18 amino acids, among which 8 amino acids are essential for human body, accounting for 40% of the total amino acids. Its proportion is close to the pattern of amino acid requirement of human body, and it also contains many minerals, vitamins and trace elements, so it is called "the treasure house of animal nutrition". Foreign studies show that Tenebrio molitor protein has the functions of improving human immunity, anti-fatigue, delaying aging, reducing blood lipid and promoting cholesterol metabolism. The optimum technological conditions of extracting Tenebrio molitor oil by supercritical CO2 extraction technology to prepare Tenebrio molitor defatted powder were studied. Using the obtained Tenebrio molitor protein powder as raw material, Tenebrio molitor protein was extracted by alkali extraction and enzymatic method, and the two extraction processes were compared.
Firstly, Tenebrio molitor was defatted to prepare crude protein powder, and then the Tenebrio molitor was defatted by supercritical CO2 extraction technology. Taking the extraction rate of Tenebrio molitor oil as an index, the optimum technological conditions of extracting Tenebrio molitor oil by supercritical CO2 were determined by orthogonal design of three factors and three levels: extraction temperature 45℃, pressure 25MPa and time 65438±080min. The extraction rate of Tenebrio molitor oil was 95.99%.
Alkaline extraction has the characteristics of high extraction rate and low cost. The results of single factor experiment and orthogonal experiment showed that the optimum conditions of alkali extraction were: alkali concentration 1.0%mol/L, extraction temperature of Tenebrio molitor protein at 70℃, liquid-solid ratio 12: 1, and extraction time of 90min. Under this extraction process, the extraction rate of Tenebrio molitor protein can reach 90%.
2 1 century, human beings are facing more severe pressures and challenges of population growth, shortage of important resources and environmental pollution. It is the only way to develop agricultural industrialization in China by opening up new resources and taking the road of sustainable development. As the largest underutilized resource treasure house on the earth, insects have attracted more and more attention. The exploitation and industrialization of insect protein resources will enter a multi-level and comprehensive utilization stage characterized by high technology and high yield. Insects are rich in protein, unsaturated fatty acids and trace elements, and they are high-level nutrition sources for human beings.
Tenebrio molitor protein contains 18 amino acids and 8 essential amino acids, accounting for 40% of the total, which is close to the amino acid pattern needed by human body. It also contains many minerals, vitamins and trace elements. It is known as the "treasure house of animal nutrition". Foreign studies show that Tenebrio molitor protein can improve human immune system, resist fatigue, resist aging, reduce blood lipid and promote cholesterol metabolism. In this paper, the optimum conditions of extracting Tenebrio molitor oil to prepare Tenebrio molitor defatted powder were studied by supercritical CO2 extraction technology. Using the obtained Tenebrio molitor protein powder as raw material, the two extraction processes of Tenebrio molitor protein were compared by using basic formula and enzyme preparation.
Tenebrio molitor was defatted by defatted powder and supercritical CO2 extraction technology. Taking the extraction rate of oil in Tenebrio molitor as an index, the orthogonal experimental design of three factors and three levels was carried out. The optimum conditions for extracting oil from Tenebrio molitor by supercritical CO2 were determined as follows: extraction temperature 45℃, pressure 25MPa and time 65±438±080min. The extraction rate of Tenebrio molitor oil was 95.99%.
Alkaline extraction has the characteristics of high extraction rate and low cost. The results of single factor test and orthogonal test show that the optimum formula conditions of alkali are: alkali concentration 1 .0% mol/L, liquid-solid ratio 12: 1, and the extraction condition of Tenebrio molitor protein is 90min. Under this extraction condition, Different proteases extract Tenebrio molitor protein in different ways. Taking the protein extraction rate and the quality of protein extract as indicators, the effects of various proteases on extracting Tenebrio molitor protein were compared. It was concluded that the extraction efficiency of compound protease and compound flavor protease was high, and the final protein extract was of good quality. In order to improve the utilization rate of raw materials and the extraction rate of Tenebrio molitor protein, these two enzymes were selected as extraction enzymes. The results of single extraction, stepwise extraction and compound extraction of the two enzymes were compared. Taking protein extraction rate as the index and hydrolysis degree as the reference index, the optimum technology of extracting Tenebrio molitor by protease was determined by orthogonal test and single factor test: the dosage of enzyme was 6%, the ratio of compound protease to compound flavor protease was 1:3, and the liquid-solid ratio was 9: 1. Under the optimum conditions, the extraction rate of Tenebrio molitor protein can reach 64. The purity is 92. 17%.
Tenebrio molitor contains various pigments and polyphenols, among which polyphenols are easy to produce Maillard reaction in the reaction and more or less produce bitter peptides in the enzymatic extraction process. In order to keep it in the optimum pH range, it is necessary to add acid and alkali to produce a large amount of salt, and the obtained Tenebrio molitor protein extract is dark in color, so it is necessary to refine Tenebrio molitor protein. A clear and delicious protein extract can be obtained by adding 3% activated carbon for decoloration and debittering. 9 1.20% salt can be removed by anion exchange resin, and finally light yellow protein powder can be obtained by spray drying.
The safety toxicological evaluation results of alkali-extracted protein products showed that the alkali-extracted protein products were basically safe and non-toxic (LD50 of mice was greater than 120g/Kg), and could be used as high-protein resources for human beings and other animals.
In a word, through the comparative study of two extraction methods of protein, the best extraction method and technology of protein from Tenebrio molitor were preliminarily established, which provided a theoretical basis for the future development of protein resources of Tenebrio molitor.
Keywords: Tenebrio molitor; Protein; Supercritical extraction; Alkaline method; Enzymatic method; Extraction process; amino acid
Enzymatic extraction is characterized by mild reaction conditions and good substrate specificity. Different proteases of Tenebrio molitor have different ways of extracting protein. Taking protein extraction rate and protein extraction quality as indicators, the effects of proteases on protein extraction of Tenebrio molitor were compared, and it was considered that the extraction efficiency of compound protease and flavor protease was high, and the final protein extraction quality was good. The results of extraction, step-by-step extraction and re-extraction of two enzymes were compared. Taking the protein extraction rate as an index and the degree of hydrolysis as a reference, the best extraction process of Tenebrio molitor protease was determined by single factor experiment and orthogonal experiment. The compound protease and compound flavor protease were extracted by two enzymes: the dosage ratio of compound protease and compound flavor protease was 6∶5438+0∶3, the liquid-solid ratio was 9∶ 1, and the extraction time was 8 hours. 5 The temperature is 55℃. Under the optimum conditions, the extraction rate of Tenebrio molitor protein can reach 64.83% and the purity is 92.65438 07%.
Tenebrio molitor contains a variety of pigments and polyphenols, among which polyphenols are prone to Maillard reaction and produce more or less bitter peptides in the process of enzymolysis. In order to maintain its optimum pH range, it is necessary to add acid and alkali, thus producing a lot of salt. However, the protein extract of Tenebrio molitor is dark in color, so it is necessary to refine the protein of Tenebrio molitor. 3% is decolorized and debittered by adding activated carbon, which can be extracted by protein with clear color and good taste. 9 1.20% salt can be removed by cation-anion exchange resin, and finally the protein can be obtained into light yellow powder by spray drying.
The safety evaluation results of toxicological protein products obtained by alkali formula show that protein products derived from reference alkali are basically safe and nontoxic (LD50 of mice is greater than 120g/Kg), so they can be used as high protein and other animal resources.
In a word, through the study of two extraction methods of protein, the extraction method and the best technology of protein from Tenebrio molitor were preliminarily established, which provided a theoretical basis for the development of protein resources of Tenebrio molitor in the future.
Keywords: Tenebrio molitor; Protein; Supercritical fluid extraction; Alkali; Enzyme; Extraction process; amino acid