Enzymatic Auxiliary Extraction Of Quinoa Straw Protein And Its Food Features

Quinoa yield is low,as a kind of whole nutrition plant,the whole development potential of the plant is large,as the main body of the quinoa straw is still rare research and reports.The quinoa straw protein was studied in this paper,the purpose is to broaden the source of plant protein,to solve the quinoa after harvesting and cutting a large number of straw discard,pollution of the environment and other problems,the development and use of quinoa straw protein,improve the economic value of straw.The plant protein in quinoa straw was extracted by biological enzyme method,and the nutritional value,structure and food functional properties of the extracted quinoa straw protein were studied,in order to provide a basis for the further development and utilization of quinoa straw protein.The main research results are as follows:1?The total crude protein content of quinoa straw is about 11.4%,on the basis of single factor test,the use of orthogonal test to optimize the process parameters,to determine the optimal extraction process conditions: solid-liquid ratio of 1:3,reaction time of 8 h,extraction temperature of 50?,cellulase added amount of 275 U/mg,the optimal extraction rate of 40.68%.2?By quinoa straw protein composition of amino acids were analyzed,and concluded that quinoa essential amino acid content in the straw protein accounts for 41% of total amino acid content,EAA/NEAA(E/N)is 0.69,the two values are slightly higher than the standards stipulated by the FAO/WHO essential amino acid content of 40% and E/N value of 0.6,according to RCAA values calculated further SRCAA quinoa straw protein 72.25.3?The analysis of the molecular weight of quinoa straw protein showed that there were 8 bands of quinoa straw protein,and the corresponding molecular weights were 78.7 KDa,42.1 KDa,35.6 KDa,20.7 KDa,17.8 KDa,15.5 KDa,11.2 KDa and 6.1 KDa,respectively.4?The determination results of disulfide bond content of quinoa straw protein indicated that the content of free sulfhydryl group in quinoa straw protein was about 10.21 mol/g,and the content of disulfide bond was about 23.57 mol/g.The results of Fourier transform infrared spectroscopy showed that,among the secondary structure of quinoa straw,the Beta Angle was relatively high,accounting for 36.42%,the relative content of Alpha-helix was 25.19%,the relative content of Beta-fold was 25.91%,and the relative content of random curl was 12.48%.5?The denaturation temperature of quinoa straw protein was higher,the water content was 9.6%,the starting temperature was 131.06?,the denaturation temperature was 132.72?,the termination temperature was 134.51?,the denaturation enthalpy into 7.82 J/g.6?The results of food functional of quinoa straw protein showed that its solubility and water absorption were relatively best at 60? and p H of 9.Oil absorption at 70? reached the best;Foaming at 60?,p H of 11 is the best;The foam stability was the highest when the temperature was 70? and the p H was 5,and the p H and temperature had a significant effect on the food functional properties of quinoa straw protein.The comprehensive results showed that the utilization of biological enzymes to extract quinoa straw protein and the study on its nutritional value,structural characteristics and food function provided a theoretical basis for the research and development of quinoa straw plant protein in food.