Study On The Extraction And Application Of Lycium Barbarum Leaf Protein

In this study,the extraction technology of lycium barbarum leaf protein was optimized,the quality of lycium barbarum leaf protein in different seasons was compared,and the antioxidant activity and other functional properties of lycium barbarum leaf protein were investigated,it provides a theoretical basis for the development and utilization of lyciumbarbarum Leaf protein-related products.The main results were as follows:（1）The leaf protein of lyciumbarbarum was extracted by ultrasonic enzymatic extraction from lyciumbarbarum leaves.The influence factors were D>C>A>B;extraction time（D）>extraction temperature（C）>Enzyme Amount（A）>material-liquid ratio（B）.The optimum combination was A ₂B₃C₃D₂with 30U/g of enzyme,1:9 ratio of material to liq uid,35℃,120min of extracting time.（2）According to the experiment,the leaf protein yield and protein content of lyciumbarbarum varied with months and seasons,and the leaf protein content of lyciumbarbarum was 10-14%.The protein yield and protein con tent of lycium barbarum leaves increased gradually from June to August,and decreased gradually from September to November,so that the protein content of lycium barbarum leaves reached its peak in August,to provide scientific basis for reasonably and accurately grasping the harvest time.（3）According to the experiment,different temperature,p H value and concentration of salt ions have significant effect on the solubility of lycium barbarum leaf protein.At p H 5.0,the solubility of lyciumbarbarum leaf protein was the smallest.When the concentration of Nacl was 0-0.2 mol/L,the solubility and water absorption of lyciumbarbarum leaf protein increased linearly with the concentration of Nacl,and the emulsifying power of lyciumbarbarum leaf protein increased with the concentration of salt ions,and reached the maximum at 0.4 mol/L.The solubility and water absorption of lyciumbarbarum leaf protein increased at first and then decreased with the change of temperature.The solubility of lyciumbarbarum leaf protein reached the maximum at 60℃and the water absorption reached the maximum at 40℃.（4）the results showed that the DPPH scavenging rate of lycium barbarum leaf protein hydrolysates increased with time in 0-7h,and the scavenging rate of hydroxyl radical of lycium barbarum leaf protein hydrolysates increased with time in 0-4h,the reduction ability of lycium barbarum leaf protein increased with the increase of degree of hydrolysis in 0-3h,and decreased slowly after 3H.The optimum hydrolysis time was 4h,and enzymatic hydrolysis time had significant effect on the antioxidant activity of lycium barbarum leaf protein hydrolysates.At the same time,the higher the concentration of lycium barbarum leaf protein hydrolysate,the stronger its reducibility and scavenging ability to DPPH and oh.（5）the processing technology of lyciumbarbarum leaf protein nutrition powder is as follows:adding 0.5%purple sweet potato anthocyanin into lyciumbarbarum leaf protein which is extracted by the best extracting technol ogy mentioned in chapter 2,then Papain 10000U/g,neutral protease 50U/g,Poirot Protease 100U/g and enzyme hydrolysis at50℃for 50min were added,and supernatant was obtained by centrifugation The supernatant was concentrated to about 15%of water content at vacuum 0.095 MPA,rotating speed 3000 r/Min and constant temperature 55℃.In order to keep the nutrition powder of lycium barbarum leaf protein original color and luster,the biological active substance contained in it can be retained,and the original nutrition ingredient is not destroyed,the concentrated solution was freeze-dried at a vacuum of 50 PA,the heating plate temperature was 60℃,and the condensing temperature was-25℃.finally,the dried solid was ultra-micro-pulverized at 3500 r/min for 5 min,after 80 mesh,the lycium barbarum leaf protein powder was freeze-dried and then 20%sugar was added,7%almond powder,4%siraitiagrosvenorii powder,goji berry leaf protein powder nutritional products.