Research On Separation,Modified And Features Of Rice Residue Protein

Our annual production of rice is about 180 million to 200 million tons,of which a large number of early rice,stock rice,broken rice were used as production material of industrial fermentation and rice syrup,a large amount of by-product rice residue were produced,rice residue protein content up to 40%-70%,is rich in high-quality vegetable protein resources.Rice protein has high biological prices,a reasonable balance of amino acids,a low antigenicity and important health function,however,rice residue is a product of high-temperature liquefied protein,structure changes,poor solubility and other functional properties,its food industry application were limited.This issue use rice residue as raw material,through double enzyme preparation of high-purity rice residue protein,the use of rice residue protein and glucose/ maltodextrin Maillard reaction modifier to improve the functional properties of rice residue protein.on the basis of process optimization,the features and physicochemical properties of Maillard reaction product were studied,in order to improve the comprehensive utilization of rice residue laid a theoretical and practical basis.Firstly,the chemical composition of rice residue were analyzed,the main component of protein(60.5%),polysaccharides(21.6%),fat(7.4%),crude fiber(5.8%);on basis of determining a degreasing,amylase,cellulase combination of the three basic enzyme preparation of high purity rice residue protein,by discussing the impact of solid-liquid ratio,the amount of high-temperature ?-amylase,cellulase dosage,high temperature ?-amylase and cellulase hydrolysis time on rice residue protein purity,using orthogonal experiment to prepare the optimum conditions for the rice residue protein,liquid to solid ratio of 8:1,high temperature ?-amylase amount of 300U/mL,cellulase enzyme dosage 110U/g,high temperature ?-amylase hydrolysis time 1.5h,cellulose enzymatic hydrolysis time 2.5h.Under these conditions,the protein purity of 93.8%,the yield was 88.76%.Then,the degree of grafting,functional properties were ueed as evaluation index of the Maillard reaction of protein and carbohydrate modification effect,under dry and wet conditions on the rice residue protein and glucose,maltodextrin Maillard reaction modifier process variation were compared,results showed that Rice residue protein and glucose,maltodextrin Maillard reaction modifier can significantly improve their functional properties,including higher degree of glycosylation under wet conditions rice residue protein and glucose,maltodextrin..Different degree of grafting rice residue protein-glycoconjugates features were studied,determine the degree of grafting as an index of protein and carbohydrate modification effect of the Maillard reaction.Wet reactive protein glucose/malt quality ratio,pH,reaction temperature,reaction time and dextrin to the degree of grafting were studied,response surface optimization test results showed that rice residue protein glycosylation and glucose optimal change of the process as follows,glucose/protein ratio of 4.31,pH10.26,the reaction temperature 73.14?,reaction time 3.13 h,this time rice residue protein-glucose composite graft of up to 43.15%.maltodextrin and rice residue protein glycosylation best modification process,maltodextrin/protein ratio of 6.23,pH10,reaction temperature 60.17?,reaction time 2h,this time rice residue protein-maltodextrin composite grafting degree of 46.18%.Finally,the rice residue protein and glucose/maltodextrin Maillard reaction product of physical and chemical properties and functional characteristics under different pH were studied,the results showed that within the range of pH2~12,compared with the rice residue protein,protein-glycoconjugates feature has been significantly improved,pH10,the rice residue protein-dextrose/maltodextrin complex solubility were increased by 1.14 times,0.92 times,emulsification were increased by 2.66 times and 2.18 times,respectively,emulsion stability were improved 1.87 times,2.31 times.Amino acid analysis showed that,compared with the rice residue protein,rice residue proteintyrosine and arginine relative content of glycoconjugates has decreased significantly.IR spectrum analysis indicated that rice residue protein-sugar complex is rice residue protein and carbohydrate covalently bound.Differential scanning calorimetry analysis showed that,compared with the rice residue protein,rice residue protein-carbohydrate complexes thermal denaturation temperature did not change significantly.Circular dichroism spectroscopy results showed that rice residue protein-sugar complex secondary structure changes,?-fold were significantly increased,decreased ?-corner content,reducing random coil content.Scanning electron microscope analysis showed that rice residue protein-glucose complexes lose their original morphology,structure and morphology as a gum,rice residue protein-maltodextrin complexes lose their original morphology,flaky morphology.