| This paper studied the changes of wheat gluten-vegetable oil?peanut oil:soybean oil:rapeseed oil=2:2:1?system through extrusion modification.It aimed to improve the quality of wheat gluten-oil system through extrusion processing.Based on a large number of exploratory experiments in the early stage,in the wheat gluten-lipid system,the oil was established as a blended oil?peanut oil:soybean oil:rapeseed oil=2:2:1?.Previous studies showed that the blend oil was added to Extruded wheat gluten protein,the product of the best degree of organization,and the product of the emulsification,emulsion stability and foaming and other functional properties of the best,so this study established a wheat gluten protein-mixed oil extrusion experiment.In this study,gluten meal?wheat gluten protein?was used to add 300 g of the sample to 100 m L of deionized water and24 mL of mixed oil?peanut oil:soybean oil:rapeseed oil=2:2:1?and uniformly mixed.Through four experimental conditions?oil content,sleeve temperature,screw speed,feeding speed?,the protein molecular weight,protein structure,and the change of the microstructure of the sample surface were measured after the extrusion treatment.The extrusion treatment was applied to the wheat gluten protein.Effect of grease interactions.The analysis by SDS-PAGE gel electrophoresis showed that the protein content of the un-squeezed gluten protein and the extruded gluten protein sample were quite different.In the four single-factor conditions?oil content,sleeve temperature,screw speed,feed rate?,no new bands appeared during extrusion.According to the polymerization behavior of proteins,the changes of protein networks after extrusion were studied.With the increase of screw speed?40-80 r/min?and feeding speed?30-40 g/min?,the increase of high molecular weight protein subunits and the decrease of low molecular weight protein subunits indicate that the protein was aggregated during extrusion processing.The determination of thiol disulfide bonds by UV spectrophotometry showed that the structure of the protein molecules changed regularly during the extrusion process.With the increase of four single-factor conditions,the free sulfhydryl group showed a decreasing trend,and the disulfide bond content showed an increasing trend.The reduction of free sulfhydryl group after extrusion indicates that wheat gluten protein has been denatured during the extrusion process,and its cross-linking reaction has been deepened through intermolecular disulfide bond polymerization,and the content of disulfide bonds and the content of macromolecule proteins have increased.The secondary structure of the protein was measured by Fourier transform infrared spectroscopy.The experimental results showed that as the oil content increased,the?-helix(1650–1660 cm-1)and the?-fold(1610–1642 cm-1)increased first and then decreased.When the amount is 8%,?-helix and?-sheet are the highest.The specific?-sheet structure of gluten increases significantly,and the?-helix and?-sheet fluctuate,forming a tight gluten network.The use of X-ray diffractometry for the determination of tertiary structures indicates that extrusion processing has a decisive influence on the spatial structure of the protein.The proportion of the appropriate gluten protein-compounded oil?oil content of 8%?can increase the protein content during extrusion.Crystallization conversion efficiency.At different screw speeds,the protein conversion was lower at the feed rate?30-40 g/min?and the protein conversion was higher at the feed rate?50g/min?.Confocal laser scanning microscopy?CLSM?evaluation of the protein network results showed that a uniform dense gluten network was formed during the extrusion process when the sleeve temperature was high,which was related to the aggregation of low molecular weight protein subunits,and scanning electron microscopy showed that extrusion After the protein has polymerized.This study can provide theoretical basis for the improvement and control of extrusion quality in wheat gluten extrusion process. |
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