Preparation Of Potato Protein-Polysaccharide Complex And Its Effect On The Quality Of Dumpling Wrappers

Potato protein has a total variety of amino acids and a reasonable ratio,which is a highquality plant protein.At present,potato protein is mainly derived from the by-products during starch processing.However,in the extraction,purification and other recovery processes,the functional properties.(e.g.,emulsification)of protein are easy to be destroyed,which greatly limits its application in food industry.Glycosylation is a green protein modification method that can improve protein emulsification properties,water retention and other functional properties.The modified products are widely used in food.Quick-frozen boiled dumplings are popular among consumers because of their convenience.However,the quality of dumpling wrappers will deteriorate during the frozen storage process,such as poor cooking and easy aging.And emulsifiers are the common quality improvers.Therefore,this study used wet method to modify potato protein,systematically studied the effects of different ionic polysaccharides and different reaction time on the functional properties and structure of the potato protein,and the modified potato protein was applied in dumpling wrappers.The main conclusions are as following:(1)The effect of three polysaccharides on the emulsification characteristics of potato protein was studied.The results showed that the three glycosylation complexes PP-XG,PP-CS,and PP-GG all improved the emulsifying properties of potato protein.Among them,PP-XG has the best emulsification properties,and the emulsification activity and emulsification stability are increased by 211.49% and 99.15% respectively compared with potato protein.After glycosylation modification,the protein molecule stretches and the spatial structure becomes looser,which is conducive to the improvement of the emulsification properties of the glycosylation complex.(2)The effect of the reaction time on the functional properties and structure of the PP-XG composite during the wet modification process was studied.The results show that the reaction time has a significant impact on the functional properties and structural characteristics of the glycosylation complex.With the increase of the reaction time,the emulsification and emulsification stability of PP-XG complex increased first and then decreased.When the reaction time is 4 h,the emulsification activity,emulsification stability and water holding capacity are the highest.The reason may be the modification of glycosylation.The sex enhances the hydrophobicity of the potato protein surface,increases the absolute value of the Zeta potential,and increases the hydrophilic hydroxyl groups.(3)The effect of PP-XG compound on the quality of dumpling wrappers during the freezing and thawing process was systematically explored.With the increase in the number of freeze-thaw cycles,the bound water in the dumpling wrapper gradually turns into adsorbed water,and the content of freezable water presents an upward trend.Analysis of the rheological properties of the dumpling wrapper reveals that the tan δ value continues to rise during the freezing and thawing process;The cooking loss rate is on the rise,and the water absorption is on the decline;the texture results show that the hardness and chewiness of the dumpling wrappers are on the rise,while the elasticity and resilience are decreased;the addition of PPXG slows down the migration of water during the freezing and thawing process,and inhibits In order to increase the content of freezable water,it will reduce the further damage of ice crystals to the gluten network,thereby reducing the change of tan δ of the dumpling wrapper,reducing the cooking loss rate,and improving the quality of the dumpling wrapper.(4)The effects of PP-XG on the structure of quick frozen dumpling wrappers during freeze-thawing were studied by infrared spectroscopy,Raman spectroscopy,sulfhydryl disulfide bond and scanning electron microscopy.The results showed that during the freezing and thawing process,the content of sulfhydryl groups in the dumpling wrappers increased,and the content of disulfide bonds decreased;the content of β-sheets and random coils in the secondary structure showed an upward trend,and the content of α-helix and β-turn showed a downward trend;And infrared analysis found that the degree of ordering of starch short chains increased;SEM intuitively showed that the area protein network was continuously destroyed during the freezing and thawing process.The addition of PP-XG enhances the interaction with protein and starch,thereby reducing the destruction of the gluten network,slowing down the changes in protein secondary structure,sulfhydryl groups and disulfide bonds during the freezing and thawing process,and reducing the short-chain and short-chain content of starch.degree of ordering.