Preparation Of Chickpea Protein-surimi Hybrid Gel And Effects Of Processing And Storage On Its Quality

Surimi products have the advantages of low fat content,high quality protein content and easy digestion and absorption by the human body.Compared with traditional surimi products,surimi products produced by partially replacing surimi protein with plant protein can meet consumers’ needs for a healthy diet and a vegetarian lifestyle,and relieve environmental pressure caused by overfishing.As a high-quality protein,chickpea protein has physiological functions such as anti-oxidation and lowering blood fat.Adding it to surimi products can produce high-quality hybrid surimi products.In this paper,silver carp surimi gel was taken as the research object,and the effects of the addition of chickpea protein on its texture,gel strength,water holding capacity,color and dynamic rheology were explored;The influence mechanism of chickpea protein on surimi gel was explored by methods such as intermolecular forces,SDS-PAGE gel electrophoresis and microstructure analysis;this paper also further studied the effect of chickpea protein hybrid surimi gel during processing and storage.The effects of cooking time and frozen storage time on the eating quality and nutritional characteristics of chickpea protein hybrid surimi gel were explored,in order to provide a certain theoretical basis for the application of chickpea protein in surimi products and technical references.The main research content and results are as follows:1.Effect of chickpea protein on the quality of low-salt surimi gelWith hybrid surimi prepared using different formulations as the research object,the effects of chickpea protein(CPP)and transglutaminase(TGase)on the quality of surimi gel in low salt system were explored.The results showed that whether TGase was added or not,CPP would reduce the whiteness of surimi,gel strength,hardness,storage modulus(G’)and loss modulus(G"),and increase the water holding capacity.The stress relaxation test results reflected not only the change of gel strength,but also a drop in springiness with CPP addition that is not captured by the TPA test.TGase could improve the mechanical strength,especially the gel strength and G’.The results of reducing and non-reducing SDS-PAGE showed that TGase reduced the strength of myosin heavy chain(MHC)bands,indicating that TGase catalyzed the formation of irreducible cross-linking of MHC and decreased its solubility;There was no covalent cross-linking between CPP and myofibrillar protein,and the interaction force was mainly hydrophobic force or hydrogen bond.2.Effect of long time boiling on the gel quality of chickpea protein hybrid surimi.With regular level salt(3%)and low salt(0.3%)surimi as control,the effect of long-term boiling(85℃,0,6,12 and 18 h)on the quality of chickpea protein hybrid surimi gel(50% chickpea protein replacement)was investigated.The results showed that with the extension of boiling time,the carbonyl content in all samples decreased,the protein denaturation and aggregation intensified,the network structure of protein gel was destroyed,and the network pores increased.The gel strength decreased,and the gel strength decreased by 61.03%,11.32%,and 33.33% respectively after 12 hours of boiling,which had no significant difference from that of frozen and reboiled gels;The water holding capacity and whiteness decreased.The electronic nose analysis results showed that the content of sulfides and nitrogen oxides increased in the control group,while decreased in the hybrid group(50% group);The relative content of aldehydes and alcohols in all samples decreased overall,and the flavor characteristics deteriorated.There was no significant change in the texture characteristics of the control group after 6 hours of boiling,but the resilience,cohesion,gumminess and chewiness decreased significantly after 12 hours,and further decreased after freezing and reboiling;The texture characteristics of the hybrid gel group were not significantly affected after 12 hours of boiling,but the hardness,springiness and chewiness of the hybrid gel group were significantly decreased after freezing and reboiling.Gastric digestibility increased in regular salt group and hybrid gel group,and decreased in low salt group;The total gastrointestinal digestibility of all samples decreased.There were 4000 different peptides in the gastric digestive products of the regular group,the low salt group and the hybrid gel group,and 4176 different peptides in the gastrointestinal digestive products.With the extension of boiling time,the number of different peptides increased,and the difference between the control group and the hybrid gel group was large.Both boiling time and formula had significant impact on the digestion products.3.Effect of frozen storage on the gel quality of chickpea protein hybrid surimiWith regular level salt(3%)and low salt(0.3%)surimi as the control,the effect of frozen storage time(-18℃,0-5 months)on the quality of chickpea protein hybrid surimi gel(50% chickpea protein replacement)was investigated.The results showed that with the extension of freezing storage time,the carbonyl content of all samples decreased,the sulfhydryl content and particle size maintained the regular salt group >low salt group > hybrid gel group,and the particle size maintained the regular salt group group > hybrid gel group > low salt group.The network pores gradually increased.Water holding capacity and whiteness decreased.Hardness,resilience,cohesion,gumminess and chewiness changed smoothly,and there were significant differences among groups.Digestion first increased and then decreased,with significant differences in digestion products.Compared with the control group,the number of small molecular peptides(0-1000 Da)in the digestion products of the hybrid gel group was lower;There were a total of 4047 different peptides in the gastric digestive products of the three groups of samples,and 4262 different peptides in the gastrointestinal digestive products.With the extension of freezing storage time,the number of different peptides increased.The formula had a significant impact on the texture of gel,and the frozen storage time had a significant impact on the digestion products.