Gelation And Flavors Binding Capability Of Porcine Myofibrillar Protein Prepared With Calcium,Magnesium And Potassium Chloride As Partial Substitutes For Sodium Chloride Under Oxidation Conditions

In the fast pace of life,fast consumption food,such as cooked food or semi-cooked food,is favored by consumers.A large percentage of processed meats,can be categorized as“gelatinous meat products”because they are composed of pieces of bound muscle.Textural,water-binding properties and flavors binding capability of such products critically depend on the protein gel formed by salt-soluble myofibrillar protein?MFP?.The structural changes in myofibrils and its dissociation into individual protein components at high concentration of salts contributes to meat protein gelation,so sodium chloride becomes a main ingredient and largely used in processed meats.There is a positive correlation between chronic diseases and excessive sodium intake.The production of reduced-sodium processed meats will become the development trend of meat products industry.The reduction of salt addition in the gelatinous meat products will cause deterioration of product quality,so the production of reduced-sodium processed meats with high quality has become a problem urgently to be solved in meat products industry.Otherwise,oxidation is a commonplace in the storage and processing of meat.Firstly,this study built an oxidation model relevant to real meat processing procedures.Then studied the gelation and flavors binding capability of porcine myofibrillar protein with 25%and 50%reduction in sodium chloride by its partial substitution with potassium,magnesium,and calcium chloride salts.Furthermore,the interaction between MP and nonanal was studied by fluorescence quenching method.The studies attempt to provide useful guidance when producing reduced-sodium processed meats.The main contents and results are listed as follows:1.In·OH oxidation system,the effects of salts substitution on MP structure and gelation properties were studied.It was observed that KCl blending 25%NaCl resulted in the unfolding of MP,which was conducive to the formation of MP gel during heating.When 50%NaCl was replaced by KCl,insoluble MP aggregates was formed by hydrophobic interaction,which restrained the formation of uniform and continuous gel networks during heating,finally destroyed the gel structure.The presence of CaCl₂ and MgCl₂ contributed to reduce the extraction of myofibrillar protein,resulted in a significant decrease in gelation properties of MP.2.In·OH oxidation system,this chapter mainly studies the effect of composite substitution treatment on MP structure and gel properties.The results showed that,the gel quality of composite substitution of KCl,CaCl₂ and MgCl₂ were between at those of monovalent salts and bivalent salts separate substitution under the same degree of substitution,,which showed that there was no synergistic effect.When the replacement level of NaCl reached 50%,the quality of gel properties was still severely reduced.So the substitution of NaCl should not go beyond the limit of 50%in the produce of meat products.Therefore,this study concluded that the composite substitution of NaCl by KCl,CaCl₂ and MgCl₂ didn't improve the quality of MP gel essentially.3.This chapter mainly studied the influence of salts substitution on the binding ability with typical flavor compounds?2-methylbutyraldehyde,2-pentaldehyde,2-heptanone,3-methyl-propyl aldehyde and positive nonaldehyde?of cold-set MDA-MP gel.The study found that,when 25%NaCl was replaced,KCl,CaCl₂ and MgCl₂ promoted MP denaturation and unfolding which enhanced the flavor adsorption capacity of MP.However,when 50%NaCl was replaced,appeared a reversed effect.In addition,the results of fluorescence quenching study showed that the binding of MP with nonanal was spontaneous and the hydrophobic interaction played a major role in the reaction.