Interaction Mechanism Between Lecithin And Myofibrillar Protein And Its Effect On Protein Functional Properties

China is not only a big country of sheep breeding,but also an important consumer country.However,the development of mutton industry is greatly limited due to the short shelf-life,easy corruption and short sales.With more and more attention paid to the safety of meat products,centralized slaughtering and cold chain sales will become a major trend.Furthermore,how to effectively extend the good edible period of fresh mutton has also become the difficulty in production and research hotspot.In this study,the tea polyphenol(natural antioxidant,TP)and 2,6-di-tert-butyl-4-methylphenol(chemical antioxidant,BHT)were used as control.On the one hand,the effect of different cumin essential oil concentrations on antioxidant activity were investigated.On the other hand,the fat oxidized,functional structure of myofibrillar protein and eating quality of treated with different cumin essential oil concentrations during micro-freezing storage were systematically studied by using the frozen hind leg meat as raw material.Therefore,the purpose of this study is to provide theoretical and technical basis for further development and utilization of cumin resources,the preservation of mutton and improvement of product quality.The main results are as follows:1.The antioxidant activity of cumin essential oil: cumin essential oil exhibited good antioxidant activity in removing DPPH free radicals,hydroxyl radicals,superoxide anion radicals and reducing ability,and there was a positive correlation between antioxidant effect and concentration in a certain concentration range.When the concentration of cumin essential oil reached 12 mg/mL,the antioxidant capacity was equivalent to TP and BHT at appropriate concentrations.2.The changes of fat oxidation and fatty acid composition of mutton treated with different cumin essential oil concentrations during micro-freezing(-3?): the acid value,peroxide value and thiobarbituric acid value of mutton fat increased with the storage time.The results of GC-MS showed that palmitic acid(C16:0),stearic acid(C18:0),oleic acid(C18:1)in MUFA,linoleic acid(C18:2)in PUFA were the main fatty acids in mutton.With the extension of micro-freezing storage time,the content of SFA and MUFA increased,but the content of PUFA decreased.The cumin essential oil could delay the oxidation of mutton fat and fatty acid to a certain extent,and when the cumin essential oil concentration reached 12 mg/mL,the effect cumin essential oil as comparable to TP and BHT.3.The changes in myofibrillar protein properties of mutton treated with cumin essential oil of different concentrations during micro freezing(-3?): With the increase of storage time,the carbonyl content and surface hydrophobicity increased,the relative content of ?-helix decreased,the relative content of ?-fold and irregular curl increased.The II and III structures of myofibrillar proteins were destroyed and aggregated due to oxidation;the solubility,emulsifying activity and emulsifying stability of myofibrillar protein decreased;the hardness,elasticity,water holding capacity and whiteness of gel decreased,and cooking loss increased,but the cooking loss increased.The modulus of elasticity(G ')shows a trend of rise-fall-rise.The addition of cumin essential oil could inhibit the oxidation of myofibrillar protein,reduce the damage degree of space structure and maintain functional properties during micro-freezing storage.Moreover,the effect of cumin essential oil was better than TP and BHT when the concentration was ? 12 mg/m L.4.The changes of mutton quality treated with cumin essential oil of different concentrations during micro freezing(-3?): With the increase of storage time,the freshness index of mutton decreased gradually,and the pH value first decreased and then increased,the volatile basic nitrogen,the total number of colonies,the rate of juice loss,the rate of cooking loss and the value of B * showed increasing,the values of L *,a *,and shear force decreased continuously,indicated that the juiciness,tenderness,color and quality of mutton became worse.The addition of cumin essential oil could inhibit the change.When the concentration of cumin essential oil reacheed 12 mg/mL,it could prolong the shelf life of frozen mutton to 30 days,which is similar to the TP and BHT at appropriate concentration..In summary,the cumin essential oil could play an important role in antioxidation,delay the changes of structure and function of mutton fat and myofibrillar protein,prolong the shelf life of mutton,and protect the quality of mutton.The suitable concentration of cumin essential oil was 12 mg/m L.