Improve The Water Retention Of Chicken Breast Meat Combined With Pulsed Electric Fields And CaCl₂

The water holding capacity of muscle reflects the ability of muscle tissue to maintain water.It directly or indirectly affects the tenderness,color,juiciness and other sensory characteristics of meat.It can be used as an important index to evaluate the quality of poultry meat.In addition,it has a greater impact on the output,structure and color of meat products,so it plays a role in the meat yield and the economic benefits of meat manufacturers and processors.Chicken breast meat as the first consumption of poultry products,because of its high protein content and low fat content,is considered to be better than red meat,and more popular among consumers.However,there still exists some excessive processing methods,freezing and thawing treatments during storage and transportation,which causes poor meat quality and reduces water holding capacity.Calcium salt is used as a nutritional enhancer in the food industry and it can activate calpain in muscle tissue to promote meat quality.At the same time,it has also been used as a low sodium substitute in recent years.In addition,pulsed electric field,a novel technique in meat processing,can influence the microstructure of meat by changing the permeability of cell membrane,so as to improve the meat quality.In this study,through pulsed electric field(PEF)and calcium chloride(Ca Cl₂)synergistic effects,we explored the water holding capacity,meat color,protein oxidation,protein denaturation and water distribution of chicken breast meat.On this basis,we explored the characteristics of myofibrillar protein and gel properties.Furthermore,combined with sous vide cooking technology,in order to provide theoretical reference and technical support for practical production and application.The main research contents and results are as follows:(1)The effects of different calcium chloride concentrations(0,0.1,0.2,0.3,0.4,0.5 M)and different electric field intensities(0,0.5,1,1.5,2 k V/cm)on chicken breast meat quality were studied by measuring the color,pH,water holding capacity and cooking loss.The results showed that the lowest cooking loss of 19.78%and the highest water holding capacity of 82.06%can be obtained under the condition of Ca Cl₂ concentration of 0.4 M and electric field strength of 1.5 k V/cm.Through low field nuclear magnetic resonance(NMR),we found that the effect of ion and electric field caused the water to move from exterior of myofibrils to interior,which promoted higher contents of immobilized water.(2)Myofibrillar protein was extracted from chicken breast meat after different pretreatment.The carbonyl content,total sulfhydryl content,solubility,surface hydrophobicity and other indicators were measured.The protein conformation was characterized by ultraviolet absorption spectrum,fluorescence spectrum and Fourier transform infrared spectrum.The results showed the synergistic effect of calcium chloride and pulsed electric field could decrease the total sulfhydryl content and fluorescence intensity,as well as increase the solubility and surface hydrophobicity,which indicated that the microenvironment of amino acid residues in the side chain was changed by protein molecular expansion and hydrophobic group exposure.At the same time,the pretreatment of ion and electric field caused lower carbonyl change,which demonstrated the protein oxidation could be inhibited a certain to some extent.(3)Through the determination of physical and chemical indexes such as gel whiteness,cooking loss,water holding capacity and strength,combined with scanning electron microscopy and Raman spectroscopy,the effects of different pretreatment on the properties and structure of myofibrillar protein gel were explored.The results showed that the synergistic effect of calcium chloride and pulsed electric field can improve the whiteness of the gel,making it formed a more compact and uniform three-dimensional network structure during the thermal induction process,and retained more moisture.(4)The chicken breast meat pretreated by calcium chloride and pulsed electric field was cooked by a new vacuum low temperature cooking method under different temperature and time conditions,and the physical and chemical indexes such as moisture content,color,pH,cooking loss and fat oxidation were determined.The results showed that the moisture content of chicken breast decreased significantly with the increase of temperature and time,and the moisture content of chicken breast at 60?was generally higher than that at other cooking temperatures.At the same time,the denaturation degree of myoglobin was reduced at the temperature of 60?,so it had a better appearance.In addition,when the cooking temperature was at 60?and the cooking time was 5 hours,the fat oxidation value was lower,so that the high-quality product can be obtained.