Effect Of Partial Replacement Of NaCl With KCl Combined With High-temperature Drying-ripening Technology On Proteolysis And Color Of Ham Muscle

Dry-cured ham is one of the most representative international traditional cured meat products with characteristics of rich flavor,bright red color and rich taste substances.Currently,dry-cured hams in Europe are almostly produced with low salt(4%?5%)technology and the flavor quality have been guaranteed.But dry-cured hams in China are still produced traditionally with long processing time,high salt content(8%-12%).All these limit the production and consumption of dry-cured ham.Many domestic and foreign studies have shown that the technology of partial replacement of NaCl with KCl has great potential in reducing the sodium content of meat products,but the influence of this technology on proteolysis and color changes during processing have not been researched enough.This study aimed to improve dry-cured ham process by combining partial replacement of NaCl with KCl technology with high-temperature drying-ripening technology and the effect of KCl on proteolysis and color formation will be studied.We try to provide a technical basis for the dry-cured ham modern processing.The research contents and results are as follows:1.Study of dry-cured ham process by combining partial replacement of NaCl with KCl with high-temperature drying-ripening technologyThe L9(3~4)orthogonal experiment was conducted to study the effect of intensifying high-temperature temperature,salt content,intensifying time and the replace proportion of KCl on proteolysis and sensory quality.The results indicated that:Proteolysis index(P.I.%)was correlated with intensifying time significantly positively(p<0.05),free amino acids(FAA)content was correlated with intensifying time significantly positively(p<0.05)but correlated with salt content significantly negatively(p<0.05),sensory scores and intensifying time had a significant positive correlation(p<0.01).There was no significant effect of intensifying high-temperature temperature and the replace proportion of KCl for each index(p>0.05).The interaction between intensifying time and the replace proportion of KC1,intensifying temperature and intensifying time had a significant negative correlation with sensory scores(p<0.01).The interaction between salt content and the replace proportion of KCl,the interaction of intensifying temperature and intensifying time had a significant positive correlation with FAA content(p<0.01).Taking all factors,the optimum process conditions are as follows:intensifying temperature 35?,salt content 5%,intensifying time 55d,the replace proportion of KCl 30%.2.The influence on muscle proteolysis of dry-cured ham with partial replacement of NaCl with KClDry-cured hams were produced with high-temperature drying-ripening technology(intensifying temperature 36?,salt content 6.5%,intensifying time 45d).A comparative study was carried out to study the effect of the two salts on salt content,moisture content,pH value,proteolysis index,peptide nitrogen(PeN)and ammonia nitrogen(AN)content,FAA content,cathepsin(B and L)potential activities of biceps femoris during processing.The results showed that the penetration of salt had been speed up and the salt content of products,especially Na+ content had been reduced and there was no significant difference(p>0.05)with cathepsin(B and L)potential activities of biceps femoris when 40%NaCl was replaced by KC1.So did physical and chemical indicators,proteolysis index,PeN and AN content of the two final products at the end of the processing(p>0.05).The kinds of FAA in the two kinds of products were the same but the content of 8 kinds of FAA,i.e.Tau,Asp,Asn,Gly,Val,Lys,Arg,Trp increased and the total content of FAA increased about 10.99%when 40%NaCl was replaced by KC1.3.Study on the color formation of dry-cured ham muscle and the influence of partial replacement of NaCl with KCl on colorDry-cured hams were produced with high-temperature drying-ripening technology(intensifying temperature 36?,salt content 6.5%,intensifying time 45d).A comparative study was carried out to study the color formation of dry-cured ham and the effect of the two salts on salt content,moisture content,pH value,color value,oxidation state of myoglobin,haem pigments content,Zn porphyrin IX(Zn-PP IX)of semimembranosus during processing.The results showed that there was no significant difference(p>0.05)with physical and chemical indicators,color value,the content and state of red pigments in the two products when 30%NaCl was replaced by KCl.The unique color of dry-cured ham was formed by the oxidation state of myoglobin,content of red pigments and state of muscle tissue.The relative content of oxymyoglobin(OMb)and metmyoglobin(MMb)increased about 22.07%and 25.21%,but deoxymyoglobin(DMb)relative content decreased about 47.27%.L*value was positively correlated with relative content of DMb significantly(p<0.01),negatively correlated with relative content of OMb and MMb significantly(p<0.01)and the ratio of OMb and MMb also influenced the L*value.In the low range(0?27.49%),the higher MMb relative content was,the bigger a*value was and the influence of MMb was bigger than OMb.The content of haem pigments and Zn-PP IX increased about 553%and 5296%during the processing and were positively correlated with a*and C value significantly(p<0.01).