The Relationship Between Protein Degradation And Quality Of Jinhua Hams

The relationship between protein degradation and quality of Jinhua hamsJinhua ham is a kind of traditional excellent food that is 1,200 years old and famous for bright color, pleasant aroma, delicious flavor and wonderful shape. In despite of it's above virtue, there are such questions to be improved as outdated processing, long processing time, the instability in quality, singleness of product variety, and the control of quality, etc. At present, Jinhua ham is classified only according to sensory assess not physicochemical properties, so that the control of quality doesnt keep the same pace with international standard. According to this research, we can realize the relation between protein and quality of jinhua ham, explore the mechanism of protein degradation of Jinhua ham during maturing, establish physicochemical properties and scientific management of Jinhua ham.The quality of jinhua ham is determined by lots of factors, including different physicochemical properties and sensory assess, therefore, completely describe the difference among all hams is complicated question. Because the most important component in jinhua ham is protein whose transformation can directly affect quality of ham, nitrogenous compounds, amino acid and multipeptides are analyzed in excellent Jinhua ham according to sensory assess in comparison with raw meat and bacon.By principal components principal factor analysis of nitrogenous compounds, we found the principal components distinctly effecting quality of jinhua ham and the structure of every principal factor. The correlation analysis dealed with the effect of processing conditions on the composition of nitrogenous compound. At last 15 samples of excellent Jinhua hams were roundly assessed in order to observe relationship between sensory assess and physicochemical analysis.Dissociative and hydrolyzed amino acids were assayed in ham, bacon and raw material, in order to discuss their contribution to flavour or nutritional development in jinhua ham. RP-HPLC/MS was used to separate small water-soluble peptidesextracted from jinhua ham, so that we can study the evolution of peptides in high-quality jinhua ham and from those peptide maps to try to charaterise flavour development in jinhua ham.The physicochemical analysis showed that bacon equaled raw material in the degree of protein degradation (14.17%VS.15.54%) that was the first peak of protein degradation (conditioning). Two times degradation peak (22.10%) of protein in Jinhua ham happened and the second time equaled the first time in the degree. At last, two times protein degradation developped the flavor of jinhua hams. The average degradation percentage in sarcoplasmic proteins, myofibrillar proteins and stroma pronteins were ordinally 62.07%, 46.15% and 8.56%, so that substances coming from degradation of sarcoplasmic proteins and myofibrillar proteins notabily effected qualities of jinhua hams. According to principal components principal factor analysis, First 5 pincipal components in cumulative percentage components for physicochemical quality of jinhua hams added up to 81.38%. The C.V. of total judgement in jinhua ham was 0.0017698, the variance among samples is slight, there wasnt discrimination between physicochemical analysis and sensory assess. There were good relativity between water percent, NaCI%, Aw, pH and nitrogenous compounds, Correlations between sarcoplasmic proteins, AN, pH and NaCI% were 0.32, -0.74 and -0.20, it showed that increased NaCI may stay degree of protein degradation. In the processing of jinhua hams NaCI% is commonly controlled at 8%. Correlations between pH, AN, TVBN and NaCI% and stroma pronteins were 0.44, 0.18 and 0.12. Correlations between PeN, nucleic acid and stroma pronteins were -0.23 and -0.07, it showed that low pH value (acid) could prevent meat from alkali putrefaction. The above relations will help to improve the present processing technology of Jinhua hams.The amino acid analysis showed that varities and content of dissociative amin...