| Summary: | 碩士 === 國立屏東科技大學 === 食品科學系 === 94 === The changes of contents of chemical composition (moisture, crude protein, crude fat, sodium chloride), flavor components and the value of water activity (Aw), pH were examined during processing of raw ham. Effect of salt on the protein of raw ham during curing period by DSC and texture analyser were also studied. The results obtained were as followed. The value of Aw went down from 0.99 of the fresh ham to 0.91 of the cured ham, as moisture content decreased too, but the crude protein and crude fat content increased relatively during the curing process. The salt contents of ham increased from 0.3% of raw meat to 3.81% after curing day1 by 6% (w/w) NaCl addition, and then its contents was almost constant (6.5%). The value of pH went down from 6.06 of the fresh ham to 5.86 and then up to 5.92 of the finished product. Contents of each free amino acid and ammonia in the ham were increased during the processing. Especially increases of threonine, serine, glutamic acid, alanine, valine, leucine and lysine etc. The DSC analysis, it became clear that denaturation of the meat mainly occurred on myosin by salting. As the denaturation proceed, the enthalpy change, ΔH of 1.212 cal/g rapidly decreased to 0.824 cal/g on curing day3, and then gradually decreased to 0.727 cal/g. Rupture strength of the meat increased during process as a whole, the change of dynamic rigidity of the pork meat pastes by heating exhibited the tendency to decrease at the temperature range from 52℃ to 58℃ after curing day7. The result was considered to come from the structure change of the sample due to thermal denaturation of myosin.
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