三川焐灰火腿和风干火腿发酵过程中理化性质变化

研究三川焐灰火腿和风干火腿发酵过程中理化性质的变化，分析发酵方式不同的2 种火腿在发酵6～12 个月期间主要理化性质，如pH值、水分含量、水分活度、总挥发性盐基氮（total volatile basic nitrogen，TVB-N）含量、NaCl含量、蛋白质含量、色差（亮度值（L*）和红度值（a*））及游离氨基酸含量的变化。结果表明：发酵6～12 个月期间，三川焐灰火腿的pH值由6.05升至6.13，风干火腿由6.02升至6.09，在发酵成熟过程中，焐灰火腿的pH值始终高于风干火腿；焐灰火腿的水分含量由54.2%降至43.0%，水分活度由0.71降至0.65，风干火腿的水分含量由50.3%降至41.4%，水分活度由0.69降至0.65；焐灰火腿的TVB-N含量由30.1 mg/100 g上升至65.1 mg/100 g，风干火腿由31.7 mg/100 g上升至60.9 mg/100 g；焐灰火腿的NaCl含量由4.48%上升至5.40%，风干火腿由4.60%上升至5.52%；焐灰火腿的蛋白质含量由28.8%上升至38.4%，风干火腿由30.2%上升至40.9%；焐灰火腿和风干火腿的色差值呈一系列复杂变化；焐灰火腿和风干火腿发酵过程中均检测出17 种游离氨基酸，各游离氨基酸含量变化趋势与游离氨基酸总含量相似，且各游离氨基酸含量在发酵过程中的变化有明显的差异性。

Changes in Physicochemical Indexes of Ash-Covered Ham and Air-Dried Ham from Sanchuan County of Yunnan Province during Fermentation

To study the changes in physicochemical properties of ash-covered ham and air-dried ham from Sanchuan during the fermentation process, the main physicochemical properties including pH value, moisture, water activity, total volatile basic nitrogen (TVB-N), sodium chloride, protein and free amino acid contents, and color difference (luminance value (L*), redness value (a*)) were measured between 6 and 12 months of fermentation. The results obtained indicated that the pH value of ash-covered ham rose from 6.05 to 6.13 and was always higher than that of air-dried ham between 6 and 12 months of fermentation, which increased from 6.02 to 6.09. Besides, the moisture content and water activity of ash-covered ham decreased from 54.2% to 43.0% and from 0.71 to 0.65, respectively; the moisture content and water activity of air-dried ham fell from 50.3% to 41.4% and from 0.69 to 0.65, respectively. The TVB-N content of ash-covered ham increased from 30.1 to 65.1 mg/100 g and air-dried ham from 31.7 to 60.9 mg/100 g. The sodium chloride content of ash-covered ham rose from 4.48% to 5.40% and air-dried ham from 4.60% to 5.52%. The protein content of ash-covered ham rose from 28.8% to 38.4% and air-dried ham from 30.2% to 40.9%. The color difference values of both hams changed in a complex manner, and a total of 17 free amino acids were detected in either of them. The individual free amino acid contents changed in a similar manner to the total content, and significantly differently from each other.