Simon M, Hansen A P
North Carolina State University, Raleigh 27695, USA.
J Dairy Sci. 2001 Apr;84(4):784-91. doi: 10.3168/jds.S0022-0302(01)74534-1.
Raw milk from three different dairies (each a separate trial: 1, 2, and 3) was standardized to 2% fat and processed at 140.6, 129.4, 118.3, and 107.2 degrees C (temperatures 1, 2, 3, and 4, respectively) for 2 s and packaged into six different packaging boards, [standard (A) milk boards with standard seam, juice boards with standard (B) and J-bottom (D) seams, barrier boards with standard (C) and J-bottom (E) seams and foil (F) boards with J-bottom seam], resulting in 24 different treatments. Standard plate count (SPC) was used to test for microbial quality, and taste panels were employed for flavor acceptability and difference in the milk stored at 6.7 degrees C at 1, 2, 3, 5, 10, and 15 wk. Lipolysis was measured by standard procedures for acid degree value (ADV) of milk. Statistical analysis of taste panel data showed that the flavor of 14 milk samples deteriorated over time. The flavor of UP milk packaged in standard (A) and juice (B and D) boards deteriorated at a faster rate than UP milk packaged in barrier (C and E) and foil (F) boards. At wk 6, a slightly hammy or cardboardy flavor was detected for milk packaged in boards with standard seams (A, B, and C) and a slightly cooked flavor was detected for milk packaged in barrier and foil boards with J-bottom (E and F) seams. The hammy or cardboardy flavor intensified with storage time, and all of the cooked flavor dissipated at wk 10. Milk processed at 118.3 and 129.4 degrees C maintained the lowest bacterial growth rates, and milk processed at 107.2 degrees C had the highest bacterial growth rates during 15 storage wk. More than 87% of milk processed at 118.3, 129.4, and 140.6 degrees C maintained acceptable level of bacterial counts at wk 15. The extent of lipolysis showed that ADV of milk increased with storage time. The ranges of ADV for trials 1, 2, and 3 were 0.76 to 0.85 (from 12 to 22 wk), 0.39 to 0.51 (from 6 to 16 wk), and 0.53 to 0.60 (from 6 to 16 wk), respectively.
来自三个不同奶牛场的生牛奶（每个为单独试验：试验1、试验2和试验3）被标准化至2%的脂肪含量，并分别在140.6、129.4、118.3和107.2摄氏度（分别为温度1、温度2、温度3和温度4）下处理2秒，然后包装到六种不同的包装板中，[带有标准接缝的标准（A）牛奶板、带有标准（B）和J型底部（D）接缝的果汁板、带有标准（C）和J型底部（E）接缝的阻隔板以及带有J型底部接缝的铝箔（F）板]，从而产生24种不同的处理方式。采用标准平板计数法（SPC）检测微生物质量，并使用味觉小组评估在6.7摄氏度下储存1、2、3、5、10和15周的牛奶的风味可接受性和差异。通过牛奶酸度值（ADV）的标准程序测量脂解作用。味觉小组数据的统计分析表明，14个牛奶样品的风味随时间变差。包装在标准（A）和果汁（B和D）板中的超高温灭菌（UP）牛奶的风味比包装在阻隔（C和E）和铝箔（F）板中的UP牛奶变差得更快。在第6周时，包装在带有标准接缝（A、B和C）的板中的牛奶检测到轻微的火腿味或纸板味，而包装在带有J型底部（E和F）接缝的阻隔板和铝箔板中的牛奶检测到轻微的煮熟味。火腿味或纸板味随储存时间增强，并且所有煮熟味在第10周消散。在118.3和129.4摄氏度下处理的牛奶在15周的储存期内保持最低的细菌生长速率，而在107.2摄氏度下处理的牛奶在15周储存期内细菌生长速率最高。在第15周时，在118.3、129.4和140.6摄氏度下处理的牛奶中超过87%保持了可接受的细菌计数水平。脂解程度表明牛奶的ADV随储存时间增加。试验1、试验2和试验3的ADV范围分别为0.76至0.85（从第12周到第22周）、0.39至0.51（从第6周到第16周）和0.53至0.60（从第6周到第16周）。
