A decade of improvement: New York State fluid milk quality

作者：Martin N H; Carey N R; Murphy S C; Wiedmann M; Boor K J^*

来源：Journal of Dairy Science, 2012, 95(12): 7384-7390.

DOI：10.3168/jds.2012-5767

• fluid milk
• shelf life
• milk quality

The microbiological and sensory qualities of New York State (NYS) fluid milk products were assessed as part of an ongoing fluid milk quality program. Commercially packaged pasteurized fluid milk samples were collected twice a year over the 10-yr period from 2001 to 2010 from 14 NYS dairy processing facilities and analyzed at the Milk Quality Improvement Program (MQIP) laboratory. Each sample was tested throughout refrigerated storage (6 degrees C) on day initial, 7, 10, and 14 for standard plate count (SPC), coliform count (CC), and sensory quality. Over the 10-yr period, the percentage of samples with bacterial numbers below the Pasteurized Milk Ordinance (PMO) limit of 20,000 cfu/mL at d 14 postprocessing ranged from a low of 21.1% in 2002 to a high of 48.6% in 2010. Percent samples positive for coliforms during that same period ranged from a high of 26.6% in 2002 to a low of 7.5% in 2007. Mean d 14 sensory scores ranged from a low of 6.0 in 2002 to a high of 7.3 in 2007. Samples contaminated with coliforms after pasteurization have significantly higher SPC counts and significantly lower sensory scores on d 14 of shelf-life than those not contaminated with coliforms. Product factors such as fat level were not significantly associated with SPC, CC, or sensory quality of the product, whereas the factor processing plant significantly affected overall product quality. This study demonstrates that overall fluid milk quality in NYS, as determined by microbiological and sensory analyses, has improved over the last decade, and identifies some challenges that remain.

• 出版日期2012-12