cornell_apr2007_懂得原奶细菌数的含义3页.pdfVIP

MILK QUALITY Sponsored by Understanding raw milk bacteria counts The results of milk testing procedures shed light on your dairy’s hygiene practices By Steven Murphy Good quality raw milk is the starting place for limit for Grade A is 100,000/ml. FYI good quality dairy products that meet consumers’ Milk from clean, healthy cows generally has an ■ Steven Murphy expectations for appearance, smell and taste. SPC less than 1,000/ml, consisting primarily of is a senior Unfortunately, many things can destroy the cows’ “natural flora,” or bacteria natural to the Extension asso- desirable characteristics of dairy products. Of skin, teat cistern and canal. ciate with the greatest concern are contaminating microorgan- Though it’s virtually impossible to prevent Milk Quality isms. They are one of the most important fac- contamination, counts of less than 5,000/ml are Improvement Program in the tors in the quality, as well as the safety, of dairy possible and counts less than 10,000/ml should be Department of products. This is why the industry puts so much achievable (Table 1). These levels are often used in Food Science at emphasis on the microbial quality of raw milk.