Alkaline phosphatase activity and microbiological quality of heat-treated goat milk and cheeses

• Products of goat milk origin (pasteurized, UHT milk and cheeses) were examined for alkaline phosphatase activity and microbiological quality.
• Most of the samples had an alkaline phosphatase activity below 350 mU/L (milk) and 10 mU/g (cheese).
• Several products were contaminated with Enterobacteriaceae and Escherichia coli whereas Listeria monocytogenes, Salmonella spp., Staphylococcus aureus were not present.
• The results indicate that products from heated goat milk were safe for consumers.

The importance of goat milk and products of goat milk origin in human nutrition has increased in recent years. To provide a high quality and safety of this kind of food and to avoid a risk for public health, the criteria referring to microbiological quality of raw milk and final products, as well as to heat treatment have to be met. In the present study the alkaline phosphatase activity (ALP) in pasteurized goat milk and cheeses was determined. A hygiene quality and a presence of selected bacteria in goat milk products were also tested. The samples of milk (n = 100) and cheese (n = 105) originated from Polish dairies were analyzed. Ninety seven percent of milk and 94.3% of cheese samples showed ALP activity below 350 mU/L and 10 mU/g, respectively. The absence of Salmonella spp., Listeria monocytogenes and coagulase-positive staphylocci was observed in all samples tested, whereas in some of them Escherichia coli and Enterobacteriaceae were identified. The present study showed that pasteurized and UHT goat milk as well as goat cheeses from pasteurized milk were safe for consumers in terms of the absence of bacterial pathogens if proper pasteurization of raw milk is applied.