scope:

This part of ISO 11816 | IDF 155 specifies a fluorimetric method for the determination of alkaline phosphatase (ALP, EC 3.1.3.1) activity in cheese. This method is applicable to soft cheeses, semi-hard and hard cheeses provided that the mould is only on the surface of the cheese and not also in the inner part (e.g. blue veined cheeses). The instrument can read activities in the supernatant as high as 7 000 milliunits per litre (mU/l) NOTE - In large hard cheeses where the whey curd mixture is scalded at temperatures above 50 °C, high temperatures remain for a relatively long time, especially in the centre of those cheeses, promoting phosphatase inactivation. To determine the alkaline phosphatase activity in this kind of cheese a specific cheese sampling shall be applied (see 6).