ISO 29981:2024

Milk products — Enumeration of bifidobacteria — Colony-count technique

Scope

This document specifies a method for the selective enumeration of bifidobacteria in milk products by using a colony-count technique at 37 °C under anaerobic conditions.
The method is applicable to milk products, such as fermented (e.g. yoghurts) and non-fermented milks (e.g. pasteurized milks, skim milks, whey protein concentrates), milk powders and formulae (e.g. infant formulae, follow-up formulae for older infants, products for young children) where these microorganisms are present and viable, in combination with other lactic acid bacteria or alone. The method is also applicable to starter and probiotic cultures. For proposed quality criteria of dairy products, see, for example, CXS 243-2003.
Bifidobacteria used in milk products usually belong to the following species (e.g. References [7] and [10]):
—     Bifidobacterium adolescentis;
—     B. animalis subsp. animalis;
—     B. animalis subsp. lactis;
—     B. bifidum;
—     B. breve;
—     B. longum subsp. infantis;
—     B. longum subsp. longum.