LACTULOSE CONTENT IN COMMERCIAL UHT-MILKS

Within the framework of a state survey 38 UHT-milk samples obtained from German producers and 13 UHT-milk samples from neighbouring EEC-countries were analysed for their lactulose content. Analytical determination of lactulose was made using both a gas chromatographic method and an enzymic official" method according to sectional sign 35 LMBG. Between both methods good agreement was established. The graph of frequency distribution of the lactulose contents in the German UHT-milk samples showed an asymmetrical frequency distribution which is indicative of milk samples having been subjected to higher heat treatment. 70% of the German producers had observed the limit of 400 mg/kg UHT milk introduced in the German Milk Ordinance (as from 23.06.1989) without encountering difficulties as regards the bacteriological quality. The samples obtained from the other EEC-countries did not show any peculiarities as regards the frequency distribution of the lactulose content so that the introduction of the limit of 400 mg lactulose/kg UHT milk discussed in the member countries appears also appropriate.