Published online by Cambridge University Press: 01 June 2009
This paper presents in statistical form the results of the bacteriological examination of over 1200 samples of National Dried Milk during the period 1944–9. Factors which may affect the results are discussed. The general level of bacterial quality disclosed is high, but appreciable differences are shown in the standards reached at different factories and repacking depots. No general trend with time was observed in the figures throughout the period of 6 years considered, and no correlation was observed between the counts obtained and the time which had elapsed since packing into 20 oz. tins. Between counts at 37 and at 55° C. some correlation was noted in the products of most factories and depots, and the significance of this observation is discussed. The counts obtained are compared with various standards which have been put forward or are now in operation, and ways are suggested in which the figures might be used to set up standards of bacterial quality for roller-dried milk powder in this country.