367. Bacterial growth in reconstituted spray-dried milk

Abstract

1. Over 200 samples of spray-dried milks from eight British plants have been examined for total and spore counts, numbers of β-haemolytic colonies and for moulds, yeasts and conliform bacteria.2. The mean count and standard deviation range for total and spore count are reported. No β-haemolytic colonies other than those due to spore-forming bacilli were detected.3. After ageing the reconstituted milk for 24 hr. at 15–5° C. the mean count (37° C.) was unchanged; at 22° C. the increase was 2000-fold and at 37° C. the milk had clotted within this time.4. The predominating organisms in a random selection of the reconstituted milks are described, both for the fresh milk and after ageing at 15·5 and 22° C. A marked increase i n spore-forming bacilli was noted at 22° C.5. The relation of the flora of reconstituted milk to its food-poisoning potentialities is briefly discussed.