HlGt-i TEMPERATURE-SHORT TIME (HTST) PROCESSING OF SUSPENSIONS CONTAINING BACTERIAL SPORES

HTST sterilization of nutrient broth containing particles inoculated with B. subtilis 5230 spores was evaluated. The particles were tight rolls of chromatography paper 12.7 mm long by 7.64 mm in diam. Presence of these particles increased the time needed to sterilize the broth. These results are quantitatively presented as a protection ratio. For nutrient broth containing paper rolls, the protection ratio was of no concern at a processing temperature of 240° F, began to become important at 250° F and became the dominant factor at 260° F and above. It is thus established that the time of a HTST process of liquids containing particles differs significantly from HTST processing of clear liquids. For example, this difference should apply to commercial HTST processing of meat in a gravy stew or dumplings in a chicken soup as contrasted with consommes or to fermentation mashes as compared to fermentation broths.