Modelling the growth of Clostridium sporogenes in tomato juice contaminated with mould

Abstract

Tubes of tomato juice agar were inoculated with Clostridium sporogenes and an Aspergillus sp. and incubated aerobically. The clostridium only grew when the Aspergillus was present. pH and oxygen concentration were measured through the depths of the tubes. The Aspergillus grew as a mat on the surface of the gel, removing oxygen and causing a local rise in pH. It was thought that the production of a microenvironment adjacent to the mycelial mat, consisting of raised pH and decreased oxygen concentration, enabled the clostridium to germinate and grow.

Microbiological profile and potential hazards associated with imported and local brands of tomato paste in Nigeria

“…Whereas Lactobacillus and Leuconostoc are both aciduric in nature, the former is more acid-tolerant 1988). The influence of mould growth on acidic foods is of health significance because of metabiotic phenomena (Huht-(Sneath et al 1986 ;Becker et al 1994), and this may have favoured their proliferation in the products (particularly anen et al 1976 ;Efiuvwevwere and Eka 1991 ;Robinson et al 1994), thereby altering the safety margin commonly brand C) with a favourably low pH range (Fig. 1).…”

“…constituted the highest proportion whether in normal or tamination of the raw materials (Anon. 1980 ; Robinson et al 1994), the temperature-time process regime (Hersom and defective samples. Bacillus coagulans was the predominant organism among the Bacillus spp.…”

“…1980 ;Speck 1984). It is public knowledge that cans of tomato paste often Tomato products are of considerable importance world wide show external evidence of spoilage under tropical retail con- (Gould 1983 ;Sidhu et al 1984 ;Robinson et al 1994). In ditions.…”