Nature of Tomatoes Microflora under Storage

Aims: The aim of this study is to determine microbial load of tomatoes including microbial species it constitute under storage with particular reference to raw and canned tomatoes.

Study Design: Random sampling of Tomatoes, from selected sources in Ondo State, Nigeria.

Place and Duration of Study: Sample: Akungba-Akoko and some communities in Ondo State. Analysis at Microbiology Laboratory, Adekunle Ajasin University, Akungba-Akoko. August, 2011 to July, 2012.

Methodology: Pour plate techniques were used to enumerate microbial load of the samples. Discrete isolated colonies from these sources were sub-cultured using streak plate method to get purified cultures for the study. The bacterial isolates were Gram stained while fungal species were examined using lactophenol cotton blue stain. Standard microbiological methods were subsequently used to identify the tomatoes microflora.

Result: The bacterial load observed during the study ranged from 1 x 105 in CT3 to 38 x 105 in CT2 which are the canned sample sources. Similar range of 10 to 21 cfu/mL was recorded for the raw tomatoes. Microorganisms generally encountered include eight bacteria species such as, Leuconostoc Species, Pediococcus species, Staphylococcus species, Planococcus species, Micrococcus Species, Bacillus Species, Streptococcus species and Clostridium species. Similarly, three fungal species were encountered during the study. These include Saccharomyces species, Aspergillus species and Neurospora species.

Conclusion: The microbial load and isolates from raw (local) tomatoes sources are at close range to those isolated from the canned tomatoes sources which still shows the natural protective lactic acid components of this food source. Exposure of canned tomato to air gives room for deterioration by microorganisms as shown in this study. So, both raw and canned tomato should be well protected from contaminants to limit proliferation of spoilage organisms coupled with improvement of canning Technology. Similarly, the nature of microorganism encountered can be used to determine some food preservation systems in the study area