Abstract

This study investigates the effects of preservation techniques and storage on the microbiological and sensory properties of five tomato varieties: Marzanino, Xina, NHle 158-3, Picenza 0161, and Roma VF. Preservation methods included freezing and home canning, with additives such as sodium chloride (0-2.5%) and lime juice (0-10%). Using spread plate techniques, microbial loads were enumerated over a storage period of 0-4 months. Fresh tomatoes exhibited total viable fungal counts ranging from 1.60 x 10³ to 2.68 x 10⁴ CFU/g, with the highest counts in the Picenza 0161 variety. Frozen tomatoes stored for 4 months had counts between 1.2 x 10² and 4.6 x 10³ CFU/g, while freshly canned tomato paste and quartered tomatoes showed no bacterial growth. Total viable counts for canned tomatoes ranged from 0 to 6.00 x 10³ CFU/g. Fungal counts in fresh tomatoes ranged from 2.20 x 10³ to 5.10 x 10⁴ CFU/g, while frozen tomatoes ranged from 1.70 x 10³ to 6.30 x 10³ CFU/g. Six bacterial and nine fungal species were isolated, namely Acetobacter sp., Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Sarcina sp., and Staphylococcus aureus. The fungal isolates included Aspergillus sp., Cladosporium sp., Debaryomyces sp., Fusarium oxysporum, Geotrichum candidum, Penicillium expansum, Pichia sp., Rhizopus stolonifer, and Saccharomyces cerevisiae. Penicillium expansum were the most predominant fungal species in fresh, frozen, and canned tomatoes, while Rhizopus stolonifer was the least. In the bacterial species Pseudomonas aeruginosa was the most predominant in fresh, frozen, and canned tomatoes, while Sarcina sp. was the least. Stews made from fresh and canned tomato pastes were rated higher in aroma and taste, with canned quartered tomatoes preserved with 1.25% NaCl showing the best sensory qualities.