Determination of pH and Microbiological Quality of Commonly Used Tomato Pastes in Katsina Metropolis, Katsina State, Nigeria

Abstract

Tomato products are of considerable importance worldwide and the demand for tomato paste is increasing rapidly both in domestic and international market. Tomato samples of six different local and international brands were purchased from various retail outlets and analysed for pH values and microbiological quality. The pH values of all the tomato paste samples analysed were lower than the critical level of 4.6, with Mamia (a local brand) having the highestpH value of 4.15. Substantially higher bacterial count was observed in De Rica (an imported brand) and the least viable count was observed in Gino (an imported brand) with no bacterialisolate detected. Five different bacterial species (Staphylococcus aureus, Staphylococcus epidermidis, Bacillus spp, Streptococcus spp and Lactobacillus) were isolated fromthe different brands with Bacillus spp having the highest percentage occurrence. Higherfungal count was observed in De Rica and least was observed in Mamia with no fungi detected.Four different fungal species were detected (Penicilium spp., Mucor spp., Aspergillus niger and Rhizopus spp) in the tested samples, withMucor spp having the highest percentage occurrence. All samples of tomato pastes examined show acceptable pH values but poor microbiological quality, which poses significant public health hazard. This necessitates the need for further studies to investigate the extent of microbial contamination of canned and sachet products used in the preparation of routine cuisines, imposition of strict HACCP principles on processing plants to ensure safety of products and prevention of food-associated diseases and poisoning as well as public enlightenments on sterilization of such products at high cooking temperatures prior to consumption.e