Comparative Evaluation of the Qualities of some Selected Tomato-Paste Brands Sold in Kano Market

Abstract

Tomato fruits suffer postharvest losses due to poor storage facilities. One of the few efficient ways of preserving the nutrients, ensuring the availability of tomato all year round and increasing the bioavailability of lycopene is through processing tomato into a paste. In this study, selected tomato-paste brands sold in Kano market were evaluated for their qualities with the aim to identify possible adulteration. A total of eight different tomato-paste brands were collected from Yankura market in Kano. The physicochemical properties, proximate, lycopene and vitamin C contents and microbial quality were determined. The results showed that the tomato pastes had high moisture content (89.27-91.11 %) and low amount of ash (1.06-0.72 %), protein (3.28-1.64 %), fat (1.09-0.81 %) and carbohydrate (6.32-4.42%). The pH (3.73-4.35) and acidity (0.36-0.49%) of the samples were within the Codex Alimentarius Commission (CAC) recommended limit for tomato pastes. The total solids (8.89-12.26%) of the tomato pastes were below the CAC recommended limit which is evident in their low viscosity (210.70-270.20 mPas) values. Microbiologically, the tomato pastes exceeded the CAC maximum limit (10 cfu/g) for coliform content. However, the tomato pastes were rich in vitamin C (19.36-23.58 mg/100 g) and contain an appreciable concentration of lycopene (20.35-27.92 mg/kg). Importantly, they are free from adulteration. Practical application The tomato pastes evaluated in this study is largely popular in the Nigerian market, particularly Kano, leading to their wide consumption. The data obtained can be used to provide informative assessment on the quality of tomato pastes sold in Kano, thereby informing end-users on their quality status, providing recommendations to manufacturers on possible improvements on the quality of their products as well as attract the attention of regulatory agencies on the need to critically assess the quality of imported and locally produced tomato pastes and ensure they meet quality standards before they are launched into the market.