ASSESSMENT OF ANTIOXIDANT ACTIVITY, PHYTONUTRIENTS AND NUTRITIVE QUALITIES OF SELECTED TOMATO PASTE SOLD IN UMUAHIA METROPOLIS

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3.3.2    Determination of chemical properties of tomato sample   23

5.3:      References                                                          41

Tomato (Lycopersicon esculentum) is an annual vegetable commonly consumed in Nigeria. Over 170 million tonnes of tomato were produced in the world in the year 2014 (FAO, 2014). It is widely a distributed crop which can be grown on several climates. This confers on the crop its ability to survive at various temperatures. More than 30% of global tomato is grown from the Mediterranean (Ahmet and Vedat, 2009).

Tomato is consumed raw, in salads, or after cooking but because they are highly perishable and large wastage is recorded in fresh tomato fruit yearly. Processing operations such as concentration and heat treatment have been applied to ensure their availability all year round (Khachik et al., 2002). Both fresh and processed tomato possesses a high nutritional value, due to its content of vitamins, folates, carotenoids and phenolic compounds (Savatovic-Cetkovic, Canadanovic-Brunet and Dilas, 2010).    

Lycopene, the carotenoid which gives tomato its reddish colour, is one of the most powerful scavenger of oxygen singlet and free radicals in body, and plays an important role in many biological functions, such as the modulation of intercellular gap-junction communication, hormonal and immune systems, and metabolic pathways ( Livny et al., 2002; Blum et al., 2005; Basuny et al., 2009).

In addition to carotenoids, tomato contains a variety of natural antioxidants, including ascorbic acid and phenolic compounds (phytochemicals). Dietary intake of tomato and tomato products containing lycopene has been shown to be associated with a decreased risk of chronic diseases such as cancer (breast, colon, prostate) and cardiovascular diseases (Agarwal and Rao, 2000; Willis and Wians. 2003).  This implies that commercially sold processed tomato paste should contain a good amount of these phytochemicals. However, adulterated tomato paste, lacking in these important nutrients have entered the market and consequently resulting to economic losses and possibly food poisoning (Ndife et al., 2020). Umeofia, (2016) lamented that the country loses huge sums of money to importation of fake tomato products. He reported that a good number of tomato products imported into the country from Asia were often adulterated with starch which could have adverse effects on the health of Nigerians. Several parameters have been used to assess the quality of tomato paste. These include: the consistency, total solids content, titratable acidity, pH and levels of sugar (Ahmet and Vedat, 2009, Lu et al., 2014). But according to Ndife et al. (2020) the main quality parameters of tomato pastes, as perceived by consumers are colour, consistency and flavour but less emphasis is laid on the nutritional and health benefits derived from consuming the processed tomato. Well- structured studies which examine the quality of different tomato brands sold in Nigeria are limited. Therefore, the aim of this study was to assess the antioxidative and nutritive qualities of selected tomatoes paste sold in Umuahia Metropolis which include the following brands;  Sonia, Clappa, Star, Gento and Super delicieux.

The infiltration of poor-quality tomato products into the country has been attributed to the activities of unpatriotic marketers conniving with unethical foreign companies to bring into the country tomato pastes loaded with starch and treated with food colour additives in order to achieve the deep red colour. Therefore evaluating the nutritional quality of tomato products sold in Nigeria will reduce the level of adulteration of such products as they are being envisiaged.

The major objective of the study was to assess the antioxidative and nutritive qualities of selected tomatoes paste. This is to be achieved through the following specific objectives:

With poor regulatory systems and porous borders there is no doubt that it is the responsibility of researchers to generate evidence based data and information which could be helpful in strengthening regulatory agencies, formulate better policies that will benefit the Nation, improve public health and quality of life of citizens. Also, considering the lack of documented information on the assessment of the antioxidative and nutritive qualities of selected tomatoes paste, the information generated would help consumers to make an informed decision when choosing available products.