Project Materials

PHYTOCHEMICAL ANALYSIS OF SELECTED TOMATO PRODUCTS

Chapter one

INTRODUCTION

Consumption of tomatoes and tomato-based products aids in the absorption of a diverse variety of carotenoids in human serum and tissues. Lycopene is the most prevalent carotenoid in tomatoes, and it is primarily responsible for the deep red colour of tomato fruits and tomato products. More than 40 carotenoids are found in fruits and vegetables, and humans frequently absorb and metabolise these compounds.

Tomatoes and tomato products are currently being studied for their possible significance in prostate cancer prevention and treatment. This study summarises in vitro and in vivo evidence, as well as molecular data, demonstrating tomatoes’ anticarcinogenic potential.

Raw and processed tomatoes are among the most popular veggies. They are high in phytochemicals, carotenoids, and polyphenols. Lycopene and quercetin are the most abundant carotenoids and flavonoids, respectively.

Canned tomato sauce is the principal source of lycopene, but tomato peel contains flavonols. The majority of epidemiological studies suggest that eating tomatoes and tomato derivatives lowers your risk of developing prostate cancer.

The health professionals’ follow-up study discovered that men who ate 2 to 4 servings of raw tomatoes per week had a more than 20% lower risk of prostate cancer than those who did not eat tomatoes.

In a case-control research with the physician’s health study, high lycopene plasma concentrations were linked to a low risk of prostate cancer and aggressive prostate cancer. In vitro studies reveal that the chemicals present in tomatoes are powerful anticarcinogens.

The polyphenols quercetin, kaempferol, and naringerin inhibit cancer cell proliferation in a dose-dependent way. These chemicals do not have harmful effects. In a prostate cancer rat model, tomato powder, but not lycopene, reduced prostate cancer-related mortality.

This shows that the chemicals found in tomatoes have an additional effect on prostate cancer. Lycopenes are classified as either cis or trans isomers. Lycopene has a half-life of about 10 to 14 days and hence remains in the body during the washout period.

The trans isomer predominate in tomatoes, while the cis isomer dominates serum and tissues, as well as during a washout period. Thus, recent lycopene intake is represented in blood concentrations, but long-term exposure is determined in tissues.

Lycopene is a bioactive carotenoid present in numerous red fruits and vegetables, including tomatoes, watermelon, and pink grapefruits. Lycopene concentrations vary between fruits, vegetables, and their products. This natural red pigment is only produced by plants and microorganisms (fungi, bacteria, and algae).

It enhances light absorption during photosynthesis and protects against photosensitisation (Adam et al., 1996). Animals, including humans, cannot synthesise lycopene, hence they must receive it from diet (Tapiero et al. 2004; Omoni and Aluko, 2005).

Although tomatoes have a lower nutritional concentration than other commercially grown fruits, they are a rich source of lycopene. Lycopene accounts for 83% of the total pigment content in tomatoes (Shi et al., 1990).

As a result, the amount of lycopene found in tomatoes, other fruits, and vegetables varies depending on variety, ripeness, and other climatic and agricultural factors.

The amount of vitamin C in the diet that is absorbed and the rate at which the excess is removed from the body vary greatly depending on the dose. There have been no large-scale, randomised clinical trials on the effects of high dosages in the general population.

Venturi proposed that the antioxidant effect of ascorbic acid originated in the plant kingdom around 500 million years ago (mya), when plants began to adapt to antioxidant-deficient fresh waters of estuaries. Ascorbic acid, or vitamin C, is a ubiquitous enzyme cofactor in animals that aids in the formation of collagen.

Ascorbate is an effective reducing agent capable of quickly scavenging a variety of reactive oxygen species (ROS). Freshwater fish also require vitamin C in their food or they may develop scurvy. The most common indications of vitamin C deficiency in fish are scoliosis, lordosis, and dark skin colouration.

The name “carotene” was coined in the early nineteenth century by the chemist Wachenroder, who crystallised this molecule from carrot roots. Carotenoids are highly coloured (red, orange, yellow) fat-soluble substances found naturally in many fruits, cereals, oils, and vegetables (green plants, carrots, sweet potatoes, squash, spinach, apricots, and green peppers).

Beta-carotene is one of them. Alpha, beta, and gamma carotene are termed provitamins because they can be transformed into active vitamin A. The carotenes have antioxidant effects.

Vitamin A has a variety of biological roles, including involvement in the synthesis of some glycoproteins. Beta-carotene that is commercially accessible is synthetic or derived from palm oil, algae, or fungi. Beta-carotene is transformed to retinol, which is required for vision, and then to retinoic acid, which is used in processes such as growth and differentiation.

1.1 Objectives Of The Study 

The primary goal of this project is to conduct a comparative analysis (quantitative analysis) of phytochemicals found in tomatoes and some selected tomato products (canned tomatoes) sold in any ordinary market in Nigeria.