**5. Tomato as the functional food ingredients**

Fresh vegetables are an essential source of minerals, dietary fibres, and especially vitamins. Humans get 90% of their vitamin C from vegetables, which are also rich in B group vitamins. Vegetables stand out from other food products due to their high energy value. They are very important for human nutrition, and they supplement the human body with minerals, vitamins, proteins, fats, and carbohydrates [2, 81, 82]. Due to their biochemical composition, tomatoes are very valuable vegetables. Their fruit is prized for its good taste and its nutrition value. Tomato fruit contains soluble sugars, organic acids, fibre, pectins, proteins, fats, minerals (potassium, phosphorus, sulphur, magnesium, calcium, iron, copper, and sodium), many vitamins (B1, B2, B3, PP, C, A, I, and H), and the alkaloid tomatine with phytoncide properties. The greatest influences on both valuable and harmful substances in tomato fruits are envi‐ ronmental and growing conditions, fruit ripening stage, and cultivar characteristics [70, 83, 84]. Tomatoes can be eaten fresh, fried, boiled, or pickled in various salads and other dishes. In addition, processed tomatoes (paste, juice, sauce) retain all nutritional characteristics of the fresh fruit [2, 85].

Long ago, it was believed that tomatoes contained oxalic acid, which adversely affects metabolic processes; therefore, older people were advised not to eat them. It has been con‐ firmed that the amount of oxalic acid in tomatoes is less than in lettuce, potatoes, or red beets, and the influence of purines (protein metabolic products that lead to gout (podagra)) is less than in many other plant products. Tomatoes can be eaten by children, adults, and the elderly. If someone's stomach is very sensitive, fresh tomatoes should be peeled first because the skin can stick to the stomach walls and cause inflammation. Vitamins and other valuable nutritional compounds found in tomatoes not only improve human nutrition but also prevent various diseases. Ascorbic acid directly removes free radicals of oxygen and superoxides. The human body does not synthesise ascorbic acid, so it must be obtained from food. Ascorbic acid is one of the most important antioxidants found in tomato fruits [86, 87]. It is believed that carote‐ noids, found in tomato fruits (which can reach 3.67 mg 100 g-1), may reduce the risk of human diseases, in particular cardiovascular diseases and prostate cancer [88, 89]. Epidemiological studies have shown the existence of an inverse relationship between lycopene intake and prostate cancer risk. Patients with prostate cancer had lower lycopene levels in their blood plasma than control patients [90]. The inverse relationship is also expressed in aggressive prostate cancer cases. Prostate cancer risk was lowered by 83% for the patient group with the highest lycopene plasma levels (0.40 μmol l-1) compared to the lowest concentration (0.18 μmol l -1) group [91]. Similar results were obtained in other studies, where it was found that two or more tomato dishes per day can reduce the risk of developing prostate cancer [89, 92].

There have been several epidemiological studies that have outlined the relationship between lycopene concentrations in the blood plasma and cardio vascular disease risk. One found that men who had coronary disorders had lower lycopene levels in their plasma compared to men without coronary disorders [35]. Alternatively, a study of the relationship between the lycopene level in fatty tissues and heart disease showed that an increased lycopene concen‐ tration had a protective effect against cardiac dysfunction [93, 94].

Lycopene consumption efficiency is determined by lycopene (the active principle compound of tomatoes, which acts as an antioxidant) bioavailability. Unfortunately, the mechanism of lycopene uptake remains unclear. It is known that absorption of consumed lycopene reaches only 10% (in some cases can increase up to 30%). Furthermore, lycopene absorption from fresh tomatoes is less than from the processed products (tomato paste or sauce) [7] because the mechanical and thermal treatment of tomatoes enhances lycopene uptake. There are other factors that affect the process of lycopene absorption. It has been found that the addition of oils in tomato dishes enhances carotenoid absorption [95], but the addition of various fibre substances can reduce absorption [96].

It is believed that processed fruits and vegetables are less valuable than fresh, but lycopene is better absorbed from processed tomatoes. Heat-treated tomatoes can have more bioavailable lycopene, and this justifies tomatoes as a functional food [2, 5, 6]. Undoubtedly, the effect will be negligible or absent, if the consumed amount of lycopene is 6-8 mg per day. It has been reported that 25-35 mg of lycopene should be consumed daily, that is, approximately 200 g tomatoes per day [97].

Thus, tomatoes, as a source of various antioxidants and vitamins, can increase the human's body resistance to the impact of radiation, reduce cholesterol accumulation, heal some skin diseases, and prevent cardio diseases and prostate cancer [8, 98].
