Mexican tomato, a natural medicine, containing vitamins and minerals

A brief description of the importance of Mexican tomato consumption and use, the wealth of genetic resources currently available, and health benefits.

Mexican tomato, a natural medicine, containing vitamins and minerals
Mexican tomato should preferably be consumed raw, because it preserves its properties better. Photo by Josephine Baran / Unsplash

Tomato (Solanum Lycopersicum L.) is one of the most demanded vegetables in the world, either fresh or processed. It belongs to the Solanaceae family, which includes more than 3,000 species. In particular, the cultivated tomato, Solanum Lycopersicum, is the only domesticated species. Per capita consumption in Mexico is 15 kilograms. The USDA Economic Research Service estimates that 35% of raw tomatoes are processed into sauces, 18% into tomato paste, 17% into canned tomatoes, 15% into juices, and 15% into tomato sauce.

It is a rich source of bioactive compounds with beneficial effects that include vitamins, minerals, and antioxidants. Mexico has been considered the center of domestication and diversification of this plant. Native populations of tomatoes have a diversity of qualities for quality, greater firmness, diversity of colors, variety of flavors, and a myriad of aromas, as well as greater resistance to biotic and abiotic factors.

Mexican tomato, source of beta-carotene and lycopene

Tomatoes are widely consumed throughout the world, as they are a source of carbohydrates, minerals, organic acids, vitamins, fiber, and nutraceutical compounds. From 1994 to 2014, world production of this vegetable has been concentrated, in order of importance, in China, the United States of America (USA), India, Turkey, Egypt, Italy, Iran, Spain, Brazil and, in tenth place, Mexico (FAO, 2017).

According to the Agrifood and Fisheries Information Service, in the last fifteen years, Mexico has produced between two and three million tonnes of tomatoes annually.

In the world the intake of this vegetable is very dynamic, the ten major producing countries have a variable annual behavior: in Brazil, Mexico and India are consumed less than 20 kg, in China, USA and Italy from 20 to 40 kg, in Iran and Spain between 40 and 60 kg, and in countries like Egypt and Turkey up to 90 kg. However, at the global level, the per capita consumption of tomatoes in the last five years is about 20 kg per year.

Commercially, ball, saladette, cherry, and kidney tomatoes are produced. In the latter, Mexico has a great genetic wealth in the center and south of the country, so that current efforts are made through genetic improvement, to exploit the diversity of this species, and present alternatives in the production of conventional tomatoes. In this sense, evaluations of native populations of tomatoes have been reported, which presented superior quality in total soluble solids, acidity, vitamin C, color, and carotenoids, for commercial cultivars.

It has been reported that lycopene consumption may reduce the risk of chronic diseases such as prostate, colon, osteoporosis, and cardiovascular cancers.

The deterioration of the flavor quality of modern commercial tomatoes about traditional varieties is one of the main causes of consumer complaints. Mainly because the objective, in the beginning, was to obtain higher yields leaving aside the flavor of the fruit. Nowadays, commercially available tomatoes are famous for their soundness, but perhaps not for their flavor. Likewise, the flavor of any food is the sum of the interactions between taste and smell. For tomatoes, sugars and acids activate taste receptors, while a diverse set of volatile compounds activate olfactory receptors.

Native tomato varieties have a better taste than commercial varieties, mainly due to the amount of total soluble solids (sugars) that accumulate in their fruits, as well as organic acids (citric and malic) that confer a diversity of aromas.

Health benefits in every bite

From a nutritional point of view, tomatoes are considered a rich source of minerals and different antioxidant molecules such as carotenoids, ascorbic acid, flavonoids, and vitamin E. Among these, the most abundant is lycopene, responsible for the color and health benefits. Therefore, regular intake of this fruit and its derivatives has been associated with a lower risk of suffering from inflammatory processes, neurodegenerative, chronic, and cardiovascular diseases, hypertension, diabetes, obesity, and different types of cancer. It also reduces cholesterol levels and increases oxidation resistance.

Although it has been reported that this compound is also found in other fruits, the tomato has the highest concentrations, more than 80% of total carotenoids. This set of benefits places the tomato in a status of "functional food", that is, it demonstrates benefits to the health of human beings not only at a nutritional level but also in reducing the risk of disease. The use and conservation of genetic material from native populations represents an important source of germplasm.

Currently, the use of native populations or autochthonous varieties in Mexico is mainly carried out in states such as Nayarit, Jalisco, Michoacán, Guanajuato, Veracruz, Oaxaca, Guerrero, Puebla, and Hidalgo, among others, mainly for self-consumption and backyard, not commercially. Geographic location has a great impact on carotenoid content. For example, the carotenoid content of several tomato populations grown in the southern part of the country differs from those grown in the center. Thus, many factors such as genetics (cultivar or variety), environment (light, temperature, mineral nutrition), and cultural practices (a ripening stage in the harvesting and irrigation system) affect the chemical composition of tomatoes.