Traditional fermented drinks from Mexico with high biotech potential

The traditional fermented drinks that are still produced in Mexico and are generally characterized as follows: they are ancestral processes (before and after the Spanish conquest), they use different substrates of vegetable origin, they normally use rustic and traditional methods in which uncontrolled spontaneous fermentations occur, they are produced on a small scale, they are popularly consumed in urban and rural areas, some of them with great potential for industrialization. In some of these drinks, there are few scientific studies carried out on their characterization and properties.

The following is a very brief description of some of the studies carried out on these beverages, organized according to the main raw material used, mentioning the origin of the same and their respective production processes.

Mexico is a biodiverse country mainly due to its geographical characteristics, it is bordered by two oceans, the Pacific and the Atlantic, and its rugged geography with mountain ranges that border the coasts, with some valleys and plains in the interior of the same, being located in the tropic of cancer between North and Central America, this gives it a large number of habitats, such as high mountains, temperate forests, jungle areas, and arid and semi-arid zones, which favor the production of a great diversity of crops, some of them endemic to Central America and produced since ancestral times in Mexico by different pre-Hispanic cultures, such as corn, beans, squash, tomatoes, chili, agave, cacao, nopal, and tuna.

Crops whose products, along with those introduced by the Spanish conquest, have become the raw materials used to make traditional fermented drinks. Due to the composition of these raw materials and the manufacturing processes used, the microbiota and molecules produced in these fermentations have a high potential, as a source of enzymes and ingredients, useful for the production and/or formulation of functional foods with positive impacts on human health, such as nutraceuticals, prebiotics, and probiotics.

Fermented corn drinks

It is said that Mexicans are the children of the corn. Indeed Mexico and Central America are known as the origin of this grain, Mexican food base from pre-Hispanic times to date, Mesoamerican cultures discovered the process of nixtamalization, which consists of cooking the corn in water with lime, which causes the calcium ions to open the starch chains (swelling of the grains). These grains are then ground to form the corn dough, which is the basis for making the tortilla and a wide range of foods, including fermented drinks.

The traditional fermented drinks based on corn can be classified into two groups, fermentation of corn without nixtamalization, as is the case of Ticino, and those that are made from the fermentation of the nixtamalized corn dough. In the case of the first drink, Tesgüino, this is elaborated by the ethnic groups of northern Mexico, raramuris (taraumaras) and tepehuanos, who soak the corn grains so that they germinate, After a cooking process, a kind of malt rich in free sugars is obtained (like the one obtained for beer production), which is fermented spontaneously until a viscous drink with a high alcoholic content (8-14 % v/v) is obtained. This drink is used ceremonially by these ethnic groups.

Few or almost no scientific works exist regarding the microbiota of the tesguin, only some reports from the '60s and '70s made by researchers of the UNAM, found some yeasts, however, they used biochemical methods for the identification of the same ones, methods that at the moment are not considered reliable, by the type of substrate used and by the characteristics of the drink, it must contain yeasts and saccharolytic bacteria (therefore also of these enzymes) and producers of alcohol like those of the Saccharomyces genus.

In the case of the second group of corn-based beverages, in the first place, it is necessary to describe Tejuino, this acetic-lactic drink with low alcohol content (less than 1% v/v). According to recent studies made in CIATEJ, it has been found that there are two processes to elaborate this drink, a solid fermentation of the corn mass (3 to 5 days), later it is liquefied with water, and piloncillo, salt, and lemon are added besides ice. The second process, and the most popular one used by producers who sell it in carts in the metropolitan area of Guadalajara and the west of the country, consists of first elaborating atole, by cooking the diluted corn dough, to which piloncillo is added, once it thickens and becomes viscous, it is left to cool and ferment spontaneously for 24-48 hours.

This drink is very popular in Guadalajara, and according to urban legends, Tejuino relieves children's diarrhea and cures hangovers, which is why its probiotic properties are being studied.

Fermented agave drinks

The genus Agave comprises about 200 species, most of which are endemic to Mexico. These plants have crease-like metabolism, that is, they carry out photosynthesis during the day and perspire at night to avoid water loss. Throughout their lives, the agaves accumulate as reserve sugars to the agaves or fructans (fructose polymers) for the flowering process (7-12 years), once this happens the plant dies.

One of the most ancestral drinks in Mexico made from agave is Pulque, made from species such as Agave salmiana, A. Americana, and A. potatorum among others, a viscous drink with high alcoholic content, since pre-Hispanic times the Aztecs made it for religious ceremonies, spontaneously fermenting the agave sap, also popularly known as aguamiel (agave juice collected in the heart of mature agaves), a drink that is still made in the central highlands of the country by the Nahua and Otomi cultures.

Agave is also used to produce distilled alcoholic beverages such as the traditional drinks Tequila, Bacanora, Sotol, Raicilla, and Mezcal (depending on the region), all of which use the same process for their elaboration, which includes the stages of jima (stripping the plants to obtain the pineapples or heart), cooking, fermentation, distillation and in some cases an aging process in oak barrels.

These distilled beverages vary in terms of the type of agave used (about 20 species throughout the country) and the level of industrialization of the process. There is a debate as to the origin of distilled agave drinks since some historians claim that pre-Hispanic cultures were already familiar with the distillation process, while others document that this practice was introduced by the Spanish during the conquest in their attempt to make brandy.

Fermented pineapple, coconut palm, and tuna drinks

Pineapple

Pineapple does not originate from Mexico. It is a fruit produced by a bromeliad (Ananas comosus), presumably of South American origin (Brazil), a region where bromeliads are abundant. It is also not clear how it arrived in the country, possibly from the commercial exchanges derived from the conquest. In Mexico, it is cultivated in the tropical areas of the country, from which a refreshing drink known as Tepache is made, obtained from the spontaneous fermentation of the pulp and peels of pineapple with piloncillo (24-48 hours), sometimes mixed with apple or orange juice.

The drink is acetic-lactic with low alcohol content and is consumed cold in a popular way in Mexico City to accompany the tacos al pastor. There are very few related scientific studies on the microbiota of the Tepache. Studies made mainly by the UNAM and the Universidad Iberoamericana, as well as some institutions in Guanajuato and Querétaro, have found the presence of hanseniaspore yeasts (typical of fruit fermentations) and a great amount of acid-lactic bacteria, some of them producing bacteriocins that inhibit pathogenic bacteria.

Coconut palm

Tuba, similar to pulque, is made from the spontaneous fermentation of the sap of the coconut palm. According to historians, this practice reached the coasts of Colima (1600-1700) from the Philippines, from the trade that Spain carried out with China through its colonies in Mexico and the Philippines. It is an acetic-lactic drink with low alcohol content. It is popularly consumed in Jalisco, Colima, Michoacan, and Guerrero, especially in coastal areas. There are very few scientific studies on Tuba and it has been found mainly to contain lactic acid bacteria.

Nopal cacti

Like the Agave plants, the plants of the genus Opuntia are very diverse in Mexico, most are endemic to the country and there is a great diversity of them, with about 200 species. These cacti are adapted to arid and semi-arid climates, they have crease-like metabolism also to avoid water loss. Since pre-Hispanic times, the leaves of opuntia (cladodes) have been used as a vegetable, better known as nopal, as well as its fruit the tuna, which is highly varied in the country.

The consumption of nopal is deeply rooted in Mexico, it is a national emblem, it can even be found on the shield of the Mexican flag.

On a Nopal, the eagle was found devouring a snake, an event that occurred on an island in the ex-Lake of Texcoco, a sign that indicated to the Aztecs (Mexicas) in their journey from Aztlan (North of Nayarit), the founding of their capital city Tenochtitlan (now Mexico City). In the north-central highlands of Mexico, which include the states of San Luis Potosi, Guanajuato, Zacatecas, and northern Jalisco, the tuna cardona (Opuntia streptocantha) is produced wild. Since pre-Hispanic times a fermented drink has been made, known as Colonche with a carmine red color, which is obtained from the spontaneous fermentation of the tuna cardona juice (rich in pigments such as anthocyanins), resulting in a kind of beer (4-6% ethanol).

Few studies have also been conducted on the microbiota of the fermentation of the colonche, have found a large number of yeasts of the genera Saccharomyces, Hanseniaspora, and Torulaspora among others should also contain a high amount of bacteria. It is not known what enzymes or properties the microorganisms present in this drink have.

Source: CIATEJ