Tortillas are Mexico’s most popular finger food. Whereas the thin, flat rounds of bread sold from street and market stalls are always baked and eaten fresh, packed industrial products from supermarkets must stay soft and flexible for weeks. By using highly functional enzyme compounds, manufacturers can achieve a shelf life of around 90 days.
Mexican cooking is like the country itself: colorful, diverse, and full of surprises. In the south, the traditional recipes of the Mayas and Aztecs are still popular — prepared mostly with beans, maize, chili and tomatoes. In the north, the eating habits of the Spanish conquistadores have asserted themselves, with dishes containing pork and rice. And in the coastal areas of the east, fish and seafood bring a Caribbean flair to the table.
In 2010, the United Nations Educational, Scientific and Cultural Organization honored this extraordinary diversity by adding the Mexican cuisine to the official list of the Intangible Cultural Heritage of Humanity.
Despite all the regional differences, one culinary preference can be traced throughout the country: tortillas — thin rounds of bread made from maize or wheat flour — are an essential part of every meal. They might be called the real star of Mexican cooking.
Tortillas are eaten with the fingers — and Mexicans are immensely creative where their favorite finger food is concerned. Filled, rolled, deep-fried or grilled — tortillas are the indispensable base for tacos, quesadillas, burritos, huaraches, enchiladas or tostadas. Typical accompaniments are baked beans, grilled meat, cheese, vegetables, avocados and salad.
A day without a tortilla is unthinkable for a Mexican. The arterial roads of the cities are lined with taco fast-food chains, one next to the other. But the authentic national cuisine is mainly to be found in the markets and family-run taquerias, where the dough pieces are prepared in the traditional manner on thin, hot griddles called comales. Freshness is imperative. The cooks (taqueros) often have only a tiny space to work in, and yet they conjure up an astonishing diversity of flatbread specialities from regional ingredients and seasonings. Homemade, spicy salsas and creamy sauces (mole) served for dipping and seasoning are featured in every taqueria.
Wheat flour tortillas
In the artisan sector and in private households, tortillas are generally made from maize (corn) flour, whereas wheat flour is the more common raw material in the baking industry. Wheat flour tortillas have a softer consistency and are easier to roll and fold. Tortillas of better quality are prepared mainly from hard wheat flour with a medium protein content. Hard wheat flour is preferred in industrial production. However, soft wheat flour also may be used, particularly when the product is made at home.
Mexican consumers have precise ideas as to what their wheat flour tortillas should be like: a perfect tortilla should have a uniform shape and a pale beige color with a scatter of brown toasted spots and must neither break nor become soggy when prepared. The chart on the right shows a typical recipe for flour tortillas.
Tortilla production process
In the industrial manufacture of wheat tortillas, first the ingredients are weighed and the dough prepared. After mixing, the dough is rested for five minutes, then cut and shaped into balls of approximately 15 to 60 grams each with the help of a rounding machine. These dough pieces are allowed to rest for 10 to 15 minutes, then pressed into disks with hot plates set to 200°C to 230°C (392°F to 446°F). Since both thick and thin versions of this product are consumed, thickness ranges from 0.2 to 0.5 centimeters.
Tortillas are baked industrially in a conveyor oven at approximately 190°C to 220°C (374°F to 428°F) for 20 to 30 seconds and flipped multiple times. In small-scale production, the process takes place on a hot griddle or hot plate at approximately 200°C (392°F). When the tortilla puffs (after 15 to 20 seconds, depending on its thickness), it is flipped to bake the other side for 10 to 15 seconds. Finally, it is cooled and packaged.
Focus on shelf life
The crucial topic for industrial producers is the shelf life of the tortillas. Some retail chains demand a minimum shelf life of three months for wrapped bread, and even periods of up to 120 days are sometimes discussed.
The main reason for this is the logistics aspect. It may take several weeks for the wrapped products to be delivered to the most distant parts of the country or exported abroad. To ensure that the tortillas remain edible in the customer’s home for as long as possible, they must have a shelf life of several months.
Whereas microbiological problems can be solved easily with preservatives like sorbic acid, propionic acid and lactic acid, the product-specific attributes present a much bigger challenge.
Enzyme design
For mills, these targets can only be achieved with the use of highly functional flour improvers. To ensure that the tortillas stay soft and succulent for months and do not stick together in the pack or break when filled or rolled, precise interaction between enzymes, emulsifiers, oxidizing agents and hydrocolloids is necessary. MC Mühlenchemie offers a toolbox with a host of different agents that ensure the right solution, depending on the application and the quality of the flour. They include the enzyme system Flexizym, the dough softeners MCsoft and MCrelax, baking premixes from the MCbest series and the ascorbic acid product Elco C, that is suitable for flour applications.
Besides the shelf-life topic, some retail chains have another requirement that is very important to them in connection with tortillas: namely a label-friendly list of ingredients. With innovative raw material concepts, the baking and milling industry can find appropriate, modern answers to clean label questions. Synergistically-acting flour improvers consisting solely of enzymatic components can replace emulsifiers like mono and diglycerides, SSL or CSL partially or even wholly.
Credit: ©SOSLAND PUBLISHING CO.Problems and solutions
The following is a list of the most common challenges encountered in tortilla production and how to avoid them:
Problem: Sticky dough
Possible causes: Prolonged mixing and resting; high amylolytic activity; high dough temperature; low-fat formulation.
Solutions: Reduce mixing and resting time; use flour with low enzymatic activity (high Falling Number); reduce the addition of amylolytic enzymes (if any), add enzymes for anti-sticking (e.g. Alphamalt Gloxy TGO); check the water temperature frequently; add fat to the recipe; use glycerides or other emulsifiers (e.g. Mulgaprime 90F, Mulgaprime SSL).
Problem: Poor machinability of the dough
Possible causes: Addition of an inappropriate amount of water (more or less than required); with weak flour: low gluten content and high tenacity; with strong flour: high gluten content.
Solutions: Choose the best flour, with special emphasis on its rheological characteristics; use more water in the recipe; incorporate shortening, emulsifiers such as monoglycerides (e.g. Mulgaprime 90F) or lipases (e.g. Alphamalt EFX Tera) to improve dough machinability; for weak flour incorporate oxidizing agents like ascorbic acid (Elco P-100) or azodicarbonamide (OXEM) or oxidizing enzymes (e.g. Alphamalt Gloxy TGO) to strengthen the dough; for strong flour use dough softeners like cysteine (e.g. MCsoft S) or enzyme-based solutions (e.g. MC T-REX); adjust mixing and resting times.
Problem: Drying and staling of tortillas
Possible causes: Dough too firm; low water retention; starch retrogradation; use of thermosensitive amylolytic enzymes.
Solutions: Add water and emulsifying agents to improve the softness of the dough (e.g. Mulgaprime SSL); use hydrocolloids like guar gum (e.g. MCgum) to facilitate water retention; use moderately thermostable amylolytic enzymes (e.g. Flexizym Plus).
Problem: Short shelf life (microbial); tortillas are decomposed rapidly by microorganisms.
Possible causes: pH of the product 6.5 or higher; high microbial numbers in the process environment.
Solutions: Adjust the pH with acidifying agents (e.g. MCprop G) and control the addition of leavening powder; check hygiene conditions and sanitation in the production area; use air filters for ventilation of the packaging area; produce per GMP; add preservatives such as propionate (e.g. MCprop P).
Problem: Tortillas are not inflated.
Possible causes: Insufficient mixing and resting time; too little leavening agent and/or yeast; strong wheat flour, high tenacity.
Solutions: Increase mixing and resting time; add a larger proportion of leavening agents and/or yeast (e.g. MCrise SD); use reducing agents that facilitate the extensibility of the dough (e.g. MCsoft S).
Problem: Dark tortillas
Possible causes: High pigmentation of the wheat; high content of phenols and phenol oxidase.
Solutions: Use different wheats; standardize processes and flour milling; use improvers to brighten the color of the tortillas.
Problem: Color variation of flour tortillas.
Possible causes: Use of flour from wheat of varying quality; changes in the flour production process.
Solutions: Use wheats with similar characteristics; standardize processes and flour milling; use improvers to standardize the color of the tortillas (e.g. Decolox).
Sven Mattutat is a product manager with Mühlenchemie. He may be reached at smattutat@stern-wywiol-gruppe.de for more information on this topic.
