Everything You Ever Wanted to Know about Tortilla Manufacturing
The word “Tortilla” was first introduced by the Spaniards in Mexico, and is derived from ‘Torta’, which means cake. The Mexicans used the word to describe their flour cakes and flat corn. Tortillas soon became the bread staple in the Mexican diet, and were made from the pulp of ground corn, which was considered to be the native grain of the New World. It was the Spanish people who introduced wheat to the New World, after which flour tortillas became popular.Nowadays Tortillas are made from machines and are very high in nutritional value. They can be deep fried, cut into wedges, and made into tortilla chips. The Latin Americans introduced tortilla into the United States, and the popularity of the food quickly spread throughout the country. Tortilla chips come in different shapes and sizes like rectangular strips, rounds, and triangles, and their seasonings differ, since they can be eaten with several toppings and salsas.The basic production method of tortillas has undergone a lot of changes over the years, and traditional preparation was done by cooking corn in pots on top of fires. It would be soaked for 8 to 16 hours, and the cooking liquor would be poured and washed with nixtamal. This would then be ground into masa with hand-held grinders to mold it into thin discs that are baked on hot griddles.The most integral industrial advancement made over the years has been the production method of dry masa flour. It is extremely popular because it can be used for all applications, is easy to use and is highly convenient. However, foods made from dry masa flour don’t have much flavor, and their cost per unit is also on the higher side. That is the reason why most small manufacturers supply tortilla chips made from dry masa flour to local restaurants, while larger manufacturers prefer fresh masa flour.
The Raw Materials Used
Tortilla chips are made using blue cornmeal, whole wheat, flour, white corn, and yellow corn. The coarse masa will be used to make corn tortilla chips, and it will be soaked in a water and food-grade lime solution to break the hulls, after which the kerns will be grounded into flour. The main ingredients include different seasonings, salt, frying oil, acidulants, gums, emulsifiers, and preservatives. These are added to maintain and improve the shelf-life and properties of the product. It is the characteristics of the raw materials used in tortilla manufacturing that will define the color, cooking parameters, and quality of the tortilla chips.
The Manufacturing Process
· Preparing the masa (dough)
The first part of manufacturing process for tortilla chips is preparing the dough. This will mean adding 2.5 to 3.0 liters of water to create a mixture that will include 0.01 kilo of food grade lime, 1 kilo of 12% moist corn, which are mixed in a large industrial cooker. The lime will remove the hull during the steeping and cooking, and will increase the shelf life of the product by managing the microbial activity. It will also affect the nutritional value, color, aroma, and flavor of the tortilla chips.In the second stage of the manufacturing process, the mixture will be added to a vertical closed cooker or Hamilton steam kettle to be batch-cooked. The grain contents will be agitated mechanically through the heat from the steam, and are deigned to be cooked at boiling point. The agitation ensures that heat transfer is uniform in the limewater-corn solution, and is great for steeping and cooking.
Cooking time for the tortillas depends on the characteristics of the corn, the interaction of the agitation, cooking vessel size, lime concentration, temperature, and time. Nixtamal, which is commonly used for fried products, will be used for manufacturing table tortillas. Once the solution has cooked, it will be quenched, and this is done to decrease water absorption during the cooking and steeping process, which results in consistent dough that doesn’t absorb much oil in the frying process.
The grain will be then steeped for about 8 to 16 hours in the cooker and will be transferred to a holding cooking vat for the steeping process to take place. This is done to allow water to be absorbed, which softens the kernel and disintegrates the hull. After the steeping process is completed, the solution will be placed into washers where the cooking liquor will be drained and the nixtamal will be washed with spraying systems and pressurized waters. This is done to remove any excess lime and pericarp, and in commercial processes is done through separate pieces of equipment.
After steeping, the washed nixtamal will be ground by carved stones, which are made from volcanic materials and consist of synthetic materials. The lave stones should be re-carved frequently for maximum efficiency. There are different types of stones used for the grinding of tortilla chips, and the best ones are the ones that have shallow grooves, since they help produce finer dough.The milling or grinding process starts with a screw conveyor at the bottom of the hopper, which pushes the nixtamal through a central opening for shearing to take place. Water is then added during the milling process to cool down the stones, reduce dough temperature, and prevent excessive wear. The amount of water used during the grinding process is subject to the size of the dough, the depth and size of the grounding stones, the type of corn used and the degree of cooking required for the nixtamal.The grinding process is important because it helps to break up the kernel structure, and helps promote cohesive properties in the dough. After the dough has been produced, it must be kept covered immediately to protect against moisture loss.
· Forming chips
The next part in the manufacturing process of tortilla is the forming of chips, which will be produced from the coarse dough. It must be mixed and kneaded properly by extruders and mixers, and then put into sheeter rolls for the best results. After that, the dough will be sheeted into thin layers – they will be forced or cut into a specific shape. The overall thickness of the sheet will be determined by the weight of the product. During the sheeting process, the dough will be put onto smooth rollers that have been coated with Teflon and will be rotating clockwise and counter-clockwise.You can adjust the gap between the rollers to produce the product with varying thickness. The dough will be pushed between the rollers and then separated by wires at the back and front of the rolls. The wire at the back will clean the sheeted dough from the back, while the front wire will cut the dough into little pieces. The cutter will be rotating under the front roll, and you can also choose different configurations for the cutter, which could be rectangular, circular, or triangular depending on the product. Excess dough can also be recycled with the help of plastic or copper bands.
· Baking and cooling
To cook the dough, a three-tiered gas-fired oven will be used, and the chips will be baked at temperatures starting from 500 to 554 degrees Fahrenheit with the baking time being from 35 to 50 seconds. This is done to reduce oil and moisture absorption during frying and to increase the alkaline flavor.After the baking process, the tortilla chips will be cooled by a series of cooling tracks, and they can be cooled for nearly 20 minutes before they are fried so that there isn’t any blistering. You will also be able to get more uniformed consistency and that is why the cooling process is so important. The chips will lose additional moisture during the cooling process, and this will ensure that the moisture inside the chip is evenly distributed.
· Frying and seasoning
Now we come to the frying and seasoning process in tortilla manufacturing, where you will fry the chips in oil temperatures that should be from 338 to 374 degrees Fahrenheit. The frying time and temperature depend on the type of product and if your tortilla chips are made from yellow corn, they need to be fried at lower temperatures for longer times compared to chips made from white corn. Most commercial fryers tend to use the continuous frying technique, and may include indirect or direct heating elements.The indirect-fired fryers are expensive, but very efficient and don’t have many operational costs. The fryers available today are made to filter out the small pieces and are also easier to clean, which is why they have made tortilla production so much easier. The modern-day fryers also ensure that they fry the chips more consistently by not allowing much oil retention and getting rid of moisture.Once the frying process has been completed, the seasonings and salts will be applied to the chips when they are still hot out of the fryer. The chips will be then placed into an inclined rotating cylinder, where liquid seasoning mixes will be sprayed on them. This liquid mixture will have coloring agents, flavorings, seasonings, salt, and hot oils added to them. Once they are cooled the oil will crystalize, and this will form the seasoning coat, and the salt will also be deposited on the chips. This is done through a granulated salt dispenser or a liquid spray, and will be positioned on the conveyor belts as the chips pass through and tumble around. The amount of salt added to the tortilla chips depends on their weight percentage, and should only be around 1% to 1.5%.
· Cooling and packaging
Once the tortilla chips have been properly seasoned, they will be cooled in an ambient temperature, before being packed into bags that are moisture-proof. The reason for that is because fried products are hygroscopic in nature, which means they will absorb and retain moisture easily and quickly. This can influence their crispness and will ruin the quality of the product. The tortilla chips will be placed on a conveyor belt after they have been properly cooled and will be packaged by a bagging machine, which will weigh the chips and deposit them into bags before sealing them.
· Quality Control
Tortilla chip production must undergo strict quality control if the manufacturer wants to deliver the highest quality of chips to customers. It is imperative that they are fresh and crisp. The most important parameters for quality control during tortilla chip production are:
- Temperature and humidity of storage rooms and corn silos
- The cooking
- Frying times and temperatures
- Types of grinding stones and adjustments during the milling process
- Moisture content of the corn
- Tortilla chips
- Operating conditions of the equipment
- Frying oil and product deterioration
- Sanitation of personnel and equipment
There may be other quality control measures added depending on the type of tortilla chips being manufactured by the company.
There is massive demand for tortilla and corn chips in the market and manufacturers have now started producing thinner, smaller, and lighter chips to meet that demand. This has meant that recent tortilla chips are being made from blue cornmeal of the Southwest, whole wheat flour, and white corn, which has made it increasingly popular. The combinations of different dough with flours, legumes, and wheat have resulted in a lot of interesting and new products, which contain less oil and fatty acids. The major tortilla chip producers are focusing on using new baking techniques and modifying frying to increase the nutritional value of the corn used in the tortilla chip production. This has meant that there will be newer foods produced with textures that are like fried foods and contain lower calories. The industry has already moved towards faster production lines with more automation, higher quality control, and increased labor and equipment efficiency. The demand for tortilla chips will continue to increase in the United States and all over the world in the coming years.