In recent years life has been changed and become busier than ever before, that’s why people are inclined to eat “ready to eat” food, or food which is with minimal need for further processing i.e. expansion. Extruded snacks are an example of such products, and they are consumed worldwide. The extrusion technological process provides the opportunity to produce a wide range of products such as snack-foods, baby-foods, breakfast cereals, noodles, pasta, and expanded snacks frying lines too.
Let us know the types of snacks food in the market. Each snack processor may use a specific unit operation and somewhat different technologies to produce unique snacks. However, snack manufacturers use three main terms to identify the snacks:
First Generation Snacks Food
The first generation snack is also called simply extruded snacks. In this category all the natural products used for snacking, such as nuts, potato chips line (Fully Automatic Potato Chips Line & Economical Potato Chips Line),and popped popcorn are included.
Second Generation Snacks Food
The second-generation snack is also called “expanded snacks” or “collet”. These products are similar to direct expanded cereals in that they are finished snacks which are shaped and expanded at the extrusion die at moisture levels between 7-12% and generally require no further processing except for some minimal drying. The majority of the snacks fall in this category. All the single ingredients snacks, simple shaped products like Corn Tortilla Chips and Corn Puff Snacks like puff corn curls, and all directly expanded snacks are included in this category.
Co-Extruded Snacks Food
Co-extruded snacks food is direct expanded hollow tubes which are filled in the die with creams, jellies, or other ingredients. This is a relatively new innovative technology introduced for the snack food industry. In the co-extrusion process, two different materials are extruded from one die. The two materials can come from two extruders or one extruder and one pump. This process can produce a snack with two different flavors, or two textures or two colors. The most common snack produced by co-extrusion is a cereal-based outer tube with a cheese filling inside.
Third Generation (Half-products or Pellets) Snacks Food
The third generation snacks food (i.e. indirect expanded or half products) are extrusion cooked, and formed snacks at low pressure to prevent expansion, and then dried to a final moisture content of about 10% to form a glassy pellet. These are non-expanded and semi-finished snack products that are converted into finished snacks after expansion, through exposure by
- hot-air puffing,
- deep fat frying,
- baking, or microwave.
In developing third-generation snacks, “half” of the process is completed to prepare “pellets” such as pellets chips snack frying line or fully automatic pellet frying line which are shelf-stable for periods of up to a year without refrigeration, provided they are properly packed to retain their moisture. These snacks products are in high demand for marketing scope due to long shelf-life and high bulk density before frying or puffing. This third-generation snack food provides an alternative to fully prepared or finally expanded puffed snack foods. These products in the snack pellets market are available in various forms, shapes, textures, and flavors. The various types of snack pellets that are usually utilized by the extruded snack manufacturers are tapioca, potato pellet frying, mixed grains, and corn pellet frying. Potato snack pellets are the most widely produced and consumed snack pellets, followed by corn snack pellets. These pellets are manufactured by potato pellet frying machine, corn pellet frying machine, fully automatic pellet fryums frying line.
Food extrusion is a technological process in which food material is forced to flow under one or more varieties of conditions of mixing, heating, and shear through a die which is designed to form and/or puff-dry the ingredients. Extruders are used to cook, form, mix, texturize, and shape food products under conditions that favour quality retention, high productivity, and low cost.
The extrusion process with the help of technological innovations for the production of 3rd generation snacks food adds new dimensions to its marketing potential due to its long shelf life, and high density that simplifies storage and economizes the cost of transportation. Thus, third-generation snack foods or snack Pellet Frying Line are semi-finished expandable snacks that are manufactured using the extrusion process.
Third-Generation (3G) Snacks Food & its Raw Material
Third-generation snacks food or snack pellet frying line are also called semi food products because after extrusion cooking they are dried to stable moisture content and then expanded by
- frying in hot oil,
- puffing in hot air or
- microwaving, and
- infrared heating
with the help of technological innovation as new types of snacks food. After expansion third-generation snacks are spiced with various types of spices and then packaged and sold as ready-to-eat (RTE) snacks food directly to food stalls to sell or consumers to eat. They can also be flavored before expansion and sold as corn pellet frying line, for preparation at home by consumers according to their need or hunger or taste.
Basic raw materials used in manufacturing third-generation snacks are flours of (corn, potato, rice, wheat, oat, etc.), the starch of (corn, wheat, potato, tapioca), liquid shortenings, and monoglyceride. Manufacturers can also add flavor or nutrient containing ingredients such as meat (shrimp, crab, chicken, beef), vegetable powders or by-products of the food industry (sugar beet pulp, apple pomace, tomato pomace, bran, etc.), milk components (yogurt, cheese, whey), etc. that will be interesting for the tastes of customers (pizza, ham, onion, etc.).
Expansion Process of Third Generation Snacks
For maximizing the expansion of 3G snacks it has to contain relatively high levels of starch. Starch has many contributions to the final 3G snack food, such as final expansion, flavour, caloric value, resilience, binding, viscosity, hardness, firmness, crunchiness, etc.
For reducing stickiness, control expansion, and import more uniform cellular structure into the final product, different types of shortenings, vegetable oils, salts, and emulsifiers are used. Salt helps in moisture migration after dying. Baking soda gives a special flavour and textural attributes after complete expansion.
Expansion 3G Snacks by Deep-Oil/Fat Frying
The expansion process by deep-oil/fat frying is a unit operation that involves immersion, cooking, and frying of food in hot oil, in which high oil temperature (150 to 180 °C) facilitates rapid heat transfer and short cooking time (30-40 seconds). However, the temperature inside the fried-food product does not rise above 100 °C and that is why leaching of water-soluble components from the food is minimal.
Expansion 3G Snacks by Hot Air
The conventional frying line process absorbs oil, so hot air expansion is an alternative, typically reducing oil content from 30% to 10%. Snack Pellets like wheat pellets, potato pellets, etc. are exposed to heat, which evaporates water. For that type of snacks pellets product, the most important is gelatinization and it depends on time, temperature, and moisture. After expansion, products can be coated with an oil-based flavoring.
Temperature is important for the expansion of the 3G product because below glass transition temperature (Tg), the starch does not flow and the structure does not expand, but above Tg the polymer acts mostly ‘‘rubbery’’ and expansion is easier. Increasing the moisture content of pellets reduced the extent of expansion and salt addition was not important for the expansion of the starch matrix, but both the puffing extent and the rate were increased by additions of sodium chloride or potassium chloride. The addition of dextrin can also increase the expansion ratio due to decreasing the viscosity.
Expansion 3G Snacks by Microwave Heating
Cooking, heating, and expanding 3G snacks food with microwaves is a fast, convenient, and inexpensive technique. In this processing food is placed in an electromagnetic field at room temperature, heat is produced in food and then it spreads outward to expand fully.
Microwaves technology for the expansion of 3G snacks is a form of high-frequency electromagnetic radiation of certain wavelengths. There are two main mechanisms by which microwaves produce heat in snacks food:
1. Dipole rotation: In the presence of an electric field, the polar molecule (i.e. water) tries to align and the polarity of the field changes. In this field, the molecule behaves like a dipole and, while oscillating around the axis, acquires potential energy while trying to reach the positive or negative pole. The collected energy is released in the form of random kinetic energy or heat.2. Ion polarization: In this mechanism the result of the electric field ions (i.e. electrical charges) which are moving in the water and accelerating. They crush and kinetic energy turns into heat. The more concentrated the solution is the higher number of the crushes. There are a lot of crushes on the microwave frequency resulting in the release of energy that causes 3G snacks to fully expand.