Advances In Food Extrusion Technology REPACK
This is a new technology for directly extruding curved profiles/sections from billets employing two opposing punches in a single extrusion process. Its mechanics are based on internal differential material flow, and it is known as differential velocity sideways extrusion (DVSE). A tool set that allowed sideways extrusion with opposing punches running at various speeds was employed in a series of trials in which the punch velocity ratio and extrusion ratio were process factors.
Advances in Food Extrusion Technology
Extrusion technology is gaining traction in the global agro-food processing industry, especially in the food and feed industries. Extrusion cooking technologies are utilized in the food industry for grain and protein processing.
Conveying, mixing, shearing, separation, heating or cooling, shape, co-extrusion, venting, volatiles and moisture, flavor production, encapsulation, and sterilizing are some of the processing roles they do today. They can be relatively low temperatures, as with pasta, spaghetti, noodles etc. keeping in this view, the present article describes in detail about the types of extruders, physio-chemical changes occurring during extrusion process and recent developments in food industry regarding extrusion process.
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. Food products manufactured using extrusion usually have a high starch content. These include some pasta, breads (croutons, bread sticks, and flat breads), many breakfast cereals and ready-to-eat snacks, confectionery, pre-made cookie dough, some baby foods, full-fat soy, textured vegetable protein, some beverages, and dry and semi-moist pet foods.
Many food extrusion processes involve a high temperature for a short time. Important factors of the extrusion process are the composition of the extrudate, screw length and rotating speed, barrel temperature and moisture, die shape, and rotating speed of the blades. These are controlled based on the desired product to ensure uniformity of the output.
Moisture is the most important of these factors, and affects the mix viscosity, acting to plasticize the extrudate. Increasing moisture will decrease viscosity, torque, and product temperature, and increase bulk density. This will also reduce the pressure at the die. Most extrusion processes for food processing are carried out at low to intermediate moisture (moisture level below 40%). High-moisture extrusion is known as wet extrusion, but it was not used much before the introduction of twin screw extruders (TSE), which have a more efficient conveying capability. The most important rheological factor in the wet extrusion of high-starch extrudate is temperature.
The amount of salt in the extrudate may determine the colour and texture of some extruded products. The expansion ratio and airiness of the product depend on the salt concentration in the extrudate, possibly as a result of a chemical reaction between the salt and the starches in the extrudate. Colour changes as a result of salt concentration may be caused by "the ability of salt to change the water activity of the extrudate and thus change the rate of browning reactions". Salt is also used to distribute minor ingredients, such as food colours and flavours, after extrusion; these are more evenly distributed over the product's surface after being mixed with salt.
The first extruder was designed to manufacture sausages in the 1870s. Dry pasta and breakfast cereals have been produced by extrusion since the 1930s, and the method has been applied to pet food production since the 1950s (first extruded dog food: Purina Dog Chow in 1957, and first extruded cat food: Purina Friskies in 1962). Some domestic kitchen appliances such as meat grinders and some types of pasta makers use extrusion. Pastry bags (piping bags), squeezed by hand, operate by extrusion.
Extrusion enables mass production of food via a continuous, efficient system that ensures uniformity of the final product. This is achieved by controlling various aspects of the extrusion process. It has also enabled the production of new processed food products and "revolutionized many conventional snack manufacturing processes".The extrusion process results in "chemical reactions that occur within the extruder barrel and at the die". Extrusion has the following effects:
High-temperature extrusion for a short duration "minimizes losses in vitamins and amino acids". Extrusion enables mass production of some food, and will "denature antinutritional factors", such as destroying toxins or killing microorganisms. It may also improve "protein quality and digestibility", and affects the product's shape, texture, colour, and flavour.
The various types of food products manufactured by extrusion typically have a high starch content. Directly expanded types include breakfast cereals and corn curls, and are made in high temperature, low moisture conditions under high shear. Unexpanded products include pasta, which is produced at intermediate moisture (about 40%) and low temperature. Texturized products include meat analogues, which are made using plant proteins ("textured vegetable protein") and a long die to "impart a fibrous, meat-like structure to the extrudate", and fish paste. Confectionery made via extrusion includes chewing gum, liquorice, and toffee.
Some processed cheeses and cheese analogues are also made by extrusion. Processed cheeses extruded with low moisture and temperature "might be better suited for manufacturing using extrusion technology" than those at high moisture or temperature. Lower moisture cheeses are firmer and chewier, and cheddar cheese with low moisture and an extrusion temperature of 80 C was preferred by subjects in a study to other extruded cheddar cheese produced under different conditions. An extrudate mean residence time of about 100 seconds can produce "processed cheeses or cheese analogues of varying texture (spreadable to sliceable)".
Other food products often produced by extrusion include some breads (croutons, bread sticks, and flat breads), various ready-to-eat snacks, pre-made cookie dough, some baby foods, some beverages, and dry and semi-moist pet foods. Specific examples include cheese curls, macaroni, Fig Newtons, jelly beans, sevai, and some french fries. Extrusion is also used to modify starch and to pellet animal feed.
Introduces the history, nomenclature, and working principles of extrusion technology
Presents an overview of various types of extruders as well as parts and components of an extruder for design considerations
Discusses extruder selection and design, fluid flow problem with different types of raw materials, and heat transfer and viscous energy dissipation, with advantages and limitations for particular cases
Emphasizes recent research while providing an overview of trends previously reported in the literature
Covers the coinjection of food substances into an extruder die with the objective of creating defined colored patterns, adding internal flavors, and achieving other food injection applications into cereal-based extruded products
Describes thermal and nonthermal extrusion of protein products
Discussing the influence of design and raw materials on extruder performance and nutritional value, this book covers current and developing products from cereal-based snacks to pet food. In addition to the usual benefits of heat processing, extrusion offers the possibility of modifying and expanding the functional properties of food ingredients. Designed for both the active and future food scientist, this book is an exciting addition to a creative and ever-evolving field.
Professor Medeni Maskan is currently a professor at the University of Gaziantep, Engineering Faculty, Food Engineering Department. He received a B.Sc. degree in Food Engineering from Middle East Technical University in 1988. He received his M.Sc. and Ph.D. degrees in Food Engineering from Gaziantep University in 1992 and 1997, respectively. He worked on the storage stability of pistachio nuts at various atmospheric conditions problem during his Ph.D. studies. Dr. Maskan has been a faculty member since 1998, and became a full professor in 2007. He has published more than 70 articles in national and international top class journals. His research program focuses on fats and oils, dehydration of food materials, and extrusion technology. He acts as a reviewer in several journals being published in the food science and technology area. Professor Maskan lives in Gaziantep, Turkey with his wife, Aysun, and their two children, Serhat and Ozan Emre.
Abstract:Three-dimensional printing technology enables the personalization and on-demand production of edible products of individual specifications. Four-dimensional printing technology expands the application scope of 3D printing technology, which controllably changes the quality attributes of 3D printing products over time. The concept of 5D/6D printing technology is also gradually developing in the food field. However, the functional value of food printing technology remains largely unrealized on a commercial scale due to limitations of printability and printing efficiency. This review focuses on recent developments in breaking through these barriers. The key factors and improvement methods ranging from ink properties and printer design required for successful printing of personalized foods (including easy-to-swallow foods, specially shaped foods, and foods with controlled release of functional ingredients) are identified and discussed. Novel evaluation methods for printability and printing precision are outlined. Furthermore, the design of printing equipment to increase printing efficiency is discussed along with some suggestions for cost-effective commercial printing.Keywords: food printing; printability; printing efficiency; personalized foods 041b061a72