Extruded Snacks

Onwulata, C. I., Konstance, R. P., Strange, E. D., Smith, P. W., and Holsinger, V. H. (2000). High-fiber snacks extruded from triticale and wheat formulations. Gereal Foods World 45, 470-473. 

Starches are added to processed meats—lunch meats, hot dogs, sausages, etc.—as fillers, binders, moisture retainers, and fat substitutes. They are added to soups, sauces, and gravies as thickeners. They are used in extruded cereals and snacks to hold the shape of the material. 

Rios, A.O. and Mercadante, A.Z., Novel method for the determination of added annatto colour in extruded corn snack products. FoodAddit. Contamin., 21,125, 2004. 

Whey proteins are known to increase immune response and maintain muscle mass (Phillips et ah, 2009). In one instance, when an immunosti-mulatory vitamin and mineral mixture developed at Tufts University Human Nutrition Research Center on Aging was blended with texturized WPI (TWPI) in an extruded snack bar, immunostimulatory effects were enhanced in young (< 5 months) and old (> 22 months) mice fed ad libitum for 5 weeks. The mineral mixture and TWPI improved T cell proliferation and reduced upregulated production of proinflammatory mediators in... 

Whey may be substituted for starch by as much as 25% in extruded corn snacks, but the product does not puff as much as com alone, as the water-holding whey protein does not react with the starch matrix (Onwulata et al., 1998). WPCs or isolates can be added along with starch to create expanded snack foods with boosted nutritional content however, without texturization, whey proteins in amounts larger than 15% may interfere with expansion, making the products less crunchy. To counter this effect, whey proteins can be texturized with starch to improve their interaction with other food components in a formulation, principally to increase extmdate expansion. In one successful application, between 25% and 35% of the flour was replaced with whey protein (Onwulata et al., 2001a,b). 

Hazell, T. and Johnson, I. T. (1989). Influence of food processing on iron availability in vitro from extruded maize-based snack foods. /. Sci. Food Agric. 46, 365-374. 

Plunkett, A. and Ainsworth, P. (2007). The influence of barrel temperature and screw speed on the retention of L-ascorbic acid in an extruded rice based snack product. /. Food Eng. 78,1127-1133. 

Products where this is the sole expansion system are extruded products. This sort of cooking is used for the production of breakfast cereals, savoury snacks and some crisp breads. Of these, only the crisp breads are really within the scope of this book. 

Packaging films (extruded, blown, and cast) are used in pressure-sensitive tapes and electrical applications and as replacements for cellophane and glassine films in liners for cereal boxes, wraps for snack foods, cigarettes, bread, and cheese. Blow-molded containers are used in applications where the higher use temperature of polypropene is needed (compared to HDPE), such as in packaging of syrups that are hot-filled. 

Morama texturized Milled flour extruded into Snacks, breakfast... 

Currently, many types of extruded food products are produced (9) and include ready to eat (RTE) cereals, snack foods, beverage bases, as well as soft-moist and dry pet foods. 

Wheat starch has been formulated in a variety of snack foods, whether they are extruded, expanded, microwaved or in the form of a stick or half products.570-574 In the case of yogurt or custard-type milk desserts, modified wheat starches were used for their thickening or gelling properties.575,576... 

Starch modifications can be classified as physical modifications, chemical modifications and genetic modifications.45 Physical modification of cassava starch involves application of shear force, blending and thermal treatment. A combination of thermal treatment and shear force has been widely used to produce many extruded products and snacks. Well-known physically modified cassava starch products are alpha starch or pregelatinized starch and heat-moisture treated starch. 

Rapid cook (microwaveable) foods Ready-to-eat meals Crispness agent Breakfast cereals Extruded snacks... 

In the extrusion of snack foods, cereals and pet foods, cooking prior to extrusion is required. This can be accomplished in a steam pressure cooker integral with the extruder such as shown in Fig. 5.17. Screw diameters up to 10 in. (25 cm) are used in this application yielding typical capacities of 4,000 lb/h (1.8 Mg/h) with a 50 hp (37 kW) extruder drive to 12,000 lb/h (5.4 Mg/h) with a 150 hp (112 kW) extruder drive, depending on formulation and product requirements. 

Figure 1-25 Modified State Diagram Showing Relationship Between Glass Transition Temperature (Tg), Water Activity (GAB isotherm), and Water Content for an Extruded Snack Food Model. Crispness is lost as water plasticization depresses Tg to below 24X2. Plasticization is indicated with critical values for water activity and water content. Source Reprinted with permission from Y.H. Roos, Glass Transition-Related Physico-Chemical Changes in Foods, Food Technology, Vol. 49, No. 10, p. 99, 1995, Institute of Food Technologists.

Fgerch Plast is an extruder of film and thermoforms packaging. Packaging is made from PS, CPET, APET, PP and PLA plastics. Principal end use sectors served are ready meals, fresh meat, cold food, snacks and disposables. 

The machinery has been borrowed from the plastics industry. An early single screw extruder was used in the 1940s to produce a snack product from maize grits but the operational advantage of twin screw machines was demonstrated later. It appears that they are more efficient in mass transport, less heat is dissipated, and therefore heat transfer can be better regulated by barrel heating (Lo et al. 1998). 

Soy, and Other Legume Proteins Two quite different product types have been constructed by extrusion, high-density flaked structures for meat analogues, and lower density and crispy products for high-protein snacks. The latter uses conditions similar to that of starch-based cereal extrusion to obtain low bulk density in the expanded product the former uses a higher water content in the extruder barrel and lower exit temperatures to obtain a dense material with open pores or even flaked structmes. For these two types of processes, molecular changes in the extruder barrel are not dissimilar. Post-die structuring of the extrudates determines final product properties. 

Crispness is a desirable sensory property in many cereal foods such as toast, the crust of bread, crispbreads, crisps, biscuits, extruded snacks and breakfast cereals. Since it is a subjective sensory assessment crispness is difficult to define unambiguously and its perception varies greatly between individuals and also between countries (Bourne 2002). In general it is known that crisp foods are at low moisture, in the brittle or glassy state well above Tg and fracture rapidly (see also Chapters 5 and 7). We can... 

There are many extruded snack products that are fried, seasoned, and packaged for distribution. One of the popular products is extruded com chips, made either from the cooked com or from masica, and is extmded through extmders. The product is... 

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