Starch native, products from

Starch is obtained from a variety of plant sources. Corn, cassava, sweet potato, wheat, and potato are the major sources of food starch while sorghum, barley, rice, sago, arrowroot, etc. serve as minor sources of starch in different localized regions of the world (Gaillard, 1987 Ratnayake and Jackson, 2003). Raw starch granules do not disperse in cold water. This limits the use of raw native starches for food as well as industrial applications, and therefore starch is often cooked during product-manufacturing... 

Sweetening orange juice with cane sugar or glucose-fructose syrup from com starch lowers the 8( C) value of sugar, which is —25.5%o in the native juice (Table 18.45). On the other hand, the addition of beet sugar (C3-plant) can be recognized only via the 8( H) value. The addition of synthetic products from petrochemicals (8( C) —27 5%c) to foods from C3-plants cannot be detected via the 8( C) value, but via the 8( H) value in many cases. 

Walenta, E., Fink, H. R,Weigel, R, Ganster,J., Schaaf, E. (2001]. Structure-Property relationships of extruded starch. 2. Extrusion products from native starch, Macromol. Mater. Eng., 286,462-471. 

Fats contribute to the rheological properties in flowable and pastry foods. By combining with starches to form a clathrate, a product different from the native starch is formed, eg, shortening in baked goods. The highly developed shortness of pies baked in eadier times resulted from the use of high levels of lard. The use of less fat in pie cmsts is evident, ie, the cmsts are harder and readily become soggy. 

Native potato starch, which is used in the food, paper and textile industries, is often not optimal for a particular application. Modifications are done to obtain the properties needed for specific uses.26 28 More than 500 modifications of potato starch are currently known. This chapter presents an overview of the major commercial modifications rather than a complete bibliography of all potato starch reactions. With a distinction based on the chemical character of the product, three groups can be distinguished. Some derivatives are made from starch by a combination of reactions. 

Surimi is fish paste from deboned fish used to make simulated crab legs and other seafood. For preservation the paste is blended with cryoprotectants, such as sucrose, sorbitol and phosphates, and frozen. To make the final product, the frozen paste is thawed, blended with starch and extruded as a film onto a belt. The belt takes the film into an oven that heat-denatures the fish protein and cooks the starch. The film is then rolled to form striations, shaped, colored and cut. Depending on the required distribution, the product is frozen or refrigerated. Potato and tapioca starch were used in surimi products 400 years ago, since they provided a cohesive, elastic matrix consistent with seafood. Frozen distribution has made the use of highly-stabilized, moderately crosslinked tapioca starch popular, alone or with native tapioca starch. Modified waxy maize products are used, as is unmodified com starch, for increased cuttability. Kim188 reported that the gel strengthening ability of starch correlates with starch paste viscosity. 

Starch is the other carbohydrate-based feedstock. Approximately 10 Mt is produced annually from corn (maize), wheat and potato, out of a total agricultural production of 1.6 Gt a-1 carbohydrate equivalents. A minor fraction of starch is amylose, a linear a 1 ->4 polymer of glucose (Fig. 8.2b). The native structure of amylose is helical loose random coils are formed upon dissolution in water. The branched glucose polymer amylopectin is the major (approximately 75%) component of starch. 

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