Production of Modified Starches and Syrups

The global starch production in 2010 was of more than 70 Mio mto of primary starch, of this, historically 32% are dry, native and modified starches and 68% are refined liquid starches. °° Global starch consumption is projected to reach 133.5 Mio mto by the year 2018, driven primarily by the diversity and sheer number of end-use applications in both food and nonfood industries, including native and modified starches, but also the large volume of starch that is converted into syrups for direct use as glucose and... 

Starches may be used directly as feedstocks, or in more technical uses in modified form (typically as starch esters and ethers), or simply converted to glucose syrups for use in industrial fermentation processes or for onward conversion to isoglucose (fructose). After use of unmodified starches in ethanol production, the largest industrial user of both unmodified and modified starches is the papermaking... 

Starch-Modifying Enzymes Starch is one of the most abundant carbohydrates in terrestrial plants and the most important polysaccharide used by humankind. This polymer is normally processed and used in a variety of products such as starch hydrolysates, starch or maltodextrin derivatives, fructose, glucose syrups, and cyclodextrins [148, 149]. In addition, starch is widely used as a raw material in the paper industry, in polyol production, and as economic substrate for many microbial fermentations [149]. Starch consists of a large number of glucose units that can be linearly attached as hehcal amylose [ 99% a-(l-4) and 1% a-(l-6) bonds] or branched as amylopectin [ 95% a-(l-4) and 5% a-(l-6) bonds] [69]. In nature, four types of starch-converting enzymes exist (i) endoamylases (ii) exoamylases (iii) debranching enzymes and (iv) transferases. 

Constit. of corn syrup. Product of action of a-amylase on starch. Also isol. from Streptomyces sp. Maltooligosaccharide mixtures are important food additives (sweeteners, gelling agents and viscosity modifiers). Exhibits antimicrobial activity against Erwinia carotovora. Amorph. Sol. H2O, MeOH fairly sol. EtOH, 2-propa-nol, butanol poorly sol. Mc2CO, hexane. Mp 169.5-173° dec. [a]o +165.5 (c, 5.0 in H2O). Md +177 (H2O). 

Modifications. Besides the property of gelatinization, starch may be modified to yield some unique and useful properties which are used advantageously by the food industry and others syrups and sugars are well-known products of modification. 

The type and composition of dietary carbohydrates varies greatly among different food products. Dietary carbohydrates can be predominantly found in the form of sugar (monosaccharides and disaccharides) and starch or nonstarch polysaccharides. Furthermore, in the food industry they can be used in the form of hydrolyzed cornstarch, high-fructose com syrups, modified starches, gums, mucilages, and sugar alcohols. 

Plant starch is found in potatoes, maize, rice, wheat and other cereals in abundant quantities, estimated to amount to 10 tons per annum worldwide. Most commercial production is from maize (corn). About two-thirds of this is used in the food industry and most of the remainder by the paper and textile industries. Food applications include flours, breakfast cereals, corn syrups and thickeners for jellies, pie fillings, gravies, salad dressings and so on. Manufactured starches include various modified varieties. 

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