Starch-based technology

In nature, the availability of starch is just second to cellulose. Starch represents a link with the energy of the snn, which is partially captured during photosynthesis. It serves as a food reserve for plants and provides a mechanism by which non-photosynthesising organisms, such as man, can ntilise the energy supplied by the sim. 

The most important indnstrial sonrces of starch are corn, wheat, potato, tapioca and rice. Today, starch is inexpensive and is available armually from such crops, in excess of current market needs in the United States and Europe [1]. 

Corn production, has risen over time, as higher yields followed improvements in technology and in production practices. 

US corn production in 2003 passed the level of 10 billion bushels (560 billion kg) and from 1970 to 2000 the bnshels per acre increased from 80 to 140 (4480 to 7840 kg) (National Agricultural Statistics Service, USD A). In Europe (15 member states) corn starch production in 2001 was 8.4 million tons. 

Approximately 75% of US domestic corn use is allocated to livestock feed. Food, seed, and industrial uses of corn comprise 25% of domestic utilisation. The market for food made from corn is matnre, and food nses of corn are expected to expand at the rate of popnlation growth. Besides starch, corn is also processed by wet millers into high-fructose corn syrup (HFCS), glucose, dextrose, corn oil, beverage alcohol and fuel ethanol. 

Catia Bastioli, Paolo Magistral and Sebastia Gesti Garcia 

Starch is, in general, a low-cost and readily available product but in recent years it has been subjected to financial speculation, as are several natural and fossil raw materials, so its price can fluctuate substantially from one year to the next. This fact arises from the change in nutritional habits in emerging countries, and from the use of crops and by-products as fuel sources. In this regard, the percentage of starch and ethanol used for fuel production, with respect to the overall corn production in the US, was 16 and 25% respectively in 1990, and moved to 4 and 77% in 2009 [1]. 

Worldwide, the main sources of starch are corn (82%), wheat (8%), potatoes (5%) and cassava (5%), from which tapioca starch is derived. The worldwide production of corn in 2010 was approximately 800 x 10 tonnes. The main corn producer in 2010 was the US (331 x 10 tonnes), China (158 x 10 tonnes), and Brazil and the European Union (EU), comprising 27 countries, (57 x 10 tonnes each) [1]. 

In the US, 39.4% of the corn produced in 2010 was used as livestock feed, 10.5% was processed into food, seed and industrial products (excluding ethanol), and 34.9% was converted into ethanol the remaining 15.2% was exported [2]. 

Besides the food, pharmaceutical and paper industries, the availability of starch in association with its renewability has aroused, since the late 1980s, an increasing 

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Novamont s Mater-Bi starch-based technology implies processing conditions able to destroy the crystallinity of amylose and amylopectin, in the presence of macromolecules, such as specific polyesters, which are able to form a complex with amylose. They can be of natural or synthetic origin. The specification of the starch, that is, the ratio between amylose and amylopectin, the nature of the additives, the processing conditions and the nature of the complexing agents allow engineering of various supramolecular structures with very different properties. 

Bastioli C (2005) Starch-based technology. In Bastioli C, editor. Handbook of biodegradable pol3cmers. Shawbury, Shrewsbury, Shropshire Rapra Technology. pp.257-286. 

The reference commercial starch-based biodegradable polymers are marketed by Novamont in Italy imder the name Mater-Bi . This starch-based technology permits going beyond conventional compounding. In the presence of different synthetic polymers, starch can undergo a thermoplastic transformation up to destructurisation the destructurised starch composites can reach starch contents higher than 50% [83]. 

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