Examine zein isolate fractions as films for packaging.Wheat gluten Noun 1. wheat gluten - gluten prepared from wheat gluten - a protein substance that remains when starch is removed from cereal grains; gives cohesiveness to dough and corn zein zein the principal protein in maize. Has low nutritive value, being deficient in lysine and tryptophan. are alcohol-soluble proteins that have hydrophobic hydrophobic /hy·dro·pho·bic/ (-fo´bik) 1. pertaining to hydrophobia (rabies). 2. not readily absorbing water, or being adversely affected by water. 3. properties. Zein proteins characteristically form hard and glossy coatings on drug tablets. Others have coated tomatoes with zein films of various thicknesses to optimize the oxygen content of the film in order to improve the product storage life and quality. USDA/ARS scientists (Eastern Regional Research Center, 600 E. Mermaid Lane, Wyndmoor, PA 19038) are working with zein films with an eye toward their use in food packaging as a possible substitute for polyolefin films. They also are contemplating incorporating antimicrobial agents Antimicrobial agents Chemical compounds biosynthetically or synthetically produced which either destroy or usefully suppress the growth or metabolism of a variety of microscopic or submicroscopic forms of life. into the films that would then be applied to food products or packaging materials to inhibit microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. growth. The investigators prepared zein films containing different levels of starch starch, white, odorless, tasteless, carbohydrate powder. It plays a vital role in the biochemistry of both plants and animals and has important commercial uses. from extracts of dry milled corn which had been previously rinsed in a hydrocyclone to improve the extractability of the zein as well as film formation. Zein was isolated from the rinsed dry-milled corn by extraction with 70% (v/v) ethanol. Scientists found certain zein fractions in the extracted isolate that were not found in commercial zein. There's an economic advantage to using isolate fractions. Zein films themselves are expensive. They can cost between $10/lb and $22/lb. But zein isolate fractions are only between $1/lb and $2/lb. Water vapor barrier A vapor barrier (or more accurately, vapor retarder) is any material, typically a plastic or foil sheet, that resists passage of moisture through wall, ceiling and floor assemblies of buildings. properties of the glycerine-plasticized films prepared from extracted zein isolates, containing approximately 8% starch, were comparable to films prepared from commercial zein. The water resistance of zein isolate films decreased with increasing starch content. Hydrophobic films prepared from zein isolates containing 1% starch had lower water vapor permeability and were more water-resistant than films prepared from commercial zein, even with the 8% starch content. Further information. Nicholas Parris; phone: 215-233-6453; fax: 215-233-6559; email: nparris@arserrc.gov. |
|
||||||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion