Zein (protein)

Corn kernels

Zeine are a group of proteins from Zea mays that occur as storage proteins in maize kernels.

properties

Zeine are colorless, odorless and tasteless, hardly soluble in water and edible. Zein is one of the alpha- prolamines and has relatively high proportions of the amino acids glutamine , proline , alanine and leucine as well as several repetitions in their amino acid sequence . In maize, the zein proteins of 22 kDa and 19 kDa make up about 70% of the storage proteins. They each consist of nine obliquely cylindrically arranged anti-parallel helices . The zein of 22 kDa by 23 genes in a gene cluster encoding , which in their gene expression are differentially regulated.

Zein proteins are approved in the USA as a coating for tablets and food and classified by the USFDA as Generally Recognized As Safe . The extraction is carried out from corn flour or corn proteins (as a coupling use ) by alkaline water-and isopropanol - extraction with sodium hydroxide . A precipitate of zein is formed by cooling or by extrusion into an acidic bath .

Zein is being developed as a thermoplastic bio-based plastic , partly as a mixture with starch- based fillers .

From 1948 to 1958, zein was also used as a raw material for regenerated fibers by the Virginia-Carolina Corporation under the brand name Vicara in blends with wool , nylon , cupro (25% each), since Vicara alone tended to shrink and was less resistant to abrasion.

Web links

USFDA: Section 184.1984 Zein. . Retrieved August 22, 2013.

Individual evidence

↑ Momany, Frank A .; Sessa, David J .; Lawton, John C .; Selling, Gordon W .; Hamaker, Sharon AH; and Willett, Julious L .: Structural characterization of alpha-zein. In: J Agric Food Chem. (2006), Vol. 54, No. 2, pp. 543-547. PMID 16417318 .
↑ R. Song, V. Llaca, E. Linton, J. Messing: Sequence, regulation, and evolution of the maize 22 kD alpha zein gene family. In: Genome Res. (2001), Vol. 11, No. 11, pp. 1817-1825. doi : 10.1101 / gr.197301 (currently not available) . PMID 11691845 . PMC 311139 (free full text).

[momany-1] Momany, Frank A .; Sessa, David J .; Lawton, John C .; Selling, Gordon W .; Hamaker, Sharon AH; and Willett, Julious L .: Structural characterization of alpha-zein. In: J Agric Food Chem. (2006), Vol. 54, No. 2, pp. 543-547. PMID 16417318 .

[2] R. Song, V. Llaca, E. Linton, J. Messing: Sequence, regulation, and evolution of the maize 22 kD alpha zein gene family. In: Genome Res. (2001), Vol. 11, No. 11, pp. 1817-1825. doi : 10.1101 / gr.197301 (currently not available) . PMID 11691845 . PMC 311139 (free full text).