title: Influence of various nitrogen applications on protein and amino acid profiles of amaranth and quinoa.
abstract: The effect of nitrogen application levels (0.16 and 0.24 g N kg(-1) soil) on seed proteins and their amino acid compositions of amaranth (Amaranthus spp.) and quinoa (Chenopodium quinoa Willd) was studied. Total proteins of amaranth and quinoa had high contents of lysine (6.3-8.2 g 100 g(-1) protein) but low contents of methionine (1.2-1.8 g 100 g(-1) protein). Seed proteins were fractionated on the basis of different solubility in water, saline, and buffer as albumin-1 (Albu-1), albumin-2 (Albu-2), globulin (Glob), and glutelin (Glu) and were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Albu-1 was high in lysine (5.4-8.6 g 100 g(-1) protein), while Albu-2, which is a part of storage proteins, had a high leucine content (7.2-8.9 g 100 g(-1) protein) as an effect of different nitrogen application levels. Glu fractions were well-balanced in their essential amino acids with the exception of methionine. In conclusion, nitrogen application can be used for the nutritional improvement in human diet by increasing and maintaining protein and essential amino acid contents.
authors.affiliation: Department of Agronomy, Chiang Mai University, Thailand.
authors.forename: Sa-nguansak
authors.initials: SN
authors.lastname: Thanapornpoonpong
authors.forename: Suchada
authors.initials: S
authors.lastname: Vearasilp
authors.forename: Elke
authors.initials: E
authors.lastname: Pawelzik
authors.forename: Shela
authors.initials: S
authors.lastname: Gorinstein
mesh_terms: D027721:Amaranthus / Q000737:chemistry* / Q000378:metabolism; D000596:Amino Acids / Q000032:analysis*; D027465:Chenopodium quinoa / Q000737:chemistry* / Q000378:metabolism; D005308:Fertilizers / Q000032:analysis*; D009584:Nitrogen / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D000596:Amino Acids; D005308:Fertilizers; D010940:Plant Proteins; D009584:Nitrogen