Protein Content and Amino Acid Composition in Seed of Bread Wheat (Triticum aestivum L.)

Abstract

The aim of this study was determination of protein content and amino acid composition in seeds of bread wheat, with particular focus of evaluation essential amino acids (EAAs). For analysis used flour samples of grained seed of 10 wheat variety, which selected in different breeding center (in Novi Sad and Kragujevac, Serbia). Kjeldahl method was used for determination of nitrogen (N) contents which value multiplied with coefficient 5.7 for computing protein content (protein contents = 5.7 x % N contents). Amino acids analyses of wheat samples were performed by ion exchange chromatography, followed by the ninhydrin colour reaction and photometric detection at 570 nm and 440 nm (for proline). The results showed that the mean protein content for wheat varied from the lowest value 10.24% in Ljubičevka to the highest 14.21% in Fortuna variety. The mean contents (g 100 g-l protein) of nonessential amino acids (NEAAs) were aspartic acid 5.42%, serine 4.23%, glutamic acid 18.51%, proline 12.18%, glycine 4.17%, alanine 3.64%, tyrosine 2.52%, arginine 5.02%, while mean contents of essential amino acids (EAAs) were threonine 2.86%, valine 4.52%, methionine 1.28%, isoleucine 3.87%, leucine 5.87%, phenylalanine 4.62%, histidine 2.46%, lysine 2.91%. The wheat variety contained relatively high concentration of the most deficient EAAs. The variety Ljubičevka contained relatively high concentration of the most deficient EAAs (threonine, valine, leucine, lysine,). The highest value (29.31 g 100 g-l protein) of total essential amino acids (TEAA), 59.79 g 100 g-l protein of total nonessential amino acids (TNEAA) as well as the highest value (90.35 g 100 g-l protein) of total amino acids (TAA). Obtained results provide variability of wheat variety on the base of amino acid contents and indicate reliable variety for selecting desirable parents in breeding program for improving nutrient quality.

Cilj ovog istraživanja je bio određivanje sadržaja proteina i sastava aminokiselina u semenu hlebne pšenice, sa posebnim fokusom na procenu esencijalnih aminokiselina (EAA). Za analizu su korišćeni uzorci brašna mlevenog semena 10 sorti pšenice, koje su selekcionisane u različitim oplemenjivačkim centrima (u Novom Sadu i Kragujevcu, Srbija). Za odredjivanje sadržaja proteinakorišćen je Kjeldahlov metod za određivanje sadržaja azota (N) čija je vrednost pomnožena sa koeficijentom 5,7 (sadržaj proteina = 5,7 k % N sadržaj). Za analizu aminokiselina uzoraka pšenice korišćena je jonoizmenjivačka hromatografija, reakcija bojenja ninhidrinom i fotometrijska detekcija na 570 nm i 440 nm (za prolin). Rezultati su pokazali da je srednji sadržaj proteina pšenice varirao od najmanje vrednosti 10,24% kod Ljubičevke do najveće 14,21% kod sorte Fortuna. Srednja vrednost sadržaja (g 100 g-1 proteina) neesencijalnih aminokiselina (NEAA) je nađena za asparaginsku kiselinu 5,42%, serin 4,23%, glutaminsku kiselinu 18,51%, prolin 12,18%, glicin 4,17%, alanin 3,64%, tirozin 2,52%, dok je srednja vrednost sadržaja esencijalnih aminokiselina (EAA) bila za treonin 2,86%, valin 4,52%, metionin 1,28%, izoleucin 3,87%, leucin 5,87%, fenilalanin 4,62%, histidin 2,46% i lizin 1,2%. Sorta pšenice je sadržala relativno visoku koncentraciju najdeficitarnijih EAA. Kod sorte Ljubičevka je nadjena relativno visoka koncentracija najdeficitarnijih EAA (treonin, valin, leucin, lizin,). Najveći sadržaj (29,31 g 100 g-1 proteina), ukupnih esencijalnih amino kiselina (TEAA), i najveći sadržaj (59,79 g 100 g-1 proteina) ukupnih neesencijalnih amino kiselina (TNEAA) kao i najveća vrednost (90,35 g 100 g-1 proteina) ukupnih aminokiselina ( TAA). Dobijeni rezultati predstavljaju varijabilnost sorti pšenice na osnovu sadržaja aminokiselina i ukazuju na pouzdanu sortu za odabir poželjnih roditelja u oplemenjivačkom programu za poboljšanje kvaliteta hranljivih materija.