Assessment of Protein Quantity and Quality of Turkish Maize Landraceswith Different Opacity Level

Protein ratio and amino acid composition vary considerably in maize according to the level of opacity. In this study, the total protein content, amounts of some essential amino acids (lysine and tryptophan) and quantitative and qualitative variation of protein fractions in maize seed samples separated according to different opacity levels were investigated. In the study, 6 local maize landraces with opaque kernel structure and 3 standards were used. The field trial was carried out in 2021 according to the complete blocks trial design with 3 replications. Samples of local maize landraces from the field experiment were separated on a light table according to 5 different opacity levels (0%, 25%, 50%, 75% and 100%). Protein content, lysine and tryptophan contents, albumin + globulin, glutelin and zein contents were analyzed in the samples separated by their opacity. In addition, protein fractions were subjected to SDS-PAGE analysis and the changes in protein bands according to opacity level were examined. Differences between genotypes, opacity levels and their interaction were illustrated with box plot and PCA-Biplots. Two-way dendrograms were created for qualitative discrimination. The results of the study showed that there were significant changes in protein amount and quality according to the opacity levels of the genotypes. The protein contents of the genotypes were 5.95–10.22%, lysine contents 0.33–0.46%, tryptophan contents 0.032–0.083%, albumin + glubulin contents 1.92–2.72%, glutelin contents 0.64–1.08%, and zein contents 1.59–1.99%. There was a significant difference in presence or absence according to the opacity levels in the protein fractions.