Protein and amino acid profiles of Tunisian Deglet Nour and Allig date palm fruit seeds

Abstract

Introduction. The fruit of the date palm (Phoenix dactylifera L.) is an important crop of the arid and semi-arid areas of the world. It has always played a genuine economic and social part in the lives of the people of these areas. Nevertheless, there are few studies related to the composition and the functional properties of the different components (fibres, fats and proteins) of the date seeds. In order to obtain more information on the nutritive value and the chemical composition of the pits of the most important and most valuable Tunisian date palm varieties (Deglet Nour and Allig), we studied their profiles of proteins and amino acids. Materials and methods. Date seeds of two Tunisian cultivars, Deglet Nour and Allig, were separately milled in a heavy-duty grinder to pass 1-2 mm screens; then, they were preserved at - 20 °C until analysis. The soluble proteins from defatted date seeds were extracted with water at pH 10, and were analysed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Results and discussion. Amino acid profiles revealed that date seeds from the Deglet Nour and Allig varieties contained the majority of essential amino acids: lysine, isoleu- cine, leucine, methionine, threonine, valine and phenylalanine. Seventeen amino acids were detected in the seeds of the two studied cultivars. Glutamic acid was the major amino acid in Deglet Nour and Allig date seeds, representing 17.83% and 16.77%, respectively, of the total amino acids. Date seeds appeared to contain a number of proteins with molecular weights ran- ging from 22 kDa to 70 kDa. Three prominent bands appeared at 32 kDa, 60 kDa and 70 kDa. Tunisia / Phoenix dactylifera / fruits / seeds / chemical composition / proteins / amino acids