Amino acid content in traditional potato cultivars from the Canary Islands

The amino acid profile, amino acid score and total protein content were determined in ten traditional potato (Solanum tuberosum) cultivars from Tenerife (Bonita, Bonita negra, Azucena negra, Mora, Borralla, Terrenta, Colorada de baga, Negra, Peluca blanca and Palmera lagarteada). There were significant differences among the potato cultivars in total protein content, and in the amino acids that were studied, except methionine. Azucena negra and Negra cultivars showed the highest mean protein content, while the Colorada de baga cultivar showed the lowest. In general, the Colorada de baga and Palmera lagarteada cultivars had the highest content of amino acids, and the Bonita cultivar the lowest. The production region did not influence the concentrations of amino acids. The chemical score of the potato protein varied considerably among the potato cultivars, ranging from 26.2% for the Palmera lagarteada to 66.5% for the Bonita negra. Sulphur amino acids were the limiting amino acids for all the potato cultivars, except Borralla. Lysine was the limiting amino acid for the Borralla cultivar, and the second limiting amino acid in the rest of the potato cultivars. After application of stepwise discriminant analysis, 93.1% (65.5%, after cross-validation) of the potato samples were correctly classified according to the cultivar, when the variables selected were glycine, histidine, leucine and total proteins.