Evaluating dried salted cod amino acid signature for nutritional quality assessment and discriminant analysis

• Published in: Frontiers in Nutrition
• Main Authors: M. A. G. Quaresma, G. Pereira, M. L. Nunes, C. Sponda, A. Jardim, H. Gonçalves, C. Santos, L. C. Roseiro
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2023
• Subjects: Gadus morhua; Gadus macrocephalus; dried salted cod; total protein content; amino acid profile; canonial discriminant analysis; Nutrition. Foods and food supply; TX341-641; Norway; Pacific; atlantic cod; Iceland; Alaska
• Online Access: https://doi.org/10.3389/fnut.2023.1144713; https://doaj.org/article/149d24c983fc48aabb918d34a6ddf520

AimThus, the aim of this study was to answer three scientific questions: (1) Are the protein content and amino acid profile of dried salted cod influenced by species (Gadus morhua and Gadus macrocephalus)? (2) Are the protein content and amino acid profile of dried salted cod influenced by the geographical area of capture (Iceland and Norway)? and (3) Does the amino acid profile have the potential to be used as a discriminator of species and geographical areas of capture?MethodsA total of 45 dried salted cods (2–3 kg of dry weight; n = 15 samples/origin) were used in this study. The Atlantic cod was fished in the Atlantic northeast (FAO 27 area) within the Exclusive Economic zones (EEZ) of Norway (n = 15) and Iceland (n = 15), while the Pacific cod was caught in the Pacific northeast (FAO 67 area) within the Alaska EEZ (n = 15). Total protein content was determined by the Kjeldahl method, in accordance with the AOAC procedures. The amino acid profile was analyzed by HPLC with fluorescence detection (at excitation and emission wavelengths of 338 and 425 nm, respectively).ResultsThe Atlantic cod presented higher contents of total protein (33.90 versus 33.10 g/100 g of cod edible portion; p = 0.017) and total amino acid contents (32.52 versus 32.04 g/100 g of cod edible portion; p = 0.015) but displayed lower percentage of indispensable amino acids (32.16 versus 32.83 g/100 g of protein; p < 0.001) than Pacific cod. Among the Atlantic cod harvesting locations, the Norwegian cod displayed higher total amino acid contents (96.91 versus 96.81 g/100 g of protein; p = 0.012) and higher percentage of indispensable amino acids (35.38 versus 28.94 g/100 g of protein; p = 0.042) than the Icelandic counterpart. A correct classification of 100% was obtained for the Pacific and Icelandic cod varieties, but the classification accuracy in the Norwegian cod was of just 86.67%, since 2 samples out of 15 were incorrectly classified as Icelandic.ConclusionThe comparison of cod species showed that the Atlantic cod had a ...