Protein, polyamine, phenolic composition and their correlations in Canadian barley grains for different end-use purposes

Barley is an important cereal grain in Canada, classified into food, malting, and general-purpose cultivars based on their end-use purposes. In this study, protein, polyamine, phenolic composition and content of 25 Canadian barley genotypes representing different end uses were analyzed on a dry base. The protein content was measured between 10.38% and 15.47%. Total polyamines (TPA) were found in the range of 64.62 to 135.11 μg/g. The free phenolic content (FPC) showed values from 761.46 to 1174.27 μg gallic acid equivalents (GAE)/g, and the bound phenolic content (BPC) ranged from 390.76 to 825.34 μg GAE/g. Putrescine (Put), spermidine (Spd), and spermine (Spm) were identified as the predominant polyamines, while ferulic acid (FA) was the most abundant phenolic acid, followed by p -coumaric acid (CA). Food barley exhibited the highest levels of protein, Put, Spd, Spm, and TPA, whereas malting and general-purpose barleys contained higher levels of BPC, FA and CA. Correlation analysis revealed strong positive relationships among protein, Put, Spd, Spm, and TPA, but negative correlations between these components and BPC, FA and CA. These findings provide new insights into the compositional characteristics of Canadian barley genotypes intended for different end uses and underscore the importance of considering quality and functional attributes when selecting barley varieties for food, malting, and feed applications. • Food barley had higher protein content than malting and general-purpose barley. • Food barley had a higher polyamine content than malting and general-purpose barley. • Malting and general-purpose barley had higher bound phenolic content than food barley. • Protein and polyamine contents were positively correlated. • Bound phenolics showed negative correlations with protein and polyamines.