Nguyen, Si Nhat2026-06-172026-06-172026-06-162026-06-17http://hdl.handle.net/1993/39826Barley (Hordeum vulgare L.) is one of the important and climate-resilient crops that serves as a rich source of health-promoting bioactive compounds. While recent research has focused on β-glucans and phenolic compounds in barley grains, this thesis investigated the occurrence, distribution and enrichment of polyamines. Polyamines (e.g., putrescine, spermidine and spermine) are aliphatic nitrogenous compounds recognized for their antioxidant and anti-inflammatory properties. The study first examined a polyamine extraction method, reporting that 1 M hydrochloric acid was more effective than 5% (w/v) trichloroacetic acid for recovering free polyamines from barley flour. Analysis of thirteen Canadian varieties revealed significant genotypic variations. The total polyamine content ranged from 5.48 to 11.23 mg/100 g dry basis (db), with hulless food-grade varieties generally exhibiting higher levels (average 9.73 mg/100 g db) than malting (average 7.00 mg/100 g db) or feed (average 7.81 mg/100 g db) cultivars. Mechanical fractionation (pearling, dehulling and milling) and hand-dissection techniques demonstrated gradient distribution within the kernel. Polyamines were highly concentrated in metabolically active tissues, particularly the germ (52.0–65.5 mg/100 g db) and the aleurone layer, whereas the starchy endosperm was relatively depleted. A significant and persistent positive correlation was established between polyamine levels and protein content (r = 0.70–0.84, p < 0.001) across both whole kernels and processed fractions. Furthermore, polyamine concentrations correlated with other markers of whole-grain status, such as ash, germ agglutinin, and total phenolic content. These results provide a scientific basis for using dry fractionation to create value-added and polyamine-enriched barley ingredients for functional food applications.engbarleycereal graincorrelation analysisdry fractionationpolyamineprotein