Effect of roasting on antioxidative properties, polyphenol profile and fatty acids composition of hemp (Cannabis sativa L.) seeds

This study was done to investigate the effect of roasting time (7, 14, and 21min) at 160 ᵒC on proximate composition, colour attributes, bioactive compounds, and fatty acids composition of hemp (Cannabis sativa L.) seeds. Roasting of the seeds for different periods significantly (P < 0.05) increased the protein, oil, total phenolic, total flavonoid, and DPPH scavenging. The lightness (L*) and yellowness (b*) of the samples were significantly (P < 0.05) decreased with roasting time but redness (a*) was increased. Moreover, phenolic acids, flavones, polyphenols, and glycosylated flavonoids were increased significantly with the roasting time. Roasting of the seed slightly affected fatty acid contents. The contents of P, Mg, B of hemp seeds was significantly decreased while those of Ca, Fe, Cu, Mn, and Zn were significantly (P < 0.05) increased with roasting time. The results showed that roasting for 14 min enhanced hemp seeds nutritional and oxidative properties by improving oil, protein, potassium, magnesium, total phenolic, and flavonoid contents. Therefore, roasting for 14 min could be considered as the most suitable duration to process hemp seeds based on the parameters measured.