Investigating the Influence of Drying Methods on the Quality and Bioactive Properties of Hemp (Cannabis sativa L.)...

This research investigates how oven and microwave drying methods influence mass reduction, oil yield, chemical composition, and bioactivity of Cannabis sativa seed oil, from two C. sativa L. varieties-Beldia and Critical-grown in Ketama and Taounate, Morocco. Microwave drying resulted in greater mass loss (2.1%-1.8%) compared to oven drying (1.48%-1.1%), but reached moisture stabilization within just 25 min, significantly faster than the 21 h needed for oven drying. Drying enhanced oil yield, with the highest recorded at 23.12% in oven-dried Ketama Critical seeds and 23% in microwave-dried Taounate Critical seeds, whereas untreated seeds yielded between 18.75% and 20.36%. GC-MS analysis identified linoleic acid as the predominant fatty acid, comprising 79.85% in fresh Ketama Beldia seeds and decreasing to 66.40% (oven-dried) and 79.27% (microwave-dried). Antioxidant capacity, assessed via the DPPH assay, peaked in the non-dried Ketama Beldia oil (IC₅₀ = 9.617 μg/mL), surpassing even ascorbic acid (IC₅₀ = 61.34 μg/mL). However, drying significantly diminished antioxidant activity, with IC₅₀ values rising to 31.185 μg/mL (oven), and 20.377 μg/mL (microwave). Antibacterial tests revealed inhibition zones ranging from 11 to 15.7 mm, with the microwave-dried Taounate Beldia variety showing the strongest effect. Antifungal assays also indicated improved activity post-drying, with a minimum inhibitory concentration (MIC) of 0.25% against Geotrichum candidum in oven-dried Taounate Beldia seeds. These findings highlight the potential contribution of Cannabis sativa seed oil to food security through its nutritional and bioactive properties.