Dietary minerals in seeds of industrial hemp (Cannabis sativa L.) varieties differ with the origin of sources

The seeds of Cannabis (Cannabis sativa L.) has been considered as a vital source of nutrition for thousands of years in ancient world culture. However, industrial hemp has not been studied extensively for its nutritional potential though hempseed, which contains a considerable amount of oil, protein, dietary fibre, vitamins and minerals. Here, we assessed the dietary mineral concentration in seeds of 14 industrial hemp varieties locally available and imported in Western
Australia to see the differences among the varieties in respect to six macro-minerals (Ca, K, Mg, Na, P and S) and 12 trace metals (Al, As, Cd, Co, Cu, Fe, Mn, Mo, Pb, Zn, Cr and Ni). Briefly, hempseeds were oven-dried, ground and digested with cHNO3 (concentrated Nitric acid) followed by cHClO4
(concentrated Perchloric acid) and solutions were analysed by ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry) technique. Significant variations were observed among the varieties with respect to different macro- and micro-minerals concentration. Overall hempseeds are rich in the macro-minerals, P (0.883%), K (0.729%) and Mg (0.406%) and the micro-minerals, Fe (156.06 mg/kg), Mn (120.07 mg/kg) and Al (35.63 mg/kg). Among the 6 macrominerals, Ca (0.215%), K (1.00%), Mg (0.517%) and Na (0.046%) were found highest in the French monoecious variety, Felina 32. The P (1.058%) and S (0.314%) concentrations were highest in the Canadian monoecious variety, Morpeth and the Chinese dioecious variety, Han NW respectively. The French monoecious variety, Ferimon was lowest in Ca (0.106%) and Na (0.001%) and the Chinese dioecious variety, SI 1 was lowest in Mg (0.296%) and P (0.589%). The Chinese dioecious variety, Han FNH was lowest in K (0.647%), and Morpeth was lowest in S (0.197%). Among the 16 micro-minerals, As and Cd were not detected in any of the varieties though Pb was detected in the French monoecious variety, Santhica (0.42 mg/kg), followed by Chinese dioecious varieties, Puma 3 (0.33 mg/kg) and Han COLD (0.37 mg/kg). The variety, Felina 32 was highest in Al (93.00 mg/kg), Cu (17.61 mg/kg), Fe (219.49 mg/kg), Mo (1.07 mg/kg) and Zn (90.24 mg/kg) but was found lowest in Cr (1.45 mg/kg) and Ni (0.73 mg/kg) content. The Chinese dioecious variety, Yuma 1 was highest in Co (0.46 mg/kg) and Mn (175.55%) concentrations and the Chinese dioecious varieties, Bama 4 and Puma 3 were highest in Ni (4.30 mg/kg) and Cr (4.95%) respectively.