Changes in the composition of a cold-pressed hemp seed oil during three months of storage

• Changes in the composition of hemp seed oil were monitored. • An “oxidative wave” was observed without a subsequent degeneration of the oil. • The oil, stored for 3 months in a dark-light cycle, did not significantly oxidize. Several analytical parameters were evaluated to investigate changes in the composition of a cold-pressed hemp seed oil over a period of 3 months of storage. The environmental conditions applied for the conservation were 12 h of light and 12 of darkness at room temperature, to mime a grocery or supermarket shelf, and the oil was stored in amber glass bottles. The peroxide value was quite low on freshly produced oil (2.66 ± 0.29 mEqO 2 /kg of oil) and decreased after 3 months (1.35 ± 0.08 mEqO 2 /kg of oil), as confirmed by free radical concentration, while no other statistically significant (one-way ANOVA, Tukey’s HSD test, p < 0.05) differences were observed (e.g. conjugated diene and triene systems, Oxidative Stability Index and free acidity). The fatty acid, cannabinoids and tocopherols composition did not statistically change; expect for δ-tocopherol, for which a decrease was observed. The overall results did not show a strong effect of photooxidation on the oil, despite its high degree of unsaturation.