A new study highlights the potential of hemp infructescences—typically discarded after seed harvesting—as a valuable and sustainable source of essential oils.
Published in Industrial Crops and Products, the research analyzed the morphology and chemical profile of mature hemp infructescences to evaluate their suitability as raw material for essential oil (EO) extraction. Two types of material were studied: the entire infructescence after threshing (I), which includes stems and branches, and a more selective sample of only bracts and leaves (BL).
The researchers found that EO yield was slightly higher for the entire infructescence (3.902 L/ha) than for the bract-leaf material (3.474 L/ha). EO content was most concentrated at the apical section of the plant and declined toward the base. The top-producing regions showed EO content as high as 0.325% in BL samples.
Light microscopic characterization of constituents of the raw material. A – bracts and leaves (BL); B – the entire infructescence after removing seeds (I); C, D – fragments of infructescence before sample preparation; E – lateral branches; F – stem; b – bract, gt – glandular trichome, l – leaf, lb –lateral branch, ngt – non-glandular trichome, s – seed, st – stem. Scale bars = 5 mm (A, B); 2 mm (C); 1 mm (D, F); 0.5 mm (E).
A total of 72 compounds were identified in the essential oils, with α-pinene, β-caryophyllene, cannabidiol, caryophyllene oxide, and myrcene being most prevalent. The chemical makeup varied by location along the plant, with monoterpenes dominating the upper sections and cannabinoids and sesquiterpenes more common in the lower parts.
The study concludes that hemp infructescences, often considered agricultural waste, offer a promising new source of bioactive compounds. This could boost the overall profitability of hemp cultivation, particularly for farmers working with fiber or seed varieties on marginal land.
More articles from The Marijuana Herald can be found below.
