1. Introduction
Cannabis sativa L., belonged to Cannabaceae family, is an annual
plant known by its long, thin flower and spiky leaves (Montserrat-de la
Paz, Marín-Aguilar, García-Giménez & Fernández-Arche, 2014).Cannabis sativa subsp. sativa is characterized by a low
content of THC (Δ9-tetrahydrocannabinol), it must be
lower than 0.2% on dry basis to be cultivated in most European
countries (Official Journal of European Union, 2008). Industrial hemp
with a low THC content has no psychoactive effects (Siudem, Wawer &
Paradowska, 2019). The most common food using hemp is hempseed oil
(HSO); it is a rich source of nutrients and not nutrients that provide
nutritional and functional support for humans (Crescente et al., 2018).
HSO represents the 25-35% of hemp seed (Callaway, 2004; Montserrat-de
la Paz et al., 2014; Crimaldi, Faugno, Sannino & Ardito, 2017) and it
contains more than 80% of polyunsaturated fatty acids (PUFAs)
(Petrović, Debeljak, Kezić & Džidara, 2015; Siudem et al., 2019)
including essential fatty acids usually not contained in oils used for
human diet (Petrović et al., 2015); in particular ω-6 linoleic acid (LA)
and ω-3 α-linolenic acid (ALA). In addition, LA:ALA ratio is 3:1 which
agrees with European Food Safety Agency recommendations (EFSA, 2009).
HSO is composed of 1.5-2% unsaponifiable fraction, a source of
interesting minor compounds like tocopherols, fat-soluble vitamin D and
E (Siudem et al., 2019) and phytosterols (Montserrat-de la Paz et al.,
2014). Therefore, HSO has a lot of beneficial effects: cancer and
cardiovascular disease prevention, cholesterol level normalization,
blood pressure lowering (Devi & Khanam, 2019) and rheumatoid arthritis
and dermatitis treatment (Oomah, Busson, Godfrey & Drover, 2002; Chow,
2008). For all these reasons industries are attracted by HSO for drugs,
cosmetics, body care products and dietary supplement production
(Callaway, 2004; Kolodziejczyk, Ozimek, Kozlowska., 2012).
To the best of our knowledge, in literature are reported only two
studies about the effect of maturation on yield, quality of fiber and
oil of industrial hemp. Höppner & Menge-Hartmann (2007) studied the
yield and the quality of fiber and oil of different hemp cultivars in
Germany at two different harvest time (“intensive flowering” and
“initial seed maturity”). The different harvest stages did not have
effect on stem diameter, fiber content and yield; on the other hand,
seed yield and seed oil content increased with maturation while the
γ-linolenic acid content decreased. Burczyk, Grabowska, Strybe &
Konczewicz (2009) studied the effect of sowing density and date of
harvest (beginning of panicle forming, full bloom and full seed
maturity) on industrial hemp yields. They observed that the maximum
yields of biomass, cellulose and fiber can be obtained at 30 kg/ha
sowing density at full bloom; while considering hemp for seed or
panicles the highest yields were obtained at 10-20 kg/ha of density at
full maturity of panicles.
The aim of this study was the characterization of lipid fraction of two
different cultivar of Cannabis sativa L., Futura 75 andCarmagnola , harvested at three different harvest stages; in order
to investigate the quality of hempseed oil during the maturation, which
was never investigated before. To this end, fatty acids, tocopherols and
sterols content were determined using fast chromatographic techniques,
HPLC and GC equipped with different detectors.