3.1 Oil and moisture content
Table 1 shows oil content of Futura 75 and Carmagnola at
three different harvest stages expressed on dry basis. Futura 75showed a significantly higher (p < 0.05) oil content
during the second harvest stage (29.9%) rather than the other two
harvestings, 22.9% and 26.4% for the first and the third harvest,
respectively. On the other hand, Carmagnola did not show any
significant differences (p < 0.05) in oil content
during maturation, in fact it was 24.5%, 24.8% and 24.9% at first,
second and third harvest, respectively. Our results are in line, or
slightly lower, with literature, Latif & Anwar (2009), Da Porto,
Decorti, Tubaro (2012) and Kostić et al. (2014) that reported an oil
content of 26-32%, 30% and 25-29%, respectively. The lower oil
content may be attributed to cultivation techniques and climatic
conditions; in addition, seeds were covered by a green skin that
certainly influenced the oil content, since it covered completely the
seed.
As regard moisture (Table 1), an expected reduction in percentage of
moisture was recorded in both varieties with the increasing of
maturation; it is well known that immature seeds contain a higher water
content rather than mature seeds (Matthäus & Brühl, 2006). Futura
75 starting from a moisture value of 50% at F1, that decreased
significantly (p < 0.05) at F2 (32%) reaching a final
value of 20% at full maturity. Moisture content in Carmagnolahad the same trend, starting from a value of 31% at C1 and decreasing
significantly (p < 0.05) at C2 (17%) and finally at C3
(10%). Moisture value reported in various studies, Oomah et al. (2002),
Tang, Ten, Wang & Yang (2006) and Da Porto et al. (2012), are much
lower than ours; in fact, they reported values of 7.7, 6.7 and 7.8%,
respectively. This could be due to the green skin, as previously
mentioned, that covered the seeds that certainly had a high impact on
moisture content. Sacilik, Öztürk & Keskin (2006) conducted a study on
physical properties of hemp seeds (size, density and porosity) as a
function of moisture content and found out values more similar to ours
(ranging from 8.6 to 20.9%).