2.2. Seed oil determination by Soxhlet extraction method
Seed oil content was measured by AOAC method no. 920.85
(AOAC, 1990) with an automatic Soxhlet apparatus (Soxtec 2050,
FOSS, Denmark)following themanufacturer’s guidelines. The Sacha
inchi seeds were ground using a Philips mill and passed through a
16-mesh sieve. The dried seed powder (0.8–2.6 g) was packed in
a thimble and the oil was extracted with petroleum ether (boiling
point: 60–90 ◦C) for 1.5 h. Upon completion of the oil extraction,
the oil was dried at 105 ◦C for 5 h to remove residual water and
petroleum ether. The oil content of the samples was calculated on
the basis of dry weight of the seeds.
2.3. Seed oil determination by time-domain nuclear magnetic
resonance (TD-NMR)
TD-NMR determination of seed oil content was carried out
with the minispec mq-one Seed Analyzer (Bruker Optik GmbH,
Germany), equipped with a sample tube of 40-mm diameter. For
oil determination in Sacha inchi seeds at different developmental
stages, immature seeds were dried at 65 ◦C until constant weight
(for about 48 h), whereas mature seeds with moisture contents
less than 10% were used without drying. A calibration curve was
obtained fromreference samples of oil extracted by Soxhletmethod
from mature seeds of Sacha inc