KEYWORDS
silphium seeds, silflower seeds, physical properties, oil extraction,
seed protein
INTRODUCTION
Silphium integrifolium Michx. (rosinweed, silflower), a native to
the central United States, has been the subject of domestication efforts
since the early 2000s. The perennial silflower has long taproot that can
penetrate deeper into the soil to access water and nutrients below the
root zones of most annual crops (Van Tassel et al., 2017; Vilela et al.,
2018). Other desirable agronomic traits of silflower include drought
tolerance, erect stems, relatively large seeds, and high competitiveness
with annual weeds (Van Tassel and DeHaan, 2013). As a close relative of
sunflower, silflower seed has potential uses in the food industry both
as a grain or for its oil (Kowalski and Wiercinski, 2004; Van Tassel et
al., 2014). The seed contains 20.0% crude fat, 33.5% crude protein,
and 22.1% cellulose (Kowalski and Wiercinski, 2004). Seed yields
ranging from 312 to 1,319 kg/ha have been reported (Van Tassel and
DeHaan, 2013; Schiffner et al., 2020).
Like other new crops under development, in addition to seed production
and post-harvest handling, processing of silflower seeds need to be
investigated. No study has been conducted on the processing of silflower
seeds. Information on the physical properties of the seeds is necessary
for selecting and designing process equipment needed for cleaning,
drying, storage, milling, and oil extraction. The seed’s chemical
composition will also point to potential products that can be obtained
from the seed and its oil. The objectives of this work were to evaluate
selected physical properties of silflower seeds, conduct seed processing
for oil extraction and production of defatted meal, and perform
preliminary characterization of the proteins.