Although cottonseed meal is valuable as animal feed, the use
of cottonseed meal is limited by the presence of free and total
gossypol (1). Extraction of cottonseed with either ethanol or
isopropyl alcohol has previously been studied (2,3), in part to
test the potential of these alternative extraction solvents to remove
gossypol. Although the technical viability of the extraction
process with alcohols was established, the cost of the alcohol
extraction process made the process economically unfeasible
(4). The main difficulties were the energy required for the
evaporation of isopropyl alcohol or ethanol and the necessity
of working around a water–alcohol azeotrope to remove co-extracted
moisture. Early work with acetone showed it to be a
suitable oilseed extraction solvent that could also extract gossypol
from cottonseed (5). However, acetone-extracted cottonseed
meal has a pronounced “catty odor” that may limit its
feeding potential (6). Reduction of the seed moisture content
has been suggested to reduce this problem. However, the high
costs associated with drying seed to a low enough moisture
level make this solution economically unfeasible.
In this study mixed solvents that use a relatively small
amount of acetone in hexane were considered for the extraction extraction
of oil and gossypol from cottonseed. The study also aimed
to investigate whether cottonseed meal without the catty odor
can be produced by extraction with a solvent mixture containing
reduced amounts of acetone.