Engineering Session
Luis F Castro, Washington State University
Co-author(s): Carolyn Ross, Washington State University, USA
ABSTRACT: In order to study flavors and their
interactions, these volatile compounds often need to be removed from
their matrix. The removal of volatile compounds from complex beverage
matrices like beer remains a challenge, due to the difficulty of
separating these compounds from the non-volatile beverage matrix without
altering their properties. The aim of this study was to develop a novel
method for the removal of volatile compounds from beer. The new
technique, designated nitrogen gas stripping coupled with high vacuum
(NSHV), applies a vacuum to the beer sample while using forced gas
(nitrogen) stripping without the application of heat. Application of
NSHV to beer samples spiked with known amounts of selected volatile
compounds commonly isolated from beer (ethanol, isoamyl acetate, ethyl
hexanoate, myrcene, benzaldehyde) resulted in higher reduction
percentages for each compound when compared to commonly used rotary
evaporation. Four of the five volatile compounds studied showed >85%
concentration reduction following 90 min of treatment by NSHV compared
to only one compound (myrcene) showing a >70% reduction using the
rotary evaporation technique. The new method was demonstrated to be a
promising method for volatile compound removal from beer samples and
possibly other liquid samples as well.
Luis Castro received a
B.S. degree in chemistry from the University of Costa Rica in San Jose,
Costa Rica. After two years of working in both industry and academia, he
moved to the Washington State University, School of Food Science, to
pursue graduate studies. After obtaining his M.S. degree in food science
under Barbara Rasco working in the field of food safety, he enrolled in
the Ph.D. program at the same institution working with Carolyn Ross. It
was here that he started research on the impact of beer matrix
components and their interactions on the sensory perception of beer. He
is currently a research assistant in the sensory laboratory at
Washington State University and is working on his dissertation to obtain
a Ph.D. degree in food science.
VIEW PRESENTATION 125
