versus natural cork; 73 (32 male, 41 female) subjects participated
in test 2, screwcap versus synthetic cork; and 67
(29 male, 38 female) subjects participated in test 3, natural
cork versus synthetic cork.
For the quality assessment tests, 106 (40 male, 66 female)
subjects between ages 21 and 65 were selected on
the basis of their interest, availability, and frequency of
white and red wine consumption. All were Portland area
residents. Forty-two consumers (17 male, 25 female) who
participated in one of the difference tests also participated
in the quality assessment tests.
Sensory protocol. The entire study was conducted at
the Oregon State University FIC. Upon arrival, participants
were asked to read and sign informed consent forms to
ensure they understood the nature of the test and that
participation was voluntary. They were then given oral instructions
on operating touch-screen computers and a basic
overview of the test and were told that they could expectorate
or swallow the wine samples. Each test was
conducted with participants assigned to one of 10 partitioned
taste booths equipped with a computer and touchscreen
monitor. Participants were prompted to taste and
respond to ballot questions via computer and were served
wine samples through a pass-through window with a sliding
door. The server only provided the samples and did
not act as a test facilitator. Participant data was collected
using Compusense 5 (version 4.2; Compusense, Guelph,
Ontario) throughout the study. All taste tests were conducted
under white fluorescent light at room temperature