464 Chapter 26
Irradiation
This process has been the cause of much
dispute among both consumers and regula-
tors, and consequently an impasse has been
reached where at present, bacon that has
been irradiated is not for sale. However,
there has been some research by Risvik
(1986) into the effects of irradiation on
bacon quality. Bacon was produced, vacuum
packed, and then irradiated using a Co^60
source with doses varying from 0, 1, 2.5, 5.0,
and 10.0 KGy.
A ten - descriptor sensory profi ling proce-
dure was adopted covering appearance of the
fat and lean, fatness, fi rmness, juiciness,
chewing resistance, off - taste, rancidity, and
sweetness. Assessors rated the samples on a
nine - point linear intensity scale where 1 is at
a low intensity and 9 is a high intensity for
the attribute. Tests were conducted within
one week of irradiation and again after 3
months. Nonirradiated bacon was classifi ed
as juicier, sweeter, and with less off or metal-
lic taste. It was noted that off - fl avors such as
rancidity increased with increasing doses of
irradiation. Doses above 1.0 KGy were iden-
tifi ed as signifi cantly different from nonirra-
diated samples.P â t é
Siret and Issanchou (2000) investigated the
infl uence of traditional processing and non-
traditional processes on the eating quality of
p â t é. The essential differences in production
between traditional and nontraditional pro-
cesses are that in the former, the raw materi-
als used are more diverse; nitrate is used
instead of nitrite. The precuring process is
longer, comminution is coarser, eggs are
used as binding agents, thickeners are not
used, and cooking is done in a dry atmo-
sphere. The expectation of the product was
that the traditional process would produce
p â t é s with larger pieces of fat, less smooth
texture, and a more complex fl avor profi le.491 consumers who were asked to assess
appearance, fl avor, texture, and juiciness.
The appearance of hot - cured gammon was
judged acceptable by 474 consumers and
unacceptable by 17; the corresponding
fi gures for cold - cured gammon were 469 and
22 respectively. On eating the gammon, there
were no signifi cant differences for any of the
eating - quality attributes.
The general conclusion was that hot
curing could produce bacon and gammons of
equivalent eating quality to those produced
under the more traditional cold - cured process.
White Exudate
A particular problem that can occur in bacon
concerns the amount of “ white exudate ” that
is present on cooking. Initially, it appears as
a milky white liquid that eventually turns
brown and leaves an unsightly residue that
adheres to the pan.
From a sensory analysis viewpoint, it is
diffi cult to accurately provide good sensory
information when the amount of exudate
varies betweens cooking sessions; assessors
also need to be present at the time of cooking.
A possible solution was to photograph
successive cooking trials of bacon and build
up what was essentially a photographic stan-
dard. This procedure was adopted by Sheard
et al. (2001). Assessors were given 20
photographs of bacon that had been fried.
Assessors were asked to rank the photo-
graphs in increasing order of exudates. The
results followed the procedures given in the
British Standard BS5929. This ranking
revealed differences in bacon types in rela-
tion to the amount of exudates produced. The
amount of exudate produced by the different
bacon types from least to most was: dry -
cured, Wiltshire cured untempered, Wiltshire
cured tempered, rapid cured untempered, and
rapid cured tempered. A further experiment
confi rmed the effect that the Wiltshire cured
bacon had less exudate loss than the rapid -
cured bacon.