Meat and meat products is the area on which most information
has been published to date, both in terms of processing and in relation to the effects of RF treatment on the quality of foods. Laycock
et al. (2003) compared the heating rate, time temperature profiles
and quality of three meat products (ground, comminuted and noncomminuted muscle) cooked in a water bath or by a 1.5 kW RF
heater (a cylindrical chamber set between two electrodes wrapped
around the RF applicator). This system operated at 27.12 MHz and
RF cooking was found to reduce cooking times to up to 1/25 of conventional cooking times in a water bath. The results of these workers also indicated that the surface of the RF cooked products heated
at a faster rate than the centre, with differences in temperatures of
10–20 °C at the end of the process, which the authors attributed to
an uneven salt distribution. Instrumental quality measurements
indicated that RF cooked samples had lower juice losses and also
acceptable in terms of colour and water holding capacity. Instrumentally measured textural attributes of RF cooked whole muscle
were not significantly different to water bath cooked samples.
However, some textural differences were noted between RF and
water bath cooked ground and comminuted meats with RF cooked
ground beef having higher springiness and chewiness and RF
cooked comminuted meat having lower hardness and higher
springiness than water bath cooked samples. Power efficiency
was highest for comminuted meat with muscle having the lowest
power efficiency. Overall the authors postulated that well mixed
comminuted and ground meat products appeared to be the most
promising for RF cooking.
Orsat et al. (2004) pasteurised vacuum-packaged ham slices in an
RF applicator (600 W at 27.12 MHz) and subsequently examined
samples for moisture loss, colour changes, total bacterial surface
counts and sensory quality attributes, such as off odours, and sliminess. The ham samples were packed in three different plastic films
(composed of nylon–polyethylene, polypropylene and high density
polyethylene), and were brought to internal temperatures of 75 °C
and 85 °C in 5 min by RF heating and maintained at those temperatures for an additional 5 min by adjusting the RF power. The authors
concluded that RF heating, coupled with appropriate packaging,
could improve the storability of repacked hams by decreasing the