Abstract SCHIRACK, ANDRIANA VAIS. The Effect of Microwave ...

y-product (Giese, 1992). Drying is conducted with combination of conventional
heating and microwaves for pasta, which utilizes less energy and less case
hardening (Mudgett, 1989). In addition, many industrial processes combine
conventional and microwave heating to raise the surface temperature and improve
browning and crisping, to accelerate drying rates, or to reduce microbial counts
(Mudgett, 1989).
Other applications are still being explored for microwave processing.
Microwaves are commonly used for drying cookies and biscuits, but are not used for
commercial bread baking despite energy savings reported. Microwave sterilization
is currently conducted at 110-130 °C under pressure, although problems are still
being addressed such as development of proper packaging materials, excessive
surface heating, and cooling after sterilization (Giese, 1992). Microwave processes
with potential include vacuum and freeze drying, fat rendering, roasting, and
pasteurization (Mudgett, 1989). In the drying of mushrooms, combined microwave
and hot air drying allowed a shorter heat treatment; as a result, the mushrooms had
a higher aroma retention and preservation of the volatile ratios which are significant
to mushroom flavor (DiCesare et al., 1992). Microwaves have also been
investigated as an alternative method to blanch vegetables (Sevirini et al., 2003),
and this method has shown advantages in vitamin C and carotenoid retention in
microwave-blanched carrots, spinach and bell peppers (Ramesh et al., 2002)
In peanut processing, microwave vacuum drying has been researched as a
method for curing (Delwiche, 1986). Microwaves have also been investigated as an
alternative method to roast peanuts (Megahed, 2001). However, Megahed (2001)
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