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

content, which are factors impacting subsequent quality (Adelsberg and Sanders,
1997). Blanching allows for electronic color-sorter removal of damaged or discolored
seed, which are associated with aflatoxin contamination (Sanders et al., 1999).
Several methods are used for blanching: dry-blanching, spin-blanching,
water-blanching, alkali-blanching, and hydrogen peroxide blanching. In general, the
most common method in industrial processing is dry-blanching. In this process,
peanuts are placed on conveyor belts and moved through large ovens in which the
direction of airflow is alternated in successive zones (Adelsberg and Sanders, 1997).
The peanuts are heated in sequential zones from 30 °C to 90 °C, with a total normal
processing time of approximately 45 minutes. During this time, moisture is removed
from the peanuts, the seed coat is loosened, and after cooling, the seed coats are
mechanically removed (Sanders et al., 1999). Paulsen and Brusewitz (1976)
suggested that the mechanism of blanching is due to differences in thermal
expansion and subsequent contraction of the seed and seed coat, resulting in a
loosening of the seed coat.
Adelsberg and Sanders (1997) studied the effects of varying parameters on
peanut temperature distributions and blanchability using a lab-scale simulation of
conventional blanching methods. The magnitude of temperature variation in the
peanut bed during blanching was related to the final set point temperature of the
oven and to the dwell time at each temperature setting. In general, with increased
temperatures and increased moisture loss, blanching percentage increased
(Paulsen and Brusewitz, 1976; Katz, 2002). Adelsberg and Sanders (1997)
provided specific detail of that information when they reported that reduction of
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