Abstract:

The effects of pretreatments, namely, blanching, ultrasonic-assisted blanching and ultrasound on hardness,
crispness, color, VC content and microstructure of dried Agaricus bisporus products during far infrared drying were
investigated. Results showed that ultrasound pretreatment could induce reduction of the drying time. Compared with
unpretreated dried Agaricus bisporus products, ultrasonic pretreated samples showed an obvious decrease in hardness, and
a significant increase in crispness. Ultrasound pretreatment significantly improved the rehydration rate and reduced the
shrinkage rate of dried products. In addition, ultrasonic-assisted blanching and blanching pretreatments induced the loss of
color, rehydration rate and VC content, and an increase inshrinkage rate. These changes may be due to the destructive effect
of high temperature on the cellular structure of Agaricus bisporus. Thus, the application of ultrasound as a pretreatment
method can improve the quality of dried Agaricus bisporus products.

Key words: ultrasound, pretreatment, Agaricus bisporus, quality