Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

The objective of this study was to evaluate the feasibility of using medium and far infrared heating for blanching and dehydration of various fruits and vegetables. The infrared blanching was referred as infrared dry-blanching (IDB) in this study since no water or steam was used. A catalytic infrared blancher/dryer was used to perform the blanching and dehydration functions. For blanching study, the fruits and vegetables, including pears, baby carrots, sweet corn and french fries, were blanched with radiation energy intensity of 5.7 kW/m2. The pears were cut into 12.7 mm cubes and french fries had cross section of 12.7 x 12.7 mm. The sweet corn kernels were removed from the cobs before the blanching. The whole baby carrots had diameter of 15 mm. It took 2, 4, 1, and 3.5 min to inactivate the peroxidase in the pear cubes, whole baby carrots, cut corn and french fries, respectively. The IDB also showed high heating rate. It was concluded that all tested fruits and vegetables were effectively blanched in relatively short times and products had good appearances. When the pear cubes were further dehydrated to 50% weight reduction with radiation energy intensity of 2.7 kW/m2 after the blanching, total time saving of IDB was 43.9% compared to steam blanching followed by heated air drying. The texture and appearance of IDB processed pears appeared to be superior compared to the control samples produced with steam blanching and heated air drying. Therefore, the IDB can be used for performing simultaneous blanching and dehydrations.