Catalytic Infrared Blanching and Drying of Carrot Slices with Different Thicknesses: Effects on Surface Dynamic Crusting and Quality Characterization

Abstract

This study investigated the effects of catalytic infrared (CIR) as an emerging dry-blanching and drying technique on carrot quality and textural properties, and dynamic surface crusting in blanching was studied. The optimal CIR conditions for different carrot thicknesses were determined concerning the water reduction, carotenoid and color retention under 90% peroxidase inactivation. Surface crusting was observed under these conditions and the corresponding hardness values increased over blanching time and thickness, reaching 25.29%-38.20% of fresh tissue. Micrographs showed that cell structure of surface crust collapsed, and the degree of cell deformation decreased from surface to the inside tissue. The cell quantitative parameters were extracted by image processing, and the information on surface crust was visible through the cell area, perimeter, roundness, and elongation factor. Results showed that the crust cell area and perimeter were higher than the non-crust part, while the roundness and elongation factor was lower than the non-crust tissue.

Keywords: Catalytic infrared, Dry-blanching, Surface crusting, Quality properties, Carrots