Microwave-assisted blanching

This chapter presents publications showing evidence of the advantages of microwave-assisted blanching in food commodities as an alternative to other methods. In all of these studies, a reduction of time and energy required to achieve the inactivation of enzymes (peroxidase, polyphenol oxidase, and pectinases), is evident when using microwave technology as compared to traditional techniques. Furthermore, the preservation of bioactive compounds may be enhanced as a consequence of the short processing times required to achieve microwave blanching and avoiding a leaching effect of water soluble phytochemicals. Research includes the study of preservation and extractability of antioxidant compounds such as anthocyanins, epicathequin, polyphenols, and chlorophylls. The microwave blanched food materials include fruits, leaves, vegetables, tubers, fish, and mushrooms. Patents concerning microwave-assisted blanching are reviewed, describing intellectual property on combined processes such as microwave and hot water, microwave and water vapor, and a multistage continuous system with a row-knife slicing device pressing unit. It is concluded that the applications and combinations of treatments using microwave technology in blanching achieve a better retention of biological activities of phytochemicals as compared to other methods.