Research Progress of New Blanching Technology for Fruits and Vegetables

Fruits and vegetables are of high moisture content which leading to low food stability and high deterioration after harvest. Dehydration is one of processing and preservation method for fruits and vegetable which could be used to extend their shelf-life. Blanching is the key step to inactivate enzymes and protect color. Conventional blanching methods which generally use hot water or steam will cause adverse effects on quality of fruits and vegetables. Therefore,new blanching methods have been proposed and investigated recently. This review mainly focused on the principle and research progress of improved conventional methods(super-heated steam blanching,ultrasonic-assisted blanching)and new dry-blanching methods(far infrared blanching,ohmic blanching,microwave blanching and radio-frequency blanching). New blanching methods had better blanching efficiency,and dry-blanching methods could obviously reduce loss of water-soluble nutrient caused by water as heating medium and obtain better quality. Besides,dry-blanching methods could reduce waste water production and lower energy cost,which showed a promising application future in food processing industry. The review illustrated recent advances in blanching methods which would hopefully provide a reference for the future study to develop a new blanching and hybrid dehydration method for fruits and vegetables.