Development and dissemination of novel semi-dried fruit prepared by microwave irradiation pretreatment and hot air drying

Abstract

Hot air drying is conventionally applied for the production of dried fruit; however, hardening and browning of the fruit pulp surface often occurs during processing. We demonstrated that microwave irradiation of Japanese pear pulp or grape, followed by hot air drying, produced high quality semi-dried fruit. Dried Japanese pear produced using this method showed uniform softness and a vivid yellow-orange color. In the case of dried grape products, microwave irradiation pretreatment improved the retention of both skin color (yellow-green and red) and original flavor (such as Muscat and foxy). In addition, microwave pretreatment shortened the subsequent hot air drying period by approximately 30% for Japanese pear and 60% for grape. This method could be applied to other fruits such as apple, pear and peach. Dissemination of the method has resulted in commercialization of some dried fruit and confectionary products. However, a system capable of mass production, resulting in reduced production costs, is needed to promote the practical use of this method.