Overall Quality of Fruits and Vegetables Products Affected by the Drying Processes with the Assistance of Vacuum-Microwaves

Abstract

Abstract:The seasonality of fruits and vegetables makes it impossible to consume and use them throughout the year, thus numerous processing efforts have been made to offer an alternative to their fresh consumption and application. To prolong their availability on the market, drying has received special attention as currently this method is considered one of the most common ways for obtaining food and pharmaceutical products from natural sources. This paper demonstrates the weakness of common drying methods applied for fruits and vegetables and the possible ways to improve the quality using different drying techniques or their combination with an emphasis on the microwave energy. Particular attention has been drawn to the combined drying with the assistance of vacuum-microwaves. The quality of the dried products was ascribed by chemical properties including the content of polyphenols, antioxidant capacity and volatiles as well as physical parameters such as color, shrinkage, porosity and texture. Both these fields of quality classification were considered taking into account sensory attributes and energy aspects in the perspective of possible industrial applications. In conclusion, the most promising way for improving the quality of dried fruit and vegetable products is hybrid drying consisting of osmotic dehydration in concentrated fruit juices followed by heat pump drying and vacuum-microwave finish drying.

Effects of microwave vacuum drying and conventional drying methods on the physicochemical and microstructural properties of squid shreds

“…The hardness of all dried samples decreased after rehydration for 20 min; the decrease was noticeable in the case of MVD samples. Figiel and Michalska stated that the puffing phenomenon associated with microwave vacuum drying creates a porous structure in the dried product, resulting in lower force and deformation values at breaking point during a compression test. Springiness represents the ability of a sample to recover its original form after removing the external force and is related to the elastic behavior of the food.…”

The Effect of Selected Fruit Juice Concentrates Used as Osmotic Agents on the Drying Kinetics and Chemical Properties of Vacuum-Microwave Drying of Pumpkin

“…Drying is one of the most common technological operations used for prolongation of the shelf life of vegetables [1]. Pumpkin is a source of vitamins, especially ascorbic acid, riboflavin and tocopherols, carotenoids, and tannins and also minerals like magnesium, potassium, iron, phosphorus, and selenium [2].…”

Modulation of Antibacterial, Antioxidant, and Anti-Inflammatory Properties by Drying of Prunus domestica L. Plum Juice Extracts

“…Plum powders can be obtained from whole fruit [3], plum by-products [4], or juices/concentrates [5]. Commonly used drying industrial processes include, apart from conventional air-drying, freeze-drying (FD), vacuum drying (VD), and spray drying (SPD) [6]. However, the drying techniques, used to obtain powders from whole fruit, modify some of their physical and chemical properties [3,7].…”