Latest Apple Drying Technologies: A Review

Abstract

Drying is known as one of the oldest preservation methods and can be applicable to many fruits. Sun drying of apple has been known from ancient times. However, this technique is weather-dependent and has contamination problems such as dust, soil, sand particles and insects. Hot
air drying of apples has low energy efficiency and requires longer drying period. The desire to eliminate these problems, prevent quality loss, and achieve fast and effective thermal processing has resulted in an increase of researches on other techniques. In recent years, drying technology is being developed and designed to reduce the nutrient loss as much as eliminating the possible any pre-treatment residues. Also, these new methods ensure food safety, increase the quality of dried apples and reduce drying time, risk factors and product losses. In this way, during drying facilities undesirable chemical reactions, microbial growth and mycotoxin formation are eliminated by the new drying technologies. Microwave, osmotic and infrared dehydration, calcium pre-treatment application before irradiation and combined drying methods are the new drying techniques studied in recent years. The aim of this work is to explicate the latest apple drying technologies with their advantages and disadvantages.