Recent Advances in the Production of Fruit Leathers

Fruit leather is a sheet or flexible strip of dried fruit that is made typically by hot air drying of fruit puree or fruit juice concentrate, with or without the addition of other ingredients. Dehydration is the most important step for fruit leather production. Processing prior to the drying step is crucial to obtain high-quality fruit leathers. The heat treatment that is widely applied before drying the fruit pulp is aimed at enzyme inactivation, microbiological decontamination, and pulp concentration. However, this heat treatment results in color changes, significant degradation of nutrients, and possibly in the production of some toxic compounds. Therefore, recent studies have focused on producing fruit leathers without heat treatment to yield products with higher bioactive compound content. The literature reports some innovative methods, such as infrared drying, cast-tape drying, and freeze-drying, as suitable alternatives in producing fruit leathers with improved sensory attributes and retention of nutritional compounds. The presentreview of published studies discusses the effects of the heat treatment on fruit pulp before the drying process, the presence of additives in the pulp, and different innovative drying methods on the physicochemical, nutritional, and sensory properties of the resulting fruit leathers, with an overview of the development, advantages, and limitations of these drying techniques.