Color and Bioactive Compounds Characteristics on Dehydrated Sweet Cherry Products

It is widely known that quality properties of fruits can be affected by drying processes. The approach was the quality improvement of dried cherry products through the application of combined technologies of drying and pretreatments. The objective of this work was to analyze the effect of blanching or sugar infusion prior to air-drying or freeze-drying on quality properties such as color, bioactive compounds, and antiradical power of two cherry products (discs and dices). Air-drying caused darkening, whereas freeze-drying provoked higher lightness of discs compared to fresh fruit (p < 0.05). Cherry dices were lighter than the fresh fruit. A high retention of total anthocyanin (ACY) and phenolic content (TPC) was obtained in blanched freeze-dried discs (ACY = 165 ± 22 mg Cyd-3-glu/100 g d.w.; TPC = 739 ± 55 mg GAE/100 g d.w.). Sugar infusion pretreatment caused an important decrease in ACY (31–89 mg Cyd-3-glu/100 g d.w.) and TPC (222–271 mg GAE/100 g d.w.). When blanching was applied prior to air-drying, samples presented the highest antiradical power, similar to that observed in fresh fruit. In dices, the best quality attributes in terms of superficial color were found in control freeze-dried samples since they presented minor shifts in hue angle and a greater preservation of anthocyanin pigments (ACY = 211 ± 30 mg Cyd-3-glu/100 g d.w.). However, control air-dried dices presented the highest phenolic content (TPC = 771 ± 65 mg GAE/100 g d.w.). Regarding the possible application of the dry cherry products, discs could be directly consumed as snacks, while dices could be incorporated as ingredients in fruit bars, cookies, or muffins.