Effect of three drying methods on the drying kinetics and quality of acerola cherry

The effects of hot air drying (HAD), vacuum drying (VD), and microwave drying (MD) on the drying kinetics of acerola cherry were investigated and the quality attributes of acerola cherry powder obtained by vacuum freeze-drying (VFD), HAD, and VD were compared and analyzed, as well as the effects of four antioxidants on the ascorbic acid (AA) content. Results showed that the drying time shortened with the increase in temperature, which required by MD was the shortest. The Logaritmic model and Two Term model accurately described the drying kinetics of acerola cherry. The phytic acid was more effective in protecting the AA of cherry powder obtained by VFD, which had excellent rehydration and solubility, and its reducing sugar and total sugar contents were significantly different from that of HAD and VD. However, the total acid content of acerola cherry powder dried by VD was the highest. These findings provide a theoretical basis for the drying of acerola cherry. Practical applications As one of the veritable "king of natural vitamin C", acerola cherry has rich nutritional value. Drying has become an important trend in the processing of acerola cherry due to its high moisture content, as well as perishable and unpreservability. The results provide a choice for the drying technique of acerola cherry and show that the Logarithmic and Two Term models accurately described the drying kinetics, and the best preservation of AA, reducing sugar, and total sugar in acerola cherry powder obtained by VFD.