Objective  Conditions of dehydration process to preserve jabuticaba, Myrciaria cauliflora, were studied for optimization.

  Method  Sensory quality and nutritional contents of fat, protein, crude fiber, starch, reducing sugar, ash, fructose, glucose, sucrose, moisture, vitamin C, selenium, and total polyphenols of the dried fruits were used as criteria to evaluate the dehydration by hot air at 50℃, 60℃ or 70℃ and by vacuum freeze-drying. Experimental data were analyzed using one-way ANOVA.

  Results  The sensory quality of the freeze-dried jabuticaba was the best among all samples. The dried product remained a color and shape of the peel and pulp close to those of the fresh fruit, and the texture was uniform and palatable. In contrast, the hot air drying darkened and dulled the color, severely shrunk and deformed the appearance, and hardened the fruit. Nutritionally, the contents of protein, fat, sucrose, vitamin C, and total polyphenols in the dehydrated products processed by freeze-drying were significantly higher than those by the hot air-drying. Furthermore, the moisture content of the freeze-dried samples was 5.92%, which was significantly lower than that by the hot air-drying. It appeared that the vacuum freeze-drying was superior among the 4 methods. The fruits dried with hot air at 50℃ had the highest contents of starch, crude fiber, ash, and amino acids, followed by the freeze-dried counterparts. And, the higher the hot air temperature applied for the dehydration, the lower the contents of starch, protein, ash, vitamin C, selenium, moisture, total polyphenols, and amino acids, and the higher the contents of reducing sugars, fructose, and glucose in the dried jabuticaba.

  Conclusion   The vacuum freeze-drying was considered the choice for jabuticaba dehydration as it yielded desirable sensory quality as well as nutritional value for the product.