Effects of application of ultrasound waves in the shelf life of an amazon fruit: araçá-boi

Resumo

The aim of this work was to evaluate the effects of ultrasonic treatments in quality of araçá-boi fruits (Eugenia stipitata McVaugh) during storage. Araçá-boi fruits were processed at a constant ultrasonic frequency of 40 kHz at 5 and 15 min. In the sequence, they were divided in three groups: control (CG), 5 min (G5M) and 15 min (G15M) of ultrasonic treatment and stored at room temperature for six days. The quality of the untreated and treated fruits was evaluated at 0, 3 and 6 days of storage and the following quality parameters were analyzed: weight loss, vitamin C, pH, titratable acidity, soluble solid content, total and reducing sugars. The maximum shelf life of fruits was between 3 and 6 days after harvest, for the three groups. The exposure time to the ultrasonic treatment influenced the quality of the fruits. The fruits of the group G5M presented less degradation, for some parameters (weight loss, pH, titratable acidity and concentration of sugars). In contrast, the fruit of the group G15M showed accelerated degradation. The effect of the cavitation phenomenon provoked by ultrasound treatment cause the irreversible destruction and inactivation of enzymes. Thus, it is assumed that 5 min of the treatment may have been more effective in reducing the action of some enzymes, and with15 min, the cavitation phenomenon may have been excessive for cell tissue and caused degradation and anticipated senescence. The results of this study suggest that ultrasonic treatment can be effective in preserving the quality of fruits, but, the treatment time needs to be better investigated.