Author：Gang-Jhy Wu¹, Yi-Chieh Huang², Jian-Xun Chen², An-Pan Cherng³, Poching Johnny Wu³

¹ Associate Professor, Department of Biomechatronic Engineering, National Ilan University
² Graduate Student, Department of Biomechatronic Engineering, National Ilan University
³ Professor, Department of Biomechatronic Engineering, National Ilan University

Abstract：

    This research aimed to explore feasible methods to extend the shelf life of atemoya fruit from both mechanical and physiological aspects. Mechanically, a monitoring system which includes an impact record device (IRD), and a wireless vibration sensing and recording module, was developed to study the effects of marketing processes on the fruit products. The vibration reduction effects of 5 different packaging methods were checked through a simulated one-hour, 10Hz, 1.25 mm vertical vibration created by a shaker. As for the physiological aspect, after harvest pre-cooling treatment combinations of 10 and 15℃ pre-cooling temperatures, and 7 and 14 days storage time were tested to evaluate the shelf life extension effect. Condition of quality degradation of atemoya fruit was determined by checking the change of its firmness, which was represented by its penetration force measured by a texture analyzer. Results showed that the vibration RMS G values of atemoya fruits for the whole transportation processes were in the range of 0.2062 to 0.3037, with main frequencies fell within 0.1 to 0.2 Hz. The severest vibration condition occurred in Nanhuei Highway, especially from Shunwu to Fenggang. The IRD measured maximum instant impact force of the same processes is within 3 to 8 G. As for the effectiveness of packaging treatments, box with shredded paper as cushion material seemed to be the most effective vibration reducing treatment. Firmness of atemoya fruits packaged in this way also appeared to last longer. Conventional packaging method adopted by farmers nowadays worked well. Adding additional cushion materials to the conventional packaging box did not significantly enhance the vibration reducing effect. The best consuming time, was about 4 to 6 days after harvest, while the penetration force of fruit meat fell just below 3 N. A large number of black spots appeared and quality degradation speeded up around 7 days after harvest, while the penetration force of fruit peel fell just below 1 N. As for the pre-cooling effect, the results suggests that the treatment of 15℃ pre-cooling temperature, 7 day storage period, and no shredded paper added packaging is the best one for shelf life extension. This process can prolong about 7 days shelf life, which is approximately equal the pre-cooling period.

Keywords: Atemoya, Fruit marketing processes, Vibration, Pre-cooling, Shelf life.