延長釋迦及鳳梨釋迦銷售期技術之探討

Abstract

釋迦名列十大經典國產水果，其中的鳳梨釋迦更是重點外銷水果。臺灣生產優質釋迦與鳳梨釋迦，又與澳洲釋迦產期相反，極具外銷潛力。然而其熟軟度不易控管，熟軟後儲存不易，故收穫後銷售期短暫。本研究的目的即在探討從機械及生理機制，減少釋迦與鳳梨釋迦在運銷過程中的損傷，進而延長其銷售期的方法與技術。在機械機制上，以衝擊量測儀器球與無線振動感測器檢測釋迦運銷過程中受到的振動與衝擊，並探討5種包裝方式的減傷效果，尋找適當的包裝運輸方式。在生理機制上則探討以收穫後冷藏延長鳳梨釋迦銷售期之可行性及其相關技術。而釋迦品質變化則以精密物性分析儀進行穿刺試驗所量測的穿刺力，即其堅實度，作為指標。結果顯示釋迦配銷運輸過程的振動RMS G值介於0.2062～0.3037之間，主要振頻在0.1～0.2 Hz之間。而振動情形以南迴公路段最為嚴重，尤其是尚武至楓港段。然而瞬間衝擊量為3~8 G之間，小於釋迦運銷第一階段（集貨與分級包裝）中所受到的振動量（8~12 G）。釋迦採收後4至6天為最佳食用期，此時果實穿刺力為3 N左右。傳統包裝加填碎紙的方式能提供最佳減傷效果與較長銷售期；但目前農民所用包裝方式也已能提供合理減振效果。收穫後冷藏則以15℃收穫後冷藏7日，傳統無碎紙充填包裝為較佳之收穫後冷藏處理；相較於無收穫後冷藏之運銷方式，約可延長鳳梨釋迦銷售期7日，亦即收穫後冷藏的天數。 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.