本論文展示了 UVC LED 技術在延長採後水果保質期方面的一些進展。首先，我們開發了一種新型的 UVC LED 光學模型，利用螢光膜捕捉二維輻照度分佈模式，在 5 毫米時達到 99.8% 的歸一化互相關（NCC）值，在 8 毫米和 10 毫米時達到 99.9% 的值，達到高精度的效果。其次，我們設計了一個 尺寸為30 × 30 × 30公分的UVC LED 腔體，以減少香蕉上的黑斑，並仔細監測輻照度分佈（6-9 W/m2）。最佳 UVC 劑量估計在 0.030 × 103 到 0.045 × 103 W∙s/m2之間，能有效防止黑斑，且不會明顯損害香蕉皮。第三，我們製作了一個 由4 × 4 LED矩陣排列組成的UVC LED 陣列系統，以控制茂谷橘子的綠黴，達到高輻照度均勻性，並在 0.9 × 10³ 到 4.5 × 103 W∙s/m2 的最佳劑量下維持茂谷的品質長達四週。最後，我們調查了 UVC 處理對芒果的有效性。結果顯示，UVC 處理能有效延長初始感染症狀較少的芒果的保質期，但對於那些在處理前已存在病症的芒果則無效。根據結果，我們研究了 UVC 光穿透芒果黑斑的情況，並開發了芒果黑斑的光學模型，以準確預測光在這些斑點中的透射。研究結果表明，UVC 光穿透芒果黑斑的能力不足以滅活已經侵入芒果的真菌。我們建議，選擇外觀良好且初始可見感染症狀最少的芒果，對於實現有效的 UVC 處理至關重要。總體而言，這項研究提出了有效的 UVC LED 系統，並為優化 UVC LED 處理提供了重要指南，以提高採後水果的品質和保質期，旨在提升水果產業的經濟效率。;This study presents several advancements in UVC LED technology for prolonging the shelf life of postharvest fruits. First, we developed a novel optical model for UVC LEDs using fluorescent film to capture 2-D irradiance patterns, achieving high precision with normalized cross-correlation (NCC) values of 99.8% at 5 mm and 99.9% at 8 mm and 10 mm distances. Second, a UVC LED cavity with dimensions of 30 × 30 × 30 cm was designed to reduce black spots on bananas, with careful monitoring of irradiance distribution (6-9 W/m2). The optimal UVC doses, estimated between 0.030 × 103 and 0.045 × 103 W∙s/m2, effectively prevent black spots without visible harming the peel. Third, we fabricated a UVC LED array system with a 4 × 4 LED matrix arrangement to control green mold in murcotts, achieving high irradiance uniformity and maintaining murcott quality for up to four weeks at an appropriate dose ranging between 0.9 × 103 to 4.5 × 103 W∙s/m2. Finally, we investigate the effectiveness of UVC treatment for mangoes. The results demonstrated that UVC treatment effectively prolong the shelf life for mangoes with minimal initial infection symptoms but is ineffective for those with exhibiting disease symptoms pre-treatment. According to the results, we investigated the UVC light penetration through mango black spots and developed optical model for mango black spot to effectively estimate light transmittance through them. Our finding indicated that UVC light penetration through mango black spots is insufficient to inhibit fungi that has already invaded the mango. We suggest that selecting mangoes with a healthy appearance and minimal infection symptoms is essential for obtaining effective UVC treatment. Overall, this research proposed effective UVC LED systems and provides essential guidelines for optimizing UVC LED treatments to enhance the quality and shelf life of postharvest fruits, with the aim of improving the economic efficiency of fruit industry.
