葡萄干的生产,一种自古以来保存葡萄的方法,随着各种干燥技术的发展,这些技术显着影响最终产品的质量和安全性。这项研究评估了太阳能间接干燥机与传统的阳光干燥方法相比的功效,以干燥克里特岛的百年无核和Sultanina葡萄品种,希腊。评估的关键参数包括环境条件,干燥时间,葡萄的颜色,真菌污染,和曲霉毒素A(OTA)水平。葡萄在受控的太阳能室中和在开放的阳光条件下干燥。与外部条件(24.2°C和58.7%,太阳能室保持较高的平均温度(34°C)和较低的相对湿度(39.7%),分别),显著减少干燥时间从12到7天。在太阳能室内干燥的葡萄干显示出改善的颜色质量,具有较高的亮度(L*),色调角(h),和色度(C*)值,归因于最小化的酶和非酶褐变。真菌学分析显示,室内干燥的葡萄干中的黑曲霉切片Nigri污染大大减少,每克的平均菌落形成单位显着低于晒干的葡萄干。因此,室内干葡萄干中的OTA水平也显着降低,百年无核的平均浓度为1.01µg/kg,而晒干的样品为2.66µg/kg,Sultanina显示0.70µg/kg与2.05µg/kg,分别。这些发现强调了使用太阳能间接干燥机提高干燥效率的优势。改善颜色质量,减少真菌和OTA污染,强调采用受控干燥技术以提高安全性的重要性,更高质量的葡萄干.
The production of raisins, a method of grape preservation since antiquity, has evolved with various drying techniques that significantly impact the quality and safety of the final product. This study evaluates the efficacy of a solar indirect dryer compared to traditional sun-drying methods for drying Centennial Seedless and Sultanina grape cultivars in Crete, Greece. Key parameters assessed include environmental conditions, drying time, grape color, fungal contamination, and Ochratoxin A (OTA) levels. Grapes were dried in a controlled solar chamber and under open sun conditions. The solar chamber maintained higher average temperatures (34°C) and lower relative humidity (39.7%) than outside conditions (24.2°C and 58.7%, respectively), significantly reducing the drying time from 12 to 7 days. Raisins dried in the solar chamber exhibited improved color quality, with higher Lightness (L*), Hue Angle (h), and Chroma (C*) values, attributed to minimized enzymatic and non-enzymatic browning. Mycological analysis revealed a substantial reduction in Aspergillus section Nigri contamination in chamber-dried raisins, with mean colony-forming units per gram significantly lower than those of sun-dried raisins. Consequently, OTA levels were also significantly reduced in chamber-dried raisins, with Centennial Seedless showing a mean concentration of 1.01 µg/kg compared to 2.66 µg/kg in sun-dried samples, and Sultanina showing 0.70 µg/kg versus 2.05 µg/kg, respectively. These findings underscore the advantages of using solar indirect dryers to enhance drying efficiency, improve color quality, and reduce fungal and OTA contamination, highlighting the importance of adopting controlled drying technologies for safer, higher-quality raisins.