Key Laboratory of Green Processing and Intelligent Manufacturing of Lingnan Specialty Food of Ministry and Rural Affairs, College of Light Industry and Food, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
Food Res Int. 2024 Sep;191:114716. doi: 10.1016/j.foodres.2024.114716. Epub 2024 Jun 29.
Dehydration is an effective method for the long-term storage and aroma retention of gonggan (Citrus sinensis Osb. 'Deqing Gonggan'), which is a Chinese variety of citrus, with unique and characteristic floral, fruity, and citrus flavors. However, the aroma profiles of gonggans prepared using oven- and freeze-drying, the most widely-used drying methods, remain unclear. In this study, a total of 911 volatile organic compounds (VOCs) were detected in dried gonggan. These were primarily composed of alcohols (7.69%), aldehydes (7.03%), esters (15.38%), ketones (7.58%), and terpenoids (23.19%). A total of 67 odorants contributed significantly to the overall aroma of dried gonggans, with the major odor qualities being detected as green, citrus, fruity, floral, and sweet. These were mainly attributed to the presence of aldehydes, esters, and terpenoids. Freeze-drying was more effective in maintaining the unique citrus and mandarin-like aromas attributed to compounds such as limonene, citrial, β-myrcene, β-pinene, and γ-terpinene. Moreover, (E,E)-2,4-decadienal had the highest relative odor activity value (rOAV) in freeze-dried gonggans, followed by (E)-2-nonenal, furaneol, (E, E)-2, 4-nonadienal, and E-2-undecenal. Oven-drying promoted the accumulation of terpenes such as octatriene, trans-β-ocimene, cyclohexanone, copaene, and ɑ-irone, imparting a soft aroma of flowers, fruits, and sweet. Increasing the temperature led to an increase in existing VOCs or the generation of new VOCs through phenylpropanoid, terpenoid, and fatty acid metabolism. The findings of this study offer insights into an optimized procedure for producing high-quality dried gonggans. These insights can be valuable for the fruit-drying industry, particularly for enhancing the quality of dried fruits.
脱水是 Gonggan（Citrus sinensis Osb. 'Deqing Gonggan'）长期储存和保留香气的有效方法，它是中国柑橘的一个品种，具有独特而独特的花香、果香和柑橘风味。然而，使用最广泛的干燥方法——烤箱干燥和冷冻干燥——制备的 Gonggan 的香气特征仍然不清楚。在这项研究中，共检测到干 Gonggan 中 911 种挥发性有机化合物（VOC）。它们主要由醇（7.69%）、醛（7.03%）、酯（15.38%）、酮（7.58%）和萜烯（23.19%）组成。共有 67 种气味物质对干 Gonggan 的整体香气有显著贡献，主要气味特征为绿色、柑橘、水果、花香和甜味。这些主要归因于醛、酯和萜烯的存在。冷冻干燥更有效地保持了特有的柑橘和橘味香气，这归因于柠檬烯、柠檬醛、β-苎烯、β-蒎烯和γ-萜品烯等化合物的存在。此外，（E，E）-2，4-癸二烯醛在冷冻干燥的 Gonggan 中的相对气味活度值（rOAV）最高，其次是（E）-2-壬烯醛、糠醇、（E，E）-2，4-壬二烯醛和 E-2-十一烯醛。烤箱干燥促进了萜烯如八碳三烯、反-β-罗勒烯、环己酮、古巴烯和α-依兰油的积累，赋予花朵、水果和甜味的柔和香气。提高温度会导致现有 VOC 的增加或通过苯丙烷、萜烯和脂肪酸代谢产生新的 VOC。本研究的结果为生产高质量干 Gonggan 提供了优化程序的见解。这些见解对于水果干燥行业，特别是提高干水果的质量，具有重要意义。
