Recent Development in Bioactive Compounds and Health Benefits of Kumquat Fruits

This review paper aims to compile recent literature available regarding the overall chemical compositions, nutritional properties, essential oils, bioactive compounds and health benefits of Kumquat fruits. Kumquat fruits contain a high level of polyphenols, essential oils, minerals and vitamins, especially vitamin C. The essential oil (EO) profile of Kumquat fruit varies among different sub-species and parts of fruits. Limonene was the major EO detected in the Kumquat fruit. In addition, a significant amount of total phenolic content (TPC) and flavonoids was also observed in the kumquat extract. The TPC and flavonoid content of Kumquat fruit were significantly influenced by drying temperature, drying duration, and extraction solvents. The application of hot water as an extraction solvent resulted in efficient extraction of TPC and flavonoids compared to ethanol and methanol. In addition, Kumquat fruits exhibit potent antioxidant activity, antimicrobial activity, liver protection, and anti-cancer activity. Overall, this review will be a positive addition to the existing knowledge of this field. This paper will support the researchers and industries to select raw materials with high nutritional value and potent biological activity. In addition, this report will help to select an appropriate method and raw material to generate value-added products from Kumquat by-products.本综述旨在系统梳理当前有关金桔（Kumquat）果实整体化学组成、营养特性、精油、生物活性成分及健康益处的最新研究文献。金桔果实富含多酚、精油、矿物质与维生素，其中维生素C含量尤为突出。金桔果实的精油（essential oil, EO）组成特征因不同亚种及果实部位而异，柠檬烯为其中检出的主要精油成分。此外，金桔提取物中亦含有可观的总酚含量（total phenolic content, TPC）与黄酮类物质。金桔果实的总酚与黄酮类物质含量显著受干燥温度、干燥时长及提取溶剂的影响；相较于乙醇与甲醇，以热水作为提取溶剂可更高效地提取总酚与黄酮类物质。另外，金桔果实还表现出较强的抗氧化活性、抗菌活性、肝脏保护作用及抗癌活性。整体而言，本综述将为该领域现有知识体系提供有益补充，可为科研人员与产业界筛选高营养价值及强生物活性的原料提供支撑。此外，本报告还将助力研究者选定合适的方法与原料，利用金桔副产物开发高附加值产品。