School of Chemical Sciences, The University of Auckland, Auckland, New Zealand.
Riddet Institute, Centre of Research Excellence in Food Research, Palmerston North, New Zealand.
Crit Rev Food Sci Nutr. 2023;63(28):9052-9073. doi: 10.1080/10408398.2022.2064422. Epub 2022 Apr 22.
Fruit aroma makes an initial flavor impression and largely determines the consumer preference and acceptance of fruit products. Free volatile organic compounds (FVOCs) directly make up the characteristic aromas of fruits. While glycosidically bound volatile compounds (GBVs) can be hydrolyzed during fruit ripening, postharvest storage, and processing, releasing the attached aglycones as free volatiles that could alter the overall aroma attributes of fruits. GBVs typically exhibit significantly higher concentrations than their free counterparts in fruits such as grapes, cherries, kiwifruits, tomatoes, and tamarillos. This review highlights the biosynthesis of FVOCs and GBVs in fruit and illustrates their biological transformations for various functional purposes such as detoxification, aroma enhancement, plant defense, and pollinator attraction. Practical applications for regulating the levels of aroma compounds emitted or accumulated in fruit are also reviewed, emphasizing the metabolic engineering of free volatile metabolites and hydrolytic technologies on aroma glycosides. Generally, enzymatic hydrolysis using AR2000 is a common strategy to enhance the sensory attributes of fruit juices/wines, while acidic hydrolysis induces the oxidation and rearrangement of aglycones, generating artifacts with off-aromas. This review associates the occurrence of free and glycosidic bound volatiles in fruit and addresses their importance in fruit flavor enhancement and industrial applications.
水果的香气会产生最初的味道印象，并在很大程度上决定消费者对水果产品的偏好和接受程度。游离态挥发性有机化合物（FVOCs）直接构成了水果的特征香气。而结合态挥发性化合物（GBVs）在果实成熟、采后贮藏和加工过程中会发生水解，释放出与之结合的糖苷配基作为游离挥发物，从而改变水果的整体香气特征。在葡萄、樱桃、猕猴桃、番茄和 tamarillo 等水果中，GBVs 的浓度通常明显高于游离态的同类物质。本文综述了 FVOCs 和 GBVs 在水果中的生物合成，并举例说明了它们在各种功能方面的生物转化，如解毒、增强香气、植物防御和吸引传粉者。还综述了调节水果中释放或积累的香气化合物水平的实际应用，强调了游离挥发性代谢物的代谢工程和对香气糖苷的水解技术。通常情况下，使用 AR2000 的酶解是增强果汁/葡萄酒感官属性的常用策略，而酸性水解会诱导糖苷配基的氧化和重排，产生带有异味的副产物。本文综述了游离态和结合态挥发性物质在水果中的存在情况，并讨论了它们在增强水果风味和工业应用方面的重要性。
