Aroma generation of fermented fruit wines: potential enhancement strategies via fermentation and aging process

Aroma plays a key role in decisions to purchase fruit wines. Fermented fruit wines (FFWs) are produced through endogenous means of microorganisms/enzymes and aging processes without additional additives to produce natural volatile aroma compounds (VOCs). However, most FFWs lack sufficient aroma, and the diversity of raw fruits complicates the effective regulation of flavor. Fermentation and aging processes are critical for the development of aroma profiles, significantly related to the metabolism of aroma precursors and the transformation of VOCs. Fermentation strains and bio-enzymes are regarded as direct driving forces for fermentation aroma generation, accompanied by the release of bound aroma. Consecutively, high efficiency and eco-friendly emerging technologies (e.g. microwave, ultrasonic, and ultra-high-pressure) are replacing traditional long-aging processes, which perfect aroma profiles by releasing cell intracellular matrix, accelerating chemical reactions, improving mass transfer, modifying enzyme activity, and degrading aroma-bound macromolecules. This review systematically outlines recent significant points on aroma generation in FFWs and potential aroma enhancement strategies regulated by key driving factors, namely fruit pretreatment, fermentation parameter optimization, aroma precursor reinforcement, bio-enzyme application, microbial interactions, and emerging aging technologies. It is desired that theoretical basis and technical support for the establishment of flavor-oriented regulation strategies of FFWs can be provided.