Decoding Walnut Flavor: From the Formation of Odor and Taste to the Reproduction of Walnut Flavor

The unique flavor of walnut (Juglans regia L.) is a key driver of consumer preference. With the advancement of technologies in food analysis, sensory science, and oral perception, the design and regulation of walnut flavors have emerged as a hot topic in research on food flavor chemistry. Therefore, research spanning from walnut flavor identification to studies based on metabolism, growing environment, processing, and oral processing specially focus on flavor design and personalized perception which represents an important future direction in nut flavor chemistry. This review summarizes the latest advances in the major chemical components of walnut flavor and their formation mechanisms, and explores multifactorial effect including metabolic regulation, variety-specific characteristics, and processing technologies. The integrated application of instrumental analysis, sensory evaluation, and oral processing links flavor formation with perception mechanisms, driving walnut flavor research from simple component identification toward dynamic analysis of overall flavor. This transforms the regulation of walnut flavor into authentic sensory experiences, ultimately enabling personalized flavor customization. Concurrently, future research should focus on identifying genes involved in flavor biosynthesis, designing personalized flavor profiles and reproducing flavors. Furthermore, additional studies are needed to elucidate the interrelationships among flavor compounds, define the characteristic aromas of walnuts, and gain a deeper understanding of the role of oral processing in shaping flavor perception. Overall, these initiatives will contribute to the development of sustainable, health and flavor-oriented walnut products.