Fruit Astringency: Mechanisms, Technologies, and Future Directions

Fruit astringency, which primarily results from the interaction between polyphenolic compounds such as tannins and salivary proteins, is a critical sensory attribute that limits the commercial value and consumer acceptance of many fruits. A thorough understanding of the mechanisms underlying astringency formation and the development of efficient and safe de-astringency technologies are crucial for the fruit industry. This review systematically elucidates the molecular basis of fruit astringency, focusing on the biosynthesis pathways, accumulation dynamics, and transcriptional regulatory networks of key phenolic substances, such as tannins, as well as their modulation by environmental factors. It also evaluates the efficacy and current applications of existing de-astringency methods and discusses the potential impacts of different treatments on fruit quality attributes. This study thoroughly analyzes the major challenges faced by current technologies, including balancing de-astringency efficiency with quality preservation, ensuring environmental friendliness and food safety, reducing costs, and promoting wider application. Finally, future research directions are discussed, emphasizing the importance of precise genetic improvement using tools such as gene editing, developing green and efficient processes, achieving intelligent process control, and focusing on synergistic quality regulation and the exploration of functional value. This review aims to provide an integrated knowledge framework for developing innovative, efficient, safe, and sustainable fruit de-astringency solutions, offering a scientific reference to advance technological upgrades in the fruit industry.