Durian is a typical tropical fruit, with the saying 'those who love it praise its fragrance, those who dislike it complain about its odor'. What kind of changes does the flavor of a durian undergo from astringency to maturity? Why does it initially smell like green grass, but later become rich in aroma and even have a slight 'foul smell'? Recently, Dr. Ao Pingxing's team from Yunnan Agricultural University published a study in the international authoritative journal "International Food Research", which systematically revealed for the first time the mechanism of flavor evolution during the ripening process of Maoshanwang durian. This study not only explains where the flavor of durian comes from, but also provides important scientific basis for improving durian varieties and enhancing their quality. The corresponding author of the paper and director of the Durian Industry Research Center at Yunnan Agricultural University, Ao Pingxing, introduced that the research team used advanced technology to conduct a detailed analysis of the four stages of the ripening process of the Maoshanwang durian. It was found that the flavor of durian is like a "relay race" - different stages are completed by different substances "relay". In the early days, when durian was not fully ripe, the volatile components were mainly aldehydes, such as nonanal and hexanal. These substances give the fruit a fresh grassy scent, like the scent of freshly cut grass. In the middle and later stages, as the fruit matures, esters such as ethyl butyrate and ethyl caproate increase significantly, bringing a rich fruity and sweet aroma. After complete ripening, sulfur-containing compounds such as isobutyl sulfide and disulfide begin to appear in large quantities, which participate in shaping the unique "sulfur flavor" of durian - the source of what people often refer to as the "stinky" flavor of durian. The study also found that the bitterness of Maoshan King durian is not a quality issue, but is formed by the combination of amino acids such as tryptophan and tyrosine, as well as glycosides such as resveratrol and naringin. This bitterness and sweetness are intertwined, creating a unique and layered taste. The research team also found that the changes in durian flavor are precisely regulated by a set of orderly switching gene programs. The genes responsible for the early green grass aroma show high expression in the early stages of maturity, while the genes responsible for fruit aroma formation gradually increase in the later stages. Most importantly, researchers have also discovered two important regulatory pathways: auxin signaling regulates the formation of early grassy aromas, while ethylene signaling promotes the accumulation of later fruity aromas. Ao Pingxing said that these two pathways work together like a "conductor" to guide the flavor transition from grassy aroma to mature fruity aroma. Why do some people think durian is "fragrant" and some people think it is "smelly"? The research team used molecular docking technology to simulate the interaction between key odor molecules of durian and human olfactory receptors. Research has found that an olfactory receptor exhibits different binding abilities to these odor molecules. In addition, different people's olfactory receptors have different sensitivities to specific components, which explains why some people find the same durian fragrant while others avoid it. This study not only answers the questions of durian enthusiasts, but also has important practical application value. In terms of quality control, the optimal picking time and consumption window can be determined by monitoring the changes in flavor compounds during the maturation process; In terms of variety improvement, by regulating key genes, it may be possible to cultivate durian varieties that are more in line with public taste in the future. (Looking into the New Era)