Durian is reputed to be the stinkiest fruit in the world, so researchers at the German Research Center for Food Chemistry recently set out to find out exactly what makes it so malodorous. They write in the Journal of Agricultural and Food Chemistry
The sensory properties of fresh durian combine a pleasant creamy consistency, a pronounced sweet taste, and a strong, penetrating odor, not comparable to that of any other kind of fruit. The aroma profile can be best described as a combination of an intense sulfury, roasted onion-like odor with fruity, sweet, caramel-like, and soup seasoning-like notes. In Southeast Asia, durian is deeply appreciated and often referred to as the “king of fruits”, whereas some people in the Western hemisphere regard the durian odor as offensive and nauseous. The unique odor properties of durian have repeatedly attracted the attention of chemists... Despite the quite high number of studies on durian volatiles, it is still unclear which odorants predominately contribute to its aroma. Therefore, our aim was to systematically assess the odor contribution of individual durian volatiles.
Their investigation involved a) shipping Durian by air freight from Thailand to Germany; b) extracting pulp from the fruit; and then c) analyzing the pulp by means of a "Trace GC Ultra gas chromatograph" equipped with a "tailor-made sniffing port":
The sniffing port consisted of a cylindrically shaped aluminum device (105 mm × 24 mm diameter) with a beveled top and a central drill hole (2 mm) housing the capillary. It was mounted on a heated (200 °C) detector base of the GC. During a GC-O run, the panelist placed her/his nose closely above the top of the sniffing port and evaluated the odor of the effluent. If an odor was perceived, the retention time was marked in the FID chromatogram printed by a recorder and the odor quality was noted.
This effort yielded "several new aroma compounds with interesting odors," but the authors of the study caution that further investigations are still required in order to "unequivocally assess the contribution of individual odorants to durian aroma."