Changes

ATHP/ACTPY (which has two forms: 2-acetyl-3,4,5,6-tetrahydropyridine and 2-acetyl-1,4,5,6-tetrahydropyridine) has a much lower flavor threshold than ETHP (see [[Tetrahydropyridine#Thresholds_and_Quantities_Found_in_Mousy_Wine|Thresholds]]), and has been historically cited as the cause of mousy off-flavors detected in wine. In wine, its aroma cannot be detected due to the low pH of wine (it can be detected if the pH is raised), only the flavor. It is easier to detect in higher pH wines. ATHP is the form of THP that is the major contributor to the aroma of freshly baked bread, corn tortilla chips, and crackers. How different foods/wines/beers interact with ATHP on the palate may explain the different flavors that are detected by people, as well differing concentrations and peoples' ability to detect ATHP <ref name="Snowdon"></ref>. In food, ATHP has a slightly different form (6-Acetyl-1,2,3,4-tetrahydropyridin). Its formation in food is due to cooking and thought to be associated with Maillard reactions. This form has a toasty flavor of crackers and popcorn, and its presence ages out disappears quickly in food and is considered extremely volatile due to its extreme volatility <ref name="Adams_2005" />.