Aroma-active components of nonfat dry milk

Application of aroma extract dilution analysis (AEDA) on the volatile compo nents of low-, medium-, and high-heat-treated nonfat dry milks (NDM) reveal ed aroma-active compounds in the logs flavor dilution (log(3) FD) factor ra nge of 1 to 6. The following compounds contributed the highest log(3) FD fa ctors to overall NDM flavor: 2,5-dimethyl-4-hydroxy-3(2H)-furanone [(Furane ol), burnt sugar-like]; butanoic acid (rancid); 3-(methylthio)propanal [(me thional), boiled potato-like]; o-aminoacetophenone (grape-like); delta -dec alactone (sweet); (E)-4,5-epoxy-(E)-2-decenal (metallic); pentanoic acid (s weaty); 4,5-dimethyl-3-hydroxy-2(5H)-furanone [(sotolon), curry]; 3-methoxy -4-hydroxybenzaldehyde [(vanillin), vanilla]; 2-acetyl-1-pyrroline and 2-ac etyl-2-thiazoline (popcorn-like); hexanoic acid (vinegar-like); phenylaceti c acid (rose-like); octanoic acid (waxy); nonanal (fatty); and 1-octen-3-on e (mushroom-like). The odor intensities of Furaneol, butanoic acid, methion al, o-aminoacetophenone, sotolon, vanillin, (E)-4,5-epoxy-(E)-2-decenal, an d phenylacetic acid were higher in high-heat-treated samples than others. H owever, the odor intensities of lactones, 2-acetyl-1-pyrroline, and 2-acety l-2-thiazoline were not affected by heat treatment. Sensory evaluation resu lts also revealed that heat-generated flavors have a major impact on the fl avor profile of NDM.