31. Additionally, this method is the only one to discriminate between natural and biosynthetic sources of vanillin . 32. For instance, some manufacturers use vanillin instead of real vanilla, and some use more chocolate liquor. 33. Hummer said . ( Vanillin , not surprisingly, is the same chemical found in vanilla beans .) 34. However, unlike vanillin synthesized from lignin or guaiacol, it can be labeled as a natural flavoring. 35. Chemical analysis has shown that the secretions are composed of p-cresol, guaiacol, and vanillin . 36. For example, the methyl ether in vanillin can be removed by heating near 250 �C with strong base. 37. In the past " p "-hydroxybenzaldehyde was speculated to be a precursor for vanillin biosynthesis. 38. "' Isovanillin "'is a phenolic aldehyde, an organic compound and isomer of vanillin . 39. The agave plant contains many terpenes such as vanillin and syringaldehydes which presents a strong and fruity or herbal aroma. 40. Vanillin and ethylvanillin are used by the food industry; ethylvanillin is more expensive, but has a stronger note.