Changes

It's been shown that various THP compounds can be produced from heat reactions. For example, heating proline with monosaccharides produces a small amount of APY, as does the heating of yeast and sucrose. Phosphate ions are high contributors to THP production via heat reactions, with the amino acids proline, ornithine, and citrulline being precursors (the first two of which are important amino acids in yeast), and 1-pyrroline being the intermediary step. Ornithine is the precursor to heat produced ATHP in bread making <ref>[https://link.springer.com/article/10.1007/BF01197621 The role of free amino acids present in yeast as precursors of the odorants 2-acetyl-1-pyrroline and 2-acetyltetrahydropyridine in wheat bread crust. Peter Schieberle. 1990.]</ref><ref name="Adams_2005" />. 2-Acetyl-1-pyrroline forms from Maillard reactions and is key to the aroma of cooked Lipu taro <ref>[https://www.sciencedirect.com/science/article/abs/pii/S1878450X2400101X Xiatao Zhou, Liqiong Wen, Jinshan Xiao, Xueying Mo, Peng Wan, De-Wei Chen. 2- Acetyl-1-pyrroline originated from Maillard reaction is the key odorant of cooked Lipu taro. International Journal of Gastronomy and Food Science, 2024, 100968. ISSN 1878-450X. https://doi.org/10.1016/j.ijgfs.2024.100968.]</ref>. These reactions mostly occur at a relatively basic pH (7-9) <ref>[https://pubs.acs.org/doi/full/10.1021/jf970990g 2-Oxopropanal, Hydroxy-2-propanone, and 1-PyrrolineImportant Intermediates in the Generation of the Roast-Smelling Food Flavor Compounds 2-Acetyl-1-pyrroline and 2-Acetyltetrahydropyridine. Thomas Hofmann, and Peter Schieberle. 1998. DOI: 10.1021/jf970990g.]</ref>.