title: The chemistry of sour taste and the strategy to reduce the sour taste of beer.
abstract: The contributions of free hydrogen ions, undissociated hydrogen ions in protonated acid species, and anionic acid species to sour taste were studied through sensory experiments. According to tasting results, it can be inferred that the basic substance producing a sour taste is the hydrogen ion, including free hydrogen ions and undissociated hydrogen ions. The intensity of a sour taste is determined by the total concentration of free hydrogen ions and undissociated hydrogen ions. The anionic acid species (without hydrogen ions) does not produce a sour taste but can intensify or weaken the intensity of a sour taste. It seems that hydroxyl or conjugated groups in anionic acid species can intensify the sour taste produced by hydrogen ions. The following strategy to reduce the sensory sourness is advanced: not only reduce free hydrogen ions, namely elevate pH value, but also reduce the undissociated hydrogen ions contained in protonated acid species.
authors.affiliation: China National Research Institute of Food and Fermentation Industries, Beijing 100015, China. Electronic address: Li_Hong2001@163.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: China National Research Institute of Food and Fermentation Industries, Beijing 100015, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D001515:Beer / Q000032:analysis*; D011522:Protons; D055697:Taste Perception
chemical_list: D011522:Protons; D019342:Acetic Acid
keywords: Acetic acid (PubChem CID 176); Beer; Chemistry; Citric acid (PubChem CID 311); Fumaric acid (PubChem CID 444972); Hydrogen ions; Lactic acid (PubChem CID 612); Malic acid (PubChem CID 525); Oxalic acid (PubChem CID 971); Protonated acid species; Pyruvic acid (PubChem CID 1060); Sour taste; Succinic acid (PubChem CID 1110); Tartaric acid (PubChem CID 875)