title: Rapid NMR method for the quantification of organic compounds in thin stillage.
abstract: Thin stillage contains organic and inorganic compounds, some of which may be valuable fermentation coproducts. This study describes a thorough analysis of the major solutes present in thin stillage as revealed by NMR and HPLC. The concentration of charged and neutral organic compounds in thin stillage was determined by excitation sculpting NMR methods (double pulse field gradient spin echo). Compounds identified by NMR included isopropanol, ethanol, lactic acid, 1,3-propanediol, acetic acid, succinic acid, glycerophosphorylcholine, betaine, glycerol, and 2-phenylethanol. The concentrations of lactic and acetic acid determined with NMR were comparable to those determined using HPLC. HPLC and NMR were complementary, as more compounds were identified using both methods. NMR analysis revealed that stillage contained the nitrogenous organic compounds betaine and glycerophosphorylcholine, which contributed as much as 24% of the nitrogen present in the stillage. These compounds were not observed by HPLC analysis.
authors.affiliation: Department of Food and Bioproduct Sciences, Saskatoon, Saskatchewan S7N 5A8 Canada.
authors.forename: Kornsulee
authors.initials: K
authors.lastname: Ratanapariyanuch
authors.forename: Jianheng
authors.initials: J
authors.lastname: Shen
authors.forename: Yunhua
authors.initials: Y
authors.lastname: Jia
authors.forename: Robert T
authors.initials: RT
authors.lastname: Tyler
authors.forename: Youn Young
authors.initials: YY
authors.lastname: Shim
authors.forename: Martin J T
authors.initials: MJ
authors.lastname: Reaney
mesh_terms: D001622:Betaine / Q000032:analysis; D002241:Carbohydrates; D002264:Carboxylic Acids / Q000032:analysis; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D005997:Glycerylphosphorylcholine / Q000032:analysis; D007220:Industrial Waste / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*
chemical_list: D002241:Carbohydrates; D002264:Carboxylic Acids; D007220:Industrial Waste; D000431:Ethanol; D001622:Betaine; D005997:Glycerylphosphorylcholine