title: 1H NMR, a rapid method to monitor organic acids during cupuassu (Theobroma grandiflorum Spreng) processing.
abstract: The development of an analytical method using 1H nuclear magnetic resonance (1H NMR) spectrometry to monitor cupuassu (Theobroma grandiflorum Spreng) bean fermentation, drying, and roasting processes is reported. The analysis of organic acids and alcohols of crude water extracts of cupuassu ground kernels were monitored by HPLC and 1H NMR spectroscopy. The residual protein signals caused deleterious effects on acid and alcohol quantifications. Therefore, the analytical procedures were optimized by sample cleanup and water suppression pulse sequences in order to obtain compatible data using HPLC and 1H NMR. The quantification of lactic acid, acetic acid, and 2,3-butanediol by NMR is 5- to 10-fold faster than by HPLC, with the advantage of providing the identification of several chemical species in a single experiment. Application of these analytical conditions to some cupuassu samples revealed that this methodology can be applied to the quality profiles of fermentation and roasting processes.
authors.affiliation: Departamento de Química Orgânica, Instituto de Química, Universidade Estadual de Campinas, P.O. Box 6154, 13084-971 Campinas, SP, Brazil.
authors.forename: Isis M
authors.initials: IM
authors.lastname: Figueiredo
authors.forename: Nadia R
authors.initials: NR
authors.lastname: Pereira
authors.forename: Priscilla
authors.initials: P
authors.lastname: Efraim
authors.forename: Nelson H P
authors.initials: NH
authors.lastname: García
authors.forename: Nadia R
authors.initials: NR
authors.lastname: Rodrigues
authors.forename: Antônio
authors.initials: A
authors.lastname: Marsaioli
authors.forename: Anita J
authors.initials: AJ
authors.lastname: Marsaioli
mesh_terms: D019342:Acetic Acid / Q000032:analysis; D002072:Butylene Glycols / Q000032:analysis; D002264:Carboxylic Acids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D005285:Fermentation; D005511:Food Handling / Q000379:methods; D006358:Hot Temperature; D019344:Lactic Acid / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019660:Malvaceae / Q000737:chemistry*; D012639:Seeds / Q000737:chemistry*
chemical_list: D002072:Butylene Glycols; D002264:Carboxylic Acids; D019344:Lactic Acid; C026978:2,3-butylene glycol; D019342:Acetic Acid