title: Carbohydrate specification limits for the authenticity assessment of soluble (instant) coffee: statistical approach.
abstract: Carbohydrates are very good tracers for the authenticity assessment of soluble (instant) coffee. Total glucose and total xylose were determined in 1002 samples of commercial soluble coffees using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD) according to AOAC Method 995.13 and ISO standard 11292. The samples analyzed included both authentic and adulterated coffees but were all sold as 100% pure soluble coffee. The statistical model, called "mixture of distributions," was applied to all results and allowed to derive the maximum content of the 2 carbohydrates in the population of products corresponding to pure soluble coffee: 2.32% for total glucose and 0.42% for total xylose. The specification limits, above which a soluble coffee should be considered as adulterated, were calculated by adding the corresponding expanded measurement uncertainty to the maximum content. Specification limits of 2.46% for total glucose and 0.45% for total xylose were obtained. The data statistically confirm previously established criteria for the authenticity assessment of commercial soluble coffee.
authors.affiliation: Nestlé Research Centre, PO Box 44, Vers-chez-les-Blanc, 1000 Lausanne 26, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Girard
authors.forename: Paul
authors.initials: P
authors.lastname: Stöber
authors.forename: Maurice
authors.initials: M
authors.lastname: Blanc
authors.forename: Jacques
authors.initials: J
authors.lastname: Prodolliet
mesh_terms: D000838:Anions; D002241:Carbohydrates / Q000032:analysis* / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003069:Coffee; D004305:Dose-Response Relationship, Drug; D005504:Food Analysis / Q000379:methods*; D005947:Glucose / Q000032:analysis; D015233:Models, Statistical; D011336:Probability; D012015:Reference Standards; D015203:Reproducibility of Results; D014994:Xylose / Q000032:analysis
chemical_list: D000838:Anions; D002241:Carbohydrates; D003069:Coffee; D014994:Xylose; D005947:Glucose