title: Freshness indices of roasted coffee: monitoring the loss of freshness for single serve capsules and roasted whole beans in different packaging.
abstract: With the growing demand for high-quality coffee, it is becoming increasingly important to establish quantitative measures of the freshness of coffee, or the loss thereof, over time. Indeed, freshness has become a critical quality criterion in the specialty coffee scene, where the aim is to deliver the most pleasant flavor in the cup, from highest quality beans. A series of intensity ratios of selected volatile organic compounds (VOC) in the headspace of coffee (by gas chromatography-mass spectrometry) were revisited, with the aim to establish robust indicators of freshness of coffee - called freshness indices. Roasted whole beans in four different packaging materials and four commercial capsule systems from the Swiss market were investigated over a period of up to one year of storage time. These measurements revealed three types of insight. First, a clear link between barrier properties of the packaging material and the evolution of selected freshness indices was observed. Packaging materials that contain an aluminum layer offer better protection. Second, processing steps prior to packaging are reflected in the absolute values of freshness indices. Third, differences in the standard deviations of freshness-indices for single serve coffee capsule systems are indicative of differences in the consistency among systems, consistency being an important quality attribute of capsules.
authors.affiliation: Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, CH-8820 Wädenswil, Switzerland.
authors.forename: Alexia N
authors.initials: AN
authors.lastname: Glöss
authors.affiliation: Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, CH-8820 Wädenswil, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Schönbächler
authors.affiliation: Rast Kaffee AG, 6031 Ebikon, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Rast
authors.affiliation: Luna Technology Systems LTS GmbH, Wallisellen, Switzerland.
authors.forename: Louis
authors.initials: L
authors.lastname: Deuber
authors.affiliation: Zurich University of Applied Sciences, Institute of Chemistry and Biological Chemistry, CH-8820 Wädenswil, Switzerland.
authors.forename: Chahan
authors.initials: C
authors.lastname: Yeretzian
mesh_terms: D040503:Coffea / Q000737:chemistry*; D003069:Coffee / Q000592:standards*; D005504:Food Analysis / Q000379:methods; D018857:Food Packaging / Q000379:methods; D061353:Food Storage; D006358:Hot Temperature; D012639:Seeds / Q000737:chemistry*; D013649:Taste; D014835:Volatilization
chemical_list: D003069:Coffee