Phytochemical and microbiological stability of spent espresso coffee grounds in capsules

Abstract

Wet spent coffee grounds (SCG) from espresso capsules, a post-consumer organic solid residue produced worldwide, were analysed to determine their chemical and microbiological stability during storage. In particular, the changes in the total phenolic content and antioxidant capacity (based on two free radical scavenging assays and one oxygen radical absorbance assay) were determined on espresso SCG stored in capsules for up to one month at room temperature in a container open to the air. Phenolic compounds were also identified and quantified using high performance liquid chromatography coupled with diode array and mass detectors.Microbiological analysis was performed in parallel on the same stored SCG to determine the total counts and quantify the main microbial groups present during the storage. The total phenolic content, antioxidant capacity and the most important bioactive compounds, such as the total

Effects of Species, Post-Harvest Treatment, and Roasting on Fibre, Volatile Compounds, and Polyphenol Contents in Coffee Silverskin

“…The mixture was shaken (100 oscillations/min) on an orbital shaker (VDRL 711, Asal s.r.l., Milan, Italy) at room temperature in the dark for 30 min. The extract was centrifuged (15 min, 4 • C, 16,800× g) and the supernatant was collected, filtered (PTFE 0.45 µm), and brought to volume (25 mL) with the extraction solvent [39]. Each sample was extracted in triplicate and immediately analysed.…”

“…The TPC was spectrophotometrically assayed using the modified Folin-Ciocalteu's method [40,41], as described by Belviso et al [39]. The results were expressed as milligrams of gallic acid equivalents (GAE) per gram of dry powder based on a calibration curve of gallic acid (0-250 mg/L; R 2 = 0.9987).…”

“…The radical scavenging capacity (RSA) of the extracts was assessed using a PerkinElmer 2030 Multilabel Reader with 96-well black microplates, as reported by Belviso et al [39], according to the method described by von Gadow, Joubert, and Hansmann [42]. The results were expressed as µM of Trolox equivalents (TE) per gram of sample by means of a dose-response curve for Trolox (0-350 µM; R 2 = 0.9986).…”

The Antioxidant and Safety Properties of Spent Coffee Ground Extracts Impacted by the Combined Hot Pressurized Liquid Extraction–Resin Purification Process

“…Additionally, some polyphenols present different values of ORAC and DPPH. Therefore, if the polyphenol profile of the extracts changes, their ORAC and DPPH values do not necessarily change in the same magnitude [ 41 , 42 ].…”

Optimization of Espresso Spent Ground Coffee Waste Extract Preparation and the Influence of its Chemical Composition as an Eco-friendly Corrosion Inhibitor for Carbon Steel in Acid Medium

“…However, this method has led to the production of a large amount of waste containing polymeric materials, metals, and coffee residues. 1,2 Different works have addressed their attention to the treatment of polymeric and metallic waste from coffee in capsules 3 , while the spent coffee grounds (SCG) have been applied as adsorbers, 4 filters, and additives for polymer composites 5,6 , supplement in animal feed, among others 7 . It is possible due to SCG water and oil holding capacity and its vast composition that presents compounds such as caffeine, tannins, flavonoids, and trace elements 8 .…”