Characterization of Odor-Active Compounds, Polyphenols, and Fatty Acids in Coffee Silverskin

Abstract

For the first time the volatile fraction of coffee silverskin has been studied focusing on odor-active compounds detected by gas chromatography-olfactometry/flame ionization detector (GC-O/FID) system. Two approaches, namely headspace (HS) analysis by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) and odor-active compounds analysis by gas chromatography-olfactometry/flame ionization detector (GC-O/FID), have been employed to fully characterize the aroma profile of this by-product. This work also provided an entire characterization of the bioactive compounds present in coffee silverskin, including alkaloids, chlorogenic acids, phenolic acids, flavonoids, and secoiridoids, by using different extraction procedures and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) system. Coffee silverskin was shown to be a good source of caffeine and chlorogenic acids but also of phenolic acids and flavonoids. In addition, the fatty acid composition of the coffee silverskin was established by GC-FID system. The results from this research could contribute to the development of innovative applications and reuses of coffee silverskin, an interesting resource with a high potential to be tapped by the food and nutraceutical sector, and possibly also in the cosmetics and perfumery.

Single Origin Coffee Aroma: From Optimized Flavor Protocols and Coffee Customization to Instrumental Volatile Characterization and Chemometrics

“…Concerning the contribution to the coffee aroma, some of the identified compounds present an extremely low odor threshold in air, such as (E)- β -damascenone (2–4 pg/L), 2-ethyl-3,5-dimethylpyrazine (7–14 pg/L), 4-ethyl-guaiacol (10–30 pg/L) and 2-furfurylthiol (10–20 pg/L) or high odor threshold in air, such as 4-vinylguaiacol (0.4–0.8 ng/L), vanillin (0.6–1.2 ng/L), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (0.5–1.5 ng/L), 3-methyl-butanal (2–4 ng/L), 3-ethyl-2,5-dimethylpyrazine (2.4–4.8 ng/L), 2,3-butanedione (10–20 ng/L) and 2,3-pentanedione (10–20 ng/L) [ 28 ]. Other compounds, such as Strecker degradation aldehydes of branched amino acids (isoleucine, and leucine), namely 2-methylbutanal and 3-methylbutanal, 2,3-pentanedione, 2-methoxyphenol (guaiacol) and pyrazine derivatives (ethylpyrazine, 2-ethyl-6-methylpyrazine and 2-ethyl-3,5-dimethylpyrazine) have also been reported as key odorants in literature in espresso beverages and coffee silver skin [ 3 , 20 ].…”

“…Headspace solid-phase microextraction (HS-SPME) in combination with gas chromatography–mass spectrometry (GC-MS) has been successfully employed to keep track of coffee aroma contributors [ 3 , 8 , 20 ]. Additionally, acquired data can be easily chemometrically processed via mathematical and statistical tools (e.g., principal component analysis (PCA), hierarchical cluster analysis (HCA), etc.)…”

Applications of Compounds from Coffee Processing By-Products

“…Based on its nutritional and chemical composition, CSE could be consumed as a food supplement, or it could be added to the most suitable food matrix considering the sensory acceptance of consumers. Very recently, Angeloni et al studied the volatile fraction of CS for the first time, demonstrating that it contains an interesting odor-active compound fraction with high similarity to coffee beans [ 103 ], suggesting exploitation of this by-product in novel food production. In 2013, our research group patented (WO 2013/004873) its use in food and cosmetic applications [ 45 ].…”

The Role of Coffee Silver Skin against Oxidative Phenomena in Newly Formulated Chicken Meat Burgers after Cooking

“…As is known, chicken meat is poor in lipids that are mainly unsaturated fatty acids which are the elective substrate for the oxidation. Moreover, [46] have searched for the lipidic profile of CSS and their results show a small content of lipids, which are mainly saturated fatty acids (SFAs). So, one could refer all the defective odours and tastes to the lipidic oxidation complex of reactions.…”