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. 2020 May 2;25(9):2132.
doi: 10.3390/molecules25092132.

In Vitro Bioaccessibility and Antioxidant Activity of Coffee Silverskin Polyphenolic Extract and Characterization of Bioactive Compounds Using UHPLC-Q-Orbitrap HRMS

Luigi Castaldo  1   2 , Alfonso Narváez  1 , Luana Izzo  1 , Giulia Graziani  1 , Alberto Ritieni  1   3
Affiliations

In Vitro Bioaccessibility and Antioxidant Activity of Coffee Silverskin Polyphenolic Extract and Characterization of Bioactive Compounds Using UHPLC-Q-Orbitrap HRMS

Luigi Castaldo et al. Molecules. .

Abstract

Coffee silverskin (CS), the main by-product in the coffee industry, contains a vast number of human health-related compounds, which may justify its exploitation as a functional food ingredient. This study aimed to provide a comprehensive analysis of the polyphenolic and alkaloid profile through UHPLC-Q-Orbitrap HRMS analysis. The bioaccessibility of total phenolic compounds and changes in the antioxidant activity during an in vitro gastrointestinal digestion were also evaluated through spectrophotometric tests (TPC by Folin-Ciocalteu, ABTS, DPPH, and FRAP), to elucidate their efficacy for future applications in the nutraceutical industry. Caffeoylquinic and feruloylquinic acids were the most representative polyphenols, with a mean concentration of 5.93 and 4.25 mg/g, respectively. Results showed a high content of caffeine in the analyzed CS extracts, with a mean value of 31.2 mg/g, meaning a two-fold increase when compared to coffee brews. Our findings highlighted that both the bioaccessibility and antioxidant activity of CS polyphenols significantly increased in each in vitro gastrointestinal digestion stage. In addition, the colon stage might constitute the main biological site of action of these antioxidant compounds. These results suggest that in vivo, the dietary polyphenols from CS might be metabolized by human colonic microflora, generating metabolites with a greater antioxidant activity, increasing their well-known beneficial effects.

Keywords: bioaccessibility; chlorogenic acids; coffee silverskin; polyphenols.

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Conflict of interest statement

The authors declare no conflict of interest.

References

    1. Bułdak R.J., Hejmo T., Osowski M., Bułdak Ł., Kukla M., Polaniak R., Birkner E. The Impact of Coffee and Its Selected Bioactive Compounds on the Development and Progression of Colorectal Cancer In Vivo and In Vitro. Molecules. 2018;23:3309. doi: 10.3390/molecules23123309. - DOI - PMC - PubMed
    1. Sung S.H., Chang Y., Han J. Development of polylactic acid nanocomposite films reinforced with cellulose nanocrystals derived from coffee silverskin. Carbohydr. Polym. 2017;169:495–503. doi: 10.1016/j.carbpol.2017.04.037. - DOI - PubMed
    1. International Coffee Organization-(ICO) [(accessed on 10 April 2020)];2020 Available online: http://www.ico.org/documents/cy2019-20/cmr-1019-e.pdf.
    1. Jiménez-Zamora A., Pastoriza S., Rufián-Henares J.A. Revalorization of coffee by-products. Prebiotic, antimicrobial and antioxidant properties. LWT-Food Sci. Technol. 2015;61:12–18.
    1. Costa A.S., Alves R.C., Vinha A.F., Costa E., Costa C.S., Nunes M.A., Almeida A.A., Santos-Silva A., Oliveira M.B.P. Nutritional, chemical and antioxidant/pro-oxidant profiles of silverskin, a coffee roasting by-product. Food Chem. 2018;267:28–35. doi: 10.1016/j.foodchem.2017.03.106. - DOI - PubMed