{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,17]],"date-time":"2026-03-17T20:32:58Z","timestamp":1773779578950,"version":"3.50.1"},"reference-count":36,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2022,5,27]],"date-time":"2022-05-27T00:00:00Z","timestamp":1653609600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Community Structural Funds FEDER and FSE for the 2014\u20132020","award":["ACORES-01-0247-FEDER-000014"],"award-info":[{"award-number":["ACORES-01-0247-FEDER-000014"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Antioxidants"],"abstract":"<jats:p>The molecular constituents of Camellia sinensis, in particular epigallocatechin-3-O-gallate (EGCG) and, more remarkably, the galloylated theaflavins, mainly theaflavin-3,3\u2032-di-O-gallate (TF-3,3\u2032-DG), have been reported to inhibit SARS-CoV-2 3-chymotrypsin-like protease (3CLpro), an enzyme required for the cleavage of its polyproteins, to produce vital individual functional proteins for viral cell replication. Our results for total catechin content revealed the values of 174.72, 200.90, and 211.75 mg\/g dry weight (DW) in spring, and the values of 183.59, 191.36, and 215.09 mg\/g DW in summer, for tea plantation zones 1, 2, and 3, respectively. For the TF-3,3\u2032-DG content, the values of 2.68, 1.13, and 3.72 mg\/g DW were observed in spring, and the values of 3.78, 2.06, and 8.91 mg\/g DW in summer for zones 1, 2, and 3, respectively. In the same zone, different contents of TF-3,3\u2032-DG were observed across plucking months of April, June, and August, with values of 1.13, 2.77, and 4.18 mg\/g DW, respectively, showing higher values in summer. Different values of TF-3,3\u2032-DG contents were also observed in the same tea plantation zone but from different plant parts, revealing higher values in the bud and the first and second leaves (3.62 mg\/g DW) and lower values in the third and fourth leaves (1.14 mg\/g DW). The TF-3,3\u2032-DG content increased from 3.31 to 4.98 mg\/g DW with increased fermentation time from 1 to 3 h, respectively, and increased for lower temperature and longer fermentation time. The aim of this study was to investigate the processing conditions that lead to maximum TF-3,3\u2032-DG content and, given its potential impact as an inhibitor of the 3CLpro enzyme, to create a novel antiviral Azorean black tea.<\/jats:p>","DOI":"10.3390\/antiox11061066","type":"journal-article","created":{"date-parts":[[2022,5,28]],"date-time":"2022-05-28T01:40:45Z","timestamp":1653702045000},"page":"1066","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Investigation of the Azorean Camellia sinensis Processing Conditions to Maximize the Theaflavin 3,3\u2032-di-O-Gallate Content as a Potential Antiviral Compound"],"prefix":"10.3390","volume":"11","author":[{"given":"Lisete","family":"Paiva","sequence":"first","affiliation":[{"name":"Gorreana Tea Plantation, Gorreana, 9625-304 Maia, Portugal"},{"name":"Department of Physics, Chemistry and Engineering (DCFQE), Faculty of Science and Technology, University of Azores, 9500-321 Ponta Delgada, S\u00e3o Miguel, Azores, Portugal"},{"name":"Institute of Agricultural and Environmental Research and Technology (IITAA), University of Azores, 9700-042 Angra do Hero\u00edsmo, Terceira, Azores, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6736-8729","authenticated-orcid":false,"given":"Elisabete","family":"Lima","sequence":"additional","affiliation":[{"name":"Department of Physics, Chemistry and Engineering (DCFQE), Faculty of Science and Technology, University of Azores, 9500-321 Ponta Delgada, S\u00e3o Miguel, Azores, Portugal"},{"name":"Institute of Agricultural and Environmental Research and Technology (IITAA), University of Azores, 9700-042 Angra do Hero\u00edsmo, Terceira, Azores, Portugal"}]},{"given":"Madalena","family":"Motta","sequence":"additional","affiliation":[{"name":"Gorreana Tea Plantation, Gorreana, 9625-304 Maia, Portugal"}]},{"given":"Massimo","family":"Marcone","sequence":"additional","affiliation":[{"name":"Department of Food Science, University of Guelph, Guelph, ON N1G 2W1, Canada"}]},{"given":"Jos\u00e9","family":"Baptista","sequence":"additional","affiliation":[{"name":"Department of Physics, Chemistry and Engineering (DCFQE), Faculty of Science and Technology, University of Azores, 9500-321 Ponta Delgada, S\u00e3o Miguel, Azores, Portugal"},{"name":"Institute of Agricultural and Environmental Research and Technology (IITAA), University of Azores, 9700-042 Angra do Hero\u00edsmo, Terceira, Azores, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1543S","DOI":"10.1093\/jn\/138.8.1543S","article-title":"Tea is the major source of flavan-3-ol and flavonol in the U.S. diet","volume":"138","author":"Song","year":"2008","journal-title":"J. Nutr."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Khan, N., and Mukhtar, H. (2018). Tea polyphenols in promotion of human health. Nutrients, 11.","DOI":"10.3390\/nu11010039"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"729","DOI":"10.1016\/S0963-9969(99)00052-6","article-title":"Comparison of catechins and aromas among different green teas, using HPLC\/SPME-GC","volume":"31","author":"Baptista","year":"1999","journal-title":"Food Res. Int."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Zhen, Y., Chen, Z., Cheng, S., and Chen, M. (2002). Tea and health\u2014An overview. Tea Bioactivity and Therapeutic Potential, Taylor and Francis.","DOI":"10.1201\/b12659-4"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Ohgitani, E., Shin-Ya, M., Ichitani, M., Kobayashi, M., Takihara, T., Kawamoto, M., Kinugasa, H., and Mazda, O. (2021). Significant inactivation of SARS-CoV-2 in vitro by a green tea catechin, a catechin-derivative, and black tea galloylated theaflavins. Molecules, 26.","DOI":"10.3390\/molecules26123572"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"601316","DOI":"10.3389\/fpls.2020.601316","article-title":"Docking characterization and in vitro inhibitory activity of flavan-3-ols and dimeric proanthocyanidins against the main protease activity of SARS-Cov-2","volume":"11","author":"Zhu","year":"2020","journal-title":"Front. Plant Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1344521","DOI":"10.1080\/16546628.2017.1344521","article-title":"Research progress on theaflavins: Efficacy, formation, and preparation","volume":"61","author":"He","year":"2017","journal-title":"Food Nutr. Res."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.foodchem.2018.10.095","article-title":"Spatial changes in leaf biochemical profile of two tea cultivars following cold storage under two different vapour pressure deficit (VPD) conditions","volume":"277","author":"Collings","year":"2019","journal-title":"Food Chem."},{"key":"ref_9","unstructured":"Satish, S., Rathinavel, A.K., Lutz, W.E., Struble, L.R., Khurana, S., Schnaubelt, A.T., Mishra, N.K., Guda, C., Broadhurst, M.J., and Reid, S.P.M. (2020). Bromelain inhibits SARS-CoV-2 infection in veroE6 cells. bioRxiv, 20200916297366."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"153286","DOI":"10.1016\/j.phymed.2020.153286","article-title":"Antiviral activity of green tea and black tea polyphenols in prophylaxis and treatment of COVID-19: A review","volume":"85","author":"Mhatre","year":"2021","journal-title":"Phytomedicine"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1195","DOI":"10.1111\/bph.13649","article-title":"Antioxidants from black and green tea: From dietary modulation of oxidative stress to pharmacological mechanisms","volume":"174","author":"Peluso","year":"2017","journal-title":"Br. J. Pharmacol."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Zhao, C.-N., Tang, G.-Y., Cao, S.-Y., Xu, X.-Y., Gan, R.-Y., Liu, Q., Mao, Q.-Q., Shang, A., and Li, H.-B. (2019). Phenolic profiles and antioxidant activities of 30 tea infusions from green, black, oolong, white, yellow and dark teas. Antioxidants, 8.","DOI":"10.3390\/antiox8070215"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1016\/0091-7435(92)90062-M","article-title":"Tea consumption. Relationship to cholesterol, blood pressure, and coronary and total mortality","volume":"21","author":"Stensvold","year":"1992","journal-title":"Prev. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1161\/ATVBAHA.109.199687","article-title":"Specific dietary polyphenols attenuate atherosclerosis in apolipoprotein E-knockout mice by alleviating inflammation and endothelial dysfunction","volume":"30","author":"Loke","year":"2010","journal-title":"Arterioscler. Thromb. Vasc. Biol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"52","DOI":"10.1016\/j.ejphar.2016.11.027","article-title":"In vitro and in vivo anti-inflammatory effects of theaflavin-3,3\u00b4-digallate on lipopolysaccharide-induced inflammation","volume":"794","author":"Wu","year":"2017","journal-title":"Eur. J. Pharmacol."},{"key":"ref_16","first-page":"643","article-title":"Inhibitory effects of the four main theaflavin derivatives found in black tea on ovarian cancer cells","volume":"36","author":"Gao","year":"2016","journal-title":"Anticancer Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.foodchem.2006.01.008","article-title":"Influence of fermentation time on the development of compounds responsible for quality in black tea","volume":"101","author":"Muthumani","year":"2007","journal-title":"Food Chem."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"S151","DOI":"10.1002\/mnfr.200900549","article-title":"Tea polyphenols inhibit IL-6 production in tumor necrosis factor superfamily 14-stimulated human gingival fibroblasts","volume":"54","author":"Hosokawa","year":"2010","journal-title":"Mol. Nutr. Food Res."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"443","DOI":"10.1038\/ja.2016.128","article-title":"Antiviral effect of theaflavins against caliciviruses","volume":"70","author":"Ohba","year":"2017","journal-title":"J. Antibiot."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1016\/j.fitote.2013.12.011","article-title":"Comparison of in vitro antiviral activity of tea polyphenols against influenza A and B viruses and structure-activity relationship analysis","volume":"93","author":"Yang","year":"2014","journal-title":"Fitoterapia"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1152","DOI":"10.1016\/j.lwt.2014.06.004","article-title":"Value of off-season fresh Camellia sinensis leaves. Antiradical activity, total phenolics content and catechin profiles","volume":"59","author":"Baptista","year":"2014","journal-title":"LWT Food Sci. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1590\/S0101-20612006000200024","article-title":"Catechin and theaflavin levels of teas commercialized in Brazil","volume":"26","author":"Matsubara","year":"2006","journal-title":"Food Sci. Technol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Koch, W., Kukula-Koch, W., Komsta, \u0141., Marzec, Z., Szwerc, W., and Glowniak, K. (2018). Green tea quality evaluation based on its catechins and metals composition in combination with chemometric analysis. Molecules, 23.","DOI":"10.3390\/molecules23071689"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Koch, W., Kukula-Koch, W., and Komsta, L. (2018). Black tea samples origin discrimination using analytical investigations of secondary metabolites, antiradical scavenging activity and chemometric approach. Molecules, 23.","DOI":"10.3390\/molecules23030513"},{"key":"ref_25","first-page":"3283","article-title":"Effect of ultraviolet B irradiation on accumulation of catechins in tea (Camellia sinensis (L.) O. Kuntze)","volume":"7","author":"Zheng","year":"2008","journal-title":"Afr. J. Biotechnol."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"307","DOI":"10.1007\/s00217-010-1379-3","article-title":"Seasonal clonal variations and effects of stresses on quality chemicals and prephenate dehydratase enzyme activity in tea (Camellia sinensis)","volume":"232","author":"Sharma","year":"2011","journal-title":"Eur. Food Res. Technol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"192","DOI":"10.1080\/07352689.2012.747384","article-title":"Improving the polyphenol content of tea","volume":"32","author":"Tounekti","year":"2013","journal-title":"Crit. Rev. Plant Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"939","DOI":"10.3389\/fpls.2019.00939","article-title":"Environmental factors variably impact tea secondary metabolites in the context of climate change","volume":"10","author":"Ahmed","year":"2019","journal-title":"Front. Plant Sci."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"5427302","DOI":"10.1155\/2018\/5427302","article-title":"Effects of variety, season, and region on theaflavins content of fermented Chinese Congou black tea","volume":"2018","author":"Jiang","year":"2018","journal-title":"J. Food Qual."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Takemoto, M., and Takemoto, H. (2018). Synthesis of theaflavins and their functions. Molecules, 23.","DOI":"10.3390\/molecules23040918"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1468","DOI":"10.1111\/j.1365-2486.2011.02615.x","article-title":"The Michaelis\u2013Menten kinetics of soil extracellular enzymes in response to temperature: A cross-latitudinal study","volume":"18","author":"German","year":"2012","journal-title":"Glob. Chang. Biol."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Storozhuk, M. (2020). COVID-19: Could green tea catechins reduce the risks?. medRxiv, 2020102320218479.","DOI":"10.1101\/2020.10.23.20218479"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"766","DOI":"10.1016\/j.apsb.2020.02.008","article-title":"Analysis of therapeutic targets for SARS-CoV-2 and discovery of potential drugs by computational methods","volume":"10","author":"Wu","year":"2020","journal-title":"Acta Pharm. Sin. B"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"6141","DOI":"10.2174\/1381612811319340008","article-title":"Tea and health: Studies in humans","volume":"19","author":"Khan","year":"2013","journal-title":"Curr. Pharm. Des."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Menegazzi, M., Campagnari, R., Bertoldi, M., Crupi, R., Di Paola, R., and Cuzzocrea, S. (2020). Protective effect of epigallocatechin-3-gallate (EGCG) in diseases with uncontrolled immune activation: Could such a scenario be helpful to counteract COVID-19?. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21145171"},{"key":"ref_36","unstructured":"(2021, December 24). Johns Hopkins Coronavirus Resource Center: Home Page. Available online: https:\/\/coronavirus.jhu.edu."}],"container-title":["Antioxidants"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3921\/11\/6\/1066\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:19:57Z","timestamp":1760138397000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3921\/11\/6\/1066"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,27]]},"references-count":36,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2022,6]]}},"alternative-id":["antiox11061066"],"URL":"https:\/\/doi.org\/10.3390\/antiox11061066","relation":{},"ISSN":["2076-3921"],"issn-type":[{"value":"2076-3921","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,27]]}}}