Tocopherols in espresso coffee: Analytical method development and validation

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Rita C. Alves (Author) FFUP; Susana Casal (Author) FFUP; M. Beatriz P.P. Oliveira (Author) FFUP

Journal

Title: Food Control

Vol. 115 No. 4

Pages: 1549-1555

ISSN: 0956-7135

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 19 Citations

ISI Web of Science

Scopus - 22 Citations

Scientific classification

FOS: Medical and Health sciences > Other medical sciences

CORDIS: Health sciences

Other information

Authenticus ID: P-003-GQV

Resumo (PT): The present paper reports the development and validation of an analytical micro-method for tocopherols quantification in espresso coffee by normal-phase HPLC with fluorescence detection. The proposed method consists in a liquid–liquid extraction with n-hexane:ethyl acetate, followed by a clean-up with dimethylformamide to eliminate co-eluting interferences. The method showed good intra- and inter-day precisions (coefficient of variation < 6.5%), good accuracies (98 ± 6%), and high correlation coefficients (r > 0.999) for standards subjected to the entire procedure. Only α- and β-tocopherols were identified in the brews. The detection and quantification limits were 0.5 and 1.4 ng/ml, for α-tocopherol, and 0.4 and 1.1 ng/ml, for β-tocopherol, respectively. A mean total tocopherol content (α + β) of 3.5 ± 0.9 μg in commercial espresso coffee blends (30 ml) was detected. The proposed method requires low solvent consumption and proved to be sensitive, precise and accurate. <br> <br> Keywords: Espresso coffee; Coffee brew; Tocopherols; Vitamin E; HPLC <br> <a target="_blank" href=" http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-4VH8B3V-1&_user=2460038&_coverDate=08%2F15%2F2009&_rdoc=57&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info(%23toc%235037%232009%23998849995%231009083%23FLA%23display%23Volume)&_cdi=5037&_sort=d&_docanchor=&_ct=63&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=c70920bfcff820ffa4dcbe726b30974e&searchtype=a"> Texto integral</a> <br> <br>

Abstract (EN): The present paper reports the development and validation of an analytical micro-method for tocopherols quantification in espresso coffee by normal-phase HPLC with fluorescence detection. The proposed method consists in a liquid–liquid extraction with n-hexane:ethyl acetate, followed by a clean-up with dimethylformamide to eliminate co-eluting interferences. The method showed good intra- and inter-day precisions (coefficient of variation < 6.5%), good accuracies (98 ± 6%), and high correlation coefficients (r > 0.999) for standards subjected to the entire procedure. Only α- and β-tocopherols were identified in the brews. The detection and quantification limits were 0.5 and 1.4 ng/ml, for α-tocopherol, and 0.4 and 1.1 ng/ml, for β-tocopherol, respectively. A mean total tocopherol content (α + β) of 3.5 ± 0.9 μg in commercial espresso coffee blends (30 ml) was detected. The proposed method requires low solvent consumption and proved to be sensitive, precise and accurate. <br> <br> Keywords: Espresso coffee; Coffee brew; Tocopherols; Vitamin E; HPLC <br> <a target="_blank" href=" http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6T6R-4VH8B3V-1&_user=2460038&_coverDate=08%2F15%2F2009&_rdoc=57&_fmt=high&_orig=browse&_origin=browse&_zone=rslt_list_item&_srch=doc-info(%23toc%235037%232009%23998849995%231009083%23FLA%23display%23Volume)&_cdi=5037&_sort=d&_docanchor=&_ct=63&_acct=C000057398&_version=1&_urlVersion=0&_userid=2460038&md5=c70920bfcff820ffa4dcbe726b30974e&searchtype=a"> Full text</a> <br> <br>

Language: English

Type (Professor's evaluation): Scientific