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Stability of Urinary Metabolites of Strawberry Anthocyanins
Author(s) -
Carkeet Colleen,
Clevidence Beverly A.,
Novotny Janet A.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a574-c
Subject(s) - metabolite , chemistry , anthocyanin , chromatography , urine , solid phase extraction , high performance liquid chromatography , food science , biochemistry
The stability of urinary metabolites of strawberry anthocyanins was investigated. Healthy adult volunteers consumed 200g of pureed strawberries as a bolus dose and urine was collected and pooled. Urine was acidified with 1/5 the volume of 0.44M TFA, and malvidin‐3‐galactose was added as an internal standard. Urine was separated into two fractions, one for immediate prep and analysis and one frozen at −80°C for 48 hrs before work‐up. Sample prep consisted of solid phase (C18) extraction to isolate and concentrate the anthocyanins. Anthocyanin metabolites were then separated and detected on an Agilent 1100 HPLC equipped with a diode array detector and a reverse‐phase column. The impact of freezing on anthocyanin metabolite profiles was evaluated and results indicated that freezing had no effect on the peak areas of the four anthocyanin metabolites detected. An additional experiment followed the change in these metabolite profiles at hourly intervals as the samples remained on a cooled, 10°C autosampler for 18 hours. These results suggest that three metabolites degrade over time while one peak area increased over time, indicating it may be a degradation product of the other metabolites. A final experiment investigated the effect of autosampler temperature (10°C, 20°C and 30°C) on the metabolite profiles and revealed a positive correlation between degradation rate and autosampler temperature. Identification of the four metabolites is underway.