title: Determination of the caffeine contents of various food items within the Austrian market and validation of a caffeine assessment tool (CAT).
abstract: The caffeine content of 124 products, including coffee, coffee-based beverages, energy drinks, tea, colas, yoghurt and chocolate, were determined using RP-HPLC with UV detection after solid-phase extraction. Highest concentrations of caffeine were found for coffee prepared from pads (755 mg l⁻¹) and regular filtered coffee (659 mg l⁻¹). The total caffeine content of coffee and chocolate-based beverages was between 15 mg l⁻¹ in chocolate milk and 448 mg l⁻¹ in canned ice coffee. For energy drinks the caffeine content varied in a range from 266 to 340 mg l⁻¹. Caffeine concentrations in tea and ice teas were between 13 and 183 mg l⁻¹. Coffee-flavoured yoghurts ranged from 33 to 48 mg kg⁻¹. The caffeine concentration in chocolate and chocolate bars was between 17 mg kg⁻¹ in whole milk chocolate and 551 mg kg⁻¹ in a chocolate with coffee filling. A caffeine assessment tool was developed and validated by a 3-day dietary record (r²= 0.817, p < 0.01) using these analytical data and caffeine saliva concentrations (r²= 0.427, p < 0.01).
authors.affiliation: Department of Nutritional Sciences, University of Vienna, Vienna, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Rudolph
authors.forename: A
authors.initials: A
authors.lastname: Färbinger
authors.forename: J
authors.initials: J
authors.lastname: König
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001317:Austria; D001628:Beverages / Q000032:analysis; D002099:Cacao / Q000737:chemistry; D002110:Caffeine / Q000008:administration & dosage* / Q000032:analysis* / Q000378:metabolism; D002182:Candy / Q000032:analysis; D003611:Dairy Products / Q000032:analysis; D015930:Diet Records; D004034:Diet Surveys / Q000379:methods*; D005260:Female; D005504:Food Analysis / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D008297:Male; D008875:Middle Aged; D012463:Saliva / Q000737:chemistry; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D002110:Caffeine