An examination of consumer exposure to caffeine from commercial coffee and coffee-flavoured milk

A cross-section of Australian Espresso/short black coffee and coffee-flavoured milk samples were purchased and analysed for their caffeine content using micellar electrokinetic capillary chromatography (MEKC). Coffees were collected using convenience cluster sampling across four major cities. Packaged coffee-flavoured milks were collected from national grocery distributors. In all, 131 espresso samples and 20 coffee-flavoured milks were analysed. The mean (+/- SD) quantity of caffeine from espresso coffee was 107 +/- 37 mg/serving with a concentration of 2550 +/- 1030 mg/L. The mean (+/- SD) quantity of caffeine from coffee-flavoured milk was 99 +/- 50 mg/carton with a concentration of 193 +/- 90 mg/L. There was considerable variation in caffeine content across both categories and within the same espresso brand purchased at different locations. In total, 42 samples (27.5%) contained >= 120 mg per serving of caffeine, and 20 samples (13.1%) exceeded 165 mg per serving. The expanded caffeine data supports our original findings which indicated that the probability of consumer exposure to high caffeine doses from popular coffee beverages in Australia is greater than previously reported. (C) 2012 Elsevier Inc. All rights reserved.