Acrylamide in coffee: review of progress in analysis, formation and level reduction.

This paper summarizes the progress made in understanding the formation of acrylamide in coffee, as well as potential reduction strategies, as presented during the joint CIAA/EC workshop on acrylamide, held in Brussels in March 2006. Currently, there are no concrete measures to reduce acrylamide concentrations in roast and ground coffee without appreciably changing the organoleptic properties of the product. Certain approaches, such as steam roasting, have been tried on a laboratory scale, albeit without affording a significant reduction. More work on the mechanisms governing the "loss" of acrylamide during storage of roast and ground coffee is warranted, and studies in this direction have been initiated. Finally, risk/benefit analysis must be addressed in a complex food such as coffee, known to harbour numerous health beneficial/chemoprotective compounds with antioxidant and antimutagenic properties.

Studies on acrylamide levels in roasting, storage and brewing of coffee.

The content of acrylamide in coffee reaches a peak early in the roasting process, reflecting occurrence of both formation and destruction of acrylamide during roasting. Levels of acrylamide in the fully roasted product are a small fraction of the peak reached earlier. Glucose and moisture in green coffee do not show a significant correlation with acrylamide in roasted coffee. Pre-roasting levels of asparagine show a correlation only in Arabica coffee. The main factors affecting the level of acrylamide in roasted coffee appear to be the Arabica/Robusta ratio, with Robusta giving higher levels; time and degree of roast, with both shorter and lighter roasting at the edges of the normal roasting range giving higher levels; storage condition and time, with clear reduction at ambient storage. This storage reduction of acrylamide followed second order reaction kinetics with an activation energy of 73 KJ/mole. The acrylamide in roasted coffee is largely extracted into the brew and stable within usual time of consumption. As these four main factors also substantially affect the sensorial characteristics of the brew, and as modifications of the process have to comply with the consumer-accepted boundaries of taste profiles, only small effects on the acrylamide level are expected to be achievable.