With Valentine’s Day looming, it seemed an appropriate time to look into the chemistry of chocolate for the latest food chemistry graphic. In particular, here we focus on the two frequently referenced effects of consuming chocolate: its supposed aphrodisiac effect, and its harmful effects on dogs (and to a lesser extent, cats). The graphic gives a brief overview, whilst the text below gives a more detailed picture.
The latest food chemistry graphic looks at the chemistry of asparagus – specifically, why it causes the urine of some (but not all) people to smell. Over the past forty years several papers have been published on the subject, and several studies undertaken, to try and determine the chemical compounds responsible, and though there is still no definitive verdict as to the manner in which these compounds are formed, it has been suggested that they all form from asparagusic acid.
After looking at the chemistry of coffee in the previous post, it seemed only fair to also consider the chemistry of tea, just so all the tea drinkers out there don’t feel left out. Much like coffee, tea contains a hugely wide variety of chemical compounds, but some of the most important in terms of its taste and colouration are the polyphenols.
Mention coffee, and caffeine is the chemical compound name that immediately springs to mind. However, whilst caffeine’s effects on the brain are well documented – it binds to adenosine receptors in the brain – it has relatively little impact when it comes to the taste of coffee. Coffee, as it turns out, is a cornucopia of chemical compounds that influence its taste; whilst some of these compounds are poorly characterised, one group of compounds about which plenty is known are the chlorogenic acids.
The latest in the series of food chemistry graphics looks at the chemistry of onions – specifically, what causes their odour, and why chopping onions will make your eyes water. Interestingly, none of the compounds that cause these effects are present in the intact onion; rather, when the cell walls of the onion are damaged by chopping, an enzyme released produces a range of compounds as a defence mechanism, which act as irritants.
The idea for this graphic came to me whilst saving the chilli peppers from a forlorn looking, aphid-infested chilli plant that’s probably on its metaphorical last legs. I thought it would be quite interesting to look at the origin of the heat in chilli peppers, and how this can be quantified.
