The Candyman Can

This week was our last week in class and in Siena. To conclude our analytical chemistry class, Stephanie and I did a presentation on the chemistry of chocolate blooms. Chocolate blooms occur when chocolate is stored at high temperatures or for a prolonged period of time (2-3 years). They are a direct result of the substance's natural fat, cocoa butter. When chocolate is tempered, manufacturers stabilize the cocoa butter in its Beta-5 form. This form, however, is not the most stable form: form 6 is. Therefore, when chocolate is exposed to high temperatures, there is a tendency of the liquid-like protons in the cocoa butter to leave the chocolate crystalline matrix and migrate to the surface. It is there that they recrystallize and form a whitish-grey film that is unappealing to consumers.

Several groups of scientists are currently studying ways to prevent the blooming of chocolate. NMR analysis has been used to determine that certain additives slow the process. The chemical structures of the triglycerides in cocoa butter have also been studied using powder x-ray diffraction. Though the research is still young, the teams are looking for a way to produce chocolate containing cocoa butter that is already in Beta-6 form, thereby decreasing the likelihood of fat blooms. More information can be found at the websites listed below.

I will be leaving Siena in the morning, so this will serve as my last blog post. I have thoroughly enjoyed my time here at the UNISI. The people I have met and the experiences I have had will truly impact my outlook on life for years to come. Thanks to Daniela, Renzo, Gabriela, and all of our other professors from UNISI for making our time here as enjoyable as possible. Ciao ragazzi!

www.physorg.com/news1208.html
www.esrf.eu/UsersAndScience/Publications/Highlights/2004/SCM/SCM8