Something about people going Valentine’s Day overboard in response to too many advertisements promoting cheap chocolates has sent us seeking repose in the science behind the art of cacao. We still wish everyone the happiest and chocolatiest of Valentines, but our interest on this day this year has led to Penn State Professor Mark Guiltinan, who along with colleagues, has taken one of the late deepest looks ever into what make chocolate chocolate.
The professor of plant molecular biology in the Department of Horticulture in the College of Agricultural Sciences heads up the eponymous Guiltinan Lab, where he studies crop improvement and sustainable farming methods. Among his projects was playing an integral part in the International Cocoa Genome Sequencing Consortium sequencing and analyzing the heirloom, Belize Criollo variety of the Theobromo cacao plant. Their goal was to understand the cacao genome, closely related to the luxury of the Mayans and Aztecs — consumed as a hot drink laced with peppers — in order to breed healthier, higher quality trees and more disease-resistant cacao pods. It was also hoped that the research would yield economic, social and environmental advantages to the cacao farmers and nations. What it was not, was a foray into scary science, or, as he told the Philadelphia Inquirer at the time, “…the main aim of the projects wasn’t to bring the world genetically modified candy bars.”
Taking a few moments from his research and his own Valentines Day preparations, Dr. Guiltinan kindly shared a few insights into his affairs with chocolate.
Cupid Alley Chocolatieres: What was the moment or event or day or taste that was the inspiration for your personal and professional interest in studying the genome of chocolate?
Dr. Mark Guiltinan: Visiting the cacao growing regions of Bahia, Brazil, in 1995, and witnessing the effects of the witches’ broom epidemic, and how it had made thousands of people homeless, inspired me to focus on cacao. A few years later, the human genome was published, and I realized that sequencing the cacao genome could have a huge impact on accelerating the improvement of this tasty crop.
CAC: What was the most surprising thing you learned from your analysis?
MG: The cacao genome sequence allowed us to localize a gene (NPR1) that is very important in the plant immune system, to a region of chromosome 9 that is known to be very important in resistance to witches’ broom disease. We still have a ways to go to know for sure that the NPR1 gene is the reason certain plants can fight this disease better then others, but were working on that now.
CAC: How do you expect people to use your work to influence the growth and even taste of chocolate?
MG: The genome sequence will be used for the foreseeable future by anyone working with cacao improvement because it offers so many ways to speed up the process. I plan to continue to work on decoding the secrets of the cacao genome as long as I can, is there a better job anywhere?
CAC: In what ways does knowing the science of the taste of chocolate influence your personal experience of enjoying it, if you still can?
MG: When I taste chocolate I think of the different genetic types of cacao that contribute to the different flavors and even imagine the molecular structures of the compounds that we taste. Maybe it distracts from the taste…? I enjoy darker chocolates such as 65 percent to 75 percent and have become found of mixtures with fruits, nuts and other species. I love almost all quality chocolates but am quite fond of Lindt [Disclaimer: we do not receive any funding from this company, unfortunately!]. The Lindt Excellent Intense Pear is one of my most favorite, but there are many others. Come to think of it there are few chocolates I do not like, they are all just different experiences to try and enjoy.
CAC: Are you doing other work with cacao?
MG: We are studying the immune system of cacao to help breeders find better plants. We are working on the genes involved in oil biosynthesis (cocoa butter) that could lead to more or different cocoa butter. We work on the genes for flavonoid synthesis as well, which will someday lead to chocolates even higher levels of these healthy compounds. We also work on ways to propagate cacao through tissue culture which is very exciting technology that has recently been commercialized in Indonesia and is spreading worldwide. We now have made a impact throughout the cocoa growing world!
CAC: Do you have any special Valentine’s Day plans? Any favorite recipes you will be sharing with someone special?
MG: hmmmm let me get back to you on that…..
CAC: What other projects have captured your imagination?
MG: I am interested in working in large interdisciplinary teams to focus on cacao as a vehicle for economic, environmental and social improvement. To do this we need a coordinated plan that brings together specialists in all dimensions of the cocoa value chain, with a common goal to support the sustainability of the chocolate industry, and to help cocoa farmers worldwide. There are a few such projects starting and I hope our team can contribute to these. I also believe that in the future, it will be important to use all technology we have to solve agricultures and societies most pressing issues. One such technology is genetic engineering. While I am sure this is not going to be a popular comment with many of your readers, I believe that one day it will contribute to cocoa sustainability along with all the other tools we have. Towards that end, we are doing research now that will be important when that day comes. Don’t worry anti-GMO folks, there are no plans to release any GMO cocoa anytime soon! It’s just a research tool for now. I plant to spend a portion of my time to educate the public about this issue. If you want to learn more, here is a very interesting article written by Mark Lynas, one of the most anti-GMO activists of all time, who has now re-thought his position.