Four hybrid cocoa species developed in Ghana to have improved resistance to pest damage during storage have similar nutritional properties to conventional cocoa, says a study that topples a barrier to commercial trade.
Ghana is one of the world's largest cocoa producers. According to the International Cocoa Organisation the country's commercial crop in 2005/2006 reached a record high of 646,000 tonnes.
However while cocoa consumption has increased in the last decade, the researchers of the study from the University of Nottingham, UK, say that yield has been on the decline.
To combat this, and to help deal with disease and pest resistance issues, a number of hybrids have been developed. The researchers say that while these are not yet in commercial use, they are likely to be introduced in the near future.
"However, very little is known about the level of key nutrients and phenolics in these hybrids," wrote the researchers, led by Gregory Tucker. This is an issue given the increasing attention to the health benefits of cocoa and its growing reputation as a source of dietary antioxidants linked to protection against cardiovascular disease.
Polyphenols identified in the cocoa bean make-up include several different catechins, as well as procyanins, anthocyanins, and flavone and flavonol glycosides.
Tucker and team therefore set out to determine the phenolic content and antioxidant capacity of five kinds of cocoa - Amazon/Trinitario hybrids, two different Amazon/Amazon hybrids, Amazon/Amelonado hybrids, and the traditional cocoa type.
They wanted to see whether there could be any impact on the nutrient content.
Total extractable phenolics were seen to be similar in all four of the hybrids, ranging from 69.9 to 81.6 FAE g -1.
These levels are also similar to those of traditional cocoa beans.
The team then determined the phenolic profile using HPLC. They observed a total of 25 peaks, with only minor differences between the hybrid profiles and that of the traditional beans.
Most interestingly, when the researchers determined the antioxidant capacity using the FRAP test, traditional beans were seen to have levels of 12.4 micro-mol TEg -1. The capacities of the hybrid beans, on the other hand, were seen to range from 21.6 to 45.5 micro-mol TEg -1.
"Since the phenolic and antioxidant levels in these hybrid varieties were either similar to, or higher than, that obtained from traditional beans, the introduction of these new varieties would be unlikely to impact detrimentally on these nutritional components of the beans," concluded Tucker.
Several of the major chocolate manufacturers have been investigating the healthy properties of cocoa, such as Mars, Nestle, Barry Callebaut and Natraceutical.
A review of the research to date conducted by Nestle and published last year in the British Journal of Nutrition concluded that future of research into the potential health benefits of cocoa should focus on the mechanisms and active compounds, with well defined clinical trials key to this burgeoning segment.
The majority of studies to date using flavonoid-rich cocoa have focussed on potential benefits for cardiovascular health, while a small number of studies have reported benefits for diabetes and skin health.
Food Chemistry 108 (2008) 1155-1159
"Phenolic content and antioxidant capacity of hybrid variety cocoa beans"
Authors: WA Jonfia-Essien, G West, PG Alderson, G Tucker
British Journal of Nutrition
Published on-line ahead of print, Forthcoming Article, doi: 10.1017/S0007114507795296
"Cocoa and health: a decade of research"
Authors: Karen A. Cooper, J.L. Donovan, A.L. Waterhouse and G. Williamson