Chocolates taste great, but they can become even tastier when the cocoa trees are grown in dry season and in high-stressed conditions, new research suggests.But more than the agricultural methods, the weather conditions in which cocoa trees are grown could have greater impact on the flavour of chocolates, according to the study published in the Journal of Agricultural and Food Chemistry.Cocoa trees grow in hot and humid climates near the equator. Traditionally, these trees are raised together in mixed groves with other types of trees and plants that can cool the air and provide vital shade. The system, called agroforestry, provides a low-stress environment, increases nutrients in the soil and helps maintain ground water levels. But to gain higher yields, growers sometimes plant cocoa trees in solitary, "monocultural," groves, in which the trees are exposed to stressful conditions. In response to the stress, tress produce antioxidants that can potentially counteract the damage, but these compounds also could change the quality characteristics of the beans.Researchers from the Research Institute of Organic Agriculture (FiBL) in Switzerland wanted to find out whether differing growing methods can influence the chemical composition, and potentially the flavour, of cocoa beans.
The researchers harvested beans from five cocoa tree farms in Bolivia at the beginning and end of the dry season, which runs from April to September. The trees were raised in full-sun monocultural groves or in agroforest settings. The beans were fermented and dried, then analysed. The research team detected differences in the chemical composition among the beans harvested from the farms during the same weather conditions. Slightly more phenols and other antioxidant compounds were detected in beans taken from monoculturally grown trees than those that came from trees grown with agroforest methods, the researchers said. The larger contribution to chemical composition was the weather. Overall, the antioxidant content increased and fat content of the beans decreased during the dry season as temperatures rose and soil moisture dropped. These differences could contribute to variability in cocoa bean flavour, the researchers said.