Effect of roasting conditions on the fat, tocopherol, and phytosterol content and antioxidant capacity of the lipid fraction from cocoa beans of different Theobroma cacao L. cultivars

Abstract

The effect of roasting conditions on the content of fat, tocopherol, and phytosterol and antioxidant capacity of the lipid fraction from cocoa beans of different Theobroma cacao cultivars was investigated. The raw cocoa beans were roasted at four different temperatures (ranging from 110 to 150°C) and three different air humidities (0.3 to 5.0%). The results of this study show that roasting affected significantly the photochemical composition and lipophilic antioxidant activity of cocoa beans. Roasting may lead to significant degradation of α‐tocopherol and phytosterols when compared to raw cocoa beans. This was not true in samples roasted at the lowest temperatures and evaluated humidity; these samples had a higher γ‐ and δ‐tocopherol content and antioxidant capacity compared to the raw cocoa beans and samples roasted at other conditions. The present study also revealed that the content of bioactive compounds and antioxidant activity of different Theobroma cacao L. cultivars vary markedly.Practical applications: Cocoa beans are the primary raw material used in the manufacture of chocolate products, which can be great source of health‐beneficial bioactive compounds such as tocopherols and phytosterols. The differences between varieties in the levels of these bioactive compounds revealed in this study show that it is possible to increase their content in cocoa derived products by choosing an appropriate cultivar. Thermal processing at relatively high temperature may lead to the degradation of tocopherols and phytosterols.Influence of roasting conditions on the tocopherols (A), phytosterols (B), and antioxidant capacity (C) of the lipid fraction from cocoa beans of different Theobroma cacao L. cultivars