RESUMEN
Cocoa (Theobroma cacao L.) is a major, economically important, international crop and has been associated with several nutritional benefits including high antioxidant capacity. New cocoa hybrids have been developed in Ghana that exhibit resistance to pest damage during storage. The aim of this work was to assess the phenolic content and antioxidant capacity of these new hybrids in comparison to more traditional cocoa varieties. Total extractable phenolics were similar in all the four hybrids tested ranging from 69.9 to 81.6FAEg(-1). These levels were very similar to that extracted from traditional beans (73.8±2.5FAEg(-1)). The "phenolic profile" was determined by HPLC. A total of 25 peaks was observed but there were only minor differences in this profile between traditional and hybrid bean extracts. Antioxidant capacity was determined using the FRAP assay and traditional beans were found to possess 12.4µmolTEg(-1). In comparison the hybrid beans had antioxidant capacities ranging from 21.6 to 45.5µmolTEg(-1), and these were significantly higher than in the traditional beans for three out of the four hybrids. Since the phenolic and antioxidant levels and 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.
RESUMEN
New hybrid types of cocoa beans are attractive to insects in storage, however some of the insects feed little, if at all, on these beans compared to those of the traditional type (mixed genotypes). Based on a sniffing test using GCMS, differences in flavour volatiles in these types of beans have been determined and from these, six major volatiles of cocoa beans were selected for olfactometric analysis using a Pettersson olfactometer to determine which of them contributed to the attraction of Tribolium castaneum (Herbst) to the cocoa beans. The behaviour of Tribolium was affected by dose of 2-phenyl ethanol, acetophenone, 3-methyl butyraldehyde, ethyl butyrate, ethyl 3-hydroxybutyrate and butyl 2-methacrylate. Compared to beans of the new hybrid varieties, beans of the traditional type cocoa contained less 3-methylbutyraldehyde but more ethyl butyrate and acetophenone. In future breeding programmes, reducing the amount of acetophenone and ethyl butyrate but increasing the amount of 3-methylbutyraldehyde in cocoa beans may deter Tribolium from feeding on beans in storage.
Asunto(s)
Conducta Animal/efectos de los fármacos , Cacao/química , Aceites Volátiles/farmacología , Aceites de Plantas/farmacología , Tribolium , Animales , Humanos , Control de Insectos/métodos , Odorantes/análisis , Aceites Volátiles/química , Aceites de Plantas/química , Olfato , Tribolium/efectos de los fármacos , Tribolium/fisiologíaRESUMEN
Acetophenone, ethyl butyrate and 2-phenyl ethanol were used as additives to media on which Tribolium castaneum (Herbst) and Lasioderma serricorne (Fabricius) were cultured for 65 days. Acetophenone and ethyl butyrate had a positive impact on the weight and multiplication of the insects. The weight and rate of multiplication was higher in feed media containing acetophenone alone. The amount of the flavour volatiles added was high enough to deter the Lasioderma from feeding well, which affected their growth. This attraction to specific flavour volatiles in some stored products could be used in the formulation of effective control measures for insect pests.