Priscilla Efraim

Occurrence of ochratoxin A in cocoa by-products and determination of its reduction during chocolate manufacture

This work reports an investigation carried out to assess the natural occurrence of ochratoxin A in 168 samples from different fractions obtained during the technological processing of cocoa (shell, nibs, liquor, butter, cake and cocoa powder) and the reduction of ochratoxin A during chocolate manufacture. Ochratoxin A analyses were performed with immunoaffinity columns and detection by high performance liquid chromatography. Concerning the natural ochratoxin A contamination in cocoa by-products, the highest levels of ochratoxin A were found in the shell, cocoa powder and cocoa cake. The cocoa butter was the least contaminated, showing that ochratoxin A seems to remain in the defatted cocoa solids. Under the technological conditions applied during the manufacture of chocolate in this study and the level of contamination present in the cocoa beans, this experiment demonstrated that 93.6% of ochratoxin A present in the beans was reduced during the chocolate producing.

Inactivation of Salmonella during cocoa roasting and chocolate conching.

The high heat resistance of Salmonella in foods with low water activity raises particular issues for food safety, especially chocolate, where outbreak investigations indicate that few colony-forming units are necessary to cause salmonellosis. This study evaluated the efficiency of cocoa roasting and milk chocolate conching in the inactivation of Salmonella 5-strain suspension. Thermal resistance of Salmonella was greater in nibs compared to cocoa beans upon exposure at 110 to 130°C. The D-values in nibs were 1.8, 2.2 and 1.5-fold higher than those calculated for cocoa beans at 110, 120 and 130°C. There was no significant difference (p>0.05) between the matrices only at 140°C. Since in the conching of milk chocolate the inactivation curves showed rapid death in the first 180 min followed by a lower inactivation rate, and two D-values were calculated. For the first time interval (0-180 min) the D-values were 216.87, 102.27 and 50.99 min at 50, 60 and 70°C, respectively. The other D-values were determined from the second time interval (180-1440 min), 1076.76 min at 50°C, 481.94 min at 60°C and 702.23 min at 70°C. The results demonstrated that the type of matrix, the process temperature and the initial count influenced the Salmonella resistance.

Influência da fermentação e secagem de amêndoas de cacau no teor de compostos fenólicos e na aceitação sensorial

Due to the importance of the fermentation and drying stages in the sensory characteristics and in the phenolic content of cocoa products, the present study was carried out to evaluate the influence of the fermentation period and the type of drying of cocoa seeds, on the phenolic compounds content, as well as on the physical, physicochemical, and sensorial characteristics of the products. The periods of fermentation were 3 and 7 days and the fermented beans were dried naturally (sun drying) and artificially (under air circulation at 35 °C). The total phenolic compounds, flavan-3-ols and procyanidins content were quantified during fermentation and after drying. It was observed that most of the phenolic compounds were lost during the fermentation, and the beans that fermented for 3 days had higher levels of phenolic compounds. However, a significant loss in the sensorial quality was observed. The natural drying provided higher retention of phenols and the best sensorial results in comparison with artificial drying. The sensory evaluation, performed with a drink formulated with the liquor obtained from different treatments, showed that the product that fermented for 7 days presented the best sensorial notes, and the product dried naturally was considered the best among the others.

Revisão: Polifenóis em cacau e derivados: teores, fatores de variação e efeitos na saúde

O numero de estudos sobre os polifenois presentes no cacau tem aumentado consideravelmente nos ultimos anos, principalmente relacionando-os aos beneficios a saude humana. Mais recentemente, alguns trabalhos tem procurado prever o teor de polifenois em produtos derivados de cacau com base no teor de solidos desengordurados de cacau (SDC) e como o processamento afeta os polifenois do cacau. As compilacoes da literatura, em geral, aprofundam os mecanismos dos efeitos beneficos dos compostos fenolicos do cacau no organismo humano. Esta revisao fornece um panorama das principais pesquisas relacionadas aos altos teores de polifenois presentes no cacau e produtos derivados, bem como aos seus beneficios a saude. Alem disso, busca apresentar aspectos tecnologicos que influenciam o perfil dos compostos fenolicos durante as etapas de processamento. Pelas pesquisas cientificas, a destruicao dos compostos fenolicos naturalmente presentes nas sementes se da principalmente nas etapas realizadas para o desenvolvimento do sabor de chocolate, as quais favorecem a diminuicao da adstringencia e do amargor. Os polifenois, responsaveis pela capacidade antioxidante do cacau, sao drasticamente reduzidos durante a fermentacao das sementes e a alcalinizacao dos nibs e liquors, etapas que envolvem a ocorrencia de complexas reacoes bioquimicas ou uma significativa variacao do pH. A producao de chocolate ao leite ou amargo, excluindo o chocolate branco, apresenta um enorme potencial para inovacao tecnologica, visto a necessidade da manutencao destes compostos importantes para a saude, sem prejuizo do sabor agradavel, atributo esperado e de grande importância em produtos como o chocolate.O numero de estudos sobre os polifenois presentes no cacau tem aumentado consideravelmente nos ultimos anos, principalmente relacionando-os aos beneficios a saude humana. Mais recentemente, alguns trabalhos tem procurado prever o teor de polifenois em produtos derivados de cacau com base no teor de solidos desengordurados de cacau (SDC) e como o processamento afeta os polifenois do cacau. As compilacoes da literatura, em geral, aprofundam os mecanismos dos efeitos beneficos dos compostos fenolicos do cacau no organismo humano. Esta revisao fornece um panorama das principais pesquisas relacionadas aos altos teores de polifenois presentes no cacau e produtos derivados, bem como aos seus beneficios a saude. Alem disso, busca apresentar aspectos tecnologicos que influenciam o perfil dos compostos fenolicos durante as etapas de processamento. Pelas pesquisas cientificas, a destruicao dos compostos fenolicos naturalmente presentes nas sementes se da principalmente nas etapas realizadas para o desenvolvimento do sabor de chocolate, as quais favorecem a diminuicao da adstringencia e do amargor. Os polifenois, responsaveis pela capacidade antioxidante do cacau, sao drasticamente reduzidos durante a fermentacao das sementes e a alcalinizacao dos nibs e liquors, etapas que envolvem a ocorrencia de complexas reacoes bioquimicas ou uma significativa variacao do pH. A producao de chocolate ao leite ou amargo, excluindo o chocolate branco, apresenta um enorme potencial para inovacao tecnologica, visto a necessidade da manutencao destes compostos importantes para a saude, sem prejuizo do sabor agradavel, atributo esperado e de grande importância em produtos como o chocolate.

Characteristics of cocoa butter and chocolates obtained from cocoa varieties grown in Bahia, Brazil

Due to the attack of cacao (Theobroma cacao L.) plants by the fungus Moniliophthora perniciosa which caused witches’ broom disease in the state of Bahia, Brazil, resistant clonal material with elevated productivity and superior physical characteristics has been selected for use in the genetic improvement program and by the cocoa producers themselves. The present study aimed to characterize the cocoa butter and chocolates produced from nine cacao varieties and also from the Amelonado cacao produced in the same region (denominated as Common), with a view to quality improvement. The cocoa butter was characterized for its solid fat content and triacylglycerol composition, and the chocolates for their moisture and protein contents, maximum particle diameter, pH value, acidity, rheological properties and instrumental texture, as well as a sensory test for acceptability with 50 consumers. A relationship was found between the triacylglycerol composition and solid fat curves of the cocoa butters and the instrumental texture of the chocolates, the highest values for the latter parameter being observed for the varieties with greater amounts of symmetrical triacylglycerols and greater solid fat contents at the temperatures evaluated. From a sensory point of view, it was shown that overall acceptance and buying intention were mainly determined by the attributes of “astringency,” “bitterness,” “acidity” and “chocolate flavor.” It was also shown that chocolates produced from varieties descendent from the Trinitario group were differentiated from those descendent from the Forastero group, showing the preference of consumers for these materials and the possibility of a gain in quality in the genetic improvement of cacao by including varieties descended from the Trinitario and Criollo groups in the crossing programs, associating disease resistance with product quality.

Behavior of Salmonella during fermentation, drying and storage of cocoa beans

Due to cocoa being considered a possible source of Salmonella contamination in chocolate, the behavior of Salmonella during some cocoa pre-processing stages (fermentation, drying and storage) was investigated. The fermentation process was carried out on a pilot scale (2 kg beans/box) for 7 days. Every day a fermentation box was inoculated with a Salmonella pool (ca. 4 log MPN/g). The results showed that Salmonella did not affect (P>0.05) the growth of the main microorganism groups involved in cocoa fermentation. On the other hand, the pathogen was influenced (P<0.05) by yeast, acetic acid bacteria and pH. In spite of Salmonella showing counts ≤ 1 log MPN/g in the first days, at the end of fermentation it grew in all samples, reaching counts as high as 7.49 log MPN/g. For drying and storage, cocoa beans were inoculated during the fermentation (experiment A) or during the drying (experiment B). In these stages the decline of the water activity affected the pathogen behavior. In experiment A during the drying, Salmonella count increased in most of the samples. In experiment B either a slight growth or no growth in the samples inoculated up to 48 h was observed, whereas the other samples showed reductions from the initial count. After 30 days of storage at room temperature, the water activity decreased to 0.68, and reductions of Salmonella ranged from 0.93 to 2.52 log MPN/g. Despite the reductions observed during the storage, the pathogen was detected even after 120 days. Therefore, the results showed that Salmonella growth or survival depends on when the contamination occurs.

Differentiation of cocoa nibs from distinct origins using comprehensive two-dimensional gas chromatography and multivariate analysis

Headspace solid-phase microextraction (HS-SPME) combined with comprehensive two-dimensional gas chromatography was used for identification of volatiles compounds responsible for differentiation between cocoa nibs from Brazil and Ivory Coast. The unfolded GC×GC with Flame Ionization Detector (FID) chromatograms were first aligned using the correlation optimization warping (COW) algorithm and normalized. After that, Fisher ratio was calculated for each variable, and a threshold value was chosen to select the variables that best promote a separation of nibs samples from different sources in a principal component analysis (PCA) model. To identify the relevant compounds for the separation, representative samples of each source were analyzed in the same conditions by GC×GC with detection by quadrupole mass spectrometry. Finally, the average peak volumes for each key compound obtained for both classes were compared using a Student t-test and it was possible to identify 15 volatile compounds responsible for differentiation between cocoa nibs from Brazil and Ivory Coast.

Review: Polyphenols in cocoa and derivatives: factors of variation and health effects

O numero de estudos sobre os polifenois presentes no cacau tem aumentado consideravelmente nos ultimos anos, principalmente relacionando-os aos beneficios a saude humana. Mais recentemente, alguns trabalhos tem procurado prever o teor de polifenois em produtos derivados de cacau com base no teor de solidos desengordurados de cacau (SDC) e como o processamento afeta os polifenois do cacau. As compilacoes da literatura, em geral, aprofundam os mecanismos dos efeitos beneficos dos compostos fenolicos do cacau no organismo humano. Esta revisao fornece um panorama das principais pesquisas relacionadas aos altos teores de polifenois presentes no cacau e produtos derivados, bem como aos seus beneficios a saude. Alem disso, busca apresentar aspectos tecnologicos que influenciam o perfil dos compostos fenolicos durante as etapas de processamento. Pelas pesquisas cientificas, a destruicao dos compostos fenolicos naturalmente presentes nas sementes se da principalmente nas etapas realizadas para o desenvolvimento do sabor de chocolate, as quais favorecem a diminuicao da adstringencia e do amargor. Os polifenois, responsaveis pela capacidade antioxidante do cacau, sao drasticamente reduzidos durante a fermentacao das sementes e a alcalinizacao dos nibs e liquors, etapas que envolvem a ocorrencia de complexas reacoes bioquimicas ou uma significativa variacao do pH. A producao de chocolate ao leite ou amargo, excluindo o chocolate branco, apresenta um enorme potencial para inovacao tecnologica, visto a necessidade da manutencao destes compostos importantes para a saude, sem prejuizo do sabor agradavel, atributo esperado e de grande importância em produtos como o chocolate.O numero de estudos sobre os polifenois presentes no cacau tem aumentado consideravelmente nos ultimos anos, principalmente relacionando-os aos beneficios a saude humana. Mais recentemente, alguns trabalhos tem procurado prever o teor de polifenois em produtos derivados de cacau com base no teor de solidos desengordurados de cacau (SDC) e como o processamento afeta os polifenois do cacau. As compilacoes da literatura, em geral, aprofundam os mecanismos dos efeitos beneficos dos compostos fenolicos do cacau no organismo humano. Esta revisao fornece um panorama das principais pesquisas relacionadas aos altos teores de polifenois presentes no cacau e produtos derivados, bem como aos seus beneficios a saude. Alem disso, busca apresentar aspectos tecnologicos que influenciam o perfil dos compostos fenolicos durante as etapas de processamento. Pelas pesquisas cientificas, a destruicao dos compostos fenolicos naturalmente presentes nas sementes se da principalmente nas etapas realizadas para o desenvolvimento do sabor de chocolate, as quais favorecem a diminuicao da adstringencia e do amargor. Os polifenois, responsaveis pela capacidade antioxidante do cacau, sao drasticamente reduzidos durante a fermentacao das sementes e a alcalinizacao dos nibs e liquors, etapas que envolvem a ocorrencia de complexas reacoes bioquimicas ou uma significativa variacao do pH. A producao de chocolate ao leite ou amargo, excluindo o chocolate branco, apresenta um enorme potencial para inovacao tecnologica, visto a necessidade da manutencao destes compostos importantes para a saude, sem prejuizo do sabor agradavel, atributo esperado e de grande importância em produtos como o chocolate.

Formation of volatile compounds during cupuassu fermentation: Influence of pulp concentration

Cupuassu (Theobroma grandiflorum Schum) is a native fruit of the Amazon region and from its seeds fermentation, it is possible to obtain a product similar to chocolate, known as cupulate. The aim of this study was to evaluate the influence of the pulp concentration on the formation of volatile compounds during fermentation. Considering the high quantity of pulp that naturally involves the seeds (38%), which represents an obstacle for fermentation, two different fermentation experiments were conducted: with seeds totally (0%) and partially (15%) depulped. Seeds collected during and after fermentation, after drying (beans), after roasting and deshelling (nibs) and cupulates (obtained using the same methods of chocolate processing) were analyzed through identification and relative quantification by GC-MS in order to check the profile of volatile compounds formed. Results showed that the depulping implies in considerable reduction of important volatile compounds. A wider diversity of volatile compounds such as aldehydes, ketones and alcohols were found in the experiment with 15% pulp during fermentation. Tetramethylpyrazine was the unique pyrazine found in the cupulate samples that had significant difference (p<0.05) among the samples in its concentration. Among the others compounds identified, it is important to emphasize the presence of compounds with fruity and floral notes, generally present in fine/flavor cocoa. This study demonstrated the importance of the pulp in the development of important compounds responsible for the desirable flavor.

Plant and metagenomic DNA extraction of mucilaginous seeds

Graphical abstract Stages of sample treatment: (a) seeds in fermentation boxes; (b) frozen cupuassu beans; (c) maceration of beans with liquid nitrogen; (d) fat extraction under stirring with petroleum ether; and (e) initial step of DNA extraction process.