Über das Rösten von Kakaobohnen II

Roasting of Cocoa Beans II The results of comprehensive studies on isolated aroma precursors of raw cocoa and the relationships between optimum development of aroma and material changes during roasting of disintegrated cocoa cotyledon under specific conditions are initially discussed. From a practical viewpoint, experiments carried out on the roasting of raw cocoa kernels of uniform particle size are reported. Sensory characteristics of optimum cocoa aroma and modes of influencing the latter by altering the processing parameters are discussed. Experimental chocolates, prepared from kernel materials which were roasted under optimum conditions, have excellent aroma quality and aroma intensity.     

Application of Response Surface Methodology to Optimize Roasting Conditions in Cocoa Beans Subjected to Superheated Steam Treatments in Relevance to Antioxidant Compounds and Activities

Roasting is an essential technological process used to produce high-quality cocoa-based products. Response surface methodology (RSM) was employed to optimize the roasting conditions in cocoa beans based on antioxidant compounds (total phenolic, total flavonoids) and their activity (percentage inhibition of 1,1-diphenyl-2-picrylhydrazyl [DPPH] radical and ferric-reducing antioxidant power assay) using two variables: temperature and time. Cocoa beans were roasted at temperature ranging between 150 and 250°C for 10–50 min using superheated steam. The effects of the roasting conditions on the antioxidant properties of cocoa beans were investigated using a second-order central composite design. Results showed that roasting temperature and time significantly affect antioxidants in cocoa beans. Numerical optimization and superimposed contour plots suggested the optimal roasting conditions to be 192°C for temperature with 10 min of roasting time (R ² = 0.99). These conditions can be used for roasting of cocoa beans to produce high-quality cocoa products in terms of antioxidant properties.     

Das physikalische Verhalten und die chemischen Zusammensetzung von Schokolade,Kakaobutter und einigen Kakaobutter-Austauschfetten

Physical Behaviour and Chemical Composition of Chocolate, Cocoa Butter and Some Cocoa Butter Substitutes Cocoa butter, which forms the continuous phase in the dispersed system of chocolate, is responsible for the most important properties of the latter. Such properties and methods for determining the same are treated exhaustively. Physical properties of cocoa butter and its substitutes, as well as the relationship between their physical behaviour and chemical composition are discussed. Fats that can replace cocoa butter satisfactorily, have a chemical composition which is similar to that of cocoa butter, Such substitutes are available and fairly good quality chocolates can be prepared from them. Determination of fatty acid composition and aniline point are adequate for ascertaining, whether a fat is suitable as cocoa butter substitute.     

Zur Spezifität des Kakaoaromas

Specificity of Cocoa Aroma Aroma precursors in crude cocoa from Ghana were separated into substance classes and their significance in aroma formation was examined. Coaction of a peptide, which was isolated and characterized for the first time, is especially necessary for the specific reaction which occurs via a side path of Maillard-reaction. Furthermore, aroma formation in other varieties of cocoa was studied on the basis of precursors. From chemical viewpoint the 310 aroma components known so far were classified and compared with other food aromas in order to obtain information on the specific components.     

Production of cocoa butter-like fat from interesterification of vegetable oils

Cocoa butter-like fat was prepared from completely hydrogenated cottonseed and olive oils by enzymatic interesterification. The optimum reaction time to produce the major-component of cocoa butter, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS), was 4 hr. The cocoa butter-like fat was isolated from the reaction mixture by two filtration steps. The yield of cocoa butter-like fat was 19%, based on the weight of the original oils. Chromatographic analysis of the product by reversephase high-performance liquid chromatography (HPLC) has shown it contains triglyceride components similar to those of cocoa butter, but that it has slightly more diglycerides. The melting point of this product, as measured by a differential scanning calorimeter, is 39°C, which compares well to the 36°C melting point of natural cocoa butter. Presented in part at the AOCS meeting in Cincinnati, Ohio, in 1989.     

Kontinuierliches Verfahren zum Abpressen von gerösteten Kakaobohnen

Continuous Processes for Pressing out of Roasted Cocoa Beans Cocoa butter, that has been extracted by the pressing out of roasted cocoa beans, is required for the manufacture of chocolate products. So far the cocoa beans have been pressed out by means of discontinuous operational hydraulic presses, whereby, for the pressing process, a specific processing for the preparation of the raw cocoa beans is required. This pressing method is opposed to a method which utilizes a continuous operational cage screw press. The comparison shows, that by means of the continuous pressing method the number of units is reduced, that it is energy saving and that a straightforward control and supervison of the process is possible.     

Crystallization of Cocoa Butter in Cocoa Powder

Cocoa powder quality is determined by its color, flavor, dispersion, and flow properties, which can be controlled via tempering. Design of a cocoa powder tempering profile, however, requires that the mechanism of cocoa butter crystallization in cocoa powder be fully understood. Low-fat (8–12%) and high-fat (20–24%) cocoas were sourced from two commercial manufacturers at varying degrees of alkalization and compared with two commercial cocoa butters. Unrefined paired cocoa powders and cocoa butters sampled from the hydraulic press were also evaluated. Isothermal crystallization kinetics and polymorphism of cocoa powders and cocoa butters were compared at 18, 21, and 24 °C using a direct time-domain nuclear magnetic resonance method, differential scanning calorimetry, and x-ray diffraction. Crystallization was also studied under dynamic tumbling conditions. It was found that cocoa butter in cocoa powder was nucleated by the cocoa powder matrix and transitioned to higher-stability polymorphs more rapidly than bulk cocoa butters. High-fat cocoas also exhibited enhanced crystallization kinetics relative to low-fat cocoas, showing that differences in the cocoa microstructure may influence crystallization behavior. Notably, alkalization did not significantly affect the crystallization behavior of most cocoa powders. Finally, it was found that tumbling conditions led to crystallization of βV and that caking, especially of high-fat cocoas, could be reduced by a static low-temperature hold step prior to tumbling. Overall, these results demonstrated that crystallization of cocoa butter in cocoa powder is influenced both by the intrinsic attributes of the cocoa powder as well as the conditions of the tempering process.     

Quantitativer Nachweis von Milchfett in Schokoladenmischungen I: Bestimmung von Milchfettanteilen in Kakaobutter

Quantitative Detection of Milk Fat in Chocolate Mixtures I: Determination of Milk Fat in Cocoa Butter New methods for the quantitative determination of milk fat proportions in cocoa butter samples based on gas chromatographic analysis of fatty acids and triglycerides are described. 45 different cocoa butter types from 25 countries and 755 milk fat samples were analyzed by taking different feeding conditions into account. By means of triglyceride measurements mean relative deviations of approximately 5% from the 2–10% milk fat additions were established for known cocoa butter- and unknown milk fat composition. With completely unknown initial fats a mean relative deviation of approximately 6% was measured using fatty acid analysis.     

Stabilisierung von Kakaobutterersatzfetten

Stabilization of Cocoa Butter Substitute Fats There is an increasing interest in cocoa butter substitute fats, mainly in cocoa butter exchange fats (also called CBE-cocoa butter equivalent). The industry for chocolates and sweets depends on substitute fats of highest quality. The quality estimation of CBE depends on its stability and mixability with cocoa butter (similarities of physical and chemical properties). The stability of cocoa butter substitute fats can be increased to the level of cocoa butter by the ingrediences as tocopherol and lecithine, admitted in the industry for chocolates.     

Über die Kristallstruktur der Kakaobutter

Crystalline Structure of Cocoa Butter Six crystalline modifications of cocoa butter are known from the literature of which only the pre-beta and the beta forms are important for the technology of chocolate manufacture. The elucidation of the crystalline structure of these two modifications is difficult because single crystals of appreciable size can not be obtained from cocoa butter. It is shown that it is possible to analyse the structure with the help of X-ray diffraction studies of micro-crystals as well as by comparison with structures of known mono-acid triglycerides. The lattice parameters and the arrangement of molecules in pre-beta and beta forms are given.     

Neue Erkenntnisse zur Kristallstruktur von Kakaobutter

New Understandings about The Crystal Structure of Cocoa Butter Result of x-ray structure investigations of congealed chocolate and cocoa butter samples are discussed in connections with their thermal treatment and process conditions during tempering, congealing and storage. In its central point is the enlightenment of crystal structure of congealed pure cocoa butter as well as of cocoa butter free of fat substitutes in chocolate mass. The experiments give new understandings about the formation of β-modification of cocoa butter in dependence on process and storage conditions.     

Die Herstellung von Kakaoerzeugnissen unter Anwendung von Pflugscharmischern

Manufacture of Cocoa Products Using Plough Share Mixers Various problems arise during mixing and thermal treatment of powdered material in the production and further processing cocoa powder. Means for solving such problems are shown. An effective process of mixing and the plough share mixers used for the same are described; these nearly automatic mixers are widely applicable. A further development of these mixers, the so-called DRUVATHERM-units, enable the combination of several mechnical processes, such as mixing, pulverizing of agglomerates, moistening, coating, tempering, cooling, drying and carrying out reaction processes under pressure or vacuum and at higher temperature. These new type of units can compete with conventional driers and roasters. They open new economical paths in the conventional treatment of products in cocoa industry as well.     

DSC-Thermoanalyse und Kinetik der Kristallisation von Kakaobutter

DSC-Thermal Analysis and Kinetics of Cocoa Butter Crystallization A DSC method for isothermal crystallization of cocoa butter is described. The crystallization curves may be linearized according to the empirical Avrami equation. From the resulting Avrami plots the rate constant of crystallization may be calculated. This method gives valuable results about the specific crystallization tendency of cocoa butters of different origins and about temperature influence on crystallization times. The method seems to be useful for quality control of cocoa butters and for process control during the tempering step of the industrial chocolate production.     

Effects of various roasting conditions on acrylamide,acrolein, and polycyclic aromatic hydrocarbons content in cocoa bean and the derived chocolates

The effect of roasting parameters such as the temperature (135 and 150°C) and relative humidity of air (RH of 0.3 and 5.0%) on acrylamide, acrolein, and polycyclic aromatic hydrocarbon (PAH) levels in whole and crushed cocoa beans and chocolates derived from these beans was studied. Acrylamide was identified in all tested samples of roasted cocoa beans, irrespective of process conditions. Its contents in chocolates produced from these beans were similar. The highest acrylamide concentration was found in whole cocoa beans roasted at 135°C and RH of 5.0%. Small amounts of acrolein were present only in the roasted whole cocoa beans while neither the roasted crushed cocoa beans nor chocolates contained this aldehyde. Roasting conditions significantly affected the profile and content of PAHs in whole and crushed cocoa beans and the richest in PAHs were crushed cocoa beans roasted at 150°C and RH of 5.0%. The chocolates obtained in this study contained significantly higher concentrations of PAHs than the roasted cocoa beans used for their production. The results of the study demonstrate that optimization of roasting conditions may reduce levels of all these harmful substances in cocoa beans.     

Cocoa butter extenders from Kokum (Garcinia indica) and Phulwara (Madhuca butyracea) butter

Cocoa butter extenders, suitable for use in chocolate and confectionery, were prepared from Kokum fat and a Phulwara butter fraction. The latter fraction was prepared from Phulwara butter by two-stage dry fractionation and blended with Kokum fat in selected proportions to obtain a series of hard butters with different melting profiles. The blends with higher proportions of Kokum fat were harder and hence may find application in warm climates. The blends with higher proportions of Kokum fat were harder and hence may find application in warm climates. The blends had solidification properties, fatty acid and triacylglycerol compositions similar to those of cocoa butter. In addition, they had narrow melting ranges like cocoa butter, and they were compatible with cocoa butter and have tolerance toward milk fat.     

Polyphenols from Cocoa and Vascular Health��A Critical Review

Cocoa is a rich source of dietary polyphenols. In vitro as well as cell culture data indicate that cocoa polyphenols may exhibit antioxidant and anti-inflammatory, as well as anti-atherogenic activity. Several molecular targets (e.g., nuclear factor kappa B, endothelial nitric oxide synthase, angiotensin converting enzyme) have been recently identified which may partly explain potential beneficial cardiovascular effects of cocoa polyphenols. However cocoa polyphenol concentrations, as used in many cell culture studies, are not physiologically achievable. Bioavailability studies indicate that plasma concentrations of cocoa polyphenols following dietary intake are low and in the nanomolar range. Human studies regarding the effect of cocoa polyphenols on vascular health are often underpowered and lack a rigorous study design. If dietary cocoa polyphenol intake is due to chocolate its high energy content needs to be taken into account. In order to determine potential health benefits of cocoa polyphenols large scale, long term, randomized, placebo controlled studies, (ideally with a cross-over design) as well as prospective studies are warranted.     

Lipid and hardness characteristics of cocoa butters from different geographic regions

Twenty-four commercially pressed cocoa butters and 39 laboratory solvent extracted cocoa butters were evaluated. A rapid method using differential scanning calorimetry (DSC) was used to evaluate the hardness of small quantities of cocoa butter. In the DSC thermogram of a quenched sample, the percentage area under the polymorph II endotherm had a positive correlation (r=0.74) with the mechanical hardness. Soft cocoa butters were characterized by high POO, SOO content (P=palmitic acid, O=oleic acid, S=stearic acid), high iodine value, low percentage, area under the polymorph II endotherm from the DSC scanning, and low SOS. Hard cocoa butters displayed opposite characteristics. In general, South American cocoa butters were the softest and had a 37.03 iodine value, a total of 9.1% POO and SOO, and a 26.4% area under the polymorph II endotherm. Cocoa butters from Asia and Oceania were the hardest and had a 34.74 iodine value, a total of 4.1% POO and SOO, and a 35.65% area under the polymorph II endotherm. North and Central American and African cocoa butters were intermediate in hardness characteristics.     

Solidification of cocoa butter

Cocoa butter and other confectionery fats do not behave alike on molding. Explanations for the behavior of cocoa butter generally are unavailable. The linear contraction of molded cocoa butter on solidification under various conditions was determined. Maximum linear contraction of about 2% was measured when a well-seeded sample was solidified at 16C. Nearly all of this contraction occurred during the first half hour. A theoretical explanation for this contraction was developed. Linear contraction takes place after the well-seeded cocoa butter has solidified in the next-to-highest melting form and while this solid form is transforming to the most stable polymorph. Addition information was developed on the polymorphic forms of cocoa butter, the permanence of seed crystals at various temps, rates of solidification, and solidification characteristics of unseeded cocoa butter. The data were obtained by dilatometric examination of a small sample using a volumetric dilatometer and direct measurement of linear contraction during solidification in a mold. Presented at the AOCS Meeting in Atlanta, April, 1963.     

Characterization of cocoa butter extracted from hybrid cultivars of Theobroma cacao L

Cocoa butter is the most important fat used in the confectionery and chocolate industries. The main objective of the present study was to determine the physical and chemical characteristics of cocoa butter extracted from hybrid cultivars belonging to the germplasm bank of the Fondo Nacional de Investigaciones Agropecuarias (National Foundation for Agricultural Research). AOAC methods were used for the assessment of the proximal composition of the beans, physical and chemical characteristics as well as for the fatty acid profile of the fat. It was found that there were statistical differences in the proximate composition of the cocoa beans among the cultivars studied as well as the iodine and saponification indices of the butter. Saturated fatty acids were present in higher proportions than unsaturated fatty acids, with palmitic and stearic acid as the main fractions. Oleic acid content was higher than linoleic acid. The fatty acid profile found is the main factor that influences the hard texture of the cocoa butter from Venezuelan cocoa hybrids cultivars.