Evaluation of the effect of processing on cocoa polyphenols: antiradical activity,anthocyanins and procyanidins profiling from raw beans to chocolate

The content and composition of anthocyanins and procyanidins in fermented cocoa beans (from different geographic origins: Ecuador, Cameroon, Ivory Coast, Ghana and Nigeria), roasted nibs, cocoa mass and chocolate were determined, beside the determination of the total antiradical capacity. Concerning geographic origin, cocoa beans and processed products from Ecuador showed the highest levels of anthocyanins, followed by Nigeria and Cameroon. Generally, as cocoa beans were further processed, the levels of anthocyanins and flavan‐3‐ols decreased. The largest observed losses of phenolics occurred during roasting. A progressive decreasing trend in polyphenol concentration was observed in the other processed samples as well. Despite the original content of polyphenols in raw cocoa beans, technological processes imply a significant impact on cocoa quality, confirming the need of specific optimisation to obtain high value chocolate.     

The effect of supercooling on crystallization of cocoa butter-vegetable oil blends

The solid fat content (SFC), Avrami index (n), crystallization rate (z), fractal dimension (D), and the pre-exponential term [log(γ)] were determined in blends of cocoa butter (CB) with canola oil or soybean oil crystallized at temperatures (T _Cr) between 9.5 and 13.5°C. The relationship of these parameters with the elasticity (G′) and yield stress (σ^*) values of the crystallized blends was investigated, considering the equilibrium melting temperature (T _M ^o) and the supercooling (i.e., T _Cr ^o−T _M ^o) present in the blends. In general, supercooling was higher in the CB/soybean oil blend [T _M ^o=65.8°C (±3.0°C)] than in the CB/canola oil blend [T _M ^o=33.7°C (±4.9°C)]. Therefore, under similar T _Cr values, higher SFC and z values (P<0.05) were obtained with the CB/soybean oil blend. However, independent of T _Cr TAG followed a spherulitic crystal growth mechanism in both blends. Supercooling calculated with melting temperatures from DSC thermograms explained the SFC and z behavior just within each blend. However, supercooling calculated with T _M ^o explained both the SFC and z behavior within each blend and between the blends. Thus, independent of the blend used, SFC described the behavior of G′_eq and σ^* and pointed out the presence of two supercooling regions. In the lower supercooling region, G′_eq and σ^* decreased as SFC increased between 20 and 23%. In this region, the crystal network structures were formed by a mixture of small β′ crystals and large β crystals. In contrast, in the higher supercooling region (24 to 27% SFC), G′_eq and σ^* had a direct relationship with SFC, and the crystal network structure was formed mainly by small β′ crystals. However, we could not find a particular relationship that described the overall behavior of G′_eq and σ^* as a function of D and independent of the system investigated.     

可可粉固体饮料与HACCP体系的技术研究

为确保食品安全,提高可可粉固体饮料的产品质量,应用HACCP原理,对可可粉固体饮料生产过程中进行危害分析(HA),确定关键控制点(CCP),并制定和采取预防措施,是保证可可粉固体饮料产品质量的有效方法。     

Synthesis of Vegetable Fat Containing Chitosan Microparticles with Improved Physical and Delivery Properties

The present study describes the encapsulation of vegetable fats (cocoa butter and mango butter) within chitosan microparticles by double emulsion technique to prevent leaching of the internal apolar phase. Leaching studies suggested negligible leaching of the internal phase (～12–14%) when the fats were encapsulated as compared to the control (～40%). Fourier transform infrared spectroscopy and differential scanning calorimeter studies confirmed the successful encapsulation of fats. The release of drug (ciprofloxacin) from the microparticles was diffusion and erosion mediated and were capable to elicit antimicrobial activity against Escherichia coli. The study suggests that the developed microparticles have the potential for controlled delivery of antimicrobials.     

Mineral Oil Hydrocarbons (MOSH/MOAH) in Edible Oils and Possible Minimization by Deodorization Through the Example of Cocoa Butter

Mineral oil hydrocarbons (MOH) are present in many fats and oils as well as foods prepared thereof. A survey of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in different types of vegetable fats and oils is reported. Contents of MOSH/MOAH were quantified using liquid chromatography online‐coupled to gas chromatography with flame‐ionization detection (LC‐GC‐FID). Cocoa butter (n = 142) showed levels from <LOQ (2.5 mg kg^?1) to 162 mg kg^?1 ΣMOSH (sum of C10–C50) and <LOQ to 55 mg kg^?1 ΣMOAH, in palm oil (n = 21) ΣMOSH were quantified from <LOQ to 124 mg kg^?1 and ΣMOAH from <LOQ to 39 mg kg^?1. Sunflower oil showed lower levels: ΣMOSH were determined in the range of <LOQ to 17 mg kg^?1 and MOAH were not observed at all. A possible influence of deodorization and a subsequent minimization of MOSH/MOAH was investigated. Systematic model‐experiments were performed on laboratory scale using spiked cocoa butter. Significant minimization of volatile MOH subfractions ≤C24 were observed at a deodorization temperature of 210 °C. Deodorization can be considered as an important processing step to reduce or even remove volatile MOSH/MOAH ≤C24. Practical Applications: Regardless of their possible entry routes into the food chain, volatile fractions of MOSH/MOAH can be removed by deodorizing vegetable fats and oils. This model‐study identifies the temperatures of deodorization that provide a significant improvement toward minimization of undesired MOSH/MOAH.     

Contribution of triglycerides from cocoa butter to the physical properties of milkfat fractions

Milkfat was separated into major chainlength fractions by solid-phase extraction. The effect on thermal behavior and texture of replacing both saturated and monounsaturated long-chain triglycerides from milkfat by long-chain monounsaturated triglycerides with an unsaturated fatty acid in thesn-2 position is reported. Increasing proportions of cocoa butter were added to fractions of short-to medium-chain triglycerides (C₂₂−C₄₄) and medium- to long-chain triglycerides (C₃₆−C₄₈) isolated from milkfat. Thermal behavior and texture of the mixtures were measured. Results indicated that long-chain monounsaturated triglycerides from cocoa butter enhanced co-crystallization and co-operative melting and did not induce polymorphic transitions upon crystallization and melting of the fractions. At 4°C, they acted as texture builder if present in proportions of more than 30%, whereas below this level, they acted as texture softeners. The effect of the long-chain monounsaturated triglycerides on the texture of fractions that melt at low temperature could not be predicted from the proportion of solid fat at that temperature. Presented at the 1995 AOCS Annual Meeting & Expo, San Antonio, Texas, May 1995.     

无溶剂系统酶促POMF连续化酯交换反应生产类可可脂研究

通过填充床酶反应器中POMF与SME酯交换生产类可可脂(CBE)连续化反应实验,研究空速对产率(R)和连续化特异性酯交换能力(CSIV)影响。当SI为0.54时,R值为121％,比产量(PE)为3.99 g·g～1·h-1。经过差示扫描量热法(DSC)分析,产品热性能符合类可可脂质量要求。     

Preparation of sharp-melting hard palm midfraction and its use as hard butter in chocolate

Preparation of hard palm midfractions (PMF) and its use as a cocoa butter equivalent ingredient were studied. Hard PMF is obtained by multistep fractionation of palm oil involving dry fractionation (DF) and/or solvent fractionation (SF), usually using hexane or acetone. From our experience, in acetone, a polar solvent, symmetrical 1,3-disaturated triacylglycerols tend to selectively crystallize more than nonsymmetrical 1,2- or 2,3-disaturated triacylglycerols, making it suitable for obtaining the solid midfraction. Unfortunately, triacylglycerols are very soluble in hexane, and temperatures at least 15 degrees lower than those required for acetone must be used for equivalent crystal yields. On the other hand, DF is a less expensive and safer process. Thus, multistep fractionation combining DF and SF using acetone was developed to achieve sufficient removal of high-melting components, and further enrichment of 1,3-dipalmitoyl-2-oleoylglycerol and the hard PMF was obtained by triple-step fractionation of palm olein or double-step fractionation of soft PMF. Compared to conventional hard PMF, this hard PMF had a steeper melting curve and better snapping and sharp-melting qualities when used in chocolate. Heat resistance of the hard PMF chocolate was similar to the conventional hard PMF chocolate, and its bloom resistance could be improved by adding polyglycerol fatty acid esters.     

几种真菌油脂的分析

在实验室条件下培养提取所得的几种真菌油脂经水解后进行薄层层析 ,结果表明油溶性成分因菌种而异 ;脂肪酸分析表明在不同培养条件下菌种脂结构也不同 ;对土生假丝酵母在优化条件下合成的类可可脂经甘三酯组成测定和差示扫描量热法分析 ,证明了此条件下所产的类可可脂是较理想的类可可脂     

Factors affecting instant properties of powdered cocoa beverages

The increasing number of small and medium scale manufacturers of powder cocoa beverages (PCBs) in Nigeria requires relevant technical data useful in designing new and value added products from cocoa powder. This paper reports a preliminary study carried out to determine how some physical and chemical factors relate to the instant properties of some commercial samples of PCBs produced in Nigeria. The levels of chemical component like moisture, fat and sugar in the PCBs varied from 0.8% to 3.6%, 2.0% to 10.4% and 52.4% to 90.5%, respectively. Physical properties like the bulk density, angle of repose, average particle size and uniformity index of the products varied from 0.49 to 0.81 g/cm³, 25.0° to 37.7°, 0.031 to 0.796 mm and 6.25 to 7.44, respectively. Instant properties such as wettability, dispersibility and solubility ranged from 10.7 to 21.7 s, 50.0% to 94.5% and 44.2% to 76.6%, respectively. These properties differed significantly (p < 0.05) among the 10 commercial samples of PCB studied. Sugar (sucrose) content of products had the most significant (p < 0.05) main effect on their instant properties followed by the fat content. Wetting time showed a significant (p < 0.05) negative linear correlation with sugar content. Agglomeration increased the average particle size, which correlated negatively with uniformity index. The instant properties of fine PCBs (average particle size <0.294 mm) were more predictable than the agglomerated samples.