Review of cocoa butter and alternative fats for use in chocolate—Part A. Compositional data

This work reviews the literature on the compositional data of vegetable fats used or proposed as alternatives to cocoa butter in chocolate and confectionery products. Cocoa butter is the only continuous phase in chocolate, thus responsible for the dispersion of all other constituents and for the physical behaviour of chocolate. Unique to cocoa butter is its brittleness at room temperature and its quick and complete melting at body temperature. There were, and are, strong efforts to replace cocoa butter in part for chocolate production for technological and economic reasons. Such cocoa butter alternatives are the so-called cocoa butter equivalents (CBEs), cocoa butter substitutes (CBSs) and cocoa butter replacers (CBRs). These are mostly mixtures of various vegetable fats (often modified) and can consist of palm and palm kernel oil, illipé fat, shea butter, sal fat and kokum butter. In addition, a large variety of other vegetable oils can be used. Their composition according to triglycerides, fatty acids, sterols and other unsaponifiable components is discussed in this report.     

Composition and thermal analysis of ternary mixtures of avocado fat:palm stearin:cocoa butter (Avo:PS:CB)

Avocado fat is a semi-solid substance with potential functional lipid characteristics. A study was carried out to evaluate the effect of addition of palm stearin and cocoa butter on the solidification behavior of avocado fat to formulate a mixture to become similar to lard. A total of three mixtures were prepared: avocado fat:palm stearin:cocoa butter (88:7:5), avocado fat:palm stearin:cocoa butter (86:7:7), avocado fat:palm stearin:cocoa butter (84:7:9; w/w), and identified by the mass ratio of avocado fat to palm stearin and cocoa butter. The fat mixtures were compared with lard in terms of the fatty acid and triacylglycerol compositions using gas chromatography and high-performance liquid chromatography, thermal properties using differential scanning calorimetry and solid fat content using p-nuclear magnetic resonance. Although there were considerable differences between lard and the fat mixtures with regard to fatty acid and triacylglycerol compositions, some similarities were seen with regard to thermal properties and solid fat content profile. Of all the fat mixtures, avocado fat:palm stearin:cocoa butter (84:7:9) displayed closer similarity to lard with respect to thermal transitions at –3.59°C and its solid fat content profile showed the least difference to that of lard throughout the temperature range measured.     

The advantages of solid fat content determination in cocoa butter and cocoa butter equivalents by the Karlshamns method

This paper describes the preparation of samples and the evaluation techniques applied to determine the Solid Fat Content (SFC) by means of pulsed nuclear magnetic resonance (NMR) in confectionery fats characterized by distinct polymorphism (cocoa butter, cocoa butter equivalents and their mixtures). Due to the deviation of SFC values in certain softer cocoa butter equivalents at the temperature of 20 °C, an internal method devised at Karlshamns Oils & Fats AB is applied as well. When compared to the official IUPAC 2.150 (b) method, Karlshamns' method involves a lower temperature and a prolonged period of time at the stage of the final SFC stabilization in the pre-treatment of fat samples. The calculation of SFC in the analysed samples for the purposes of this paper was carried out by employing both methods (the indirect method and a serial procedure). The results are presented graphically. Differences were reflected in the SFC of the fats and their mixtures that were under observation depending on the method and temperatures applied. The obtained results indicated a considerable advantage of employing the Karlshamns method since the results yielded by this method are more lucid. Moreover, the behaviour of fats in the production process can be more easily predicted on the basis of these results.     

Production of stearate-rich butters by solvent fractionation of high stearic–high oleic sunflower oil

Cocoa butter equivalents (CBEs) are fats with a similar composition and melting profile as cocoa butter (CB), which are usually prepared by blending mid-palm fractions and stearate-rich tropical butters. In this regard, high stearic–high oleic sunflower oil contains disaturated triacylglycerols typically present in CBEs, albeit at a lower concentration than that required to produce a solid fat. Here we have assessed a means to fractionate this oil in order to produce solid fractions that can be used as stearic acid-rich butters appropriate for CBE formulations. Solvent fractionation of high stearic–high oleic sunflower oil was optimised in function of the oil/solvent ratio and temperature. Sunflower stearins with similar melting profiles as cocoa butter were obtained from oils of either 17% or 20% stearic acid in a single step. Different stearin products can be obtained by controlling the oil/solvent ratio and the temperature of fractionation. The use of these fractions as CBE components or confectionery fats is discussed in function of their melting profiles.     

Effect of nut oil migration on polymorphic transformation in a model system

Fat migration in confectionery products can lead to significant deterioration in quality. This occurs not only through loss in texture contrast between chocolate and filling but also through the appearance of fat bloom on the surface of the chocolate. This latter aspect is often, although not exclusively, linked to the transformation of the cocoa butter β_V phase into β_VI. In this study, the influence of hazelnut oil on the polymorphic transformation of cocoa butter has been determined, showing that even small additions (1%) of nut oil can have a significant impact on the rate of transformation. Additionally, use of a model system has shown that polymorphic transformation in cocoa butter is linked to the degree of migration of nut oil from a filling. Portions of the cocoa butter close to the filling experience both greater degrees of migration and faster transformation.     

Evaluation of high oleic-high stearic sunflower hard stearins for cocoa butter equivalent formulation

Cocoa butter equivalents (CBEs) are produced from vegetable fats by blending palm mid fraction (PMF) and tropical butters coming from shea, mango kernel or kokum fat. In this regard, high oleic-high stearic (HOHS) sunflower hard stearins from solvent fractionation can be used in CBE production since their compositions and physical properties are similar to those found in the above-mentioned tropical butters. In this work, three sunflower hard stearins (SHS) ranging from 65% to 95% of disaturated triacylglycerols and a shea stearin (used as reference) were blended with PMF to evaluate their potential use in CBEs formulation. Isosolid phase diagrams of mixtures of PMF/SHS showed eutectic formation for SHS 65 and SHS 80, but monotectic behaviour with softening effect for SHS 95. Three CBEs from SHS and shea stearin were formulated according to phase behaviour diagrams and solid fat content data at 25 °C. Isosolid phase diagrams of mixtures of these CBEs with cocoa butter showed no eutectic behaviour. Therefore, CBEs elaborated from SHS exhibited full compatibility with cocoa butter.     

Physical properties of tempered mixtures of cocoa butter,CBR and CBS fats

Physical characteristics of precrystallised binary mixtures of cocoa butter (CB) and 5, 10, 15, 20, 25 and 30% (w/w) cocoa butter replacer (CBR) or cocoa butter substitute (CBS) were determined. The lipid composition was obtained by chromatography and the solid fat content (SFC) by nuclear magnetic resonance. Tempering was carried out using a lab‐scale agitated jacket vessel reactor. Bars made with tempered samples were submitted to X‐ray diffraction and rupture tests. Snap values of crystallised mixtures decrease with an increase in the amount of alternative fat. X‐ray diffraction patterns confirmed the predominant formation of the beta polymorph habit for CB and beta prime form for CBR and CBS. Mixtures of CB and CBR exhibit chemical compatibility. The knowledge of the snap values and of the variation of SFC with temperature proved to suffice to adequately anticipate the influence of the addition of alternative fats on chocolates physical attributes.     

巧克力食品中可可脂及其代用品的鉴别研究

巧克力食品中的常用油脂主要包括天然可可脂、类可可脂、代可可脂和乳脂,采用高温气相色谱法对这四种油脂的甘油三酯组成进行分离。结果表明,天然可可脂与类可可脂的甘油三酯组成较相似,但与代可可脂完全不同,乳脂的甘油三脂组成非常复杂,以其特殊的峰型区别于其它各脂。通过甘油三酯组成的谱图特征可快速、直观地鉴别出这四种油脂。实际应用可区分市售可可脂巧克力和代可可脂巧克力。     

Investigation of changes in formulation and processing parameters on the physical properties of cocoa butter emulsions

The aim of this work was to understand the physical characteristics of cocoa butter water in oil emulsions made using a process typically used for margarine production (a scraped surface heat exchanger and pin stirrer). Processing parameters were manipulated, and the effect of aqueous phase volume, polyglycerol polyricinoleate (PGPR) concentration, and the addition of a hydrocolloid to the aqueous phase were investigated. This process allowed small droplets to be formed (3–5 μm). Tempering could also be mimicked, with the temperature of the units affecting the polymorphic form of cocoa butter produced. Sintered crystalline shells were observed at the oil/water droplet interface, acting as Pickering particles. This work highlights the potential for the use of cocoa butter emulsions to give fat reduction in chocolate, using a one step process to achieve emulsification and to mimic tempering.     

Identification of cocoa butter equivalents added to cocoa butter I. An approach by fatty acid composition of the triacylglycerol sub-fractions separated by Ag+-HPLC

 Separation of the six sub-fractions of triacylglycerols (TAG) from cocoa butter, three cocoa butter equivalents (CBEs: calvetta, choclin and coberine) and their mixtures was carried out by silver ion high-performance liquid chromatography. The percentage fatty acid composition of all these sub-fractions was then measured by high-resolution gas chromatographic analysis of the methyl esters of the constitutive fatty acids. In particular, the percentage quantities of all acids in the fully saturated sub-fraction of pure fats and some of their mixtures were evaluated as a function of the percentage CBEs added to cocoa butter in order to devise multiple regression models. The aim was to obtain statistical tools for the identification and/or quantification of added CBEs. The results obtained show the effectiveness of TAG sub-fraction percentage fatty acid composition data for the purposes of research, as well as the potential use of stereospecific analysis of the same sub-fractions. In fact, the stereospecific analysis of TAG fractions from cocoa butter and CBEs already carried out has enabled observation of the different distributions of various fatty acids in the glycerol backbone of TAG from cocoa butter and the CBEs under study, and this will certainly result in the development of more powerful and discriminating statistical models. Received: 12 August 1997 / Revised version: 19 December 1997     

Solid Fat Content,Pre-Crystallization Conditions,and Sensory Quality of Chocolate with Addition of Cocoa Butter Analogues

The objective of this study was to determine how the addition of two cocoa butter equivalents and cocoa butter improver affect the physical and sensory properties of chocolate. The laboratory-made chocolate samples were tempered at three different pre-crystallization temperatures (25, 27, and 29°C), using different concentrations (3, 5, and 7%) of two commercial cocoa butter equivalents as well as commercial cocoa butter improver of the chocolate. The nucleation time of the chocolate mass primarly depended on pre-crystallization temperature while the value of maximum torque of chocolate mass were influenced by both, pre-crystallization temperature and concentration of fats. Sensory evaluation revealed that cocoa butter equivalents were acceptable in chocolate formulation without producing a negative impact on the sensory quality, while usage of improver required adjustment of raw formulations or process parameters. The results of the instrumentally measured hardness revealed that addition of cocoa butter improver significantly (p > 0.05) increased hardness of chocolate samples.     

Identification of cocoa butter equivalents added to cocoa butter I. An approach by fatty acid composition of the triacylglycerol sub-fractions separated by Ag+-HPLC

 Separation of the six sub-fractions of triacylglycerols (TAG) from cocoa butter, three cocoa butter equivalents (CBEs: calvetta, choclin and coberine) and their mixtures was carried out by silver ion high-performance liquid chromatography. The percentage fatty acid composition of all these sub-fractions was then measured by high-resolution gas chromatographic analysis of the methyl esters of the constitutive fatty acids. In particular, the percentage quantities of all acids in the fully saturated sub-fraction of pure fats and some of their mixtures were evaluated as a function of the percentage CBEs added to cocoa butter in order to devise multiple regression models. The aim was to obtain statistical tools for the identification and/or quantification of added CBEs. The results obtained show the effectiveness of TAG sub-fraction percentage fatty acid composition data for the purposes of research, as well as the potential use of stereospecific analysis of the same sub-fractions. In fact, the stereospecific analysis of TAG fractions from cocoa butter and CBEs already carried out has enabled observation of the different distributions of various fatty acids in the glycerol backbone of TAG from cocoa butter and the CBEs under study, and this will certainly result in the development of more powerful and discriminating statistical models. Received: 12 August 1997 / Revised version: 19 December 1997     

Physicochemical properties and antioxidant activity of a synthetic cocoa butter equivalent obtained through modification of mango seed oil

This research describes the interesterification of Malaysian mango seed oil (MSO) and palm oil mid‐faction (POMF) to develop a cocoa butter equivalent. Fat blends, formulated by binary blends of palm oil mid‐fraction and mango seed oil at different ratios ({100:0}, {60:40}, {50:50}, {40:60}, {0:100}), were subjected to enzymatic interesterification. The solid fat content revealed that all interesterified blends except 100% POMF {0:100} melted completely at body temperature. The interesterified {50:50} blend exhibited a slip melting point (30.35 °C) and saponification value (186.89) close to cocoa butter (P < 0.05). Thermal behaviour analysis by differential scanning calorimetry showed fusion and crystallisation behaviour similar to cocoa butter. Moreover, both the blend and cocoa butter scavenging abilities were based on the 2,2‐diphenyl‐1‐picrylhydrazyl assay, with the concentration required to reduce radical absorbance by 50% (IC₅₀) of 43.08% and 41.1%, respectively. Therefore, the MSO: POMF blend may have use as a health‐promoting food in human diets.     

制备类可可脂原料用油的研究进展

近年来,巧克力市场逐年壮大,可可脂的需求也随之不断增加。而可可脂产量有限,加之成本较高,可可脂替代品成为学者和商家研究的热点。其中,类可可脂以其特有的优势,成为可可脂替代品中独具特色的一种。对制备类可可脂的原料用油进行了归纳总结,分别从类可可脂的制备方法、原料油脂组成及其相关研究方面对原料油脂进行了概述,从而加深对类可可脂的了解。     

纯脂巧克力用脂及其分析、应用研究进展

近年来纯脂巧克力日渐受欢迎,但可可原料面临产量有限且不稳定的制约因素,限制了纯脂巧克力的发展。作为与可可脂组分及特性最为接近的可可脂替代品,类可可脂的原料来源广泛,产品稳定性有提升空间,并且在提升纯脂巧克力品质方面有改善作用,因此类可可脂的相关研究也获得国内外广泛关注。通过对可可脂及类可可脂的组成、结晶特性、分析方法及纯脂巧克力的耐霜、抗热品质改善等方面进行综述,以期对纯脂巧克力用脂、巧克力品质改善等提供相关参考。     

Characteristics of palm mid-fractions produced from different fractionation paths and their potential usages

Three palm mid-fraction (PMF) groups produced from different fractionation paths were analyzed in terms of the fat, triacylglycerol and sn-2 fatty acid compositions, thermal properties (melting and crystallization behaviors, and solid fat contents (SFCs)), micronutrient levels and oxidative stability indexes (OSIs) to achieve their sufficient utilization. PMF-A (iodine value (IV), 48.4 g/100 g) fractionated from palm olein contained 43.8% 1,3-dipalmitoyl-2-oleoyl-glycerol (POP) and 16.7% 1-palmitoyl-2,3-dioleoyl-glycerol, showing soften properties (slip melting point (SMP), 27.6°C; SFC at 30°C, 2.2%) at hot weather. PMF-B (IV, 42.3 g/100g) obtained from palm stearin showed similar fat and triacylglycerol compositions as PMF-A, but the high 1,2,3-tripalmitoyl-glycerol level (6.2%) improves its thermal behaviors (SMP, 34.9°C; SFC at 30°C, 13.8%). The SFC profiles of PMF-A and PMF-B were comparable to those found in frozen and puff margarine shortenings. Furthermore, both of the PMF groups exhibited excellent OSIs (13.2 and 11.2 h, respectively) because of their high micronutrient levels (especially γ-tocopherol and campesterol). In general, γ-tocopherol and campesterol contribute to preventing lipids from oxidation under frying conditions. Therefore, PMF-A and PMF-B are recommended for manufacturing margarine shortenings and frying fasts. PMF-C (IV, 33.0 g/100g) produced from the additional fractionation of PMF-A or PMF-B contained the highest POP percentage (67.1%) and showed heat-resistant property (SMP, 31.8°C; SFC at 30°C, 22.4%). Its steep SFC profile was superior to that of cocoa butter, suggesting the fat is preferred in producing hard chocolate fats.     

Use of Palm Mid-Fraction in White Chocolate Formulation

Samples of two types of palm mid-fraction (PMF I, a commercial sample and PMF II, from a laboratory-scale acetone fractionation of PMF I) and a Malaysian deodorised cocoa butter sample were used as the main components in the fat phase for white chocolate formulation. The monounsaturatedtriacylglycerol contents of these fats were 853, 899 and 903 g kg⁻¹, respectively.All the fats had free fatty acid contents of less than 10 g kg⁻¹ and melting points in the range of 34·0–34·5°C. The solid fat content profiles for the three fats were very steep. Differential scanning calorimeter analyses showed that all the fats had two melting peaks, T1 and T2. Results of the study showed that the tempering time to produce a well-tempered chocolate using PMF I was longer than that using PMF II, whereas, the time to produce a well-tempered cocoa butter chocolate increased with increase in the tempering temperature. Chocolates made with PMF I and II were well tempered between 17 and 19°C and with cocoa butter at 23°C. Thermal analyses, carried out on the chocolate showed that PMF I and II produced three melting peaks, T1, T2′ and T2 whereas most of the cocoa butter chocolates exhibited only one melting peak, T2. Storage studies showed that most of the chocolates had good bloom resistance for up to 12 weeks storage.     

巧克力涂层基料油的理化性质及其相容性研究

选用棕榈油中间分提物(PMF)、全氢化棕榈仁液油(HPKOL)、可可脂(CB)作为巧克力涂层的基料油,对其理化性质及其相容性进行分析。结果表明,当两相体系PMF-HPKOL中PMF含量在30%以下时,共晶现象较弱。PMF和HPKOL混合可以作为涂层油脂配方,用于开发无反式脂肪酸巧克力涂层。添加可可脂会导致三相体系(PMF-HPKOL-CB)严重的共晶现象,因此在代可可脂涂层配方中不宜再添加可可脂。     

Enzymatic synthesis of cocoa butter analog through interesterification of lard and tristearin in supercritical carbon dioxide by lipase

Substrate oil composition, reaction time, acyl donor, temperature, and pressure affected the triacylglycerol (TG) content of cocoa butter analog during the interesterification reaction catalyzed by lipase in a supercritical carbon dioxide (SC-CO₂) system. Among oil sources used to interact with tristearin, the content of 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS) (P, palmitate; O, oleate; S, stearate) and 1-palmitoyl-2, 3-dioleoylglycerol (POO) in analog was most similar to the corresponding TG content of cocoa butter when analog was prepared with lard. The optimized interesterification reaction using lard and tristearin (at a mole ratio of 1.4) as substrates to produce cocoa butter analog in a SC-CO₂ system was at 17 MPa, 50 °C, pH 9, for 3 h with an immobilized lipase, Lipozyme IM-20, from Mucor miehei. The lyophilized enzyme facilitated the production of cocoa butter analog in anhydrous substrates (a_w 0.33). The yield and melting point of the purified cocoa butter analog by a silica column was 63% and 34.5 °C, respectively, when the analog was produced under optimal conditions.     

Influence of cocoa butter refining on the quality of milk chocolate

A refining step is often crucial for the removal of undesired components in fats and oils. More flexible refining technologies are required due to a global decline in cocoa butter quality and to meet industry’s demand for cocoa butters with improved properties. The aim was to investigate the impact of the cocoa butter refining process on milk chocolate quality. Therefore a crude cocoa butter was subjected to a steam refining at different temperatures and this with or without a silica pretreatment. The major effect of the silica pretreatment was the complete removal of phosphorus (thus phospholipids), iron and alkaline components. During the steam refining step mainly Free Fatty Acids (FFA) were removed at increased temperatures (T ? 200 °C). The refining of the cocoa butter influenced the rheological properties of the chocolate. An increased packed column temperature, coinciding with the removal of FFA, resulted in a lower yield stress and a higher viscosity. Reduction of FFA positively influenced the crystallization kinetics and the formation of the crystal network, resulting in differences on a macroscopic scale.