试谈由乌桕脂制类可可脂过程中的几个问题

论述了产品收率低、溶剂分提效果欠佳、巧克力生产脱模困难等问题的解决办法。     

试谈由乌桕脂制类可可脂过程中的几个问题

论述了产品收率低、溶剂分提效果欠佳、巧克力生产脱模困难等问题的解决办法。     

利用有机相酶促反应由乌桕脂生产类可可脂

研究了利用有机相酶促反应，将我国资源丰富、价格低廉的乌桕脂改良成高附加值的类可可脂的工艺，着重探讨了乌桕脂中ＰＯＰ三甘油酯与硬脂酸间的酯交换反应，并考察了温度、有机溶剂、酶浓度及底物对该反应速度及产物组成的影响，得到了一组最佳的酯交换反应条件。     

巧克力中可可脂及其代用品分析技术研究进展

介绍了天然可可脂的特性,可可脂代用品如类可可脂和代可可脂的分类和特性,并从晶体性能研究、组分对比研究、鉴定研究和检测方法研究等4个方面,重点阐述了国内外巧克力中可可脂及其代用品的分析技术研究进展,对巧克力及巧克力制品产业的发展前景进行了预测和展望。     

巧克力中可可脂及其代用品分析技术研究进展

介绍了天然可可脂的特性,可可脂代用品如类可可脂和代可可脂的分类和特性,并从晶体性能研究、组分对比研究、鉴定研究和检测方法研究等4个方面,重点阐述了国内外巧克力中可可脂及其代用品的分析技术研究进展,对巧克力及巧克力制品产业的发展前景进行了预测和展望。     

从乌桕脂中提取类可可脂方法的改进

对用溶剂从乌桕脂中提取类可可脂的方法进行了改进,将溶剂改为95％酒精,省去了原来的“三脱”设备, 采用二次分提结晶,加入了溶剂回收工艺。既简化了生产过程,同时也降低了生产成本。     

1000t/a类可可脂工程的可行性研究

介绍了生产类可可脂的酯交工艺、产品质量、原料要求、经济效益、环境保护以及一些相关问题;在技术经济方面分析了生产类可可脂的可行性,为利用乌桕籽资源找到了新途径。     

高纯度乌桕脂棕榈酸,油酸制取工艺研究

为满足日益增长的高科技市场对高纯度棕榈酸,油酸的迫切需求,充分利用中国乌桕脂的资源优势和化学组成特点,研究并提出“无催化剂分批压热釜水解,溶剂结晶－精馏,柱层析”法,原料乌桕脂水解率９７．３６％,高纯度棕榈酸纯度９８．７７％,收率９０％,高纯度油酸纯度９８．０３％,收率９２％。高纯度水解甘油纯度９８％,收率８９％．     

脂肪酶促乌桕脂组分甘油解及其反应机理研究

Glycerolysis of Chinese vegetable tallow （CVT） fraction was investigated using a 1,3-specific lipase from Rhizopus arrhizus as catalyst. Based upon a binary gradient HPLC with an evaporative light-scattering detector （ELSD）, the contents of free fatty acids （FFA）, monoglycerides （MG）, diglycerides（DG） and triglycerides （TG） with their positional isomers during the glycerolysis were determined. The effects of water content and the ratio of glycerol to oil on the product distribution of glycerolysis were studied. Under the optimum reactant conditions： 250 units lipase per gram oil at 37℃ with 1：2 molar ratio of oil to glycerol in a solvent-free system, after 24 h reaction, the product consisted of 7.2% TG, 25.6% MG, 56.1% DG and 4.9% FFA （all by mass）. Furthermore, the mechanism of glycerolysis was discussed in detail.     

Novel Cocoa Butter Equivalent from Microalgal Butters

An acetone solvent fractionation procedure was used to obtain two algal butter fractions, an algal stearin containing high amounts of 1,3-stearoyl-2-oleoyl-glycerol (SOS), and an algal mid-fraction containing high amounts of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), and 1-palmitoyl-2-oleoyl, 3-stearoyl-glycerol (POS). Algal stearin and algal mid-fraction were blended (1:9 w/w) to yield a potential cocoa butter equivalent (CBE). The amount of POP, POS, and SOS, in algal CBE was 15.8%, 32.0%, and 24.6%, respectively, compared to 15.4%, 38.8%, and 27.7% in Cocoa butter (CB). However, a higher amount of POO and SOO in the algal CBE caused a lower solid fat content at all temperatures compared to CB. This study demonstrates the potential for producing a new algal CBE using solvent fractionation and blending techniques that can be used in chocolate and other confectionery products.     

Synthesis of a Cocoa Butter Equivalent by Enzymatic Interesterification of Illipe Butter and Palm Midfraction

This study aims to synthesize a cocoa butter equivalent (CBE)‐structured lipid from a blend of illipe butter (IB) and palm midfraction (PMF) by means of enzymatic interesterification using Rhizomucor miehei sn‐1,3 specific lipase, Lipozyme^® RM IM (Novozymes North America, Inc., Franklinton, NC, USA) as the biocatalyst. Physical and chemical attributes of the CBE and cocoa butter (CB) were analyzed. The synthesized CBE matched the triacylglycerol (TAG) profile range of a commercial CB and is therefore hypothesized to show similar physical and chemical characteristics to CB. The TAG profile, fatty‐acid constituents, melting and cooling behavior, polymorphism, and crystal morphology were determined using high‐performance liquid chromatography, gas chromatography, differential scanning calorimetry, X‐ray diffraction (XRD), and polarized light microscopy, respectively. Four enzymatically interesterified blends of IB:PMF at different weight ratios were analyzed for their TAG profiles, and a ratio of IB:PMF 10:3 (%, w/w) at 5% enzyme load and a reaction time of 30 min gave similar TAG results to CB. The TAG values of the IB:PMF 10:3 interesterified product (IP) were 1,3‐dipalmitoyl‐2‐oleoylglycerol at 19.1 ± 1.0%, 1‐palmitoyl‐2‐oleoyl‐3‐stearoylglycerol at 42.7 ± 1.0%, and 1,3‐distearoyl‐2‐oleoylglycerol at 29.9 ± 0.3%. The melting and the cooling profile of IP and CB showed no significant difference. XRD of IP and CB displayed similar dominant peaks at 4.6 Å, representing a β polymorph. Both CB and IP have similar granular spherulitic crystals.     

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.     

Influence of Brazilian Geographic Region and Organic Agriculture on the Composition and Crystallization Properties of Cocoa Butter

Cocoa butter (CB) is the most important ingredient in chocolate and represents the biggest share in the continuous phase of this product. The accurate composition of CB depends, among other factors, on the genetic characteristics of the cocoa tree, its agricultural handling and the farming region's climate. The influences of the cocoa‐producing region in Brazil and the agricultural cultivation method on the composition and crystallization properties of CB are presented in this article. Raw CB was extracted from fruits cultivated in six main Brazilian states using two agricultural methods, organic and conventional. The samples were evaluated according to fatty acids, triacylglycerol composition, solid fat content, consistency, melting behavior and isothermal crystallization. The wide range of cocoa‐producing regions in Brazil causes the distinct characteristics of the chemical composition and crystallization behavior of the CB, attributes that affect the quality of products using this raw material. Differences in consistency, hardness and crystallization parameters, among others, were observed. The results showed the great potential of using Brazilian CB with similar features to those of African and Asian origin, considered more appropriate for use in chocolates. However, no clear tendency concerning the agricultural method was found.     

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.     

乌桕梓油脂肪酸组成分析

乌柏是我国四大木本油料之一,种子含油量高,乌桕梓油是由种仁榨取所得的液体油脂,是轻工业、食品和国防等行业的重要油源。乌桕梓油甲酯化后,利用100 m×0.25 mm的GC毛细管柱,气相色谱法测定乌桕梓油的脂肪酸组成。测定结果表明：乌桕梓油中饱和脂肪酸占10.68%,以棕榈酸含量最高,占7.52%。不饱和脂肪酸占89.13%,单不饱和脂肪酸占18.63%,以油酸含量最高,占14.55%;多不饱和脂肪酸占70.50%;其中含量最高的为人体所必需的脂肪酸亚油酸和α-亚麻酸,分别占30.77%和39.30%。还含有相当数量天然植物中少有的奇数碳原子脂肪酸十一烷酸,占0.29%。其中月桂烯酸（占3.19%）和十一烷酸未见报道。