Interactions of caseins with phenolic acids found in chocolate

To investigate the interactions between caseins and phenolic acids, such as the ones present in chocolate, casein was incubated with protocatechuic acid or p-coumaric acid at 55 °C. In addition, casein was isolated from chocolate and the phenolic compounds within these caseins were quantified. Electrophoresis results revealed that casein–phenolic interactions were induced by incubation; minor aggregation of casein subunits was observed after incubation of casein with protocatechuic acid. Minor aggregation of casein isolated from milk chocolate was also observed. In vitro hydrolysis of casein control, casein–protocatechuic acid, casein–p-coumaric acid, caseins isolated from milk chocolate and white chocolate using trypsin showed degree of hydrolysis of 19.3, 18.6, 17.7, 10.4 and 17.8% respectively. The presence of protocatechuic acid and p-coumaric acid in the model system and the presence of phenolic compounds in milk chocolate, in addition to the structural changes occurring during processing, affected the peptide profiles of casein hydrolysates.     

卵磷脂在巧克力中的应用

<正> 巧克力的主要成分有可可粉、可可脂、糖、奶油、奶粉和香精,其中的可可粉、奶粉和糖,是以微小的固体颗粒形式分散于可可脂和奶油的油相中。制造优质巧克力的关键,就在于使这些互不相溶的组分很好地结合在一起,添加卵磷脂,再配以适当的精烁温度(通常为80～90℃),就能够炼制出具有独特香气和香味的巧克力。     

Explaining tolerance for bitterness in chocolate ice cream using solid chocolate preferences

Chocolate ice cream is commonly formulated with higher sugar levels than nonchocolate flavors to compensate for the inherent bitterness of cocoa. Bitterness, however, is an integral part of the complex flavor of chocolate. In light of the global obesity epidemic, many consumers and health professionals are concerned about the levels of added sugars in foods. Once a strategy for balancing undesirable bitterness and health concerns regarding added sugars has been developed, the task becomes determining whether that product will be acceptable to the consumer. Thus, the purpose of this research was to manipulate the bitterness of chocolate ice cream to examine how this influences consumer preferences. The main goal of this study was to estimate group rejection thresholds for bitterness in chocolate ice cream, and to see if solid chocolate preferences (dark vs. milk) generalized to ice cream. A food-safe bitter ingredient, sucrose octaacetate, was added to chocolate ice cream to alter bitterness without disturbing other the sensory qualities of the ice cream samples, including texture. Untrained chocolate ice cream consumers participated in a large-scale sensory test by indicating their preferences for blinded pairs of unspiked and spiked samples, where the spiked sample had increasing levels of the added bitterant. As anticipated, the group containing individuals who prefer milk chocolate had a much lower tolerance for bitterness in their chocolate ice cream compared with the group of individuals who prefer dark chocolate; indeed, the dark chocolate group tolerated almost twice as much added bitterant in the ice cream before indicating a significant preference for the unspiked (control) ice cream. This work demonstrates the successful application of the rejection threshold method to a complex dairy food. Estimating rejection thresholds could prove to be an effective tool for determining acceptable formulations or quality limits when considering attributes that become objectionable at high intensities.     

巧克力米饼的研制

通过对膨化巧克力米饼的工艺特性、影响巧克力米饼质量的因素等方面的研究,将巧克力涂衣技术与膨化技术相结合,确定了最佳工艺参数,制作出涂衣巧克力米饼。     

可可脂的结晶特性对巧克力质量的影响

<正> 巧克力的物理性质很大程度上取决于制造过程中所用的可可脂质量,特别是可可脂融化、结晶和固化的方法。以下将对可可脂在巧克力制造过程中的物理与化学特性,以及各种可可脂如何充分地改变巧克力的风味、易碎程度及口感进行讨论。 可可脂的结晶性 晶形的形成 由于可可脂具有复杂的结晶性,可通过多种不同的变性而结晶成多晶型脂肪,正是这些     

巧克力起霜的研究进展

本文根据当今研究进展,阐述了引起巧克力制品起霜的机理,即相态分离理论和多晶态转化理论,针对各种不同的起霜原由,提出不同的有效万法以延缓起霜现象的发生。     

花样翻新的巧克力糖果

"巧克力糖果已经显示出了强劲的增长势头,与上年同期(2006年7月至2007年6月)相比增长了26%,在2008年上半年也增长了25%。")     

巧克力牛奶的研制

重点研究了不同产地和品牌的可可粉对产品口感的影响,以及不同的稳定剂对巧克力牛奶稳定性的影响。结果表明,选用DELFI可可粉制作巧克力牛奶脂香浓郁,口感最好,其用量为1.0%和1.25%的巧克力牛奶口感纯正。但从成本角度考虑,本实验选用1.0%的可可粉用量。该产品的稳定性需采用复配稳定剂,复配稳定剂最佳组合为卡拉胶0.015%,微晶纤维素0.13%,单甘酯0.1%。     

Analysis of potential lard adulteration in chocolate and chocolate products using Fourier transform infrared spectroscopy

Fourier transform infrared (FTIR) spectroscopy, in combination with attenuated total reflectance (ATR) and partial least square (PLS) regression, was used to detect the presence of lard in chocolate formulation. The spectral bands associated with lard, cocoa butter and their blends (ranging from 0% to 15% of lard in cocoa butter) were recorded, interpreted and identified. A semi-quantitative approach is proposed to measure the percent of lard in blends on the basis of spectral data at the frequency region 4000–650 cm⁻¹, using the equation y = 0.9225x + 0.5539. The coefficient of determination (R²) was 0.9872 with a standard error (SE) of 1.305. In this paper, the potential of FTIR spectroscopy as a rapid analytical tool for the quantitative determination of adulterants especially lard, in chocolate, is demonstrated.     

毛细管电泳安培检测法快速测定巧克力中的香兰素

运用毛细管电泳安培检测法研究了巧克力中香兰素的快速测定方法,研究了电极电位、缓冲液的浓度和pH、分离电压以及进样时间等因素对分离测定的影响。在30mmol/L的硼砂（pH9.24）运行缓冲液中,施加15kV的分离电压及+0.65V（vs.SCE）的电极电位条件下,铜电极对香兰素有很好的响应。香兰素在5.0×10-6～1.0×10-3g/mL范围内存在较好的线形关系,检测限为3.87×10-7g/mL（S/N=3）。对实际样品的测定,回收率为96.5%～102.8%,结果令人满意。      

巧克力生产中油脂应用技术

介绍巧克力生产中常用油脂种类及配方比例,指出巧克力生产中油脂应用的关键技术是制酱工序中油脂总量的控制和温度的调节。     

The production of clusters in milk chocolate

Cluster production during conching of milk chocolate leads to defects in chocolate quality. Various conditions of conching, using two types of milk chocolate were examined. Temperature and relative humidity were the parameters that were controlled. The contents of moisture, fat, sucrose and lactose and also cluster development in milk chocolate during conching were evaluated. Representative samples in the conching tests were subjected to particle size analysis (using laser diffraction and sieve methods), X-ray diffraction analysis, polarizing microscopy and sensory evaluation.     

Effects of milk powders in milk chocolate

The physical characteristics of milk powders used in chocolate can have significant impact on the processing conditions needed to make that chocolate and the physical and organoleptic properties of the finished product. Four milk powders with different particle characteristics (size, shape, density) and "free" milk fat levels (easily extracted with organic solvent) were evaluated for their effect on the processing conditions and characteristics of chocolates in which they were used. Many aspects of chocolate manufacture and storage (tempering conditions, melt rheology, hardness, bloom stability) were dependent on the level of free milk fat in the milk powder. However, particle characteristics of the milk powder also influenced the physical and sensory properties of the final products.     

螺旋藻巧克力的研制

研究在巧克力液块中添加螺旋藻干粉等物质制成营养更加均衡的螺旋藻巧克力,确定最佳配方为螺旋藻干粉5%、砂糖30%、卵磷脂0.3%和单硬脂酸甘油酯0.4%,并对螺旋藻巧克力的营养成分及理化、微生物指标进行测定分析。     

螺旋藻巧克力的研制

研究在巧克力液块中添加螺旋藻干粉等物质,制成营养均衡的螺旋藻巧克力,确定最佳配方为螺旋藻干粉5％、砂糖30％、卵磷脂0．3％和单硬脂酸甘油酯0．4％的比例添加。并对螺旋藻巧克力的营养成分及理化微生物指标进行测定分析。     

彩色巧克力工艺研究

经过对油溶性天然色素特性的分析、巧克力配方的调整、制作工艺的改进,确定天然色素法制作彩色巧克力的一组产品配方及工艺参数,确定彩色巧克力产品中油溶性天然色素的使用量(辣椒红素0.1%,叶绿素0.05%,姜黄色素0.1%),并确定彩色巧克力的产品质量标准。     

Modelling crystal polymorphisms in chocolate processing

Efforts have been devoted over the last decades towards modelling phase change kinetics of fats in chocolate. The fats in chocolate have a number of polymorphic forms and manufacturers must deliver a product with the right polymorph to the consumer. In this work a model was developed that contains only two polymorphs rather than the six polymorphs that can be identified using Differential Scanning Calorimetry (DSC) and X-Ray Diffraction (XRD). This simplification allowed the phase change kinetics to be estimated from a set of DSC experiments. The phase change reactions were coupled with heat transfer and used to successfully predict the temperature profiles and the concentration of polymorphs (within 10%). These quantities determine among others contraction and cohesion, which are essential to demoulding and cleaning processes. Indeed, deposits left on the mould surface leads to undesirable product surface and an increase of cleaning costs. During the rapid cooling step (similar to the FrozenCone process), only a thin layer (to maintain the prescribed shape) of the shell is partially crystallised (typically 20% of the thickness) with unstable crystals (typically 10%) due to the high cooling rates. The model was then used to develop of a rapid cooling process allowing the estimation of the processing time required for the rapid cooling step depending on the thickness of the shell and the temperature of the plunger.     

巧克力粟米条的研制

将挤压膨化技术与巧克力涂层技术相结合,对膨化巧克力粟米条的工艺流程、技术操作要点及生产中质量控制方法进行了研究,成功的制作出了巧克力粟米条。