Influence of formulation on the thermal behavior of ice cream mix and ice cream

The influence of fat and emulsifier types on particle size and thermal behavior of aged mixes and the corresponding ice creams was investigated. Mixes and ice creams based on partially unsaturated monodiglycerides (MDG) were characterized by an increased percentage of agglomerated fat globules compared with saturated MDG-based system. DSC thermograms obtained for refined coconut oil in mix showed a displacement of the main crystallization event toward lower crystallization teperatures compared with fat in the bulk phase. This supercooling effect was more or less pronounced for the three other fats used (hydrogenated coconut oil, refined palm oil, and anhydrous milk fat). In emulsified systems, an additional exotherm was observed that was interpreted in terms of MDG crystallization. The fact that this peak appeared at different temperatures ranging from 32 to 41°C as a function of the fat selection suggested that different fat-emulsifier interactions would occur. In the case of ice creams, although the water peak interfered with the fat peak, melting DSC curves allowed the discrimination between the fat types used in the formulation     

Impact of oxidized off-flavor of ice cream prepared from milk fat

The influence of light-induced oxidation on ice cream quality was investigated by monitoring hydroperoxide formation of the oil fraction, sensory evaluation for oxidized off-flavor, and gas GC-MS analysis of developed volatile aldehydes following steam distillation/extraction of ice cream. Two ice cream samples containing 14.3% milk fat prepared from different milk fat materials, and a sample with 1000 ppm tocopherol added were exposed to 650 lx fluorescent light at −20°C. Ice cream prepared from each milk material showed a different time dependence for peroxide formation, and the addition of tocopherol reduced hydroperoxide formation. The correlation coefficient (r ²) between the PV and the sensory score was 0.483 (n=9), and the r ² between the total concentration of 10 volatile aldehydes developed during light exposure and the sensory score was 0.365. Among the 10 aldehydes, however, the highest correlation observed was between the amount of trans-2-decenal and the sensory score (r ²=0.864, n=9), and lowest correlation was between the amount of hexanal and the sensory score (r ²=0.302, n=9). These results suggest that exposure of ice cream in the frozen state to fluorescent light produces a unique composition of volatile aldehydes related to flavor deterioration induced by photooxidation of the milk fat in ice cream.     

Microbiological quality of vanilla ice cream manufactured in Caracas, Venezuela

A total of 122 samples of vanilla ice cream, the base product used for all flavors, prepared by eight different large firms at the Metropolitan Area of Caracas, Venezuela, were analyzed for aerobic mesophilic and psicrophilic bacteria, Staphylococcus aureus, Enterobacteriaceae, and Filamentous fungi. Findings revealed that within the sampling, 56.6% complied with the international standards proposed for aerobic mesophilic bacteria, 68% for Staphylococcus aureus, and 23% for Enterobacteriaceae. Three serotypes of enteropathogenic Escherichia coli, one of Salmonella, and one of Shigella were found. Ten genera of Filamentous fungi were isolated and identified.     

膨润土的改性及其在润肤乳液中的应用

以钙基膨润土为原料,经过改型、提纯、增稠改性等工艺制备出粘度值2000m Pa.s、d(001)值11.872、蒙脱石含量95%的高纯改性膨润土悬浮剂。通过在化妆品润肤乳液中的对比应用试验表明:该改性膨润土悬浮剂可以替代美国进口Veegum样品在润肤乳液中作稳定剂用,产品工业化后将具有显著的价格竞争优势。     

Crystallization Behavior of Molecular Compound in Binary Mixture System of 1,3‐Dioleoyl‐2‐Palmitoyl‐sn‐Glycerol and 1,3‐Dipalmitoyl‐2‐Oleoyl‐sn‐Glycerol

Previous studies showed that the stable β‐form of molecular compound (MC) crystals having a double‐chain‐length structure is formed in a binary mixture system of 1,3‐dioleoyl‐2‐palmitoyl‐sn‐glycerol (OPO) and 1,3‐dipalmitoyl‐2‐oleoyl‐sn‐glycerol (POP) with a 1:1 concentration ratio of OPO and POP. The use of MC crystals made of POP and OPO for edible applications, such as margarine, is advantageous due to no‐trans, low‐saturated, and high‐oleic fats. Industrial manufacturing technology involves rapid cooling processes, and the kinetic properties of crystallization of MC of OPO and POP are required. In this study, we clarified the crystallization of MC of OPO and POP under rapid cooling at rates of 1–150 °C min^?1, using synchrotron radiation time‐resolved X‐ray diffraction and differential scanning calorimetry methods. The main results are as follows: (1) POP and OPO crystallized in separate manners without the formation of MC crystals under rapid cooling (>40 °C min^?1), while MC crystals started to form with decreasing rates of cooling in addition to the POP and OPO crystals (<30 °C min^?1); (2) metastable and stable forms sub‐α, α, β′, and β of POP and OPO were formed, whereas the MC crystals of β were formed during the cooling processes; and (3) the heating processes after crystallization by rapid cooling caused separate melting of the metastable and stable forms of POP and OPO crystals and the formation of MC crystals of β made of POP and OPO, as well as melting of the MC crystals alone.     

高效液相色谱法测定盐酸特芘萘酚乳膏中的盐酸特芘萘酚

确立了丁克制剂中的盐酸特芘萘酚的液相色谱测定方法 ,色谱柱 :C18(15 0× 4 .6mm ,5 μm) ,流动相为甲醇∶乙酸铵 (0 .0 5mol·L-1,乙酸调pH =6 .0 ) =8∶2 ,流速 :1.0 0mL·min-1,检测器为紫外检测器 ,检测波长为 2 83nm ,结果证明此方法测定丁克制剂中的盐酸特芘萘酚是可行的。     

Discrete element reduced‐order modeling of dynamic particulate systems

One of the key technical challenges associated with modeling particulate processes is the ongoing need to develop efficient and accurate predictive models. Often the models that best represent solids handling processes, like discrete element method (DEM) models, are computationally expensive to evaluate. In this work, a reduced‐order modeling (ROM) methodology is proposed that can represent distributed parameter information, like particle velocity profiles, obtained from high‐fidelity (DEM) simulations in a more computationally efficient fashion. The proposed methodology uses principal component analysis (PCA) to reduce the dimensionality of the distributed parameter information, and response surface modeling to map the distributed parameter data to process operating parameters. This PCA‐based ROM approach has been used to model velocity trajectories in a continuous convective mixer, to demonstrate its applicability for pharmaceutical process modeling. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3184–3194, 2014     

Emulsifying properties of phospholipids in the reconstitution of cream using butter oil

Phospholipids (PL) extracted from bovine milk and soybeans were tested for their emulsifying properties in reconstituted cream using butter oil. Bovine milk PL dispersed in the oil phase were found to stabilize the cream, whereas soybean PL were found to solidify the cream. Differential scanning calorimetry was carried out on the two creams, revealing that the addition of soybean PL to the butter oil retarded the onset of crystallization during cooling, which consequently led to a lower solid fat content within the fat globules. It was suggested that the difference in the crystallization behavior of butter oil due to the addition of different PL led to the different emulsion stabilities of the reconstituted creams.     

A process for the production of a diacylglycerol‐based milk fat analogue

We propose a novel process for the production of a DAG‐rich acylglycerol mixture derived from milk fat. This product has potentially interesting nutritional properties, derived from both its high content of DAG and of short‐chain fatty acids (FAs). The proposed process consists of three steps: lipase‐catalysed partial ethanolysis of milk fat, extraction of the by‐product fatty acid ethyl esters (FAEEs) using supercritical carbon dioxide (SC‐CO₂) and isomerization of DAG to increase the proportion of 1,3‐DAG. The experimental investigation of the process steps was done using milk fat and trilaurin. Several lipases were tested for maximizing the percentage of DAG in the acylglycerol mixture produced by ethanolysis. The selectivity of the chosen lipase was such that the produced AG mixture was enriched in short‐chain FAs in relation to the original milk fat. FAEEs were completely extracted from the ethanolysis mixture by SC‐CO₂. In the final process step, we explored the reaction conditions for facilitating acyl migration in the DAG mixture, so that the equilibrium proportion of 1,3‐DAG (～64%) was attained. Our results set the basis for the development of a simple process for the production of a DAG‐rich milk fat analogue.     

A comparative study of dairy whipping cream and palm oil-based whipping cream in terms of FA composition and foam stability

Nondairy creams are more stable than dairy creams, especially in hot climates. This paper considers the reasons for this stability and which FA is most suitable for producing this effect in palm oil and palm kernel oil-based whipping cream. The results show that an increase in unsaturated FA, particularly oleic acid, can produce a more stable foam in whipping cream. This study also shows that an increase in iodine value has a positive impact on the stability of foam in nondairy whipping cream as well. This study points out the advantages of a palm oil-based whipping cream over commercial dairy whipping cream, particularly when the stability of the foam is important and the product is supposed to be consumed in hot weather.     

一款含鲜奶面霜缓解皮肤红斑反应的功效评价研究

采用客观仪器评价方法对含鲜奶面霜单次使用后的缓解皮肤红斑反应的功效进行研究。选择30名18~55周岁有效受试者为研究对象,使用胶带粘贴及组胺刺激构建皮肤红斑反应模型,并采用无创仪器的方式检测并记录实验组、安慰剂组、阴性组及空白组受试者在组胺造模前、造模后、涂抹产品后30 min和60 min时的皮肤红斑指数EI值、皮肤敏感度值,采集皮肤图像,通过SPSS数据统计软件对实验结果进行统计分析。结果显示,含鲜奶面霜可以持续改善皮肤红斑指数EI值和皮肤敏感度,缓解由组胺导致的皮肤红晕反应,说明其具有一定的缓解皮肤红斑反应,改善皮肤敏感状态的功能。     

A study on the crystal structure of palm oil-based whipping cream

The crystal structure of palm oil-based whipping cream was studied. Various proportions of refined, bleached, and deodorized palm oil (RBDPO) and palm kernel oil (RBDPKO) were prepared and their crystal structure and thermal profile were observed by an X-ray diffractometer and a differential scanning calorimeter, respectively. The results showed that all blends possessed a stable and shiny β′ polymorph at 25°C, which showed that RBDPO and RBDPKO were appropriate for producing a nondairy whipping cream. Some eutectic effect was observed in some blends, which was attributed to the complex combination of TAG in RBDPO and RBDPKO.     

Effects of the Addition of Spray‐Dried Whey on the Stability of Fat‐Reduced Mayonnaise‐Type Emulsions During Storage

The applicability of the spray‐dried whey for the production of reduced‐calorie mayonnaise‐type emulsions was studied. Whey was used as a stabilizing/emulsifying agent and as a fat‐replacement component. Whey powder was spray‐dried at 130, 140, and 180 °C. As control sample, 80% w/w standard fat emulsion was prepared. Mayonnaise‐like fat‐reduced emulsions contained 65% w/w of fat and 15% w/w of three distinct types of whey. The destabilization of the emulsions was investigated within 7 days of storage by scanning the samples with laser light. Backscattering, Turbiscan stability index, elasticity index, and macroscopic viscosity index were determined. The most stable emulsion contained whey powder spray‐dried at 180 °C. The emulsion made with whey powder spray‐dried at 130 °C was less stable than that with 180 °C spray‐dried whey, but it was more stable than the control and the one with whey spray‐dried at 140 °C.     

超临界CO2萃取技术及其萃取的蛋黄油在抗皱霜中的应用

超临界CO2萃取技术是目前在食品、日化行业新兴的提取方法，它具有不破坏萃取物成分、产品纯度高的优点，用SC—CO2萃取所得蛋黄油加入抗衰霜中，提高了抗衰有效率。     

Design and synthesis of 1,3‐dicapryloyl‐2‐acetylglycerol as molecular probe for triacylglycerol metabolism study

The increasing number of health issues caused by obesity and lack of healthy and efficient fat substitutes require development on new fat substitute. This study proposes a new potential reduced‐calorie structured triacylglycerol (TAG) of “1,3‐medium‐chain, 2‐short‐chain triglycerides (MSM)” configuration, and the fat substitution method is based on the suppression of 2‐monoacylglycerol absorption into intestinal cells, which would decrease the recombination of TAG and reduce lipid absorption in the digestive tract. A molecular probe, 1,3‐dicapryloyl‐2‐acetylglycerol, is offered for nutritionists to conduct further study on its metabolism in human body. The synthesis method for this structured TAG starts from the lipase‐catalyzed esterification between glycerol and caprylic acid, yielding 1,3‐dicapryloylglycerol, and is followed by direct esterification with acetic anhydride to form 1,3‐dicapryloyl‐2‐acetylglycerol. Its structure is characterized by FTIR,¹H NMR,¹³C NMR, and LC‐ESI‐MS. Practical application: This kind of pure structured triglyceride can function as a molecular probe for nutritionists to test its metabolism in human body and conduct further evaluation on their fat substitute potential. The synthesis method can also be easily adopted by food industry since it involves only two simple reaction steps.     

Heat treatment of cream: A model of the butter texture response in relation with triglyceride composition

The effects of thermal treatments on butter texture are known and have been used since 1935 on an industrial scale, but without fundamental knowledge. Butter composition influences firmness, as observed through seasonal and regional variations. Experiments were carried out at 15°C by using a cone penetrometer and an industrial testing machine. A significant correlation between heat treatment efficiency and some prevalent triglycerides and fatty acids on butter firmness was outlined. Three fatty acids (myristic, oleic, palmitic) and four major groups of triglycerides mainly affected the firmness, sometimes leading to an inversion of the thermal effect, according to individual sample composition. A crystallographic and thermodynamic model based on triglycerides properties was developed.