油脂种类对植脂鲜奶油搅打性能的影响

通过研究不同种类的油脂在植脂鲜奶油搅打过程中脂肪球的部分附聚、搅打时间、搅打起泡率和泡沫稳定性之间的关系。结果表明：不同种类的油脂对搅打性能的影响与其熔点有着密切的关系，其实质是油脂在常温下的固体脂肪指数决定了脂肪球能否发生部分聚结与聚结的程度，熔点为35～43℃的部分氢化植物油的聚结率接近60％，可以达到最佳的部分聚结率，能够形成稳定的泡沫结构；熔点为47～53℃的部分氢化植物油的聚结率超过70％，容易产生过度的部分聚结，形成结构粗糙的泡沫；天然奶油的部分聚结率低于10％；大豆油或者极度氢化油不能发生脂肪球的部分聚结，不能形成稳定的泡沫结构。     

脂肪球在搅打乳状液中的部分聚结及其作用

综述了脂肪球在搅打乳状液中的部分聚结现象和搅打条件、脂肪种类、脂肪球吸附膜对部分聚结的影响。以冰淇淋和搅打奶油为例 ,说明脂肪球的部分聚结对于搅打乳状液最终形成充气的泡沫结构起关键作用 ,控制脂肪球的部分聚结程度对于改善搅打乳制品的质量、性能具有重要意义。联系控制脂肪球的部分聚结在冰淇淋生产中的实际应用 ,介绍了近来国际上有关脂肪球部分聚结的研究进展。     

蛋白质用量对粉末植脂奶油品质的影响

研究了蛋白质用量对植脂奶油乳浊液性质、喷雾干燥效果以及粉末植脂奶油搅打性能和流变特性的影响。结果表明:当蛋白质用量从0.9%提高到2.1%时,脂肪部分聚结率急剧降低到0.9%,乳浊液的脂肪球粒径d4,3从0.47%减小到0.37%,而粘度从170c P升高到291c P,喷雾干燥的粉末得率提高,但粉末分散性降低;粉末植脂奶油搅打过程中的脂肪部分聚结率也减小,搅打起泡率降低,当蛋白质用量为0.9%时搅打起泡率最大,达到325.38%,其弹性模量G′和粘性模量G″都较高,分别可到达7000Pa和900Pa,泡沫的粘弹性好。     

油脂熔点对植脂鲜奶油质量性能的影响及其机理的研究

利用质构分析仪分析泡沫硬度和内部质构,油溶性色素法(油红-O)测定脂肪球部分聚结率,研究油脂种类对植脂鲜奶油质量性能的影响.结果表明,不同种类油脂制备的植脂鲜奶油的质量性能有较大差异,油脂种类对质量性能的影响与其熔点有关.随油脂熔点不同,在搅打过程中发生脂肪球部分聚结的程度也不同,从而影响最终的泡沫结构.搅打5 min后,熔点为47～53℃的部分氢化植物油HP-51的部分聚结率大于70%,天然奶油的部分聚结率小于10%,大豆油和极度氢化油不发生部分聚结,均不能形成稳定的泡沫结构.熔点为36～41℃的部分氢化植物油制备的植脂鲜奶油,部分聚结率为65%,膨胀率为4.0,获得稳定的泡沫结构.     

大豆蛋白与酪蛋白比例对搅打稀奶油稳定性影响的研究

研究了大豆蛋白与酪蛋白不同配比对搅打稀奶油乳浊液的表观粘度及搅打过程中的液相蛋白浓度、脂肪部分聚结、搅打起泡率的变化和泡沫稳定性的影响,并在此基础上探讨了其作用机理。结果表明:大豆蛋白比例的增大能增加界面膜的粘弹性,抑制脂肪球的部分聚结,提高泡沫结构的稳定性,当大豆蛋白与酪蛋白比例为4∶1时,搅打稀奶油可以获得最佳的稳定性。     

瓜尔豆胶对搅打稀奶油的搅打性能的影响

研究了不同浓度的瓜尔豆胶对搅打稀奶油乳状液的表观黏度、脂肪球粒度、脂肪球界面蛋白浓度、脂肪球部分聚结率、泡沫硬度和搅打起泡率的影响。结果表明，瓜尔豆胶对搅打稀奶油乳状液的表观黏度影响非常显著；瓜尔豆胶浓度过高或过低，都会使得解冻后的乳状液粒径变大；瓜尔豆胶的质量分数越高，脂肪球部分聚结速度越快，泡沫硬度也越大；搅打起泡率随着瓜尔豆胶质量分数增大而降低。     

豌豆、大豆蛋白适度改性在低脂植脂奶油中的应用

研究了酸、碱处理豌豆、大豆蛋白的添加对植脂奶油乳状液的表观黏度、搅打后奶油脂肪部分聚集率、搅打起泡率、泡沫稳定性以及流变性质、感官品质的影响.结果表明:豌豆、大豆蛋白适度改性有利于其乳化性、起泡性的提高.酸处理的大豆蛋白和碱处理的豌豆蛋白替代部分脂肪,可增加界面膜的黏弹性,一定程度促进脂肪球的部分聚集,提高泡沫的稳定性,并获得较好的流变性质、感官品质.考虑到风味因素的影响,最终选择用碱处理豌豆蛋白替代2％脂肪制作低脂植脂奶油,其搅打起泡率为351.9％,泡沫稳定性为90 min,屈服应力为130.3 Pa,脂肪部分聚集率为80.3％.     

蛋白质用量对黄油基淡奶油搅打前乳液性质及搅打性能的影响

以黄油为油相制备淡奶油,研究蛋白质用量(1.0%～3.0%)对黄油基淡奶油搅打前乳液性质及搅打性能的影响。研究表明:蛋白质用量为1.0%～2.5%时,随蛋白质用量的增加,搅打前乳液的界面蛋白浓度明显增加,脂肪部分聚结率降低,脂肪球粒径减小,粒度分布曲线变窄,表观黏度升高,乳液的稳定性提高;蛋白质用量由2.5%增加至3.0%时,脂肪部分聚结率增加,脂肪球粒径增大,乳液的稳定性降低。乳液在200 s的搅打过程中,随搅打时间的延长,脂肪部分聚结率不断增加,平均粒径呈现先减小后增大的趋势,搅打起泡率则先升高后降低。蛋白质用量为1.0%～1.5%时,在搅打过程中脂肪部分聚结率、平均粒径、搅打起泡率均快速增加,易出现搅打过度现象,且泡沫稳定性差。蛋白质用量为2.0%～2.5%时,脂肪部分聚结率、平均粒径、搅打起泡率则缓慢增加,而泡沫稳定性较好。蛋白质用量增加至3.0%时,尽管泡沫稳定性较好,但搅打200 s后的脂肪部分聚结率仅有26.45%。因此,将黄油基淡奶油的蛋白质用量控制在2.0%～2.5%范围内较适宜。     

油脂用量对搅打稀奶油的搅打性能和品质的影响

研究了油脂用量对搅打稀奶油的粒度分布、脂肪部分聚结、液相蛋白质浓度、搅打起泡率、质构特性、感官品质和稳定时间的影响。研究表明:随着油脂用量增加,冷却后乳浊液脂肪球粒径增大;搅打过程中脂肪部分聚结速度和脂肪球粒径d4,3均随油脂用量增加而增大,且脂肪部分聚结率与脂肪球粒径d4,3有很好的相关性;液相蛋白质浓度和搅打起泡率降低;搅打稀奶油的质构特性值增加;稳定时间呈先增后减趋势,当油脂用量为23%时,搅打稀奶油的稳定时间最长达到2.7h;搅打稀奶油的感官品质以油脂用量为20%最好,综合考虑,油脂最佳用量范围是20%-23%。     

麦芽糊精与复配糖比例对降糖植脂奶油搅打性能和品质的影响

本文以麦芽糊精和复配糖（葡萄糖、白砂糖和淀粉糖浆组成）为原料制备总糖浓度为18.60 wt%的降糖植脂奶油,研究了麦芽糊精与复配糖不同的比例（0:20~9:11）对降糖植脂奶油搅打性能和品质的影响。比较了植脂奶油的水分分布、界面蛋白浓度、脂肪部分聚结率、最佳搅打时间、搅打起泡率、硬度、感官评价、储藏稳定性等指标。研究发现,当麦芽糊精与复配糖比例从0:20增加至3:17,植脂奶油的界面蛋白浓度和硬度明显增加,储藏稳定性提高,感官评价稍有降低;进一步增加麦芽糊精与复配糖比例至9:11时,植脂奶油的脂肪部分聚结率、搅打起泡率、感官评价和储藏稳定性明显降低,搅打性能和品质均较差。综合考虑搅打性能和品质的影响,当麦芽糊精与复配糖的比例分别在3:17和5:15时,降糖植脂奶油的搅打起泡率为353.3%和342.2%,硬度为325.6 g和329.1 g,横截面光滑,此时搅打性能和品质更佳。     

Production of reduced-fat whipped toppings by solid fat-based W/O/W double emulsions: proof of concept

Water-in-oil-in-water (W/O/W) double emulsions present a reduced-fat alternative to conventional O/W food emulsions, as part of the dispersed oil phase is replaced with water. In this study, the concept of a reduced-fat whipped topping produced by W/O/W technology was proven. Whipping of a W/O/W emulsion, containing only 20% oil phase and a solid fat content of 78%, produced a superior whipped topping, in terms of firmness and overrun, compared to its whipped O/W emulsion counterparts. The presence of PGPR in the oil phase increased structure formation during whipping, while the additional dispersed-phase volume resulted in a better air inclusion. Two commercial monoacylglycerols (saturated and unsaturated) were investigated to improve the whipping properties of the produced W/O/W double emulsion. Both increased the susceptibility towards partial coalescence, thereby reducing whipping time and overrun, while increasing firmness of the produced whipped topping. Furthermore, the effect was stronger for the unsaturated than for the saturated monoacylglycerol.     

乳化剂用量对搅打稀奶油搅打性能和品质的影响机理研究

研究了乳化剂用量对搅打稀奶油的乳浊液粒度分布、脂肪球部分聚结、液相蛋白浓度、感官品质和泡沫稳定性的影响。研究结果表明:乳浊液冷却及解冻后脂肪球粒径随乳化剂用量增加而减小,随着乳化剂用量增加,脂肪部分聚结速度和液相蛋白质浓度增加速度加快,搅打起泡率和感官品质以乳化剂用量为0.60%时最好,搅打稀奶油稳定时间随乳化剂用量增加呈先增加后下降趋势,当乳化剂用量为0.60%时,稳定时间达到最大2.4h。综合考虑,当乳化剂HLB值为7,乳化剂用量为0.60%时,搅打稀奶油搅打性能和品质最佳。     

Microstructural evolution of whipped cream in whipping process observed by confocal laser scanning microscopy

It is useful to carefully observe the evolution of foam structures to elucidate the factors affecting cream during whipping. In this study, confocal laser scanning microscopy and a double dyeing technology were used to investigate the microstructural evolution of a rigid foam structure in whipped cream. The location of fat and proteins were determined according to the signals they produce at different characteristic wavelengths. Protein membranes on the surface of air bubbles were clearly observed. A simple yet comprehensive characterization of the whipping process was established according to the micrographs and supported by relevant theories. The formation of a rigid foam structure depends on foaming of the protein in the plasma phase and partial coalescence of fat globules. The formation of protein foam in the cream, creation of net structure, and system breakage and collapse phenomena occurring throughout the whole whipping evolution process was depicted and distinguished visually by different colors.     

MICROSTRUCTURE AND RHEOLOGICAL BEHAVIOR OF WHIPPING CREAM

The mechanism of the formation of a rigid foam structure during whipping of reconstituted whipping cream was investigated. The rheological properties of whipped cream were estimated from an analysis of shear creep curves by a four element model. The values of each element increased exponentially during the process of whipping. From cryo-SEM observation, the surface of air bubbles consisted of a thin membrane which was penetrated by fat globules. Also, fat globules in the serum were joined together by free fat to form a framework structure.
The relationship between the rheological properties and microstructure of whipped cream was deduced from the rheological properties of two model systems. It is believed that whipped cream is a mixed matrix of a SOB O/W structure and a stiffer W/O structure.     

Tempering of dairy emulsions: Partial coalescence and whipping properties

This study investigates the effect of applying a time–temperature profile to natural and recombined cream to influence partial coalescence and, consequently, the whipping quality. To date, no clear relationship exists between the consequences of tempering on a microstructural level, partial coalescence, and whipping properties. Milk fat crystallisation was analysed using differential scanning calorimetry and the internal arrangement of fat crystals was visualised with cryo-scanning electron microscopy. Shear-induced partial coalescence and whipping properties were studied. Shear-induced partial coalescence was promoted, attributed to the observed changes in the fat crystal network. The effects on whipping properties were different for natural and recombined cream and thus dependent upon the interfacial composition. Consolidation of the partially coalesced fat droplet network by tempering increased the stability of whipped recombined cream during cold storage. Tempering is a promising tool to alter the susceptibility to partial coalescence by changing the internal fat crystal network, and influencing whippability.