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%。     

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。     

搅打稀奶油的搅打机理研究

通过研究稀奶油在搅打过程中的起泡率、泡沫硬度和浆液分离系数随搅打时间的变化规律,及搅打过程微观结构的变化,可将其分成3个阶段,即迅速充气阶段、脂肪球稳定附聚阶段和脂肪球急剧附聚阶段,在此基础上建立了搅打过程的模型,并分析了其搅打机理。     

3种市售搅打奶油的流变特性比较研究

本文针对稳定性能存在显著差异的3种市售搅打奶油,对其进行了基本成分、感官评定、流变学特性和质构特性分析实验。静态流变测试表明:搅打奶油呈现出假塑性与触变性;动态流变学测试表明:搅打呈现出凝胶特征。振荡温度扫描中复数模量G*呈现减小的趋势;而稳定性较差1号与2号样品温度扫描中有一个明显的临界温度15℃。在振荡时间扫描与频率扫描中,3号样品的弹性模量G’大于其他两个样品且相位角正切tanδ最小,其值小于0.3,故而表明3号样品的弹性成分比例最高。结合感官评定、稳定性实验和流变学分析可知,弹性模量G’可以有效表征搅打奶油的稳定性;搅打奶油的软硬程度可用触变环面积和屈服应力进行表征;其油腻感和口感分别与|?G’|和相对恢复率有关;贮藏的稳定性则与J_e和λ相关。     

均质条件对无脂搅打奶油品质的影响

搅打奶油通常是指含油脂和糖的食品配料,它通过搅打充气能形成丰富的泡沫结构.该类食品配料在面包、糕点类食品的表面装饰和夹馅等方面用途广泛.无脂搅打奶油是一种新型的食品配料,相对于传统的搅打奶油,它具有不含油脂,可以常温保存等优点.均质是无脂搅打奶油制备工艺中的重要一环.本研究在设计和优化无脂搅打奶油配方的基础上,考察拟定的生产工艺条件对无脂搅打奶油乳液的状态特性和产品稳定性的影响.本文报道通过探讨均质压力、均质温度、均质次数等均质条件对无脂搅打奶油的搅打起泡率和泡沫硬度等应用品质的影响.为无脂搅打奶油生产工艺的制订提供依据.实验结果表明:在无脂搅打奶油生产中,均质压力为5 MPa、均质温度为70℃、一次均质的工艺可得到满意的均质效果.     

老化时间对搅打植脂奶油品质的影响

研究了老化时间(0~24 h)对搅打植脂奶油乳浊液粒度分布、表观黏度、稳定性、打发时间、打发倍数、泡沫稳定性、质构性质以及感官品质的影响。结果表明:搅打植脂奶油的乳浊液粒度和表观黏度随着老化时间的延长而增加;乳浊液的稳定性先升高后降低;打发性质差异较小;泡沫稳定性较高;奶油泡沫硬度先增加后趋于稳定;感官品质在老化时间4 h时最好。因此,老化时间为4 h时,搅打植脂奶油的品质最佳。     

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。     

10种市售搅打奶油稳定性的多元分析

为了探明如何利用流变学特性指标对搅打奶油稳定性进行准确、快速的判断分析,本文通过相关性分析选取了8个与稳定性显著相关(p0.05)的流变学特性指标针对10种稳定性存在显著差异的市售搅打奶油进行了因子分析(FA)和聚类分析(CA)。因子分析表明:存在三个主因子"主要稳定因子"、"触变环因子"和"平衡形变因子";由载荷分析可知时间扫描G’、触变环面积S和平衡形变r是影响搅打奶油稳定性的关键流变学指标;总因子得分表达式为TFS=f1×0.38476+f2×0.25671+f3×0.22858,总因子得分排名可以反映出不同搅打奶油稳定性之间的差异。聚类分析表明:10种搅打奶油可以分成3类,第一类聚集了7个搅打奶油样品,即5号、6号、1号、10号、8号、9号和2号;第二类聚集了2个搅打奶油样品,即3号和4号搅打奶油样品;7号搅打奶油自成一类。     

零反式脂肪酸搅打奶油制备研究

该研究在调研搅打奶油配方及制备工艺参数基础上,以极度氢化棕榈仁油为基料油,采用正交实验设计,以打发率及保形性综合评分为指标,对影响搅打奶油产品性能主要工艺参数进行优化。结果表明,保温温度为70℃、老化时间为5 h、均质压力为30 Mpa下制备得到零反式脂肪酸搅打奶油产品打发率达到2.61%,保形性达到0.92,达到市售高反式脂肪酸搅打奶油产品性能要求。     

均质压力对UHT搅打稀奶油品质的影响

以新鲜稀奶油为主要原料,考察了不同的均质压力对UHT搅打稀奶油的脂肪球粒径、流变学特性、搅打特性的影响,分析了各评价指标之间的相关性。结果表明,UHT搅打稀奶油最适均质压力范围为3～5 MPa;随着均质压力的增大(1～9 MPa),脂肪球粒径减小,但打发成型所需时间增加;在α=0.01水平上,粒径与搅打时间、起泡率显著相关;在α=0.05水平上搅打时间与起泡率显著相关。     

不同乳化剂对大豆基搅打稀奶油的影响

本研究以大豆油体为原料,探究了不同乳化剂(大豆皂苷、大豆卵磷脂、大豆多糖、吐温80)对大豆基搅打稀奶油的粒径分布、粘度、乳状液稳定性、搅打起泡率、泡沫稳定性的影响。结果表明,不同乳化剂对大豆基搅打奶油的乳状液特性和搅打特性有一定影响。添加吐温80的大豆基搅打稀奶油有较小的粒径分布,ζ-电位为-30.3 mV,粘度比加其他大豆乳化剂的小,而且搅打起泡性最高,达到112.4%,但是泡沫稳定性只有2.1%。添加大豆乳化剂的大豆基搅打稀奶油具有类似的乳状液特性,但是添加大豆卵磷脂的大豆基搅打稀奶油比其他两种大豆乳化剂具有更高的膨胀率(134.5%),而添加大豆多糖的大豆基搅打稀奶油具有更好的泡沫稳定性(1.2%)。     

Effect of xanthan gum on the physical properties and textural characteristics of whipped cream

Xanthan gum was used as thickening agent to prepare whipped cream in this work. A dose-dependent effect was observed on the average particle size (d_3,2) of whipped cream. At each xanthan gum level (0.025–0.125%) used, whipping time also showed a positive effect on the average particle size. With the increase of xanthan gum level or whipping time, the partial coalescence of fat in the whipped cream increased gradually. However, xanthan gum level showed no significant effect on the overrun of whipped cream. The textural characteristics of whipped cream were also investigated and the results indicated that a positive correlation was found between xanthan gum level and firmness, cohesiveness or viscosity of whipped cream. A different tendency was detected for consistency. The consistency of whipped cream increased with the increase of xanthan gum level to 0.100%, thereafter decreased.     

Effect of whey protein concentrate addition on the physical properties of homogenized sweetened dairy creams

The influence on their whipping properties of homogenization at first and second stage pressures of 3.5/1.5 MPa and addition of whey protein concentrate (WPC) powder at three different (0.7, 1.4, and 2.1 wt percentage) concentrations to sweetened and homogenized creams was studied. Homogenization of cream significantly decreased maximum overrun and made the foam microstructure less open, while increasing whipping time, cream and foam lightness (Hunter L -value) and apparent viscosity. It also resulted in a less elastic foam structure with an increased drainage. Addition of WPC decreased the amount of maximum overrun, foam drainage and its lightness in parallel with developing a more compact microstructure. It increased the whipping time, apparent viscosity of unwhipped creams and foams, and resulted in a less elastic foam structure. The apparent viscosity of whipped cream with 2.1 wt percentage WPC, however, was lower than that of whipped cream with 1.4 wt percentage WPC, due most probably to the start up of gel formation at 2.1% WPC concentration in sweetened cream when it was sheared. Fresh foam whipped from sweetened cream with 2.1 wt percentage WPC also tended to have a slightly but not statistically significant lower elastic modulus (G') than fresh foam whipped from sweetened cream with 1.4 wt percentage WPC. This concentration can be considered as the critical value for gel formation in sweetened creams enriched by whey proteins when sheared. This study indicated the potential of WPC powder for reducing foam drainage from whipped homogenized sweetened cream.     

Physical,textural, and rheological properties of whipped cream affected by milk fat globule membrane protein

This work aims at improving the textural and whipping properties of whipped cream by the addition of milk fat globule membrane protein. The determination of particle size distribution and average diameter of whipped cream showed that the small particle size was shifted to a larger range after milk fat globule membrane protein was added. The average particle size (d_3,2) of whipped cream reached a maximum value of 5.05 µm at 1% milk fat globule membrane protein, while slowly decreased with increasing milk fat globule membrane protein levels from 2% to 5%. In addition, the partial coalescence of fat increased with the increase of milk fat globule membrane protein levels, and the correlation between the whipping time and the overrun of whipped cream was positive. The addition of milk fat globule membrane protein also altered the rheological behaviour of whipped cream, resulting in the increase of modulus G′ and the loss modulus G″. The results also indicated that higher milk fat globule membrane protein level decreased the serum loss of whipped cream while improved its stability. While milk fat globule membrane protein levels had no significant effect on viscosity, its increasing levels effectively improved the hardness, consistency, and viscosity of whipped cream.     

Effect of hydroxypropyl methylcellulose on the textural and whipping properties of whipped cream

In this work, hydroxypropyl methylcellulose (HPMC) was added into whipped cream for improving its textural and whipping properties. By determination of the particle size distribution, a single peak for the emulsion after homogenization and two distinguishable peaks for the emulsion after whipping for 5 min were observed. With the increase of HPMC level, the average particle size (d_3,2) decreased for the emulsion after homogenization and increased for the emulsion after whipping for 5 min. Both whipping time and HPMC level showed positive effects on the partial coalescence of fat globules. The partial coalescence of whipped cream with 0.125% HPMC after whipping for 5 min reached 56.25%, significantly (P < 0.05) higher than that (4.77%) without whipping treatment. Surface protein concentration was measured to evaluate the change of protein content at the droplet interface. The results indicated that the increase of HPMC level could decrease the surface protein concentration slightly. The overrun of whipped cream slightly increased when the HPMC level increased in the range of 0.025–0.125%. Firmness, cohesiveness, consistency and viscosity of whipped cream were analysed in this work. HPMC showed a positive dose-dependent effect on all these textural properties.     

Physicochemical properties and application of micronized cornstarch in low fat cream

With normal cornstarch (CS) as material, micronized starch was prepared first by acid hydrolyzed pretreatment and then ball-milling (HMS). A control sample (MS) was prepared by ball-milling without pretreatment. Particle size and shape of micronized starch were investigated, and its application in low fat cream was studied. The Maltase cross of HMS granules almost disappeared and the particle size clearly decreased. It was evident that acid-lintnerised starch granules were more susceptible to break down upon milling. However, the granules would aggregate with an increase in milling time. Compared with full-fat cream, the apparent viscosity of low-fat cream increased, while fat globules partial coalescence rate, overrun and textural properties decreased with the increasing of the fat replacement rate. The average particle size of whipped cream increased with the increase of whipping time. Results indicate that a 15% fat replacement rate would produce cream with good foaming and storage stability.     

复配乳化剂HLB值对稀奶油脂肪聚结及结晶的影响

将单,双甘油脂肪酸酯与蔗糖酯按一定比例复配成不同亲水亲油平衡（hydrophile lipophilic balance,HLB）值的乳化剂,研究复配乳化剂HLB值对稀奶油脂肪聚结及结晶影响,并对其乳液性质及打发性质进行表征。结果表明,随着复配乳化剂HLB值的增大,乳液粒径增大且表观黏度升高进而使搅打时间延长;热力学及Avrami等温结晶动力学结果表明,复配乳化剂HLB值为10时,高熔点乳脂熔融温度改善显著,并且结晶速率最快;HLB值为8～10时打发性较好,乳清泄漏率较低,涂抹性较佳。因此,复配乳化剂HLB值应控制在8～10,此时更适用于高品质裱花稀奶油的工业生产。     

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.