复配蛋白质添加量对黄油基搅打稀奶油稳定性及搅打性能的影响

该文以m(酪蛋白)∶m(乳清蛋白)=2∶1复配蛋白质,以无盐黄油和离心乳脂肪为原料制备黄油基搅打稀奶油。以搅打时间、搅打起泡率、脂肪部分聚结率、粒径分布、表观黏度和泡沫稳定性为评价指标,研究复配蛋白质的添加量对黄油基搅打稀奶油乳液稳定性及搅打性能的影响。结果表明,当复配蛋白质的添加量为0.9%～1.2%(质量分数)时,脂肪球粒径分布为0.81～7.16μm,乳液脂肪附聚率为6%～10%,乳液的搅打时间为277～296 s,搅打起泡率达到200%～203%,泡沫稳定性为95.86%～97.03%。故将黄油基搅打稀奶油中复合蛋白质添加量控制在0.9%～1.2%,搅打稀奶油的乳液稳定性及搅打性能较好,为以黄油为原料生产高品质搅打稀奶油奠定理论基础。     

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。     

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。     

二次均质工艺中一次均质压力对黄油基搅打稀奶油品质的影响

以无盐黄油和脱脂乳为原料制备黄油基搅打稀奶油,采用二次均质工艺,研究了一次均质压力（二次均质压力不变）对黄油基搅打稀奶油的粒径、脂肪部分聚结率、流变学特性、搅打性能的影响,分析了各评价指标之间的相关性。结果表明,黄油基搅打稀奶油的一次均质压力在10.0~15.0 MPa时,随着均质压力的增大,脂肪球粒径D4,3由1.85 μm逐渐减小到1.57 μm,且在15.0 MPa时脂肪球粒径D4,3达到最小为1.57 μm;黄油基搅打稀奶油的脂肪部分聚结率随着一次均质压力的增大逐渐增大,由13.74%增大到17.53%;搅打时间随着均质压力的增大逐渐由314 s减小到265 s且一次均质压力在15.0 MPa时搅打时间最少为265 s;泡沫稳定性由78.09%逐渐增加到87.26%,且泡沫稳定性在15.0 MPa时泡沫稳定性达到最大87.26%。因此将黄油基搅打稀奶油的一次均质压力控制在10.0~15.0 MPa范围内较适宜。     

热处理和调节pH改性乳清蛋白浓缩物对搅打稀奶油加工性质的影响

通过热处理和调节p H对乳清蛋白浓缩物80(Whey protein concentrate,WPC80)进行改性处理,并将改性后的WPC80添加至低脂稀奶油中,以改善其搅打性质。结果表明调节WPC80溶液的p H为3,在80℃下加热15min时具有最佳的溶解性和起泡性,相同p H条件下,不同的热处理时间会对溶解性和起泡性产生不同的影响;将热处理和p H改性后WPC80加入搅打稀奶油中,研究发现不同热处理时间,p H为5改性的WPC80可以显著提高搅打稀奶油的打发率(p0.05),但是p H为7处理的WPC80使稀奶油的泡沫稳定性增加了154.67%~193.42%。因此可通过热处理和调节p H改性的WPC80来提高低脂稀奶油的搅打特性,且此操作方法简单易行。     

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%。     

复配乳化剂协同作用对搅打稀奶油稳定性及搅打品质的影响

该研究固定复配乳化剂总质量分数为0.3%,使用亲水乳化剂吐温-80和亲油乳化剂单甘油酯以不同比例复配制备搅打稀奶油，从乳液界面性质及脂肪结晶性质变化的角度研究其协同作用对产品品质的影响。结果表明，当吐温-80与单甘油酯的质量比由1∶1逐渐升至1∶4,乳液液相蛋白质浓度及表观黏度下降，结晶脂肪耐热性增强，β′晶型明显，产品打发率上升，泡沫析水率下降；当吐温-80与单甘油酯的质量比变为1∶5和1∶6时，产品中结晶脂肪β′晶型含量下降，晶体尺寸显著减小，产品打发率下降，泡沫析水率上升。因此，吐温-80与单甘油酯质量比为1∶4,符合工业生产高品质搅打稀奶油的要求，此时产品搅打时间仅需(277.3±2.5) s,打发率达(158.9±1.23)%,搅打泡沫析水率仅(1.55±0.47)%,并且兼具良好的乳液稳定性。     

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。     

常用食品乳化剂对复合骨汤乳化稳定效果的影响

以稳定系数R值、平均粒径D_[4,3]及粒径分布系数PDI、Zeta电位和乳液黏度为指标,探究了不同食品乳化剂(蔗糖酯、单甘酯、吐温80、大豆卵磷脂和酪蛋白酸钠)及其添加量对复合骨汤乳化稳定效果的影响。研究结果表明,与原复合骨汤相比,添加乳化剂后复合骨汤乳液的稳定性都得到显著提高(P<0.05);5种乳化剂的最佳乳化效果添加浓度分别为蔗糖酯2.5%、单甘酯2.5%、吐温80 0.5%、大豆卵磷脂2.5%、酪蛋白酸钠2.0%;不同乳化剂对复合骨汤乳液的乳化、稳定效果和机制不同,优劣次序为吐温80>大豆卵磷脂>蔗糖酯>单甘酯>酪蛋白酸钠;结合乳液稳定性及感官评价结果,复合骨汤中分别添加2.5%蔗糖酯和1.5%大豆卵磷脂时稳定性和感官品质最好。     

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。     

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。     

二段均质压力对黄油基搅打稀奶油品质的影响

该文在黄油基搅打稀奶油经高压均质、热处理后分别使用1.0~5.0 MPa压力进行二段均质处理,并以未经二段均质处理的产品为对照,比较经不同二段均质压力处理后产品稳定性及搅打品质的变化。实验发现,对照产品脂肪球粒度分布出现明显双峰现象,乳液稳定性差,搅打时间为372.00 s,起泡率仅193.70%,并且在光学显微镜下观察到大量絮凝的脂肪球簇;当二段均质压力在1.0~ 3.0 MPa范围内增大,产品脂肪球平均粒径减小,产品稳定性增强,搅打时间缩短,打发率上升,絮凝的脂肪球簇的数量明显减少;当二段均质压力达到3.0 MPa,产品粒度分布趋于稳定,搅打时间仅需306.50 s,起泡率达235.10%,光学显微镜下未观察到明显絮凝现象。相比对照组,经3.0 MPa压力处理后的产品稳定性更好,搅打成型时间由372.00 s缩短至306.50 s,起泡率由193.70%提高至235.10%,实验结果表明,在搅打稀奶油生产中使用3.0 MPa压力进行二段均质可有效阻止乳液脂肪球絮凝,提高产品的稳定性及搅打品质,可满足工业生产高品质搅打稀奶油的要求。     

改性大豆蛋白在植脂奶油中的应用

研究了改性大豆蛋白的乳化性、乳化稳定性、起泡性,以及其替代进口酪朊酸钠应用于植脂奶油对其搅打时间、起泡率、保形性、变粗程度、入口即化感、光泽度、细腻度、油腻感的影响,研究表明,改性大豆蛋白的乳化性、乳化稳定性、起池陛介于进口酪朊蛋白和国产酪朊蛋白问,优于国产大豆分离蛋白;改性大豆蛋白替代进口酪朊酸钠50％应用于植脂奶油产品品质良好。     

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.     

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.     

搅打稀奶油的乳液特征和打发性能研究

为了对搅打稀奶油的科学应用提供参考,以19款市售代表性搅打稀奶油（常温型、冷藏型和冷冻型产品）为研究对象,通过分析乳液的离心乳析率、黏度、粒径和微观结构研究其乳液的质量,通过分析打发时间、起泡率、泄漏率和裱花性能研究其打发性能。结果显示：常温型产品的离心乳析率为22.17%～32.68%,显著高于冷藏型产品的离心乳析率(1.36%～13.09%)和冷冻型产品的离心乳析率(2.97%～12.87%);常温型和冷藏型产品的黏度、粒径分布特征接近,呈流动性较好且脂肪球分布较均匀的乳液,而冷冻型产品相对黏稠且乳液中无明显脂肪球结构;常温型产品和冷藏型产品的打发时间在13244～291.28 s之间（只有1款冷藏型产品打发时间为79.49 s）,起泡率在111.49%～202.50%之间（只有2款冷藏型产品起泡率分别为92.30%、328.25%）,部分有泡沫泄漏,裱花维持能力较弱;而冷冻型产品打发时间为89.91～158.52 s,起泡率在240.39%～27815%,无泡沫泄漏,裱花维持能力强。综合而言,常温型搅打稀奶油的乳液相对不稳定,打发性能与冷藏型搅打稀奶油接近,而冷冻型搅打稀奶油的打发性能最强。     

不同乳化剂对油酸和亚油酸乳状液稳定性的影响

本文以粒径、稳定性和流变为考察指标,利用激光粒度仪、食品稳定性分析仪、流变仪等研究不同种类和添加量的食品乳化剂(阿拉伯胶、酪蛋白酸钠、吐温20)对不饱和脂肪酸(油酸和亚油酸)乳状液的制备及其稳定性的影响。结果表明,三种乳化剂均可制备出稳定性较好的乳状液,不同乳化剂的质量分数不同得到乳状液的稳定性不同。较高质量分数的阿拉伯胶(4%,w/v)乳状液,具有最低的澄清指数并且具有最大粘度(0.30~0.40 Pa·s)。当酪蛋白酸钠的质量分数为2%时,制备出的乳状液较稳定,但粒径较大,贮藏稳定性较差。较低质量分数的吐温20(1%,w/v)的乳状液具有最小粒径(0.20~0.21 μm),经过贮藏后变化程度也最小。本文研究了不同食品乳化剂制备的不饱和脂肪酸乳状液及其稳定性,可为不饱和脂肪酸乳状液的制备和应用提供参考。     

Effect of sorbitan monostearate on the physical characteristics and whipping properties of whipped cream

In this work, the effects of sorbitan monostearate (Span 60) level on the particle size distribution, microstructure and apparent viscosity of the emulsion were investigated. Average particle size (d_4,3), surface protein concentration, partial coalescence of fat and overrun of whipped cream during whipping were also determined. As Span 60 level increased (0–0.8%) in emulsion, the apparent viscosity was increased gradually, and the particle size range was narrowed, which was also detected by microstructure. A positive effect of whipping time was observed on the average particle size, partial coalescence of fat, surface protein concentration and overrun during whipping, respectively. An increase of Span 60 level resulted in a reduction of d_4,3 values and partial coalescence of fat during 0–1 min whipping, then increasing after whipping for 2–5 min (0.6% Span 60 as the critical level). A negative behaviour was observed between surface protein concentration and Span 60. Moreover, Span 60 could improve the overrun and organoleptic properties of whipped cream efficiently.     

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.