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。     

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。     

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。     

加工工艺条件对稀奶油搅打特性的影响

研究了加工工艺条件对稀奶油搅打特性的影响。以搅打特性指标为评价依据,采用正交试验研究稀奶油加工工艺,确定最佳工艺条件为:均质温度55℃,均质压力8 MPa,杀菌温度120℃,杀菌时间4 s。在最佳工艺条件下,产品的打发率、硬度和黏度分别为119%、306 g和419 m Pa·s,具有较高的打发率和硬度。     

搅打稀奶油品质及其影响因素的研究进展

搅打稀奶油是一类可搅打起泡的水包油乳液。作为重要的食品工业原料，搅打稀奶油可作为呈味物质赋予食品良好的感官特性，应用前景广阔。本文首先介绍搅打稀奶油贮藏期内常见的失稳作用，包括乳析、聚集、聚结、部分聚结及奥氏熟化，并阐述界面特性及脂肪球间的交互作如何影响搅打稀奶油的稳定性；其次介绍搅打稀奶油的搅打过程，阐述结晶特性、界面特性和液相蛋白特性如何影响搅打特性。本文可为搅打稀奶油产品的工业化生产提供一定的理论指导。     

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。     

酪蛋白种类和二次均质工艺对再制稀奶油搅打特性的影响

本研究旨在分析3 种常见的酪蛋白产品,胶束酪蛋白浓缩物（micellar casein concentrate,MCC）、酪蛋白酸钙（calcium caseinate,CaC）及酪蛋白酸钠（sodium caseinate,NaC）对再制稀奶油搅打特性的影响,以及再制稀奶油进行二次均质后其搅打特性的变化。结果表明：MCC、CaC及NaC再制稀奶油的搅打特性受酪蛋白质量分数的影响,且其对二次均质工艺的敏感性不同。MCC和CaC的质量分数较高（1.5%和2.5%）时,制备的稀奶油具有良好的搅打特性,最大起泡率在170%～200%范围内,泄漏率在0～1.5%范围内;进行二次均质后最大起泡率和泄漏率的变化较小。而NaC在较低的质量分数（0.5%）条件下制备的稀奶油才可具有较好的搅打特性,最大起泡率为（198.2±4.0）%;当NaC质量分数增至1.5%时,最大起泡率下降至（119.0±15.4）%。二次均质后NaC再制稀奶油的最大起泡率下降,泄漏率增加。研究认为,以MCC和CaC为原料制备的稀奶油无论是否进行二次均质,均有良好的搅打特性。     

胶体对稀奶油打发及其流变学特性的影响

使用不同的胶体和不同的添加量来研究胶体对稀奶油打发及流变学特性的影响.结果表明,选择合适的胶体增加了搅打稀奶油体系的黏度、打发时间及泡沫的稳定时间,降低了产品的打发率及酪乳析出的比例.胶体与蛋白的相互作用增加了体系的稳定性,有效的阻止脂肪球的聚集.打发过程中酪乳析出比例与打发时间和泡沫的稳定时间有极显著的负相关(P<0.001),打发率与泡沫的稳定时间相关性不显著.当卡拉胶添加量为0.02%,变性淀粉添加量为0.6%,羟甲基纤维素钠添加量为0.1%时(均为质量分数)稀奶油的打发及流变学特性为最佳.     

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。     

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。     

Influence of whipping temperature on the whipping properties and rheological characteristics of whipped cream

The effects of whipping temperature (5 to 15°C) on the whipping (whipping time and overrun) and rheological properties of whipped cream were studied. Fat globule aggregation (aggregation ratio of fat globules and serum viscosity) and air bubble factors (overrun, diameter, and surface area) were measured to investigate the mechanism of whipping. Whipping time, overrun, and bubble diameters decreased with increasing temperature, with the exception of bubble size at 15°C. The aggregation ratio of fat globules tended to increase with increasing temperature. Changes in hardness and bubble size during storage were relatively small at higher temperatures (12.5 and 15°C). Changes in overrun during storage were relatively small in the middle temperature range (7.5 to 12.5°C). From the results, the temperature range of 7.5 to 12.5°C is recommended for making whipped creams with a good texture, and a specific temperature should be decided when taking into account the preferred overrun. The correlation between the whipped cream strain hardness and serum viscosity was high (R² = 0.906) and persisted throughout the temperature range tested (5 to 15°C). A similar result was obtained at a different whipping speed (140 rpm). The multiple regression analysis in the range of 5 to 12.5°C indicated a high correlation (R² = 0.946) in which a dependent variable was the storage modulus of whipped cream and independent variables were bubble surface area and serum viscosity. Therefore, fat aggregation and air bubble properties are important factors in the development of cream hardness. The results of this study suggest that whipping temperature influences fat globule aggregation and the properties of air bubbles in whipped cream, which alters its rheological properties.     

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。     

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%。     

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.     

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.     

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。     

搅打充气对搅打奶油流变特性的影响

研究了搅打充气对搅打奶油流变特性的影响,分析其变化规律及探讨搅打充气与搅打奶油结构之间的内在联系。结果表明:搅打奶油属于假塑性流体,其表观黏度、屈服应力、触变性和黏弹性(G~*)均随搅打充气进行而增加,而相对恢复率呈先增大后减小趋势。在蠕变-回复测试中,蠕变柔量随搅打充气进行逐渐减小;推迟时间先增大后减小,到了搅打过度阶段又重新增大;回复率呈先增大后减小趋势。     

植脂奶油泡沫结构形成的研究

分别测定植脂奶油乳状液在剪切、充气和搅打作用下脂肪球部分聚结率、电导率、膨胀率的变化,研究了植脂奶油形成泡沫结构的作用机理.结果表明,剪切或充气作用都不能形成稳定的泡沫结构;只有在搅打条件下才能获得60%以上的脂肪球部分聚结率,使植脂奶油由一个黏稠的液体转变为稳定的泡沫结构.