基于内源性磷脂-乳清分离蛋白交互作用的磷虾油乳液稳定性研究

构建具有较高物理稳定性的乳液体系对最大限度提高磷虾油生物利用率和拓宽其在健康食品中的应用尤为重要。基于此,本文研究了内源性磷脂-乳清分离蛋白（WPI）交互作用对磷虾油乳液理化特性、微观结构和物理稳定性的影响规律和作用机理。结果表明,当载油量为25%时,磷虾油乳液平均粒径和Zeta电位值分别为35.03 nm和?27.3 mV,乳液趋于不稳定。添加0.5% （w/v）WPI使磷虾油乳液的平均粒径和Zeta电位绝对值分别增加84.0%、31.4%（P<0.05）,低剪切速率下表观粘度值增加7倍（P<0.05）,稳定性指数（TSI）值降低70.3%（P<0.05）,乳液趋于稳定。进一步结果显示,内源性磷脂能够与WPI交互作用改善其界面活性,并使WPI中α-螺旋结构含量降低1.60%（P<0.05）,内源性荧光强度和表面疏水特性明显增强。环境胁迫稳定性结果表明,模拟巴氏杀菌热处理能够增加磷虾油乳液物理稳定性,且向弱碱性pH迁移过程中（pH6~9）表现出较强的物理稳定性。因此,内源性磷脂-WPI交互作用对构建高物理稳定性磷虾油乳液和拓宽其在健康食品体系中的应用提供了可能。     

OSA淀粉-壳聚糖复合基Pickering乳液的构建及其特性表征

本研究以不同取代度的辛烯基琥珀酸淀粉酯（OSA淀粉）为原料,将其和壳聚糖结合生成复合物,并研究了取代度对复合物官能团变化和疏水性的影响。利用复合物构建了油相体积分数分别为20%、50%、80%的OSA淀粉-壳聚糖复合基Pickering乳液,探究了不同取代度与油相体积对乳液稳定性的影响。结果表明,随着OSA淀粉取代度的提高,复合物的疏水性显著增加。当辛烯基琥珀酸酐（OSA）的添加量为2%(w/w,以淀粉干物质计),复合物的三相接触角接近90°,具有较理想的湿润性。当取代度或油相体积分数提高时,乳液粒径也随之增大,液滴分布更加均匀致密,乳液状态也更加趋向于固态;并且,油相体积分数对乳液的影响更为突出。当OSA淀粉取代度为0.00895、乳液油相体积分数为80%时,乳液的平均粒径为27.4±1.4μm,呈现良好的凝胶网络结构,在-4℃下储藏30 d后乳析指数为0,具有较高的离子稳定性和热稳定性。本研究在OSA淀粉-多糖复合基Pickering乳液的构建参数选定方面作了进一步的探索,有望推动该乳液的开发与应用。     

芝麻分离蛋白制备及其白蛋白乳液的稳定性质

该文采用Osborne 法从脱脂芝麻粕中分级分离芝麻分离蛋白中的白蛋白、球蛋白、醇溶蛋白和谷蛋白组分,对其芝麻分离蛋白及不同组分蛋白理化性质和加工性能进行比较,并制备芝麻白蛋白乳液,探究油相体积分数、白蛋白浓度和离子强度对乳液粒径、流变特性和微观结构的影响。结果表明：Osborne 法比传统碱溶酸沉法芝麻分离蛋白得率更高,白蛋白的溶解度（28.1%）、保水性（3.7 g/g）、起泡性（273.2%）和乳化稳定指数（19.1 min）较好,球蛋白的保油性（2.3 g/g）和起泡稳定性（82.2%）较强,醇溶蛋白的乳化活性指数（23.7 m2/g）较高;在油相体积分数为60%,白蛋白浓度为6.0%,pH 值为3 条件下制备的白蛋白乳液粒径最小且分布均一,表现为非牛顿流体的假塑性行为,激光共聚焦显微镜观察发现白蛋白吸附在油水界面,进一步说明白蛋白乳液具有一定的稳定性。     

盐离子对大豆乳清混合蛋白乳液的稳定性及界面特性的影响

采用大豆分离蛋白-乳清分离蛋白（SPI-WPI）作为乳化剂形成水相,加入大豆油作为油相,制备O/W乳液,通过粒径、Zeta电位、乳液稳定性系数、激光共聚焦显微镜、界面蛋白吸附量、界面压力及界面膨胀流变等指标探究不同盐离子浓度（0~0.5 mol/L NaCl）对混合蛋白界面特性及乳液稳定性的影响。结果表明：盐离子会使混合蛋白乳液表面电位增加,且随着NaCl浓度的增加,乳液的体积平均粒径（D₄₃）升高,乳液稳定系数降低,乳液稳定性降低。并且,盐离子浓度为0.05 mol/L时,乳液最为稳定。此外,盐离子会使SPI-WPI在油-水界面的相互作用较弱,从而导致SPI-WPI溶液的界面压力值增大,在油-水界面的总模量（E）、弹性模量（E_d）、粘性模量（E_v）等降低,进而影响乳液的稳定性。这为食品产业生产较稳定的双蛋白乳液提供了理论依据。     

利用两性小分子甘草酸制备乳液凝胶及其性质分析

液态油脂结构化研究目前是现代食品加工业的热点问题。本文利用三萜化合物甘草酸铵作为天然结构化材料,将液态植物油结构化形成乳液凝胶（Emulsion gel）。该乳液凝胶油含量高,且制备方法简单温和。利用激光共聚焦显微镜和偏光显微镜观察的微观结构显示,在较高的甘草酸铵浓度和油含量下,作为活性填充颗粒的油滴紧密堆积在凝胶网络中,强化了凝胶结构。流变学测试结果也显示,在相同甘草酸铵浓度下,制备的乳液凝胶强度显著高于相应浓度的水凝胶。另外,荷载β-胡萝卜素对凝胶结构性质影响不明显,而且乳液凝胶保持良好的稳定性,表明该乳液凝胶具备作为油溶性生物活性物质输送体系的潜力。研究结果显示,利用两性小分子甘草酸铵作为天然结构化材料制备的乳液凝胶在功能性食品和药品等领域都具有宽阔的应用前景。     

二醛纳米纤维素的制备及其与明胶协同稳定Pickering乳液研究

以微晶纤维素为原料,通过硫酸水解和高碘酸钠氧化制备二醛纤维素纳米晶(dialdehyde cellulose nanocrystals, DACNC)并进行结构表征。进一步以DACNC和明胶作为协同乳化剂稳定Pickering乳液,考察明胶/DACNC的添加顺序、DACNC质量浓度以及外界环境条件(温度、pH和离子强度)对乳液性质和稳定性的影响。结果表明,经过高碘酸钠氧化后,DACNC的长度变短,热稳定性增加,但Zeta电位变化较小。DACNC和明胶预混合后再加入油相制备乳液效果较好,随着DACNC质量浓度的增加,明胶/DACNC乳液的粒径、黏度和模量均逐渐增加。乳液稳定性由于明胶的氨基和DACNC的醛基之间发生Schiff碱反应而增强,同时DACNC对乳液连续相网络的增强也有利于乳液稳定性增强。乳液环境稳定性结果显示,明胶/DACNC协同稳定解决了单独明胶或纤维素纳米晶乳液在低离子强度、低pH值和较高温度下乳液稳定性较差的问题。该研究提供了一种利用DACNC和明胶作为协同Pickering稳定剂改善乳液性质的新途径,为纳米纤维素和蛋白颗粒协同稳定Pickering乳液提供参考。     

基于食品级固体颗粒稳定的Pickering乳液研究进展

结合pH对羧甲基纳米纤维素（CMCN）的ζ-电位、接触角的影响,本文以CMCN溶液为连续相,玉米油为分散相构建低油相（20%）Pickering乳液凝胶,研究了CMCN稳定的Pickering乳液凝胶的类型、微观结构、流变学特性和不同条件下的稳定性。结果表明：从pH2到pH9,CMCN的ζ-电位从−2 mV减小到−67 mV,其中在pH4时ζ-电位绝对值相对较大且具有最接近90°的接触角,因此pH4时的CMCN更适合稳定低油相Pickering乳液凝胶。荧光显微镜和流变学结果分别证明CMCN稳定的Pickering乳液凝胶为O/W型,且在低油浓度下形成了类弹性结构（G'>G'）,为假塑性流体。低油相Pickering乳液凝胶贮藏120 d后仍可保持稳定。在1.3%以上浓度85 ℃加热和pH4以上CMCN稳定的乳液凝胶无分层现象且液滴尺寸变化较小证明其具有优异的pH和热稳定性。本研究制备的低油相Pickering乳液凝胶为绿色新型食品的开发提供了一种新思路,有望解决高油乳液凝胶不利于身体健康的问题。     

乳化剂HLB值对棕榈油基乳液功能性质的影响

以搅打充气乳液为对象,运用Turbiscan、流变仪、粒度仪、显微镜测定乳液充气前后的物理稳定性,探究食品乳化剂HLB值（3.8~15.0）对棕榈油基乳液功能性质的影响。结果表明：HLB值在3.8~10.0范围对于乳液稳定性影响不明显,但进一步增加HLB值,导致乳液热稳定性下降,颗粒聚集严重;在低乳化剂HLB值（3.8~10.0）范围内,乳液搅打充气时间随着HLB值的增加而延长,样品起泡率也随之增加,但硬度变化不明显;当HLB值为10.0时,乳液的搅打起泡率达到最大,为3.17;进一步增加乳化剂HLB值（12.0~15.0）,样品搅打充气时间明显缩短,表明乳液脂肪部分聚集更容易发生,但得到的样品硬度偏大,且样品的稳定性随着时间的延长明显下降。最终确定最佳乳化剂HLB值为10.0。     

高油酸菜籽煎炸油的研究

研究开发以精炼高油酸菜籽油为基油的煎炸专用油,设计合理的煎炸油配方。根据棕榈油、棉籽油、高油酸菜籽油等常用煎炸油的煎炸特性、脂肪酸组成及最终产品的质量要求,得到了油酸含量高于45%、亚麻酸含量低于4%、多不饱和脂肪酸含量低于30%的配方油,并通过方程运算和预实验,得到最佳配方为高油酸菜籽油、24度棕榈油、棉籽油质量比范围50%～64%∶0%～36%∶0%～24%。通过计算机筛选出5种配方油,其中配方油5 (高油酸菜籽油与24度棕榈油质量比为64∶36)煎炸稳定性好,煎炸寿命长,油炸食品感官效果好,因而是煎炸配方油的最佳选择。     

花生蛋白-果胶复合乳液凝胶的流变学特性和微观结构

研究不同油相及其添加量对转谷氨酰胺酶诱导制备的花生蛋白-果胶复合乳液凝胶质地特性的影响规律,同时通过流变学和微观结构特性研究探索乳液凝胶的形成机理。结果表明：花生蛋白-果胶复合乳液凝胶的凝胶强度显著高于水凝胶。凝胶外观和储能模量（G’）结果表明油滴与蛋白-果胶组成的凝胶基质相互作用,从而影响乳液凝胶的质地和凝胶强度。油相添加量的增加可以使乳液凝胶的力学性能增强,网络结构更稳定。花生蛋白-果胶复合乳液凝胶的G’值和硬度随油相添加量的增加而增大,说明分散的油滴作为活性填料与凝胶基质相互作用。花生蛋白-果胶复合乳液凝胶的微观结构结果表明,油相添加量60%(V/V)时24度棕榈油为油相的乳液凝胶网络结构更致密。研究结果为花生蛋白-果胶复合乳液凝胶在食品领域的开发利用提供思路。     

纳米SiO2改性4 种大分子材料的乳液制备及性质

为提高乳液稳定性,采用纳米SiO2改性明胶（gelatin,GE）、大豆分离蛋白、壳聚糖和阿拉伯胶（gum arabic,GA）制备茶油乳液。以乳化活性、乳化稳定性、离心稳定性、平均粒径、流变特性为考察指标,探究质量分数3.000%的纳米SiO2对4 种大分子材料复合乳液性质的影响,并对乳液的微观结构及油滴分布进行观察。结果表明,纳米SiO2能增强乳液稳定性,其中GE-纳米SiO2复合乳液综合性质最佳。添加纳米SiO2后乳化活性和乳化稳定性显著增加（P＜0.05）,离心稳定性降低68.444%。平均粒径为8.472 μm,乳液粒径最小且分布均匀,表面光滑呈球状。流变表现为典型的弱凝胶特性,稳定性良好。研究结果可为天然高分子和纳米SiO2乳液的制备和应用提供实践基础。     

球磨-酯化复合改性槟榔芋淀粉对Pickering乳液形成的影响

为了提高淀粉颗粒的乳化能力,以球磨-酯化复合改性槟榔芋淀粉为颗粒乳化剂,大豆油为油相,制备水包油型Pickering乳液.采用激光粒度仪、研究级正置显微镜、流变仪等对Pickering乳液外观、液滴粒径、显微形态及动态流变特性进行表征,考察淀粉颗粒质量浓度(1、5、10、20、30 mg/mL)和油相体积分数(10％、...     

高压均质对大豆蛋白乳液性质影响的研究进展

大豆蛋白作为一种高分子蛋白质,具有良好双亲性和表面活性,可通过在油水界面形成粘弹性蛋白层的方式在乳液中起到乳化作用,从而提高乳液体系的稳定性。高压均质技术是一种通过静高压和均质阀产生的综合效应从而改变蛋白质的结构和加工特性的新型非热加工技术,可以制备纳米级的大豆蛋白乳液。本文聚焦大豆蛋白乳液,阐述了高压均质制备大豆蛋白乳液的过程以及均质条件的影响,分析总结了高压均质处理对大豆蛋白乳液结构（粒径、ζ-电位、空间结构）和功能特性（流变特性、乳化性能和凝胶性能）影响的国内外研究进展及作用机理。最后,针对目前研究进展对高压均质在大豆蛋白乳液的加工应用做出展望,以期为大豆蛋白乳液的研究提供一定的帮助。     

Ability of whey protein isolate and/or fish gelatin to inhibit physical separation and lipid oxidation in fish oil-in-water beverage emulsion

The effect of pH on the capability of whey protein isolate (WPI) and fish gelatin (FG), alone and in conjugation, to form and stabilize fish oil-in-water emulsions was examined. Using layer-by-layer interfacial deposition technique for WPI–FG conjugate, a total of 1% protein was used to prepare 10% fish oil emulsions. The droplets size distributions and electrical charge, surface protein concentration, flow and dynamic rheological properties and physiochemical stability of emulsions were characterize at two different pH of 3.4 and 6.8 which were selected based on the ranges of citrus and milk beverages pHs, respectively. Emulsions prepared with WPI–FG conjugate had superior physiochemical stability compare to the emulsions prepared with individual proteins. Higher rate of coalescence was associated with reduction in net charge and consequent decrease of the repulsion between coated oil droplets due to the proximity of pH to the isoelectric point of proteins. The noteworthy shear thinning viscosity, as an indication of flocculation onset, was associated with whey protein stabilized fish oil emulsion prepared at pH of 3.4 and gelatin stabilized fish oil emulsion made at pH of 6.8. At pH 3.4, it appeared that lower surface charge and higher surface area of WPI stabilized emulsions promoted lipid oxidation and production of hexanal.     

Stability and rheology of concentrated O/W emulsions based on soybean oil/palm kernel olein blends

Droplet size distribution and rheological properties of egg yolk-stabilized emulsions were studied before and after storage (25 °C, 30 days). The dispersed phase (70%) of the emulsions was based on soybean oil (SBO) and 10–40% palm kernel olein (PKO) replacements of SBO. Replacement of PKO resulted in a significant increase in droplet mean diameters and a decrease in rheological properties of the emulsions. All emulsion exhibited a gel-like characteristic with storage modulus higher than loss modulus and tan δ greater than 0.3. Significant increase (p < 0.05) was found for droplet mean diameters and rheological properties of the emulsions after storage. Emulsion with fully SBO and the highest PKO replacement (40%) were found to be the most unstable, which was ascribed to a strong flocculation. With 10–30% PKO replacements, the emulsions displayed a better stability after storage, most probably promoted by significant content of short-medium chain fatty acids in PKO.     

Effect of concentrated flaxseed protein on the stability and rheological properties of soybean oil-in-water emulsions

Flaxseed protein concentrate containing-mucilage (FPCCM) was used to stabilize soybean oil-in-water emulsions. The effects of FPCCM concentration (0.5, 1.0, 1.5% w/v) and oil-phase volume fraction (5, 10, 20% v/v) on emulsion stability and rheological properties of the soybean oil-in-water emulsions were investigated. Z-average diameter, zeta-potential, creaming index and rheological properties of emulsions were determined. The result showed that FPCCM concentration significantly affected zeta-potential, creaming rate and emulsion viscosity. The increasing of FPCCM concentration led to a more negative charged droplet and a lower creaming rate. Oil-phase volume fraction significantly affected Z-average diameter, rheological properties, creaming index and creaming rate. With the increase of oil-phase volume fraction, both Z-average diameter and emulsion viscosity increased, while creaming index and creaming rate decreased. The rheological curve suggested that the emulsions were shear-thinning non-Newtonian fluids.     

STABILITY OF OIL-IN-WATER EMULSIONS. 2. Effects of Oil Phase Volume, Stability Test, Viscosity, Type of Oil and Protein Additive

SUMMARY –Stability of oil-in-water emulsions stabilized in sodium caseinate, gelatin and soy sodium proteinate was found to be increased by either an increase in the aqueous phase protein concentration (0.5–2.5%) or oil phase volume (20–50%). Both factors were significantly interrelated. Emulsions stabilized by soy sodium proteinate were generally higher in stability as compared to those stabilized by gelatin or sodium caseinate. With emulsions containing gelatin, greater stability occurred when the stability testing temperature was increased from 37–70°C and when the time interval was decreased from 24 hr to 90 min. Maximum relative viscosities of emulsions stabilized by gelatin and sodium caseinate were 2.0 and 2.5, respectively. Emulsions stabilized by soy sodium proteinate were quite viscous, with relative viscosity from 1.5–30 depending on both protein concentration and oil phase volume. Interchanging the emulsified oil among corn, soybean, safflower and peanut oils did not alter emulsion stability when examined at three concentrations of soy sodium proteinate. Changing the oil to olive oil significantly increased emulsion stability at each soy sodium proteinate level with oil phase volumes of 30, 40 and 50%.     

Effects of different oils on the properties of soy protein isolate emulsions and gels

The emulsion properties, protein adsorption and visco-elastic properties of heat-treated soy protein isolate (SPI) emulsions containing sunflower oil, soy oil and palm stearin were studied at neutral pH. The rheological properties, textural profile and fat adsorption capacity of subsequently induced glucono-δ-lactone (GDL) gels were investigated. At neutral pH the palm stearin emulsions showed higher stability than the sunflower and soy oil emulsions. The former also showed higher protein adsorption, emulsifying activity index and visco-elastic properties than the latter, indicating a higher denaturation degree for SPI at the oil/water interface of palm stearin emulsions at neutral pH. Acidified SPI-palm stearin emulsion gels were significantly harder than the soy and sunflower oil versions as well as the control (SPI without oil), whereas gels containing the two liquid oils were softer than the control. SPI-palm stearin gels also had higher fat adsorption capacity than SPI-sunflower oil/soy oil emulsion gels.     

蛋白种类对大豆皂苷-蛋白W/O/W型乳液稳定性的影响

将大豆皂苷添加至内水相（W1）,大豆蛋白添加至外水相（W2）,以玉米油为油相（O）,两步乳化法制备W/O/W型多重乳液。探究乳液的整体稳定性、粒径特性、电位特性、微观结构、流变学特性、界面张力以及长期稳定性的变化情况。结果表明：随着时间的延长,乳液的稳定性动力指数值呈上升趋势,粒径集中在6 μm附近,大豆分离蛋白乳液的电位绝对值最大（－30.2 mV）,该体系表现出假塑性的剪切稀化行为,大豆分离蛋白乳液的黏度值最大（0.029 Pa?s）;15 d后,所有蛋白乳液都出现了一定的分层现象,大豆分离蛋白乳液的稳定性动力指数最小（21.51）。在1%蛋白质量分数下,大豆分离蛋白制备的W/O/W型乳液稳定性优于大豆11S和7S蛋白。     

Comparative study of Pickering emulsions stabilised by starch particles from different botanical origins

Starch botanical origin is a key factor for the characteristics of Pickering emulsion. Starches with different sizes from rice (2.9–7.6 µm), waxy corn (9.3–25.0 µm), wheat (11.4–33.7 µm) and potato (24.4–54.1 µm) were esterified by octenyl succinic anhydride. The modified starch particles were used as stabilisers to produce oil-in-water Pickering emulsions. The physical stability, microstructures and rheological properties of different emulsions were compared. Results indicated that the emulsion stabilised with rice starch particles had the minimum droplet size of 83.6 µm and best physical stability during 30 days of storage. Moreover, starch particle size was negatively correlated with emulsion stability (P < 0.05). The particles (3.85% of the emulsion, w/w) built up wall-like structures around oil droplets, which prevented them from freely moving. All emulsions showed pseudoplastic fluid behaviours and presented gel properties, but elastic modulus (G′) and loss modulus (G″) were mainly affected by starch botanical origins.