葡萄皮中花色苷的体外抗氧化研究

研究了花色苷清除DPPH·的能力，并用荧光化学发光法测定了花色苷对活性氧自由基（O2^-、·OH、H2O2）的清除作用。结果表明，该产品对DPPH·、O2^-、·OH、H2O2均具有清除作用，尤其对·OH的清除能力强于抗坏血酸，且清除作用与浓度呈量效关系。     

高压电场制备W/O/W复乳微囊的试验研究

为探索水溶性物质微囊化新方法，利用高压电场微胶囊成型装置制备W／O／W型微囊，内水相为蒸馏水，油相为液体石蜡，外水相为海藻酸钠溶液。研究了电压、液面距、推进速度、初乳／外相水溶液、海藻酸钠浓度对微囊粒径的影响。结果表明：在成囊范围内，电压、液面距和外水相海藻酸钠溶液浓度对微囊的粒径有较为显著的影响。在电压3．15kV～4kV，液面距2．5cm-10cm，海藻酸钠浓度0．6％～1．2％，可以制得微囊粒径范围为50μm-1000μm，大小均匀的复乳微囊。     

高压电场制备W/O/W复乳微囊的试验研究

为探索水溶性物质微囊化新方法,利用高压电场微胶囊成型装置制备W/O/W型微囊,内水相为蒸馏水,油相为液体石蜡,外水相为海藻酸钠溶液。研究了电压、液面距、推进速度、初乳/外相水溶液、海藻酸钠浓度对微囊粒径的影响。结果表明:在成囊范围内,电压、液面距和外水相海藻酸钠溶液浓度对微囊的粒径有较为显著的影响。在电压3.15～4kV,液面距2.5～10cm,海藻酸钠浓度0.6%～1.2%条件下,可以制得微囊粒径范围为50～1000μm之间,大小均匀的复乳微囊。     

复凝聚法制备西番莲果皮花色苷微胶囊及其性质分析

为提高花色苷稳定性,以西番莲果皮花色苷为芯材,明胶、阿拉伯胶为壁材,采用复凝聚法制备花色苷微胶囊。研究以包埋率为指标,采用响应面法优化西番莲果皮花色苷微胶囊最佳制备条件,进而以粒径、水分含量、形态及热稳定性研究了西番莲果皮花色苷微胶囊性质。结果表明:芯壁比1:4.7,壁材质量比（明胶: 阿拉伯胶质量比）6:7,壁材浓度1.5%,pH3.30,反应温度40 ℃,反应时间30 min,谷氨酰胺转氨酶25 U/g明胶,此时模型可靠性高,西番莲果皮花色苷包埋率最高为96.83%。最佳操作条件下所得微胶囊的粒径为12.15 μm,其水分含量为2.69%,微胶囊呈表面光滑的球形结构,熔融温度为82.51 ℃。此研究为西番莲果皮花色苷的应用提供了参考。     

负载姜黄素/花色苷的木薯淀粉基W1/O/W2型Pickering双重乳液的制备及性质

以木薯纳米淀粉、木薯醋酸酯变性淀粉为颗粒乳化剂制备食品级W₁/O/W₂型Pickering双重乳液,分别于内层水相、油相对姜黄素与花色苷进行负载。考察不同木薯醋酸酯变性淀粉质量分数对双重乳液显微形态、粒径、Zeta电位、负载率及贮藏稳定性的影响,并分析其在体外消化过程的控释性能。结果表明,木薯醋酸酯变性淀粉质量分数为6%时,乳液综合性能最好。此时,乳滴分布均匀,呈“三相两膜”结构,粒径为3.65μm,Zeta电位为-14.50mV,姜黄素、花色苷的负载率达到95.23%、93.00%,4、25、40℃时贮藏20d均未出现明显分层;经模拟消化后乳液中姜黄素、花色苷保留率为41.59%、76.29%,与游离姜黄素、花色苷相比,二者生物利用率分别提高了约4倍、3倍。证实了木薯淀粉基双重乳液能实现在模拟消化系统中对活性物质的保护,并能有效提升其生物利用率。研究结果旨在为食品工业中淀粉基功能性乳液运载体系的构建及新型食品级Pickering双重乳液的开发提供理论参考。     

黑米花色苷微胶囊的制备及其稳定性评价

以海藻酸钙为壁材,利用乳化凝胶化法制备黑米花色苷微胶囊,研究包被后黑米花色苷在高温、光照、p H条件下的稳定性,及其在模拟胃肠液中的释放性能。在海藻酸钠浓度为15 g/L,水油体积比为1∶3,壁芯比M(NaAlg)∶M(C3G)为1∶2,溶液p H值为4.5的工艺参数条件下制备的黑米花色苷微胶囊,在不同pH、温度、光照条件下的稳定性均显著高于未包被游离黑米花色苷,且在模拟胃液中能保持4h,在模拟肠液中壁材缓慢降解,释放出花色苷。基于乳化凝胶化原理的微胶囊包被技术,能提高花色苷的稳定性,实现其在体内的肠道递送和缓释。     

植物乳杆菌和发酵乳杆菌发酵对蓝莓花色苷的影响

选用植物乳杆菌（Lactobacillus plantarum）FM-LP-9和发酵乳杆菌（Lactobacillus fermentum）FM-LP-SR6分别对蓝莓花色苷进行发酵,考察发酵过程中菌落总数、pH值、色差、总黄酮含量、总糖含量、总花色苷含量、单体花色苷含量、有机酸含量等指标的变化规律。结果表明,经48 h发酵后,两种乳杆菌的菌落总数均能达到9.0 lg（CFU/mL）以上,发酵液的pH值降至3.6,总糖含量相较于发酵前分别降低了48.65%和58.97%,总黄酮含量分别增加至11.4、11.8 mg/L,总花色苷含量分别降低了48.63%和46.06%,色差值升高,颜色变暗。两株乳杆菌均能代谢花色苷和转化酚类物质,发酵过程中花色苷含量呈下降趋势,主成分分析得出两株乳杆菌发酵花色苷后的单体花色苷组分差异较大,主要来自飞燕草素-3-O-葡萄糖苷和矢车菊素-3-O-葡萄糖苷。此外,两株菌发酵后,发酵液中的乳酸、乙酸含量升高,草酸、苹果酸、柠檬酸含量降低。     

模拟体外消化对蓝靛果提取物花色苷组成及抗氧化能力的影响

研究体外消化前后蓝靛果提取物的总酚和花色苷含量、花色苷组成以及抗氧化能力的变化。实验分别采用福林-酚法和pH示差法测定总酚和花色苷含量,利用高效液相色谱-电喷雾二级质谱联用技术结合分子质量,离子碎片,出峰顺序及参考文献分析花色苷组成;采用总抗氧化能力（total antioxidant capacity,T-AOC）和氧自由基吸收能力（oxygen radical absorbance capacity,ORAC）法测定体外消化前后提取物的抗氧化能力。结果表明：模拟体外消化后样品总酚含量增加了48.2%,花色苷含量降低了67.6%,单体花色苷由11 种降为8 种,此外,ORAC值和T-AOC值分别下降了80.0%和55.6%。综上,与未经消化提取物相比较,模拟体外消化处理的蓝靛果提取物的多酚含量增加,花色苷含量和种类均减少,抗氧化能力下降。     

蓝莓花色苷体外及模拟人体胃肠环境的抗氧化活性研究

以野生蓝莓为原料提取花色苷,对其进行纯化、121℃高温加热6 min和模拟人体胃肠环境处理,测定处理后的样液的抗氧化活性,对结果进行综合分析比较,得出不同条件对花色苷抗氧化活性的影响。结果表明:同一处理环境下,水溶液中的花色苷的抗氧化活性随纯度的增大而明显增强,二次纯化物的活性是粗提物的4倍左右,但在模拟胃肠环境中活性受纯度的变化影响较小;在同一纯度下,花色苷经过模拟胃肠和高温加热处理后抗氧化活性大大的降低,水溶液中的花色苷活性是模拟胃肠环境中的2倍以上;花色苷经121℃高温加热后活性大大降低,同一条件下活性损失了一半左右,但这种损失在模拟人体胃肠环境中较小,粗提物水溶液中的花色苷的活性是121℃加热后的花色苷的2.7倍。     

氨基酸均衡小米复合粉制备及发酵乳体外消化分析

将小米与乳清分离蛋白粉和大豆分离蛋白粉复配,通过正交实验确定最优氨基酸均衡小米复合粉的质量配方;评价体外胃肠消化过程对小米浓浆未发酵组和小米发酵乳组的多酚、黄酮及抗氧化性的影响。结果表明：小米复合粉最佳质量配方为：小米粉66.8%,乳清分离蛋白粉16.6%,大豆分离蛋白粉16.6%;未发酵组和发酵乳组的多酚含量、DPPH、ABTS和羟基自由基清除率在胃、肠消化的各个阶段都显著增加。黄酮含量和铁还原力在胃消化阶段呈正增长而在肠消化时略微减少。发酵乳组的抗氧化能力在消化的每个时间段都要强于未发酵组,说明发酵工艺可以提升产品的抗氧化性。     

In Vitro Digestion and Fermentation of Microencapsulated Tributyrin for the Delivery of Butyrate

Butyrate possesses negative sensory qualities and is most effectively utilized in the intestine to provide energy to the colonocyte for the maintenance of intestinal health. Butyrate has also shown promise in the treatment of intestinal disorders and diseases such as short bowel syndrome, inflammatory bowel disease, and colon cancer. To modify sensory properties, intestinal release, and butyrate production capabilities, tributyrin (TB) was microencapsulated in whey protein isolate (WPI)‐based and gamma‐cyclodextrin (GC)‐based materials. Using an in vitro digestion and fermentation model, microcapsules containing TB were monitored for their release and production of butyrate in vitro. All samples containing TB showed limited butyrate release (<5%) during oral and gastric stages. In the small intestinal phase, all microcapsules containing TB released approximately 75% of their total butyrate with no significant differences (P > 0.05) across formulations. During the fermentation phase, GC‐based microcapsules produced significantly more butyrate (P < 0.001) on a molar basis than all WPI‐based microcapsules. Butyrate production increased significantly (P < 0.001) over each time interval with GC‐based microcapsules having the highest during the 12 h of fermentation. The GC‐based TB encapsulation systems were able to effectively deliver butyrate to the small intestine and generate butyrate in the large intestine. These microcapsules may, therefore, be beneficial for the maintenance of intestinal health and improvement of disease states across all areas of the gastrointestinal tract.     

Physical Stability of Whey Protein-stabilized Oil-in-water Emulsions at pH 3: Potential ω-3 Fatty Acid Delivery Systems (Part A)

ABSTRACT: The oxidative stability of polyunsaturated lipids can be improved by incorporating them in oil droplets surrounded by positively charged whey protein isolate (WPI) membranes. This study dealt with the factors that influence the physical properties of WPI-stabilized oil-in-water emulsions at pH 3. Emulsions containing 5 to 50 wt% corn oil and 0.5 to 5.0 wt% WPI (protein-to-oil ratio of 1:10) were prepared at pH 3. The apparent viscosity of the emulsions increased appreciably at oil concentrations ≥ 35 wt%; however, the particle size was relatively independent of oil concentration. The influence of NaCl (0 to 250 m M ) on the physical properties of 28 wt% emulsions was examined. Significant increases in mean particle size, apparent viscosity, and creaming instability occurred at ≥150 m M NaCl, which were attributed to flocculation induced by screening of the electrostatic repulsion between droplets. The influence of heat treatment (30°C to 90°C for 30 min) on 28 wt% emulsions was examined in the absence and presence of salt, respectively. At 0 m M NaCl, heating had little effect on the physical properties of the emulsions, presumably because the electrostatic repulsion between the droplets prevented droplet aggregation. At 150 m M NaCl, the mean particle diameter, apparent viscosity, and creaming instability of the emulsions increased considerably when they were heated above a critical temperature, which was 70°C when salt was added before heating and 90°C when salt was added after heating. These results have important implications for the design of WPI-stabilized emulsions that could be used to incorporate functional lipids that are sensitive to oxidation, for example, ω-3 fatty acids.     

Disulfide Bond Formation Affects Stability of Whey Protein Isolate Emulsions

The viscosity and degree of flocculation of 20 wt% n-hexadecane oil-in-water emulsions stabilized by whey protein isolate (1 wt% WPI in 0.05M phosphate buffer, pH 7.0) increased as the emulsions aged. These effects were reduced when N-ethylmaleimide, a sulfhydryl blocking agent, was added to the emulsions immediately after homogenization, but were not completely eliminated. Gel electrophoresis (SDS-PAGE) showed an increase in the extent of intermolecular disulfide bond formation between proteins absorbed at the droplet interface with time. Floes were probably formed initially by noncovalent bonding or bridging flocculation, and then stabilized by disulfide bonds between proteins absorbed to different droplets.     

提高W/O/W多重乳状液的稳定性研究

研究了W／O／W多重乳状液稳定性的影响因素。实验表明，W／O／W多重乳状液制备的较佳工艺操作条件为乳化温度40℃，pH值2．5，W／O／W搅拌时间25min，第一相体积比0．48，第二相体积比0．66。     

Impact of whey protein isolates and concentrates on the formation of protein nanoparticles‐stabilised Pickering emulsions

Whey protein nanoparticles (NPs) were prepared by heat‐induced method. The influences of whey protein isolates (WPIs) and concentrates (WPCs) on the formation of NPs were first investigated. Then Pickering emulsions were produced by protein NPs and their properties were evaluated. After heat treatment, WPC NPs showed larger particle size, higher stability against NaCl, lower negative charge and contact angle between air and water. Dispersions of WPC NPs appeared as higher turbidity and viscosity than those of WPI NPs. The interfacial tension of WPC NPs (~7.9 mN/m at 3 wt% NPs) was greatly lower than that of WPI NPs (~12.1 mN/m at 3 wt% NPs). WPC NPs‐stabilised emulsions had smaller particle size and were more homogeneous than WPI NPs‐stabilised emulsions. WPC NPs‐stabilised emulsions had higher stability against NaCl, pH and coalescence during storage.     

花青素对大豆蛋白体外胃消化结构的影响

利用胃蛋白酶对大豆分离蛋白-花青素复合物进行体外模拟消化,研究消化过程中花青素对蛋白水解度、结构、亚基组成及分子质量分布等指标的影响。结果表明：大豆分离蛋白在30?min内消化较明显,蛋白对照组最终水解度高达48.5%,花青素的添加一定程度抑制了蛋白消化。花青素抑制11S球蛋白消化,促进7S球蛋白主要致敏原α-亚基降解,因而推测花青素添加有降低大豆蛋白食用致敏性的效果。排阻色谱分析表明,体外消化将大分子蛋白水解为小分子肽,花青素的添加抑制了小分子肽的形成,最终产物分子质量分布主要集中在3～100?kDa。圆二色谱图显示,花青素改变了大豆蛋白构象,α-螺旋含量降低,β-折叠及无规则卷曲含量增加,β-转角变化无明显规律。荧光光谱分析表明,花青素添加使蛋白及消化产物λmax发生红移,并对蛋白产生了荧光猝灭作用。本研究明晰了蛋白与花青素同食过程中大豆蛋白的解离机制,并为食品生产加工领域制备易消化、高吸收、低致敏的优质蛋白产品及营养膳食搭配方式提供理论指导。     

植物球蛋白/姜黄素纳米复合物的制备及其对O/W型Pickering乳液氧化稳定性影响

本论文以两类植物球蛋白:豌豆分离蛋白(PPI)和大豆分离蛋白(SPI)为材料制备荷载姜黄素蛋白纳米复合物,并探究荷载前后蛋白所制备乳液的物理和氧化稳定性差异。结果表明:PPI和SPI在pH 3.0和pH 7.0下荷载前后蛋白纳米颗粒粒径没有明显变化。pH 7.0时两蛋白姜黄素荷载量均高于pH 3.0,各pH下SPI荷载量要高于PPI。表面疏水性的显著降低与荧光淬灭现象发生表明形成两种蛋白纳米复合物的主要作用力为疏水相互作用,同时在两pH下,PPI比SPI荧光蓝移趋势更明显且有效淬灭常数也更大,即更易形成复合物。与原蛋白相比,荷载后各蛋白颗粒所制备乳液乳化活性有少许降低,同时pH 3.0时各蛋白颗粒乳化活性要高于pH 7.0。各乳液生成初级氧化产物脂质氢过氧化物浓度的变化趋势与生成次级氧化产物TBARS相类似,均为荷载姜黄素后各乳液氧化水平加速,同时pH 3.0时各类型乳液油滴氧化程度均高于pH 7.0。     

乳铁蛋白-乳清分离蛋白乳状液微聚集体构建与酶交联对其流变学特性的影响

以乳清分离蛋白（whey protein isolate,WPI）与乳铁蛋白（lactoferrin,LF）乳状液形成微聚集体与转谷氨酰胺酶酶促交联微聚集体,以期提高体系流变特性。通过微射流分别制备WPI和LF乳状液,二者混合后,乳状液微滴之间发生异型聚集效应,通过转谷氨酰胺酶交联结合形成具有特定三维空间网络结构的微聚集体。研究结果表明：WPI与LF乳状液发生异型聚集,最大程度的聚集和最高物理稳定性体系发生在50% LF-50% WPI微滴形成的微聚集体。异型聚集效应改变了乳状液的流变特性,与单一WPI和LF乳状液相比,50% LF-50% WPI微聚集体流变学特性黏度值分别为单一乳状液的3.72?倍和2.2?倍,通过转谷氨酰胺酶交联,乳状液微聚集体的黏度值为原来的11.4?倍。因此,基于异型聚集效应结合酶促交联,可提高食品体系的流变特性,为开发食品脂质替代物提供了一定的理论支持。     

乳清蛋白的体外模拟消化过程及热处理的影响

探讨了乳清蛋白体外胃蛋白酶和胰蛋白酶的消化过程,以及热处理对该消化过程的影响。SDS-PAGE分析结果表明,胃蛋白酶和胰蛋白酶对乳清蛋白的体外消化作用的影响不明显。干热处理(75℃和100℃,1h)几乎不影响乳清蛋白的体外胰蛋白酶消化过程,而在同样条件下,湿热处理能显著提高胰蛋白酶对乳清蛋白的消化作用。乳清蛋白分别经75℃和100℃湿热处理30min后,再由胰蛋白酶消化8h,其氮释放率分别达到82.1%和91.3%,而未湿热处理的氮释放率仅为66.7%,表明不同热处理方式对乳清蛋白的体外消化过程产生不同的影响。湿热处理能有效地提高乳清蛋白的消化速率,且湿热处理温度越高,乳清蛋白的体外消化速率越快。