乳清浓缩蛋白与卵清蛋白复合膜的制备及其性能

本文以乳清蛋白（Whey protein concentrate,WPC）和卵清蛋白（Egg white protein,EWP）为成膜基质,添加5 U/g_蛋白转谷氨酰胺酶（Transglutaminase,TG）制备WPC/EWP复合膜,分别研究WPC和EWP质量比、膜液pH、甘油添加量对WPC/EWP复合膜结构及性能的影响。结果表明,当WPC/EWP质量比为1:3,成膜液pH为8,甘油添加量为35%时,电镜结果表明形成的复合膜结构致密无孔隙,红外结果显示WPC和EWP有较好的相容性。WPC/EWP复合膜的水蒸气透过率为2.08×10?10 g·s?1m?1Pa?1,透光率为73.90%,抗拉强度为1.60 MPa,断裂伸长率为151.96%。WPC、EWP和甘油在膜液pH为8时具有良好的融合性,能显著（P<0.05）提高WPC/EWP复合膜的机械性能。     

添加玉米低聚肽的紫苏籽油乳状液及其微胶囊的制备

为制备含玉米低聚肽的紫苏籽油微胶囊,选择阿拉伯胶、可溶性大豆多糖、辛烯基琥珀酸淀粉钠（HI-CAP 100）、酪蛋白酸钠和大豆分离蛋白5 种乳化剂,并添加不同质量分数的玉米低聚肽制备紫苏籽油乳状液,筛选出制备紫苏籽油乳状液的最适乳化剂及最佳的玉米低聚肽添加比例;进而采用喷雾干燥法制备高载油量的玉米低聚肽紫苏籽油微胶囊,筛选和评价高载油量玉米低聚肽紫苏籽油微胶囊的壁材。结果显示：HI-CAP 100制备的紫苏籽油乳状液的液滴粒径主要分布在0.1～2 μm之间,并且玉米低聚肽添加量为5%时,乳状液的不稳定性指数为0.275,粒径为（0.76±0.02）μm;以HI-CAP 100为壁材经喷雾干燥制成的目标微胶囊（载油量≥50%）表面油含量为3%,表明HI-CAP 100对紫苏籽油的包埋效果较好,并且微胶囊粒径分布均匀,表面较光滑适合作为高载油量玉米低聚肽紫苏籽油微胶囊的壁材;通过加速贮藏实验证明玉米低聚肽与茶多酚棕榈酸酯复配,能提高紫苏籽油微胶囊的抗氧化性。     

微胶囊化乳清蛋白水解物的降胆固醇活性、苦味和稳定性研究

利用胰蛋白酶水解乳清浓缩蛋白(WPC),经超滤、脱盐处理获得乳清蛋白水解物(WPCH)。以WPC、WPC和麦芽糊精的混合物为壁材,利用喷雾干燥法对WPCH进行微胶囊化处理,然后测定WPCH的降胆固醇活性,热处理(90℃,15 min)的WPC和麦芽糊精为壁材的WPCH微胶囊的包埋率、苦味程度、吸湿性、玻璃态转化温度及微观形态。结果表明,用胰蛋白酶水解WPC可以获得具有降胆固醇活性的WPCH,经超滤、脱盐处理后,WPCH对胆固醇胶束的溶解度的抑制率为47.53%。微胶囊化WPCH的苦味程度明显降低(P0.05)。微胶囊化处理后,样品的吸湿性从55.88 g/(100 g)降为22~24 g/(100 g),而样品的Tg值从64.17℃提高到73.63℃,表明微胶囊化处理使样品稳定性增加。与WPC相比,加热处理的WPC和添加麦芽糊精的WPC都能提高包埋效率,为62.41%。利用喷雾干燥法微囊化的WPCH与未包埋的WPCH相比,不会对降胆固醇活性产生影响。上述结果表明,以WPC与麦芽糊精为壁材的微胶囊化WPCH,能明显降低苦味并提高产品稳定性,不会对降胆固醇活性产生影响。     

喷雾干燥法制备紫苏油微胶囊

以大豆分离蛋白(SPI)、乳清分离蛋白(WPI)和麦芽糊精(MD)为壁材,紫苏油为芯材,并添加少量阿拉伯胶作为乳化剂和稳定剂,采用喷雾干燥法制备紫苏油微胶囊。以包埋率为指标,确定紫苏油微胶囊的最佳工艺配方。研究结果表明,紫苏油微胶囊制备的最佳配方:SPI、WPI和MD质量比为2∶1∶2,芯壁材质量比为2∶3,阿拉伯胶的添加量为总固形物含量的3%,固形物浓度为20%。在此工艺配方下,紫苏油微胶囊的包埋率可达到91.23%,表面含油率为3.13%。扫描电镜观察结果表明,微胶囊表面结构完整致密无裂缝。     

薏苡仁油微胶囊壁材的选择及工艺优化

选用β-环糊精、变性淀粉HI-CAP100两种碳水化合物和大豆分离蛋白、明胶两种蛋白质类壁材进行组合初步筛选薏苡仁油微胶囊的壁材,再利用单因素试验研究了壁材的配比、芯壁比、乳化液壁材含量、乳化剂添加量对微胶囊包埋率的影响,最后通过L_9(3~4)正交试验确定了壁材的最佳配比。结果表明:大豆分离蛋白/变性淀粉HI-CAP100壁材组合在选用的6组壁材组合中综合表现出了良好的潜质,通过工艺优化得到了微胶囊的最佳配方:大豆分离蛋白占壁材质量分数为5%,芯壁比为60%,壁材含量为30%,乳化剂添加量为1.0%,由此得到的薏苡仁油微胶囊的包埋率为78.52%。     

蒜头果油微胶囊制备工艺优化及性质分析

以阿拉伯胶和麦芽糊精为复合壁材,采用喷雾干燥法制备蒜头果油微胶囊。通过单因素试验,考察固形物含量、乳化剂添加量、壁材比、芯壁比、进风温度、进料量对蒜头果油微胶囊包埋率的影响,采用Box-Behnken设计响应面试验优化蒜头果油微胶囊的制备工艺,并采用扫描电子显微镜（SEM）、粒度分析仪、热重分析仪和体外模拟消化等对蒜头果油微胶囊的性质进行了分析。结果表明：蒜头果油微胶囊最佳制备工艺条件为乳化剂添加量1%、阿拉伯胶与麦芽糊精质量比4∶ 3、芯壁比1∶ 4、固形物含量16%、进风温度160 ℃、进料量4 mL/min,在最佳条件下蒜头果油微胶囊的包埋率为76.92%;蒜头果油微胶囊呈较光滑球形,其结构完整、粒径均一,且具有良好的流动性、热稳定性、分散性;体外模拟胃肠道消化后,微胶囊芯材几乎完全释放。蒜头果油微胶囊化有利于保护蒜头果油的有效成分,提高其消化吸收效果,扩大其应用范围。     

蛋白含量对牦牛乳清蛋白浓缩物功能特性的影响

通过不同截留分子质量的再生纤维素膜过滤纯化牦牛原乳清液和牦牛甜乳清液,分别制取牦牛原乳清蛋白浓缩物（native whey protein concentrate,NWPC）和牦牛甜乳清蛋白浓缩物（sweet whey protein concentrate,SWPC）,研究蛋白含量不同的乳清蛋白浓缩物（whey protein concentrate,WPC）主要成分（乳糖含量、pH值和总蛋白质含量）和功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）的特征。结果表明：10 000 Da再生纤维素膜透析得到的牦牛WPC中总蛋白含量达到80%以上,不含乳糖,功能特性（溶解性、持水性、持油性、起泡性、乳化性及热稳定性）均显著高于经3 500 Da卷式膜、5 000 Da再生纤维素膜透析得牦牛WPC,WPC蛋白含量越高,其功能特性越好;不同蛋白含量的牦牛SWPC起泡能力、泡沫稳定性、乳化活性和乳化稳定性均显著（P＜0.05）高于牦牛NWPC。牦牛乳WPC最不稳定温度为85 ℃,高于荷斯坦牛乳WPC的80 ℃,热处理会适当改善牦牛WPC的起泡性能、乳化性能和热稳定性。通过膜牦牛处理获取的高蛋白含量的WPC,功能特性较好,应用广泛,对解决牦牛乳清资源的利用问题、保护环境、提高企业的经济效益起到关键性作用。     

微胶囊化元宝枫籽油粉末油脂的工艺优化及稳定性研究

采用喷雾干燥法对元宝枫籽油进行包埋,并对微胶囊化工艺条件进行优化优化的制备工艺为：麦芽糊精与变性淀粉质量比为3.54:1、壁材浓度为28.1%、壁芯比为2.51:1,元宝枫籽油微胶囊包埋率为85.7%;大豆分离蛋白与阿拉伯糖质量比为5:1、壁材浓度为7.5%、壁芯比为1:1,元宝枫籽油微胶囊包埋率为89.09%。差式扫描量热仪（DSC）、傅里叶红外光谱分析仪（FTIR）和扫描电子显微镜（SEM）分析结果表明：用大豆分离蛋白和阿拉伯糖对元宝枫籽油的包埋效果更优,更利于微胶囊粉末油脂的贮藏和使用。     

沙棘籽油微胶囊的制备及氧化稳定性评价

沙棘籽油是一种富含不饱和脂肪酸的功能性油脂,容易氧化变质。本文将添加天然抗氧化剂与微胶囊制备技术相结合,改善沙棘籽油的氧化稳定性,延长货架期。首先测定了沙棘籽油的组成成分,然后以沙棘籽油为芯材,添加经过筛选的天然抗氧化剂L-AP,以辛烯基琥珀酸淀粉钠,酪蛋白酸钠及麦芽糊精等为壁材制备沙棘油微胶囊,并通过65 ℃烘箱加速保藏实验评价其氧化稳定性。结果表明:沙棘籽油中不饱和脂肪酸含量占总脂肪酸的80.6%±2.10%;制备沙棘籽油微胶囊的最佳配方为辛烯基琥珀酸淀粉钠15%、酪蛋白酸钠5%、麦芽糊精5%、抗性糊精30%、甘蔗浓缩汁10%、沙棘籽油30%、异麦芽酮糖5%,并添加3 g/L三聚磷酸钠,包埋率高达91.8%±1.59%;65 ℃烘箱加速保藏实验结果表明,添加抗氧化剂并制备微胶囊能有效提高沙棘籽油的氧化稳定性。     

D-混料最优设计优化茶多酚微胶囊工艺 及其脂肪氧化抑制作用

本文以壳聚糖、明胶为壁材,茶多酚为芯材,包封率为响应值,采用D-混料最优设计研究了自组装法包埋茶多酚的工艺优化,将得到的茶多酚微胶囊按一定质量比例添加到肉糜中,通过电子鼻测定其风味差异,并研究肉样储藏过程中的丙二醛含量变化对其抑制脂肪氧化作用。结果表明体系中茶多酚、明胶、壳聚糖的含量分别为0.40、0.50和0.10时(以试验体系干物质总量为1),包封率为50.87%。添加0.01%、0.03%、0.05%的茶多酚微胶囊的猪肉,4 ℃下处理10 d后其丙二醛含量(TBARs)值分别为0.183、0.135、0.108 mg/kg,均较未添加茶多酚的空白处理和非微胶囊茶多酚处理组显著降低(P<0.05),电子鼻测定结果也显示添加不同茶多酚处理组的风味和空白组有较大区别,说明得到的茶多酚微胶囊能有效抑制脂肪氧化,延长猪肉的保藏时间。     

Evaluation of Folic Acid Nano-encapsulation by Double Emulsions

In this study, optimization of spray drying for double emulsions containing pectin-whey protein concentrate (WPC) was investigated for nano-encapsulation of folic acid. Five independent variables including pectin and WPC content, dispersed phase content, pH, surfactant type of Span, and polyglycerol polyricinoleate (PGPR) were considered along with encapsulation efficiency (EE) as the main response. The experiment design was performed by a Taguchi approach. Final double emulsions were formulations containing an internal nano/micro-emulsion composed of a water in oil (W/O) system with folic acid present in the water phase, re-emulsified within an aqueous phase of pectin-WPC complexes. The average of folic acid EE was approximately 88.3 % in a range of 82.3 to 95.0 %. The main effect analysis with a Taguchi technique revealed that the dispersed phase content of double emulsions was the most important factor affecting EE (36 %) and surfactant had the minimum influence (5 %). Also, it was revealed that the most important interaction between independent variables in terms of EE was between WPC and dispersed phase content while pectin-pH had the lowest interaction. Finally, optimum conditions were determined as 1.0 % pectin, 4.0 % WPC, and 15 % dispersed phase, pH = 6, with a PGPR nano-emulsion which resulted in 99.0 % EE of folic acid.     

TG酶和羟丙基甲基纤维素改善乳清蛋白可食膜性能

以乳清浓缩蛋白(WPC)为基料,通过添加羟丙基甲基纤维素(HPMC,添加量为蛋白质量的5%~25%)和转谷氨酰胺酶(TG酶)对膜的性能进行改良,研究HPMC的添加量和转谷氨酰胺酶的交联作用对复合膜性能的影响。结果表明:HPMC能显著提高蛋白膜的抗拉强度,降低复合膜的断裂伸长率(p<0.05),TG酶能有效改善乳清蛋白-羟丙基甲基纤维素复合膜的柔韧性。当HPMC的添加量为乳清蛋白的20%时,复合膜的抗拉强度较好,表观光滑平整。制备WPC-HPMC复合膜进行奶茶粉、方便面调料包、油包,苏打饼干的初步包装实验,研究了包装产品在储藏12 d期间质量变化情况。结论:乳清蛋白-羟丙基甲基纤维素复合膜具有一定包装应用潜能。     

Hydroxypropyl methylcellulose-modified whey protein concentrate microcapsules for the encapsulation of tangeretin

The oral bioavailability of tangeretin is limited by its low water solubility and high crystallisation. In the present study, tangeretin was entrapped in whey protein concentrate (WPC)-stabilised emulsions to enhance its bioaccessibility. Hydroxypropyl methylcellulose (HPMC) was added to modify the interface of the emulsion droplets, and Ca²⁺-crosslinking was used to induce the gel formation. Spray drying of the emulsions or gels enabled to produce microcapsules. The physicochemical characteristics and in vitro digestion behavior of the microcapsules were investigated. Results indicated that HPMC modification and Ca²⁺-crosslinking increased the average particle size, altered the microstructure, ameliorated the quality of the WPC-based microcapsules and improved the encapsulation efficiency of tangeretin. Furthermore, the in vitro studies showed that HPMC modified and Ca²⁺-added microcapsules could control the release of free fatty acid. HPMC greatly increased the bioaccessibility of tangeretin from around 28% to 80%. Overall, these results confirmed that HPMC-modified WPC microcapsules could be a promising carrier to protect hydrophobic functional ingredients and improve their oral bioavailability.     

Stability of Trans‐Resveratrol Encapsulated in a Protein Matrix Produced Using Spray Drying to UV Light Stress and Simulated Gastro‐Intestinal Digestion

Trans‐resveratrol has demonstrated the potential to provide both therapeutic and preventive activities against chronic diseases such as heart disease and cancer. The incorporation of trans‐resveratrol into food products would allow for broader access of this bioactive compound to a larger population. However, this strategy is limited by instability of trans‐resveratrol under environmental conditions and within the digestive system leading to isomerization of trans‐resveratrol (bioactive form) to cis‐resveratrol (bio‐inactive form). Studies in the stabilization of trans‐resveratrol into protein microparticles are presented. Trans‐resveratrol was encapsulated using whey protein concentrate (WPC) or sodium caseinate (SC), with or without anhydrous milk fat (AMF). Binding of resveratrol and aromatic residues in protein was estimated utilizing the Stern–Volmer equation and the number of tryptophan residues. The stability of encapsulated resveratrol was evaluated after exposure to ultraviolet A (UVA) light and 3‐stage in vitro digestion. After UVA light exposure, SC‐based microcapsules maintained a higher trans:cis resveratrol ratio (0.63, P < 0.05) than WPC‐based microcapsules (0.43) and unencapsulated resveratrol (0.49). In addition, encapsulation of resveratrol in both protein microparticles led to an increased digestive stability and bioaccessibility in comparison to unencapsulated resveratrol (47% and 23%, respectively, P < 0.05). SC‐based microcapsules provided a higher digestive stability and bioaccessibility (86% and 81%; P < 0.05) compared to WPC‐based microcapsules (71% and 68%). The addition of AMF to the microcapsules did not significantly change the in vitro digestion values. In conclusion, SC‐based microencapsulation increased the stability of trans‐resveratrol to UVA light exposure and simulated digestion conditions. This encapsulation‐system‐approach can be extended to other labile, bioactive polyphenols.     

Influence of whey protein concentrate, additives, their combinations on the quality and microstructure of vermicelli made from Indian T. Durum wheat variety

Effect of whey protein concentrate (5%, 7.5%, 10%) and additives on the quality of vermicelli made from Indian durum wheat was studied. The results revealed that with increase in whey protein concentrate (WPC) from 0% to 10%, cooked vermicelli weight increased from 82.5 to 88 g/25 g, cooking loss increased from 6.0 to 8.4%, L values indicating lightness increased (47.42–52.9); b values indicating yellowness decreased (7.0–3.80) and shear force decreased (66–45 g). Sensory evaluation of vermicelli with 5%, 7.5%, 10% WPC showed that addition of above 5% WPC resulted in whitish colour vermicelli with mashy strand quality and sticky mouthfeel. Studies on the effect of additives namely ascorbic acid (0.01% and 0.015%), gluten (1.5% and 3.0%) and glycerol monostearate (GMS) (0.25% and 0.5%) individually as well as in combination on the quality of vermicelli with 5% WPC indicated that combination of 0.01% ascorbic acid, 3% gluten and 0.5% GMS resulted in vermicelli having lower cooking loss, creamy yellow colour, firm, discrete strands and non-sticky mouthfeel. The protein content of vermicelli with 5% WPC and combination of additives was 16% as against 11.5% of control vermicelli. Scanning electron microscopy study of control vermicelli, vermicelli with 5% WPC and vermicelli with 5% WPC and combination of additives revealed that vermicelli with 5% WPC showed a rough surface with a prominent rupture while vermicelli with 5% WPC and combination of additives showed a continuous, rupture free structure.     

Effect of carrier types and compositions on the production yield,microstructure and physical characteristics of spray dried sour cherry juice concentrate

In this study, the effect of different carriers including maltodextrin (MD), gum arabic (GA) and whey protein concentrate (WPC) and their combination on the production yield, moisture content, bulk and tapped density, solubility, wettability, flowability indexes (Hausner ratio, compressibility, angle of repose), hygroscopicity and deliquescence process, color index and microstructure of spray dried sour cherry juice concentrate was investigated. The results showed increased powder production yield with a mixture of MD and GA (40:10 weight ratio). Use of 5% WPC in combination with the GA and MD increased powder production yield from 45.66 to 55.66% and 42.23 to 52.86%, respectively. Bulk density, tapped density, solubility and wettability significantly decreased with increasing concentration of WPC. Also, the use of 30% WPC in combination with the MD or GA increased particle size substantially. The surface morphology of the particles (with a smooth, shrunk and dented surfaces) was affected by feed composition.     

乳清浓缩蛋白对面条黏性的影响

本实验在面粉中添加不同比例的乳清浓缩蛋白(Whey protein concentrate,WPC),并分析其对面条品质及粘性的影响,以达到增加营养价值及改善面条品质的作用。试验结果表明：WPC的添加可以明显改善面条的粘结现象,并降低其表面粘性,但较高的添加量则会降低面粉的面筋质量和湿面筋含量,并使干物质损失率和干物质吸水率升高;微观结构和TOM值的结果表明,WPC的添加使面条蛋白网络孔隙变大,减少了面条表面滞留或附着的淀粉,这可能是WPC改善面条粘结现象的原因。     

Spray‐dried encapsulation of Conjugated Linoleic Acid (CLA) with polymeric matrices

Conjugated linoleic acid was encapsulated in three different matrices: whey protein concentrate (WPC), gum arabic (GA) and a blend of WPC and maltodextrin 10 DE (1:1, w/w). Kinetic studies on the degradation of CLA and lipid oxidation of microcapsules were carried out at water activities from 0.108 to 0.892 at 35 and 45 °C. The highest values of CLA degradation and lipid oxidation were observed in the range of water activities 0.103–0.429 for all matrices at 45 °C, whereas the lowest CLA degradation and lipid oxidation were observed for WPC at a water activity of 0.743 and 35 °C. WPC microcapsules showed the best morphology and encapsulation efficiency and the lowest CLA degradation. Copyright © 2006 Society of Chemical Industry     

Nutritional,physicochemical, and textural properties of gluten-free extruded snacks containing cowpea and whey protein concentrate

Ready-to-eat extruded snacks with high protein and fibre were developed from a composite flour comprising rice flour, cowpea flour and whey protein concentrate (WPC). Nutritional, physicochemical, and textural properties of extrudates were evaluated, at five ratios of cowpea: WPC (10:0, 15:05, 20:10, 25:15, 30:20); rice flour was used as a control. The protein and fibre content in the extrudates significantly increased (P ≤ 0.05) with cowpea (10%–30%) and WPC (5%–20%) incorporation compared to the control. The extrudates with higher levels of cowpea and WPC showed a significant increase in bulk density and hardness. A slight decrease of 12% was observed in the expansion of 15% cowpea and 5% WPC fortified extrudates compared to the control. The number of peaks during compression increased with incorporations of cowpea and WPC. All cowpea and WPC containing snacks were darker than the control. Significant correlations were found between the protein, fibre, colour values and textural properties. The essential and non-essential amino acid profiles increased in the extrudates, proportionally to the cowpea and WPC fortification.