Encapsulation efficiency and oxidative stability of flaxseed oil microencapsulated by spray drying using different combinations of wall materials

This study aimed at evaluating the potential of maltodextrin combination with different wall materials in the microencapsulation of flaxseed oil by spray drying, in order to maximize encapsulation efficiency and minimize lipid oxidation. Maltodextrin (MD) was mixed with gum Arabic (GA), whey protein concentrate (WPC) or two types of modified starch (Hi-Cap 100^TM and Capsul TA®) at a 25:75 ratio. The feed emulsions used for particle production were characterized for stability, viscosity and droplet size. The best encapsulation efficiency was obtained for MD:Hi-Cap followed by the MD:Capsul combination, while the lowest encapsulation efficiency was obtained for MD:WPC, which also showed poorer emulsion stability. Particles were hollow, with the active material embedded in the wall material matrix, and had no apparent cracks or fissures. During the oxidative stability study, MD:WPC combination was the wall material that best protected the active material against lipid oxidation.     

Effects of Different Wall Materials on the Physicochemical Properties and Oxidative Stability of Spray-Dried Microencapsulated Red-Fleshed Pitaya (<Emphasis Type="Italic">Hylocereus polyrhizus</Emphasis>) Seed Oil

The aim of this research was to investigate the influence of the composition of the wall material on the encapsulation and stability of microencapsulated red-fleshed pitaya seed oil. Hylocereus polyrhizus seed oil was homogenized with various wall material solutions at a core/wall material ratio of 0.33 and was microencapsulated by spray-drying. The microstructure and morphology of pitaya seed oil powder (PSOP) were observed using a scanning electron microscope (SEM). PSOP encapsulated with gum Arabic exhibited a lower degree of microencapsulation efficiency (MEE; 77.61–85.3%) compared to PSOP encapsulated with proteinaceous bases (90.12–98.06%). The study on oil retention revealed that sodium caseinate > whey protein > gum Arabic as effective wall materials for pitaya seed oil encapsulation. The effects of different wall systems on the oxidation stability of PSOP were studied under accelerated storage conditions; the peroxide value (POV) was determined throughout the test interval at several storage times. This study indicates that the use of lactose as wall material is able to increase the oxidation stability of PSOP; however, further research is needed to evaluate its antioxidative retention toward the oxidative stability of PSOP.     

以雪莲果汁为壁材制备月见草油微胶囊粉末

以月见草油为芯材、雪莲果汁等为壁材,采用喷雾干燥微胶囊技术制备新型的雪莲果汁粉末油脂。结果表明：最佳工艺配方为月见草油30%、聚甘油酯1.7%、自制辛烯基琥珀酸糯玉米非晶化淀粉酯14%、稳定剂藻酸丙二醇酯0.5%、黄原胶0.5%、羧甲基纤维素钠0.5%、雪莲果汁(以干基计)25%、麦芽糊精27.8%。制备的雪莲果汁粉末油脂表面油含量1.20%、包埋率96.0%,富含低聚果糖,冲溶后的乳状液有雪莲果香且稳定性好。     

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、壁材质量分数为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、壁材质量分数为7.5％、壁芯比为1∶1,元宝枫籽油微胶囊包埋率为89.09％...     

Effect of Addition of Native Agave Fructans on Spray-Dried Chayote (<Emphasis Type="Italic">Sechium edule</Emphasis>) and Pineapple (<Emphasis Type="Italic">Ananas comosus</Emphasis>) Juices: Rheology,Microstructure, and Water Sorption

The effect of the combination of maltodextrin DE 10 (MD) and native agave fructans (FR) in concentrations of 0, 2, and 4% (w/v) on the rheological properties, microstructure, and water sorption of spray-dried chayote and pineapple powders was evaluated. A 10% (w/v) maltodextrin treatment was used as a control to compare treatments added with fructans. The scanning electron micrographs revealed spherical particles in a range from 16 to 105 μm with shrinkage, whereby greater caking and agglomeration occurred among particles in treatments with native agave fructans. The flow behavior of all juices can be described by the Bingham model with low plastic viscosities (0.0026 to 0.0030 Pa s^?1); the isotherms of the powders show a sigmoid shape pointing to the easy union of the fructans with water molecules. These types of isotherms are common for non-porous foods, and are indicative of physical adsorption in multi-layers where the adsorbate conserves its identity.     

响应面法优化虾青素微胶囊制备工艺

微胶囊化包埋可减缓虾青素的氧化速度。以羟丙基-β-环糊精（hydroxypropyl-β-cyclodextrin,HP-β-CD）、麦芽糊精为壁材,采用喷雾干燥法制备虾青素微胶囊。在单因素试验的基础上,以虾青素微胶囊包埋率为响应值,以壁材比例、壁材质量浓度、蔗糖酯添加质量分数3 个因素为响应因子,利用响应面法建立了二次回归实际方程模型,获得了制备虾青素微胶囊的最佳工艺条件为：m（HP-β-CD）∶m（麦芽糊精）= 2.9∶1,壁材质量浓度0.21 g/mL,蔗糖酯添加质量分数2%,虾青素添加质量分数4%,喷雾进风温度170 ℃。按此最佳工艺条件制备的虾青素微胶囊包埋率达95.31%。     

Glass Transition and State Diagram for Jujube Powders With and Without Maltodextrin Addition

Both water activity and glass transition concepts were used for stability evaluation of jujube powder in this study. The water sorption behaviour at 25, 35 and 45 °C and the relationship between water content (X _w), glass transition temperature (T _g) and water activity (a _w) were investigated for jujube powder with and without the maltodextrin addition. Moisture sorption isotherms of different jujube powders were of type III and BET model was the best for fitting the experimental data. The equilibrium moisture content of jujube powder containing 20% maltodextrin at a given a _w was lower than that of pure jujube powder. However, temperature had no significant effect on the moisture sorption of jujube powders. Values of T _g of different jujube powders were obtained using differential scanning calorimetry and the glass transition line was fitted to the Gordon-Taylor model. A depression in T _g with increasing water content was observed. State diagrams of different jujube powders were established based on the moisture sorption isotherm and the glass transition curve. Results showed that jujube powders with and without maltodextrin addition were stable at 25 °C when the water content was lower than 0.0673 and 0.0566 g/g solid, respectively.     

Influence of the microencapsulation on the quality parameters and shelf-life of extra-virgin olive oil encapsulated in the presence of BHT and different capsule wall components

The main goal of this study was to assess the influence of the microencapsulation on the oil chemical composition and its oxidative stability. Factors such as microcapsule wall constituents and the addition of the antioxidant butylhydroxytoluene (BHT) were investigated in order to establish the most appropriate conditions to ensure no alteration of the extra-virgin olive oil chemical characteristics. The microencapsulation effectiveness was determined in base of process yield and the microencapsulation efficiency. Highest encapsulation yields were achieved when maltodextrin, carboxymethylcellulose (99.79 ± 0.51%) and lecithin were used as encapsulation agents and the ratio of oil-wall material was 1:1.5. Stability studies were achieved by placing encapsulated oil and un-encapsulated oil in heated chambers at 30 °C during 4 months. Oxidative stability and oil quality studies were periodically assessed. It was concluded that the presence of protein constituents in the microcapsule wall material extended the shelf-life of the microencapsulated olive oil (protein-based model microencapsulated oil was unalterable for 9 to 11 months). For this later model, the addition of antioxidant additives did not significantly increase the oil stability.     

Butter Microencapsulation as Affected by Composition of Wall Material and Fat

A second-order central composite design was used to evaluate the influence of capsule wall materials on yield (MEY) and efficiency (MEE) of the spray-drying butter microencapsulation process. Variables were: maltodextrin concentration of wall material, emulsion solids content, and butter fat concentration related to emulsion solids. All powders showed no stickiness. MEY was always >85% and wall material composition had little influence. MEE was strongly affected by butter concentration. MEE increased as emulsion solids increased, reaching 95% at 22% of emulsion solids. Best results, MEY = 97.22% and MEE = 91.72% were obtained spray-drying an emulsion of 30 % total solids (3.6% maltodextrin and 40% butter).     

响应面优化山桐子油微胶囊喷雾干燥工艺

摘 要：本研究以山桐子油为芯材,麦芽糊精、大豆分离蛋白为壁材,单硬脂酸甘油酯为乳化剂,使用喷雾干燥技术制得山桐子油微胶囊;通过单因素实验和响应面优化实验,研究山桐子油喷雾干燥制微胶囊最佳工艺条件。响应面优化试验表明：在壁材与芯材质量比为4.8：1,麦芽糊精与大豆分离蛋白的壁材复配质量比为 2.6：1,水与壁材体积质量比为6.8：1的条件下,山桐子油微胶囊包埋率可达到84.22 % 。在运用氧化稳定性指数法（OSI）氧化稳定性测试中,山桐子微胶囊在常温条件下,保持30d 后,油脂的 OSI 值与初始值无显著变化,验证了山桐子微胶囊的稳定性;通过激光共聚焦电子显微镜观察结果显示,微胶囊具有较规则球形微观结构,囊壁比较完整,具有良好的包埋结构。     

均质压力及喷雾干燥温度对鱼油微胶囊化的影响

采用辛烯基琥珀酸酯淀粉Hi-Cap100和葡萄糖浆作为鱼油微胶囊的壁材。研究了不同均质压力下乳化液黏度、粒径和粒径分布规律,考察了不同均质压力下乳化液特性与鱼油微胶囊包埋率、表面油含量之间的相关性,探讨了喷雾干燥温度对包埋率和鱼油过氧化值(POV)的影响。研究结果表明,随着均质压力的增加,乳化液黏度和平均粒径逐渐减小,而粒径分布离散度总体呈下降趋势,在40MPa时最小,说明此时粒径分布均一性最佳;喷雾干燥温度增加时,鱼油包埋率先增后减,POV值先减后增,在进/出口温度为140℃/70℃时有最高的包埋率和最低的POV值。通过分析确定最佳工艺参数如下,均质压力为40MPa,喷雾干燥进口温度为140℃,出口温度为70℃。在上述最适工艺条件下,鱼油微胶囊平均粒径为5.97μm,表面油含量为2.03%,微胶囊化包埋率为95.6%,在扫描电镜下观察微胶囊表面和内部结构良好,具有良好的包埋效果。     

沙棘果油微胶囊化制备工艺的优化及其表征

为研究混合壁材及乳化剂对沙棘果油微胶囊包埋效果及稳定性的影响,本文以沙棘果油为芯材,以酪蛋白酸钠和变性淀粉(辛烯基琥珀酸淀粉钠)为混合壁材,单双硬脂酸甘油酯为乳化剂,麦芽糊精为填充剂,柠檬酸钾为缓冲盐,通过喷雾干燥法制备50%载油率的沙棘果油微胶囊。在单因素实验的基础上,以酪蛋白酸钠添加量、变性淀粉添加量、乳化剂添加量为实验因素,采用Box-Behnken法设计三因素三水平试验进行优化,确定微囊粉的最佳包埋效果。结果表明,所得的回归模型具有高度的显著性(P<0.0001),方程对试验拟合较好,在酪蛋白酸钠添加量8%、变性淀粉添加量16%、乳化剂添加量2%条件下,制备得到的沙棘果油微囊粉包埋率最大,可以达到91.6%;扫描电镜观察微胶囊粉表面圆润无裂痕,马尔文激光粒度分析仪测定复原乳粒径<800 nm,通过油脂氧化自动分析仪进行油脂氧化诱导期分析,对照组沙棘果油氧化诱导期为7 h,试验组沙棘果油微囊粉氧化诱导期为40 h,表明沙棘果油微囊粉稳定性强,不易氧化变质,货架期较长。     

二十二碳六烯酸微藻油乳状液稳定性的测定方法和影响因素

以二十二碳六烯酸（docosahexaenoic acid,DHA）微藻油微胶囊化过程中形成的乳状液为研究对象,探究乳状液稳定性的测定方法和影响因素。通过比较3 种不同乳状液稳定性测定方法以及显微镜观察发现：采用0.1 g/100 mL十二烷基硫酸钠溶液对乳状液进行稀释,检测乳状液形成24 h在600 nm波长处透光率的变化可以方便、准确地衡量其稳定性。壁材组成、芯材比例和总固形物质量分数都能够明显影响乳状液稳定性,从而影响微胶囊产品品质。当壁材中辛烯基琥珀酸酯化淀粉与麦芽糊精的质量比在2∶3、DHA微藻油质量分数在20%、总固形物质量分数在33%以下时,制备得到的DHA微胶囊产品的品质较高,且能够满足SC/T 3505—2006《鱼油微胶囊》规定。微胶囊化后DHA微藻油的贮存稳定期得到明显延长。     

Impact of chitosan and oregano extract on the physicochemical properties of microencapsulated fish oil stored at different temperature

Fish oil is an excellent source of omega-3 fatty acids and is easily susceptible to oxidation. Microencapsulation is a commonly employed technique to protect fish oil against oxidation. In the present study, the potential of chitosan in combination with bovine gelatin and maltodextrin as wall material for microencapsulation of fish oil by spray drying was evaluated. To improve the oxidative stability of the fish oil microencapsulates, oregano (Origanum vulgare L) extract was added at 0.50 g/100 g of emulsion. The spray-dried powder showed a moisture content of 2.8 – 3.2 g/100 g of spray-dried powder. The powder contained spherical microparticles with different sizes as indicated by scanning electron microscope images. Encapsulation efficiency of microencapsulates ranged between 68.94% and 81.88%. Differential scanning calorimetry and Fourier-transformed infrared spectroscopy analysis of microencapsulates revealed the possible structural stabilization of core and wall material. The oxidative stability of fish oil microencapsulates were monitored under three different temperature (60°C, 28 ± 2°C, and 4°C). Incorporation of oregano extract minimized the generation of secondary and tertiary oxidation products as indicated by lower peroxide value and thiobarbituric acid reactive substance values compared to control. Overall, the results suggested that combination of chitosan along with bovine gelatin and maltodextrin as wall material improved the surface morphology of the microparticle and encapsulation efficiency, whereas incorporation of oregano extract in fish oil before spray drying enhanced the oxidative stability during storage.     

Improving the emulsifying property of potato protein by hydrolysis: an application as encapsulating agent with maltodextrin

Potato protein concentrate (PPC) is a by-product from starch industry and traditionally used as a low-value ingredient. Depending on its recovery/drying methods, protein functionality and technological applications can be compromised. Hydrolysis offers an alternative to this challenge by modifying protein structure, opening a prospect to find value-added opportunities for this residue. Hence, this study aimed to evaluate the impact of enzymatic hydrolysis on the emulsifying property of PPC. More importantly, we investigated the application of PPC with maltodextrin (proportion of 30:70) as wall material in the microencapsulation of a lipophilic ingredient by spray drying. When PPC was submitted to a 2% degree of hydrolysis, its emulsifying capacity significantly increased from 359 to 416 g oil/g protein. Spray drying microencapsulation using potato protein concentrate/hydrolysate and maltodextrin as wall materials were effective in entrapping flaxseed oil. Additionally, high encapsulation efficiency was observed (92– 96%). Overall, the application of potato protein combined with maltodextrin as wall material was successful for spray drying microencapsulation.     

鱼油微粉的制备及其稳定性分析

为优化鱼油微粉的制备工艺以及初探其稳定性,本文以鱼粉加工副产物富集所得鱼油为原料,筛选复合壁材,研究喷雾干燥法制备鱼油微粉的工艺条件,考察芯壁比、固形物浓度、乳化温度、进风温度、喷雾压力、进料流量等因素对鱼油微胶囊效果的影响,并测定鱼油微粉的微观结构、溶解性及稳定性。结果表明,壁材选择阿拉伯胶/β-环糊精/玉米糖浆（质量比2:1:6）效果较好,微粉制备的最适工艺参数为:芯壁比32%、固形物浓度25%、乳化温度52 ℃、进风温度206 ℃、喷雾压力35 MPa、进料流量300 mL/h,此条件下制得的鱼油微粉包埋率达92.66%。微粉颗粒表面光滑,无破裂或孔洞,且水溶性好。鱼油微粉的贮藏稳定性显著高于未微胶囊化的鱼油（P<0.05）,且添加抗氧化剂的微胶囊鱼油具有更好的抗氧化能力。     

沙棘籽油微胶囊制备及其特性研究

基于复合壁材的沙棘籽油微胶囊制备工艺,以包埋率为指标,在单因素实验基础上采用正交实验优化制备工艺,并对其特性及微胶囊化对沙棘籽油性质的影响进行了研究。结果表明:制备沙棘籽油微胶囊的最佳工艺条件为以酪蛋白酸钠和麦芽糊精为壁材、酪蛋白酸钠与麦芽糊精质量比1∶1、壁材与芯材质量比2∶1、固形物含量20%。最佳工艺条件下制备的沙棘籽油微胶囊产品粒径分布均匀,包埋率可达96. 15%;热失重分析说明沙棘籽油微胶囊具备良好的热稳定性;微胶囊化前后,沙棘籽油不饱和脂肪酸含量变化不大;经过微胶囊包埋的沙棘籽油与未包埋的沙棘籽油相比,氧化诱导时间在高温加速储存过程中明显延长,具备较好的氧化稳定性。     

余甘子核仁油微胶囊的制备及其稳定性分析

以阿拉伯胶和麦芽糊精为壁材,对喷雾干燥法制备余甘子核仁油微胶囊的工艺进行研究。通过单因素试验和响应面优化试验考察乳化剂添加量、阿拉伯胶与麦芽糊精质量比、芯壁比及固形物添加量对余甘子核仁油微胶囊包埋率的影响,得到最优微胶囊制备条件为乳化剂添加量1%、阿拉伯胶与麦芽糊精质量比1∶3.4、芯壁比2∶3、固形物添加量14.2%,该工艺条件下得到的余甘子核仁油微胶囊的包埋率达到（90.74±0.51）%,包埋效果好,颗粒形态完整。采用油脂氧化稳定性测定仪（Rancimat法）测定该样品的氧化诱导时间,并对微胶囊在25?℃条件下的货架期进行预测发现,微胶囊的货架期为716?d,未包埋的余甘子核仁油货架期为128?d,由此可见该微胶囊具有良好的贮藏稳定性。     

OPTIMIZATION OF EMULSIFICATION AND MICROENCAPSULATION OF EVENING PRIMROSE OIL AND ITS OXIDATIVE STABILITY DURING STORAGE BY RESPONSE SURFACE METHODOLOGY

ABSTRACT

Microencapsulation is a technique by which small droplets of liquid or solid particles are coated with a thin film of wall materials to protect susceptible ingredients in food products to assure their quality or effectiveness. Microencapsulation of liquid lipid into powdery matrixes of wall materials includes two unit operations: emulsification of the lipid with an aqueous solution of wall material and drying of the emulsion. The effects of hydrophile–lipophile balance (HLB) value, emulsifier content and oil content on the evening primrose oil‐in‐water emulsion stability were studied by response surface methodology (RSM). The HLB value, emulsifier content and oil content all had significant effects on the emulsion stability (P < 0.05). Of them, the HLB value and emulsifier content contributed more effects than the oil content. The optimized HLB value, emulsifier content and oil content were used to mix with wall materials: gum arabic (GA), maltodextrin (MD) and/or sodium caseinate (NaC). The oil was encapsulated with these materials individually or in combination by spray‐drying, and their oxidative stability during storage was compared. The microcapsules with a single wall material were relatively susceptible to oxidation than those with multiple wall materials. The most desirable composition of the mixture of GA, MD and NaC by RSM was 17.2, 75 and 7.8%, respectively.

PRACTICAL APPLICATIONS

Response surface methodology (RSM) provided a valuable means to help us understand the relative or interactive effects of three important parameters: HLB value, emulsifier content and oil content on the emulsion stability of the oil‐in‐water (o/w) system. The information obtained would be useful for the preparation of similar o/w emulsion system as needed in some product development for foods. In addition, the effects of gum arabic, maltodextrin and sodium caseinate on the oxidative stability of microencapsulated oil were also studied by RSM. The results revealed the relative or interactive effects of these materials and gave the optimal conditions in minimizing the oxidative instability in this study. Since these wall materials are readily available and widely used in a variety of products, the information provided by this study would be useful for product‐developing professionals to use these materials more efficiently in terms of obtaining optimal microencapsulated products against lipid oxidation and cost effectiveness.     

婴儿配方奶粉用营养油微胶囊化的配方优化

以脂肪酸配比合理的混合植物油为芯材,大豆分离蛋白(SPI)和麦芽糊精(MD)为复合壁材,大豆卵磷脂为乳化剂,采用喷雾干燥工艺制备微胶囊化营养油。利用中心组合设计(CCD)对微胶囊营养油的配方进行优化,得到营养油微胶囊的最佳配方为:芯材质量分数为27.28%,固形物质量分数为39.74%,大豆分离蛋白质量分数为40.00%,卵磷脂质量分数为1.47%。在此条件下,得到MEE和MEY的理论最大值分别为91.188%和96.1129%,期望度为0.894。