β-环糊精包埋柠檬醛微胶囊工艺优化及其缓释性能

以β-环糊精为壁材,采用乳化法制备柠檬醛微胶囊,考察固形物质量分数、乳化剂质量分数和心壁比对柠檬醛微胶囊包埋产率和包埋效率的影响。采用响应面法对3个单因素工艺参数进行优化,回归得到二次多项式模型极显著,模型的相关系数为0.966 1,优化试验工艺条件为固形物质量分数26%、乳化剂质量分数0.8%和心壁比1∶4。在此条件下进行验证实验,柠檬醛微胶囊包埋产率值为78.8%。缓释性能实验结果表明,微胶囊化可以明显降低柠檬醛的挥发速率,Avrami’s方程也可以对柠檬醛微胶囊释放过程进行较好地拟合。     

Microencapsulation of sweet orange oil by complex coacervation with soybean protein isolate/gum Arabic

The coacervation between soybean protein isolate (SPI) and gum Arabic (GA) for sweet orange oil microencapsulation as functions of pH, ionic strength, SPI/GA ratio, core material load and micromolecules was investigated. SPI was exposed to ultrasonic to increase solubility before use and microcapsules were spray-dried before analysis. It was found that the optimum pH for SPI/GA coacervation was 4.0. High ionic strength reduced the coacervation between the two biopolymers. The highest coacervate yield was achieved in SPI/GA ratio 1:1 and the core material load for the highest microencapsulation efficiency (MEE) and microencapsulation yield (MEY) was 10%. The addition of sucrose in sucrose/SPI ratio 1:1 increased the MEY by 20%, reaching 78% compared to 65% of control. The microcapsules were spherical without holes on the surface by SEM observation and flavour components were well retained in microcapsules according to GC–MS analysis, indicating good protection for core material.     

Microencapsulation of flaxseed oil by soya proteins–gum arabic complex coacervation

Application of soya proteins (SP) in flaxseed oil microencapsulation based on complex coacervation was investigated. The effects of SP/gum arabic (GA) mixing ratio (1:2, 1:1 and 2:1) and pH (2.80, 3.15 and 3.75) on coacervate preparation were studied firstly. The highest coacervate yields (CY) were achieved at SP/GA = 1:1, pH 3.15, and SP/GA = 2:1, pH 3.75, which were 81.2 ± 2.0%, 88.1 ± 0.6%, respectively. Thereafter, the microencapsulation of flaxseed oil was detected in accordance with the results of the coacervation of SP/GA, that is the optimal condition for microencapsulation was corresponded to the condition where CY was the highest. Under the conditions of SP/GA = 1:1, pH 3.15, and SP/GA = 2:1, pH 3.75, the microencapsulation efficiency and total yield reached 81.5 ± 0.1% and 81.7 ± 0.4%, and 77.4 ± 3.7% and 86.7 ± 2.4%, respectively. Microscopic morphology revealed that the formation of a biopolymer shell around the oil droplets was achieved at specific conditions.     

洋葱精油微胶囊制备工艺优化及其品质分析

为得到包埋效果好、品质优良的洋葱精油微胶囊,采用喷雾干燥法,研究壁材种类、芯材-壁材用量比和固形物用量对微胶囊包埋率的影响及在扫描电子显微镜下的形貌、感官性状、包埋度、含水率、溶解度、堆积密度、贮藏稳定性等。结果表明：在复合壁材为阿拉伯胶＋β-环糊精（质量比4∶3）、芯材-壁材用量比1∶4（mL/g）、固形物用量20%的条件下,洋葱精油微胶囊包埋率为92.35%;扫描电子显微镜结果显示微胶囊表面连续,呈光滑的球形;且微胶囊具有良好的感官性状,粉末均匀不黏壁,能够有效掩盖洋葱精油的辛辣刺激性气味,易于被消费者接受;在最佳制备条件下微胶囊的包埋度、含水率、溶解度、堆积密度、玻璃化转变温度分别为21.32%、3.69%、97.56%、0.786?g/cm3、46.35?℃,表明微胶囊易于溶解,含水率低,玻璃化转变温度高于一般贮藏温度。因此,最佳制备条件下微胶囊产品品质较优,具有良好的贮藏稳定性及市场接受度。     

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.     

不同壁材制备油茶籽油微胶囊的研究

研究以大豆分离蛋白、酪朊酸钠、麦芽糊精、大豆膳食纤维和阿拉伯胶为壁材,通过复配组合,利用喷雾干燥法制备油茶籽油微胶囊产品,同时以乳化稳定性、微胶囊化效率和产率、微胶囊形态的微观表征颗粒完整率和微胶囊感官品质评价为评定指标,比较不同壁材组合得到的微胶囊产品之间的差异。结果表明,以大豆分离蛋白、酪朊酸钠和麦芽糊精为复配壁材的油茶籽油微胶囊产品为乳白色粉末,具有良好冲调性和流动性,微胶囊化效率83.62%和产率63.87%,微胶囊形态的颗粒完整率接近70%,是较好的喷雾干燥制备油茶籽油微胶囊产品的复配壁材之一。     

复凝聚法制备松籽油微胶囊工艺优化及其氧化稳定性分析

以明胶与阿拉伯胶为壁材,采用复凝聚法包埋松籽油制备松籽油微胶囊。考察壁材比(明胶与阿拉伯胶体积比)、芯壁比、壁材质量分数、复凝聚时间对微胶囊包埋率的影响,通过正交试验优化微胶囊制备工艺,并对制备的微胶囊理化特性及氧化稳定性进行分析。结果表明松籽油微胶囊制备的优化工艺条件为壁材比2∶1、芯壁比2∶3、壁材质量分数2%、复凝聚时间50 min,在此条件下微胶囊包埋率达到87.23%。制备的松籽油微胶囊含水率为5.1%,溶解度为98.09%,具有较好的溶解性;通过傅里叶转换红外光谱及扫描电子显微镜分析证明了微胶囊的形成;差示扫描量热分析结果显示,微胶囊热溶解温度较高,在室温下热稳定性良好。包埋后的松籽油经加速贮藏实验表明微胶囊化可以提高松籽油的氧化稳定性,延长松籽油贮藏期。     

New insights into the microencapsulation properties of sodium caseinate and hydrolyzed casein

The aim of the present study was to describe the fundamental physical characteristics of spray-dried carrier matrices based on sodium caseinate and casein hydrolyzate and microcapsules as well as their impact on the stability of a microencapsulated functional ingredient. Spray-dried carrier matrix was characterized by different physical methods (helium pycnometry, nitrogen displacement for surface area analysis, X-ray photoelectron spectroscopy, positron annihilation lifetime spectroscopy). Surface viscoelasticity of protein-stabilized oil–water interfaces was analyzed using dynamic pendant drop tensiometry. Fish oil was microencapsulated and microencapsulation efficiency as well as oxidative stability over time was monitored.     

Microencapsulation of flax oil with zein using spray and freeze drying

Microencapsulation of flax oil was investigated using zein as the coating material. Central Composite Design - Face Centered was used to optimize the microencapsulation with respect to zein concentration (x₁) and flax oil concentration (x₂) using spray drying. Also, freeze drying was carried out at two zein:oil ratios. The quality of microcapsules was evaluated by determining encapsulation efficiency, flowing properties (Hausner ratio), and evaluating the morphology with scanning electron microscopy. The response surface model for microencapsulation efficiency showed a high coefficient of determination (R² = 0.992) and a non-significant lack of fit (p = 0.256). The maximum microencapsulation efficiencies were 93.26 ± 0.95 and 59.63 ± 0.36% for spray drying and freeze drying, respectively. However, microcapsules prepared by spray and freeze drying had very poor handling properties based on the Hausner ratio. The bulk density decreased with an increase in zein concentration at the same flax oil concentration. The morphology of the flax oil microcapsules depended on the zein:flax oil ratio and the process used for microencapsulation. Flax oil microcapsules prepared by spray drying appeared to be composed of heterogeneous spheres of various sizes at high zein:flax oil ratios. Microcapsules prepared by freeze drying resulted in agglomerated small spheres. These microcapsules might find a niche as functional food ingredients.     

乳液粒径对橙皮精油微胶囊物理性质和氧化稳定性的影响

本文以橙皮精油为芯材,变性淀粉和麦芽糊精为壁材,通过高压(1000、2500、3500和22000 psi)均质制备了不同粒径橙油乳液,从而探讨乳液粒径对喷雾干燥橙油微胶囊平均粒径、包埋率、总油量、含水量、微观形貌以及重组乳液粒径分布的影响。同时以柠檬烯氧化程度评价微胶囊稳定性并预测其货架期。结果表明,均质压力越高,乳液粒径越小。乳液粒径对微胶囊的总油量(1.5 g/20 g)、包埋率(>95%)和含水量(<4%)没有明显影响,但会影响微胶囊的平均粒径、微观形貌以及重组乳液的粒径分布。乳液粒径越小,微胶囊平均粒径越小,表面越光滑,重组乳液也具有更窄的粒径分布。微胶囊在37 ℃贮藏5周,经零级动力学方程拟合氧化柠檬烯/柠檬烯(mg/g)变化的结果表明,以22000 psi制备的微胶囊货架期可长达11周左右,是其余微胶囊货架期的2.97~4.63倍。研究结果可为喷雾干燥精油微胶囊的工艺优化及质量控制提供理论参考。     

牛至精油微胶囊的制备、表征及在杏贮藏期的抑菌效果

为进一步开发植物精油在果蔬采后抑菌保鲜中的应用,本实验以牛至精油为芯材,以明胶、阿拉伯胶为壁材,采用复凝聚法,通过工艺优化制备了牛至精油微胶囊,并通过扫描电子显微镜、傅里叶变换红外光谱、热重分析和差示扫描量热分析进一步表征了其理化特性和缓释性能,最后评估了不同施用剂量的牛至精油微胶囊在杏果实采后贮藏中的抑菌效果及其对腐烂率和抗病相关酶活力的影响。结果表明：牛至精油微胶囊制备最优工艺条件为芯材和壁材质量比1∶1、壁材质量比（明胶、阿拉伯胶质量比）1∶1、反应温度45 ℃、反应时间30 min,在此工艺条件下制备的牛至精油微胶囊包埋率为83.65%,载油率为74.36%,平均粒径为147 μm;与单一牛至精油（纯度为98%）相比,牛至精油微胶囊具有更好的球形和规则表面结构,保持了更高的热稳定性,并具备了缓释特性;其中,4%（以果实质量计）的牛至精油微胶囊处理降低了杏果实在贮藏期间的菌落总数、霉菌总数和腐烂率,并提高了杏果实贮藏期间过氧化物酶、L-苯丙氨酸氨解酶、β-1,3-葡聚糖酶、过氧化氢酶和几丁质酶活性,降低了杏果实贮藏期内的多酚氧化酶活性。该结果为开发基于植物精油的缓释抑菌剂提供了新思路。     

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。     

Functional Properties and Oxidative Stability of Flaxseed Oil Microencapsulated by Spray Drying Using Legume Proteins in Combination with Soluble Fiber or Trehalose

The objective of this study was to evaluate the potential of double wall material combinations, using legume protein (soy protein isolate and pea protein isolate) in combination with wheat dextrin soluble fiber or trehalose, as alternative materials for microencapsulation of flaxseed oil by spray drying. The obtained preparations, with oil content of 35%, were fine and difficult flowing powders, regardless of their composition. The 1% addition of silica to the powders significantly reduced their cohesiveness and improved their flowability. The efficiency of microencapsulation, calculated based on oil fat content, ranged from 62 to 98% and was higher in the powders with trehalose and in the powders containing soy protein. Effective protection against oxidation of microencapsulated oil was achieved in the protein-trehalose matrix, especially in the case of the vacuum-packed powders with pea protein during storage at refrigeration temperature. Replacing trehalose with soluble fiber enabled formation of powders less susceptible to caking under conditions of increased humidity, but it resulted in decreased microencapsulation efficiency. The combination of pea protein/carbohydrate resulted in the formation of microcapsules with porous structure, especially in the system with soluble fiber. With time, the structure of the primary emulsions and those reconstituted from powders containing pea protein changed from liquid to greasy and paste-like.     

Influence of emulsion composition and inlet air temperature on the microencapsulation of flaxseed oil by spray drying

The objective of this work was to study the influence of some process conditions on the microencapsulation of flaxseed oil by spray drying. The process was carried out on a mini spray dryer and gum Arabic was used as wall material. Seventeen tests were made, according to a central composite design. Independent variables were: inlet air temperature (138-202 °C), total solid content (10-30% w/w) and oil concentration with respect to total solids (10-30% w/w). Encapsulation efficiency, lipid oxidation and powder bulk density were analyzed as responses. Powder morphology and particle size distribution were also analyzed. The feed emulsions were characterized with respect to droplet size and viscosity. Higher solid content and lower oil concentration led to higher encapsulation efficiency and lower lipid oxidation, which was related to the higher emulsion viscosity and lower droplets size. Increasing drying temperature resulted in higher lipid oxidation. Bulk density increased when higher solid content and lower inlet air temperature were used. The particles were rounded and shriveled, and their mean diameter was mainly affected by total solid content.     

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.     

牦牛酥油微胶囊的制备及其特性研究

为提高传统牦牛酥油的抗氧化性能,延长保质期,本文以阿拉伯胶和明胶为壁材,采用复合凝聚法对牦牛酥油进行包埋制备牦牛酥油微胶囊。以包埋率为指标,通过单因素和正交试验优化其制备工艺,并研究其理化特性、形貌结构、稳定性和模拟胃肠消化特性。结果表明,牦牛酥油微胶囊最优工艺为:芯壁比1:1.5、壁材质量分数1.5%、复凝pH4.2、复凝温度40 ℃,包埋率达81.39%;牦牛酥油微胶囊的平均粒径、水分含量、溶解度、休止角分别为19.728 μm、3.62%、96.48%、37.7°;扫描电子显微镜和傅里叶红外光谱分析表明,牦牛酥油微胶囊表面光滑,形状结构不规则,牦牛酥油被壁材成功包埋;差式扫描量热和热重分析表明,牦牛酥油微胶囊的热稳定性较好;此外,牦牛酥油微胶囊可以实现牦牛酥油在模拟胃肠液中的控制释放,其中,人工肠液中释放率达99.74%;贮藏实验表明,微胶囊化能减缓牦牛酥油氧化速度、延长货架期。本研究为提高牦牛酥油的生物利用率提供理论依据。     

榛子油微胶囊的制备及其稳定性研究

为缓解榛子油的氧化速度,增加储藏期和扩大其应用范围,本研究以β-环糊精（β-cyclodextrin, β-CD）为壁材,采用超声波辅助分子包埋法制备榛子油微胶囊,通过响应面法优化了微胶囊的工艺条件,同时对其理化性质进行了测定。结果表明:当壁材浓度（H₂O/β-CD）为16:1、壁芯材比例为5:1、包埋时间为62 min和包埋温度为59.3 ℃时,微胶囊的包埋率达到69.18%,产率达到59.74%。微胶囊的平均粒径为880.4 nm,水分含量为2.85%,溶解度为55.95%,休止角为42.49°。通过扫描电镜、红外光谱和热重分析等结果表明,微胶囊为块状、菱形片状或不规则柱状结构,包埋物已形成,同时具有良好的热稳定性。加速氧化实验表明,微胶囊化可以有效减缓榛子油的氧化速度,延长货架期,扩大其应用范围。     

Microencapsulated Lactobacillus rhamnosus GG powders: relationship of powder physical properties to probiotic survival during storage

Freeze-dried commercial Lactobacillus rhamnosus GG (LGG) were encapsulated in an emulsion-based formulation stabilized by whey protein and resistant starch and either spray-dried or freeze-dried to produce probiotic microcapsules. There was no difference in loss of probiotics viability after spray drying or freeze drying. Particle size, morphology, moisture sorption, and water mobility of the powder microcapsules were examined. Particle size analysis and scanning electron microscopy showed that spray-dried LGG microcapsules (SDMC) were small spherical particles, whereas freeze-dried LGG microcapsules (FDMC) were larger nonspherical particles. Moisture sorption isotherms obtained using dynamic vapor sorption showed a slightly higher water uptake in spray-dried microcapsules. The effect of water mobility, as measured by nuclear magnetic resonance (NMR) spectroscopy, at various water activities (a(w) 0.32, 0.57, and 0.70) and probiotic viability during storage at 25 °C was also examined. Increasing the relative humidity of the environment at which the samples were stored caused an increase in water mobility and the rate of loss in viability. The viability data during storage indicated that SDMC had better storage stability compared to FDMC. Although more water was adsorbed for spray-dried than freeze-dried microcapsules, water mobility was similar for corresponding storage conditions because there was a stronger water-binding energy for spray-dried microcapsule. This possibly accounted for the improved survival of probiotics in spray-dried microcapsules.     

葡萄籽油微胶囊的制备及氧化稳定性研究

研究了葡萄籽油微胶囊的制备工艺及其氧化稳定性,以葡萄籽油为芯材,阿拉伯胶与麦芽糊精为壁材,在复合乳化剂的作用下进行乳化,以喷雾干燥法得到微胶囊产品并测定其氧化稳定性。研究表明阿拉伯胶与麦芽糊精重量比为3∶1,乳化剂浓度为10%,芯壁比为1∶2,温度为45℃,均质速度为12000r/min,乳化时间为12 min时制备得到稳定的葡萄籽油乳液,在进风温度180℃、出口温度80℃、进料速率5mL/min条件下喷雾干燥得到葡萄籽油微胶囊,葡萄籽油微胶囊化效率达到72.56%,60℃条件下贮藏葡萄籽油微胶囊的氧化速率明显降低,贮存性能和抗氧化性显著提高。     

热处理肌原纤维蛋白复凝聚法制备微胶囊及性能表征

探索罗非鱼（Oreochromis niloticus）中提取肌原纤维蛋白（MP）在热处理后（HMP）作为一种新型微胶囊的壳材料,在海藻酸钠（SA）和壳聚糖（CS）共存下,采用超声复凝聚法对玉米油进行微胶囊化,并对其性能进行表征。结果表明：当海藻酸钠含量2.5%,HMP含量3.0%,玉米油含量30%时,乳液粒径小而均匀,乳化稳定性高。壳聚糖含量为1.2%、海藻酸钠和壳聚糖质量比1:1、氯化钙浓度为5.0%时,通过超声复凝聚法得到的微胶囊平均粒径为88.74±2.60μm,包封率为82.59%±1.44%;微胶囊具有不规则形状和起伏的表面;红外光谱和X射线衍射结果表明,海藻酸钠与壳聚糖因静电结合作用,与HMP共同构成了微胶囊致密的外壳;DSC结果显示HMP微胶囊具有一定的热稳定性;HMP微胶囊显著降低了贮存过程中油脂的POV值与TBA值,有效延缓了玉米油的氧化速度;HMP微胶囊在整个模拟消化阶段的游离脂肪酸（FFA）释放量为92.67%,且在肠消化阶段释放更多的FFA,表明微胶囊化对芯材的释放起到了缓释作用。这项研究显示,HMP与海藻酸钠和壳聚糖复合后,是可以用于微胶囊制备及保护生物活性...