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。     

Isolation and characterization of lecithin from squid (Todarodes pacificus) viscera deoiled by supercritical carbon dioxide extraction

Marine lecithin was isolated and characterized from squid (Todarodes pacificus) viscera residues deoiled by supercritical carbon dioxide (SC-CO(2)) extraction. SC-CO(2) extraction was carried out to extract the oil from squid viscera at different temperatures (35 to 45 °C) and pressures (15 to 25 MPa). The extraction yield was higher at highest temperature and pressure. The major phospholipids of squid viscera lecithin were quantified by high-performance liquid chromatography (HPLC). Phosphatidylcholine (PC; 80.5% ± 0.7%) and phosphatidylethanolamine (PE; 13.2% ± 0.2%) were the main phospholipids. Thin layer chromatography (TLC) was performed to purify the individual phospholipids. The fatty acid compositions of lecithin, PC and PE were analyzed by gas chromatography (GC). A significant amount of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were present in both phospholipids of PC and PE. Emulsions of lecithin in water were prepared through the use of a homogenizer. The oxidative stability of squid viscera lecithin was high in spite of its high concentration of long-chain polyunsaturated fatty acids. PRACTICAL APPLICATION: Squid viscera are discarded as a waste by fish processing industry. Since lecithin from squid viscera contains higher amounts of polyunsaturated fatty acids, it may have promising effect to use in food, pharmaceutical, and cosmetic industries.     

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.     

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。     

丁香油微胶囊的制备及表征

以明胶和海藻酸钠为壁材,采用复凝聚法对丁香油进行包覆,通过喷雾干燥法得到干燥的微胶囊产物,研究pH、明胶和海藻酸钠质量比、芯壁质量比、壁材用量、搅拌转速对微胶囊形成的影响,并对微胶囊的缓释性进行研究,采用红外、TG、SEM对优选实验条件下制备得到的微胶囊进行表征.结果表明:经过微胶囊化的丁香油挥发性明显降低,热稳定性大...     

Effects of the Emulsion Composition on the Physical Properties and Oxidative Stability of Sacha Inchi (<Emphasis Type="Italic">Plukenetia volubilis</Emphasis> L.) Oil Microcapsules Produced by Spray Drying

Sacha Inchi (Plukenetia volubilis L.) oil (SIO) is one of the vegetable oils with the highest content of polyunsaturated fatty acids (about 50% α-linolenic acid, and 35% linoleic acid), thus being prone to oxidation. The aim of this study was to evaluate the effects of the emulsion composition on the physical properties and oxidative stability of SIO microencapsulated by spray drying using modified starch (Hi-Cap 100) and maltodextrin in a mass ratio of 75:25, as wall material. The processing yield (PY), microencapsulation efficiency (MEE), and some selected physical properties (moisture content, A _w , color, sorption isotherms, flowing and thermal stability) of the SIO microcapsules (SIO-M) were investigated as a function of the oil loading (10, 20, and 30%) and the concentration of wall material solids (20 and 30%). The obtained results indicated that both the PY and MEE were significantly reduced as the oil loading increased, varying from 50 to 35%, and between 96 and 82%, respectively. FTIR analyses revealed that SIO was effectively encapsulated into the wall material. SIO-M were spherical in shape, and showed high oxidation stability upon accelerated tests. According to the thermogravimetric analysis, SIO-M could resist the pasteurization and sterilization processes used in the food industry, without suffering thermal decomposition. The sorption isotherms of SIO-M fitted better with the Guggenheim-Anderson-de Boer model. These results indicate that SIO could be successfully microencapsulated by spray drying using Hi-Cap 100 and maltodextrin as wall materials, from emulsions with a concentration of 30% wall material, and 20 to 30% oil loading.     

奇亚籽油微胶囊的制备及表征

为提高奇亚籽油的稳定性,对其进行微胶囊化。以包埋率为评价指标对冷冻干燥制备奇亚籽油微胶囊的工艺进行优化,利用激光粒度仪、扫描电镜、红外光谱仪和差示扫描量热仪(differential scanning calorimetry,DSC)等表征微胶囊性状。结果表明,微胶囊的最佳制备工艺为:壁材比(酪蛋白酸钠∶D-乳糖-水合物)1.1∶1(质量比)、固形物浓度31.32%、壁芯比2.34∶1(质量比),包埋率达到90.65%。所得微胶囊产品含有芯材、壁材的特征峰,表明形成奇亚籽油微胶囊的包埋结构。制得的奇亚籽油微胶囊呈不规则的几何形状和紧凑的结构,大小均匀,流动性较好,粉末表面光滑,黏度小,稳定性良好,可满足一般食品加工条件,为奇亚籽油微胶囊在食品工业中的应用提供参考。     

Evaluation of oxidative stability of vegetable oils by monitoring the tendency to radical formation. A comparison of electron spin resonance spectroscopy with the Rancimat method and differential scanning calorimetry

Electron spin resonance spectroscopy (ESR), based upon the spin trapping technique, was applied at 60 °C for evaluating the oxidative stability of 11 vegetable oil samples, including sunflower oil, rapeseed oil and their mixtures. The ESR results were compared with the oxidative stability values provided by the Rancimat method and differential scanning calorimetry (DSC) at 100 °C. High linear correlations were found between ESR and Rancimat (r=0.963), and between ESR and DSC (r=0.979), suggesting that ESR can predict the oxidative stabilities provided by the Rancimat method, as well as by DSC, within a wide range of stability values. In order to examine the capability of each method to evaluate antioxidant activity, different concentrations of α-tocopherol were tested in purified sunflower oil and purified rapeseed oil. Minor differences among the three methods were found when low concentrations of α-tocopherol were used, whereas similar responses were obtained at the highest antioxidant concentration assayed. In comparison with the Rancimat method and DSC, the ESR method is concluded to be useful as a method employing milder conditions and shorter time, and which can be applied for the evaluation of oxidative stability of oils containing volatile antioxidants and other lipid systems containing water.     

高价离子型辛烯基琥珀酸淀粉酯作为微胶囊壁材的研究

以钠型辛烯基琥珀酸淀粉酯为原料,制备高价离子型辛烯基琥珀酸淀粉酯(钡型、钙型、三价铁型),并以柠檬油为芯材,高价离子型辛烯基琥珀酸淀粉酯为壁材,采用喷雾干燥法制备柠檬油微胶囊,测定了高价离子型辛烯基琥珀酸淀粉酯的离子交换率,乳液的乳化稳定性及黏度,并考察了此种淀粉酯作为微胶囊壁材对柠檬油包埋率的影响,最后利用扫描电子显微镜观察微胶囊的形貌特征。结果表明,淀粉酯中离子化合价的改变对乳液黏度、乳化稳定性和柠檬油的包埋率均有显著影响(p<0.05),其中,三价铁型辛烯基琥珀酸淀粉酯作壁材时,乳液黏度为1.04 mPa·s,柠檬油包埋率达到了96.51%;扫描电镜分析表明,三价铁型壁材制备的微胶囊粒径最大,囊壁最厚。说明三价铁型辛烯基琥珀酸淀粉酯可作为一种性能良好的微胶囊壁材。     

Oxidative Stability, Structure, and Physical Characteristics of Microcapsules Formed by Spray Drying of Fish Oil with Protein and Dextrin Wall Materials

ABSTRACT: Maltodextrins and a highly branched cyclic dextrin (HBCD) were tested for their ability to serve as wall materials for microcapsules with proteins. HBCD or a maltodextrin of DE18 with sodium caseinate (SC) improved the oxidative stability of encapsulated fish oil; however, the DE18/SC wall system had 2 disadvantages: browning induced by the Maillard reaction and agglomeration. The oil load level and the selection of dextrin strongly affected the outer topography and the inner structure, as well as the ratio of the oil to dextrin on the surface of the microcapsules. It is stated that drying speeds of dextrin and oil load levels were shown to be likely related to the structural difference in the microcapsules.     

均质工艺对制备鱼油微胶囊结构和理化性质的影响

本实验分别利用高压均质、空化射流和超声破碎3 种均质方式制备以大豆分离蛋白和磷脂酰胆碱包裹的鱼油纳米乳液和微胶囊,并对纳米乳液粒径、Zeta-电位、稳定性、黏度、乳化产率及微胶囊形貌、理化性质、稳定性进行比较分析,研究均质工艺对鱼油纳米乳液和微胶囊理化性质的影响。结果发现,空化射流工艺制备的纳米乳液平均粒径小,乳化产率和乳液稳定性较高,经过空化射流10 min制备的微胶囊包埋率达87.44%,溶解度较高,微胶囊颗粒表面形态饱满、致密、无裂纹和空隙,氧化稳定性和热稳定性较好。高压均质和超声破碎制得的纳米乳液平均粒径大,乳化产率和乳液稳定性较低,经过100 MPa高压均质和400 W超声破碎制得的微胶囊包埋率分别为80.36%和78.64%,溶解度相较于空化射流差,微胶囊颗粒表面分别出现微孔和较大的孔洞,氧化稳定性和热稳定性较差。傅里叶变换红外光谱分析结果表明3 种均质工艺均有较好的包埋效果。通过实验可以得出空化射流均质工艺制备的鱼油纳米乳液及微胶囊在产品性能上要优于其他两种均质工艺。本研究可为鱼油纳米乳液和微胶囊产品的均质工艺选择以及应用评价体系的构建提供理论依据。     

Efficient encapsulation of fish oil: Capitalizing on the unique inherent characteristics of whey cream and hydrolyzed whey protein

The effects of protein concentration and of blending a phospholipid-rich whey coproduct, Procream (Salibra 700 Procream, Glanbia Nutritionals), with intact or hydrolyzed whey protein concentrate, on fish oil microencapsulation efficiency and oxidative stability were assessed. Trypsin and protease M, from Aspergillus oryzae, were used to produce 2 unique hydrolysates. All microcapsules had excellent encapsulation efficiencies (>92%) and good physical properties, regardless of protein content and Procream inclusion. Intact α-lactalbumin and β-lactoglobulin and their peptides were involved in stabilizing oil droplets. Disulfide interchange resulted in formation of protein aggregates, which were more pronounced in samples containing Procream. Although all microcapsules had relatively good oxidative stability, most had better stability at 2 versus 0.5% protein. Protease M hydrolysate + Procream microcapsules had the highest stability, regardless of protein content. Results demonstrated that Procream, at a reduced protein inclusion level, can partially replace more expensive whey protein ingredients in microencapsulation, when blended with a select hydrolysate.     

Microencapsulation of Essential Oil for Insect Repellent in Food Packaging System

Microcapsules containing thyme oil were prepared by in situ polymerization, using melamine–formaldehyde prepolymer as a wall material and 3 different emulsifiers (pluronic F‐127, tween 80, and sodium lauryl sulfate [SLS]). The general characteristics and release behavior of microcapsules, and their repellent effect against insects were investigated. The morphology of microcapsules using SLS was spherical shape with smooth surface. Microcapsules began to degrade at 150 °C. The particle size ranged from 1 to 10 μm and the loading efficiency of thyme oil was clearly affected by the emulsifier type. The highest loading efficiency appeared in microcapsules using SLS, which have good thermal resistance and smooth surface. The release rate of thyme oil from microcapsules was not only dependent on the storage temperature but also emulsifier type and microcapsules showed the sustained release properties for a long time. Diets, which were mixed with encapsulated thyme oil, expressed high insect repellent efficacy over 90% for 4 wk. Practical Application : Essential oil has various pest‐control characteristics, including repellent, ovicidal, and antifeedant efficacy. This work showed the sustained release properties and long‐lasting repellency of encapsulated essential oil. The results suggest that the great potential of essential oil microcapsules can be applied in coating or printing of food packaging materials for the insects repelling effects.     

Fish Oil Microcapsules from O/W Emulsions Produced by Premix Membrane Emulsification

Fish oil microcapsules were prepared by combining a low-energy emulsification method (premix membrane emulsification) with spray drying. Oil-in-water (O/W) emulsions were prepared using a two-step emulsification method that used a rotor–stator homogenizer followed by membrane emulsification. The influence of the emulsification method (mechanical stirring or membrane emulsification), the emulsification conditions (membrane and emulsifier type), and the amount of wall material on the physicochemical characteristics of the microcapsules was studied. The results show that the emulsification method and the type and amount of emulsifier and wall material affect the final amount of encapsulated oil. Microcapsules produced by membrane emulsification and stabilized with 2 % Tween-20 or 10 % whey protein presented the highest values (higher than 50 %) of oil encapsulation efficiency (OEE). It has been found that the OEE increases when decreasing the droplet size of the emulsions as well as with the increase of the amount of wall material employed during drying. Morphology analysis showed that the microcapsules obtained from O/W emulsions produced by premix membrane emulsification were rounder in shape, without visible cracks on the surface and no vacuoles on the inside. Oxidation stability tests performed on some selected samples indicate that the microcapsules with higher stability are the ones produced with a higher amount of wall material and have less surface oil.     

DHA乳状液制备工艺优化及氧化稳定性的研究

以二十二碳六烯酸(Docose Hexaenoie Acid, DHA)微藻油微胶囊化过程中形成的乳状液为研究对象,研究乳状液制备工艺条件及氧化稳定性。利用透射光浊度法和电导率法测定乳状液的稳定性,研究预乳化时间、乳化温度、均质压力、均质级数对乳状液稳定性的影响。以乳状液稳定性和表面张力为评价指标,在单因素试验基础上采用正交试验对乳状液制备工艺进行优化,制备后进行微胶囊包埋,分析了DHA微藻油微胶囊的氧化稳定性。结果表明,乳状液制备的最佳工艺为乳化温度50℃、均质压力30 MPa、预乳化时间3 min,2级均质,在此条件下,透射光浊度法测定得到乳状液稳定性为8.75%,表面张力为20.5 mN/m。乳状液制备工艺优化后得到的DHA微胶囊氧化稳定性得到显著提高。     

超声波法制备八角茴香油-β-环糊精微胶囊及其表征分析

为提高八角茴香油的稳定性,采用超声波法制备八角茴香油-β-环糊精微胶囊。以包埋率为评价指标,通过正交试验优化制备工艺,并考察微胶囊的加热释放特性。结果表明,最佳制备工艺为八角茴香油与β-环糊精质量比1∶6(g/g)、超声时间40 min、超声温度50℃、超声功率198 W,在此条件下包埋率为94.21%,载药量为6.93%,平均粒径为2.53μm。超声温度和超声功率的变化对微胶囊包埋率的影响显著。红外光谱、差示扫描量热分析和热重分析证实了微胶囊的形成。释放特性表明,200℃条件下加热120 min,八角茴香油保留率仅剩4.60%,而相同温度和时间条件下,微胶囊中八角茴香油保留率为78.38%,是八角茴香油的17.04倍,八角茴香油被包埋后热稳定性提高。超声波法和饱和水溶液法制备微胶囊相比,载药量相差不大,但超声制备的微胶囊包埋率及收率比饱和水溶液法分别提高7.80%和4.98%;超声制备微胶囊包埋率、收率及载药量比研磨法分别提高14.68%、1.88%和1.85%。超声波法是制备高质量八角茴香油-β-环糊精微胶囊的简便可行方法,八角茴香油被包埋后稳定性提高,有望应用于食品保鲜领域。     

沙棘籽油微胶囊的制备及其性质研究

以沙棘籽油为芯材,采用CAS/MD、OSA/MD、WPI/GA/MD 3种壁材配方,通过喷雾干燥制备沙棘籽油微胶囊,并对微胶囊的性质和微观结构进行研究,用气相色谱法测定微胶囊化前后沙棘籽油脂肪酸含量变化。结果表明:3种配方的微胶囊产品均具有较低的含水量和较高的溶解性,其中以CAS/MD为壁材制备的沙棘籽油微胶囊包埋率最高,微胶囊粒径小,表面光滑,热稳定性良好,壁厚度均一,沙棘籽油在胶囊中分布均匀,喷雾干燥制备过程未对沙棘籽油中的功能性成分产生影响。     

Micro-encapsulation of refined olive oil: influence of capsule wall components and the addition of antioxidant additives on the shelf life and chemical alteration

BACKGROUND: Although refined olive oils (ROOs) exhibit lower quality and less stability toward thermal stress than extra‐virgin olive oils, these types of oil are gaining importance in the food industry. The inclusion of ROOs in processed food may alter the oxidative stability of the manufactured products, and therefore having technological alternatives to increase oil stability will be an important achievement. For this reason the main goal of this study was to assess the influence of the micro‐encapsulation process on the ROO chemical composition and its oxidative stability. Factors such as microcapsule wall constituents and the addition of the antioxidant butyl hydroxytoluene were investigated in order to establish the most appropriate conditions to ensure no alteration of the refined olive oil chemical characteristics. RESULTS: The optimised methodology exhibited high encapsulation yield (>98%), with micro‐encapsulation efficiency ranging from 35 to 69% according to the nature of the wall components. The encapsulation process slightly altered the chemical composition of the olive oil and protected the oxidative stability for at least 11 months when protein components were included as wall components. CONCLUSION: It was concluded that the presence of proteins constituents in the microcapsule wall material extended the shelf life of the micro‐encapsulated olive oil regardless the use of antioxidant additives. Copyright © 2012 Society of Chemical Industry     

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。     

Characterization of spray-dried microalgal oil encapsulated in cross-linked sodium caseinate matrix induced by microbial transglutaminase

Sodium caseinate (SC) cross-linked by microbial transglutaminase (MTGase) for encapsulating microalgal oil was investigated. Protein cross-linking was evidenced in the SDS-PAGE graph. The emulsifying properties of SC depended on the cross-linked time with MTGase. The emulsifying activity and stability indexes of SC increased with the cross-linking time of 30 to 90 min (P30 to P90), and then declined with longer cross-linked time of 180 to 420 min (P180 to P420). The P30 to P90 as wall material for microencapsulation was superior to P180 to P420 and control sample. The microcapsules prepared with P30 to P90 showed more than 97% of microencapsulation efficiency in contrast to about 90% with the P180 to P420. During storage, the microcapsules prepared with P30 to P90 exhibited higher oxidative stability as compared with other microcapsules. A sustained release of microalgal oil was observed, and core release was time dependent and affected by cross-linking degree. Results showed that the powdered microalgal oil prepared with P30 to P90 demonstrated enhanced physicochemical properties and oxidative stability. Practical Application: The novel method using cross-linked proteins as wall material induced by microbial transglutaminase in food industry for sensitive ingredients could convert microcapsules into a stable form, which would lead to its more widespread utilization as a kind of food additive.