Impact of Wall Materials on Physicochemical Properties of Microencapsulated Fish Oil by Spray Drying

The aim of the present study was to investigate the effect of wall materials composition on physicochemical characteristics of fish oil microcapsules produced by spray drying (180 °C). Four different combination of coating materials (fish gelatin, chitosan, combination of gelatin and chitosan, and a mixture of microbial transglutaminase (MTGase) with maltodextrin) were applied to two different fish oils to produce 40 % solid emulsions. Scanning electron microscopy and extraction of surface and encapsulated oils revealed that fish gelatin provided the highest preserving effect on the covering fish oil. Meantime, addition of MTGase to gelatin could also increase this ability and reveled less surface oil than chitosan treatment (2.63 and 2.80 % versus 4.66 and 5.23 %, respectively; P?<?0.05). Mixture of gelatin and maltodextrin with MTGase as wall material led to the highest encapsulation efficiency, being selected as the best microencapsulation condition; meantime, application of chitosan with maltodextrin provided the worse encapsulation efficiency (P?<?0.05). All indices of powders (encapsulation efficiency, surface morphology, and particle size) showed that powders prepared from gelatin and gelatin with MTGase increased the encapsulation efficiency and would increase the stability of microcapsule powders.     

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.     

Physicochemical Properties and Storage Stability of Lutein Microcapsules Prepared with Maltodextrins and Sucrose by Spray Drying

The purpose of this study was to determine the physicochemical properties of lutein microcapsules. Nine types of lutein microcapsules were prepared in order to determine their encapsulation efficiency and yield. Results show that lutein microcapsules with maltodextrin M040 and sucrose at the weight ratio of 3:1 (designated as M040:1) had the highest encapsulation efficiency (90.1%) among the lutein microcapsules, as well as a higher encapsulation yield (90.4%). The onset glass transition temperatures (T_gi) and the surface dents of the lutein microcapsules decreased as the dextrose equivalent value of maltodextrin and the weight ratio of sucrose increased. Enthalpy relaxation experiments were conducted for the lutein microcapsules M040:1 at (T_gi – 5) , (T_gi – 10), and (T_gi – 15) °C, and the obtained data were fitted to the Kohlrausch–Williams–Watts model. Results show that the mean relaxation time (τ) (316 h) of M040:1 lutein microcapsules aged at (T_gi – 15) °C was greater than the τ (161 h) at (T_gi – 10) °C and τ (60.5 h) at (T_gi – 5) °C. Effects of temperature and oxygen transmission rates for package film on the storage stability of M040:1 lutein microcapsules were also investigated. Findings show that rates of lutein degradation and color change increased by an order of magnitude as storage temperature (4 to 97 °C) and oxygen transmission rate of the package film (0.018 to 62.8 cc/m² day) increased. These results suggest that lutein is highly unstable and susceptible to thermal and oxidative degradations. However, microencapsulation with appropriate wall materials of higher relaxation time and high oxygen barrier packaging can increase the storage life.     

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.     

Influence of Wall Material and Inlet Drying Air Temperature on the Microencapsulation of Fish Oil by Spray Drying

Several single and composite milk-originated wall materials were used to microencapsulate fish oil via spray drying at various inlet drying air temperatures. Skim milk powder (SMP), whey protein concentrate, whey protein isolate (WPI), 80% WPI?+?20% milk protein concentrate, and 80% WPI?+?20% sodium caseinate (NaCas) were applied as the wall for capsules generated at drying air temperatures of 140, 160, and 180 °C. The higher the drying air temperature, the higher was the particle size, encapsulation efficiency, and peroxide value and the lower was the moisture content and bulk density. The microcapsules prepared with SMP showed the highest encapsulation efficiency and lowest peroxide value for the oil due to the presence of lactose in its chemical composition. Differential scanning calorimetry and Fourier transform infrared analyses indicated the absence of any significant interaction between SMP and fish oil.     

基于内源乳化法和喷雾干燥优化制备花色苷微胶囊及其稳定性分析

以海藻酸钠为壁材,基于内源乳化法制备微胶囊化的湿态花色苷,经优化喷雾干燥条件制备花色苷微胶囊,考察花色苷微胶囊粒径和形态及微胶囊化前后花色苷的光照、温度及胃肠消化稳定性。花色苷微胶囊喷雾干燥的最佳工艺条件为加热器温度120℃、进料速率12 r/min、真空压力0.03 MPa,包埋率为75.12%,平均粒径为558.2 nm。光照5 h,花色苷和花色苷微胶囊保存率分别为63.7%、82.1%;避光5 h,花色苷和花色苷微胶囊保存率分别为78.6%、91.4%;90℃条件下,花色苷和花色苷微胶囊半衰期分别为2.54、6.39 h;2 h胃消化,花色苷和花色苷微胶囊保存率分别为45.3%、83.7%;4 h肠消化,花色苷和花色苷微胶囊保存率分别为0.9%、24.4%。研究结果表明内源乳化法结合喷雾干燥制备的花色苷微胶囊的光照、温度以及胃肠消化稳定性均高于花色苷。     

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.     

Microencapsulation of Extra Virgin Olive Oil by Spray Drying: Effect of Wall Materials Composition,Process Conditions,and Emulsification Method

Food and Bioprocess Technology - The objective of the study was to investigate the microencapsulation of extra virgin olive oil by spray drying to increase its stability and application area. The...     

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...     

Encapsulation and Oxidative Stability of PUFA-Rich Oil Microencapsulated by Spray Drying Using Pea Protein and Pectin

This study aimed at evaluating the potential of pectin combination with pea protein isolate (PPI) in the microencapsulation of polyunsaturated fatty acids (PUFA)-rich oil by spray drying, in order to maximize encapsulation efficiency and minimize lipid oxidation. The feed emulsions used for particle production consisted of PUFA-rich oil droplets coated by either PPI (primary emulsion) or PPI–pectin (secondary emulsion). Dry emulsions characteristics and oxidative stability of microencapsulated oil as a function of relative humidity (RH; from 11 % to 75 %) were determined. Scanning electron microscopy (SEM) images revealed considerable structural changes. Oil droplets retained their shape upon drying and reconstitution. However, a shift in oil droplet size upon reconstitution indicated that oil droplet coalescence occurred within the process. Oxidation of microencapsulated oil in secondary emulsion was delayed from that of primary emulsion but followed the same pattern with regards to humidity. A high rate of oxidation was found for intermediate RH conditions (33 % and 57 % RH). The lowest rate of oxidation as followed by hydroperoxide and thiobarbituric acid reactive substances values was found at 75 % RH, a condition that is likely to diverge significantly from the monolayer moisture value. The oxidative stability of encapsulated oil was influenced by both physical state of the emulsions and the different constituents at the oil-in-water interface with PPI–pectin secondary emulsion giving the best protection of the oil.     

鱼油氧化稳定性的研究（Ⅱ）

鱼油氧化稳定性的研究（Ⅱ）烟台大学脂类研究实验室（２６４００５）曹国锋，翁新楚（接上期）２鱼油的保有和抗氧化２．１鱼油的保存由于鱼油极易氧化，所以其保存显得尤为重要。油脂保存中常用的方法和措施有避光、避热、低温贮存、真空贮存、充氮贮存、使用除氧剂、添...     

Physicochemical Property and Oxidative Stability of Whey Protein Concentrate Multiple Nanoemulsion Containing Fish Oil

The objectives of this research were to produce whey protein concentrate (WPC) multiple nanoemulsion (MNE) and to study how whey protein concentration level and antioxidant type affected the physicochemical properties and oxidative stability of fish oil in MNE. The morphological and physicochemical characteristics of MNE were investigated by using transmission electron microscopy and particle size analyzer, respectively. The oxidative stability of fish oil in MNEs was assessed by measuring peroxide value (PV), p‐anisidine value, and volatile compounds. The spherical forms of emulsions with size ranging from 190 to 210 nm were observed indicating the successful production of MNE. Compared with free fish oil, fish oil in MNE exhibited lower PV, p‐anisidine value, and formation of maker of oxidation of fish oil indicating the oxidative stability of fish oil in MNE was enhanced. PV, p‐anisidine value, and makers of oxidation of fish oil were decreased with increased WPC concentration level. The combined use of Vitamin C and E in MNE resulted in a reduction in PV and p‐anisidine value, and development of maker of oxidation. In conclusion, WPC concentration level and antioxidant type are key factors affecting the droplet size of MNE and oxidative stability of fish oil.     

鱼油微丸的制备及其稳定性研究

以海藻酸钠为囊材,制备鱼油微丸,并对其稳定性进行研究。方法:鱼油和海藻酸钠混匀、乳化,滴入氯化钙冷凝液制成滴丸;用Agilent6890气相色谱仪,HP-5气相色谱柱,柱温230℃,进样口温度260℃,检测室温度280℃,测定微丸中EPA和DHA含量;测定其5、10d60℃、光照、相对湿度75%加速实验的稳定性;筛选微丸的抗氧化剂。结果:精密称取高、中、低三剂量鱼油微丸,用研磨超声法测定其中EPA、DHA含量,其测定方法精密度分别为3·06%,3·06%,2·86%;3·06%,3·61%,3·19%(n=5)。高、中、低3个剂量鱼油微丸中EPA、DHA平均加样回收率分别为100·6%,99·96%,101·7%;102·4%,100·9%,101·2%(n=3)。在60℃、光照、相对湿度75%中置5、10d后含量下降不大,仍然稳定;抗氧化性比较TBHQ>BHA>VE。结论:用海藻酸钠制备鱼油微丸简便、可行、稳定,具有一定的开发价值。     

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.     

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。