Microencapsulation and oxidative stability of spray-dried fish oil emulsions

Emulsions of menhaden oil and sodium caseinate (NaCas) incorporating carbohydrates of varying dextrose equivalence (DE) were spray-dried to yield encapsulated fish oil powders. The effects of carbohydrate DE (5.5-38), core/wall ratio and NaCas/carbohydrate ratio on microencapsulation efficiency (ME) and oxidative stability of spray-dried emulsions were examined. The effect of alpha-tocopherol or Trolox C addition on the oxidative stability of herring oil emulsions and powders was also determined. ME of fish oil powders was greater than 90% in most cases. Peroxide value (PV) of menhaden oil powders decreased on increasing the DE of carbohydrates. PV of menhaden oil powders increased as core/wall ratio increased from 0.33-1.0. NaCas/DE 28 ratio did not affect PV values of powders. The addition of alpha-tocopherol or Trolox C decreased PV throughout the storage period; this effect was most pronounced for alpha-tocopherol added to the oil at a concentration of 100 ppm. Addition of alpha-tocopherol delays the onset of oxidation in stored fish oil powders.     

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Emulsions of menhaden oil and sodium caseinate (NaCas) incorporating carbohydrates of varying dextrose equivalence (DE) were spray-dried to yield encapsulated fish oil powders. The effects of carbohydrate DE (5.5-38), core/wall ratio and NaCas/carbohydrate ratio on microencapsulation efficiency (ME) and oxidative stability of spray-dried emulsions were examined. The effect of α-tocopherol or Trolox C addition on the oxidative stability of herring oil emulsions and powders was also determined. ME of fish oil powders was greater than 90% in most cases. Peroxide value (PV) of menhaden oil powders decreased on increasing the DE of carbohydrates. PV of menhaden oil powders increased as core/wall ratio increased from 0.33-1.0. NaCas/DE 28 ratio did not affect PV values of powders. The addition of α-tocopherol or Trolox C decreased PV throughout the storage period; this effect was most pronounced for α-tocopherol added to the oil at a concentration of 100 ppm. Addition of α-tocopherol delays the onset of oxidation in stored fish oil powders.     

Effect of oil loading on microspheres produced by spray drying

Oil-loaded microspheres were produced by spray drying emulsions consisting of fish oil and modified starch suspensions with different oil loadings. The emulsion stability was assessed by oil droplet size analysis. Microspheres were characterized in terms of size, morphology, yield and microencapsulation efficiency. It was found that an increase in oil loading resulted in emulsions containing larger oil droplets. This corresponded with larger mean microsphere diameters and rounder microspheres. However, high oil loadings produced lower yields and affected microencapsulation efficiencies.     

Effect of oil loading on microspheres produced by spray drying

Oil-loaded microspheres were produced by spray drying emulsions consisting of fish oil and modified starch suspensions with different oil loadings. The emulsion stability was assessed by oil droplet size analysis. Microspheres were characterized in terms of size, morphology, yield and microencapsulation efficiency. It was found that an increase in oil loading resulted in emulsions containing larger oil droplets. This corresponded with larger mean microsphere diameters and rounder microspheres. However, high oil loadings produced lower yields and affected microencapsulation efficiencies.     

Effects of emulsification and microencapsulation on the oxidative stability of camelina and sunflower oils

Oil-in-water (O/W) emulsions were prepared using different concentrations of camelina or sunflower oil. Sodium caseinate was used as the emulsifier and dried glucose syrup as the wall material. Emulsions were subsequently spray dried to yield high-fat powders (71.7–85.0%). Emulsification and microencapsulation of bulk oils decreased their level of lipid oxidation (lipid hydroperoxide and p-Anisidine values, p-Avs). Sunflower oil, O/W emulsions and reconstituted powders generally had lower oxidation products than corresponding camelina oil-based products throughout storage at 15°C. p-Avs of bulk oils remained constant, whereas p-Avs of O/W emulsions and reconstituted powders decreased early in storage, and remained low thereafter. Microencapsulated omega (ω)-3 rich powders were produced, easily reconstituted and showed no signs of deterioration throughout storage. These powders provided functional properties with potential for incorporation into various food systems as a source of beneficial ω-3 fatty acids.     

Microencapsulation of avocado oil by spray drying using whey protein and maltodextrin

Cold pressed avocado oil was microencapsulated by spray drying in four different wall systems consisting of whey protein isolate (WPI) alone or in combination with maltodextrin (MD) DE 5 at various ratios (90 : 10, 50 : 50 and 10 : 90). The WPI only or WPI/MD (90 : 10) powders were spherical and smooth, whereas the WPI/MD (50 : 50 and 10 : 90) powders exhibited pronounced surface collapse. Increasing the MD ratio resulted in higher bulk density and wettability, probably due to more compact physical structure and hydrophilic wall matrix. Surface free oil contents and microencapsulation efficiencies of powders were 11–16% and 45–66%, respectively, and no significant differences were observed between the samples. The crude avocado oil used in this study appeared to be stable against oxidation at cold and ambient temperatures, irrespective of microencapsulation. However, at high temperature of 60°C, the oxidative stability decreased significantly in all cases but it was improved to some extent by microencapsulation.     

Hydrolyzates of silkworm pupae (Bombyx mori) protein is a new source of angiotensin I-converting enzyme inhibitory peptides (ACEIP)

Silkworm pupae protein is a good source of high quality protein. The hydrolyzates of silkworm pupae protein catalyzed by neutrase, pepsin, acidic protease (Asperqiius usamii NO. 537), flavourzyme, alcalase, and trypsin with inhibitory activity on angiotensin I-converting enzyme (ACE) were identified by HPLC. The hydrolyzates catalyzed by acidic protease exerted the highest inhibitory activity on ACE. The hydrolyzing conditions were optimized by one-factor, factional factorial (FFD), and center composite (CCD) design methods, and response surface methodology (RSM). Statistical analyses showed that regression of the second-order model equation is suitable to describe ACE inhibitory bioactivity. The predicted inhibitory activity of hydrolyzates on ACE was 73.5 % at a concentration of 2.0 mg/ml. Optimized RSM technique decreased IC(50) of hydrolyzates inhibiting ACE to 1.4 mg/mL from 2.5 mg/ml. The molecular weight of the components of the hydrolyzates with inhibitory activity on ACE varied from less than 500 to about 1000 Da by ultra-filter analysis. These studies suggest that hydrolyzates of silkworm protein contain ACE inhibitory activity that could form a potential source of ACE inhibitor drugs.     

Microencapsulation of avocado oil by spray drying using whey protein and maltodextrin

Cold pressed avocado oil was microencapsulated by spray drying in four different wall systems consisting of whey protein isolate (WPI) alone or in combination with maltodextrin (MD) DE 5 at various ratios (90 : 10, 50 : 50 and 10 : 90). The WPI only or WPI/MD (90 : 10) powders were spherical and smooth, whereas the WPI/MD (50 : 50 and 10 : 90) powders exhibited pronounced surface collapse. Increasing the MD ratio resulted in higher bulk density and wettability, probably due to more compact physical structure and hydrophilic wall matrix. Surface free oil contents and microencapsulation efficiencies of powders were 11-16% and 45-66%, respectively, and no significant differences were observed between the samples. The crude avocado oil used in this study appeared to be stable against oxidation at cold and ambient temperatures, irrespective of microencapsulation. However, at high temperature of 60 degrees C, the oxidative stability decreased significantly in all cases but it was improved to some extent by microencapsulation.     

Oil encapsulation in core–shell alginate capsules by inverse gelation. I: dripping methodology

The production of capsules by inverse gelation consists of adding dropwise oil containing calcium dispersion into an alginate bath. A dripping technique to produce capsules from oil-in-water (O/W) emulsions was proposed by Abang. However, little is known about the oil encapsulation using water-in-oil (W/O) emulsions. This work aims to develop a new method of W/O emulsions encapsulation by inverse gelation. The success of the W/O emulsion encapsulation is due to three factors: 1) use of an emulsion with moderate stability (50?min); 2) production of an emulsion with at least 90?g/L of CaCl₂ and 3) addition of ethanol (20% v/v) into the alginate bath. Both wet and dry capsules were obtained with a spherical shape with diameters of 7 and 3.6?mm, respectively. All volume of oil was encapsulated and the oil loading in the wet and dry capsules was of 23 and 68% v/v, respectively.     

Gelatin-Acacia Microcapsules for Trapping Micro Oil Droplets Containing Lipophilic Drugs and Ready Disintegration in the Gastrointestinal Tract

Nonhardened gelatin-acacia microcapsules were studied for encapsulation of microdroplets of oil solution containing a lipophilic drug as core material and ready disintegration with release of micro oil droplets in the gastrointestinal tract. Probucol and S-312-d, a Ca-channel blocker, were employed as model lipophilic drugs. Glyceryl tricaprylate and tricaprate mixture solutions containing these drugs were encapsulated according to the complex coacervation method and were recovered as free-flowing powders without any hardening (cross-linking) step. The microcapsules obtained were disintegrated, and the emulsion was reproduced within 3 min at 37°C in the first or second test solution defined in the Japanese Pharmacopeia XII. When the microcapsules were stored as a powder at room temperature in a closed bottle, no significant change in their appearance or disintegration time upon rehydration was observed even after 1 year. Oral bioavailabilities of model drugs from the microcapsules were tested in rats and dogs and compared with those from other conventional formulations. Gastrointestinal absorption of both probucol and S-312-d from the microcapsules was remarkably more efficient than that from other formulations such as powders, granules, or oil solution. The proposed method for microencapsulation could be useful for powdering drug-containing oil solutions or O/W emulsions while maintaining excellent bioavailability.     

Microencapsulation by spray drying of lemon essential oil: Evaluation of mixtures of mesquite gum–nopal mucilage as new wall materials

Mesquite gum (MG) and nopal mucilage (NM) mixtures were used for microencapsulation of lemon essential oil (LEO) by spray drying. Emulsions of MG, NM and MG–NM mixtures (25–75, 50–50, 75–25) were evaluated according to the droplet size (1.49–9.16?μm), viscosity and zeta potential (?16.07 to ?20.13?mV), and microcapsules were characterised in particle size (11.9–44.4?μm), morphology, volatile oil retention (VOR) (45.9–74.4%), encapsulation efficiency (EE) (70.9–90.6%), oxidative stability and thermal analysis. The higher concentration of MG led to smaller droplet sizes and lower viscosity in the emulsions, and smaller particle sizes with the highest VOR in microcapsules. The higher concentration of NM induced to higher viscosity in the emulsions, and larger particle sizes with the highest values of EE and oxidative stability in microcapsules. This work shows evidence that MG–NM mixtures can have synergic effect in desirable characteristics such as retention and shelf life extension of LEO in microcapsules.     

Micronized powders of a poorly water soluble drug produced by a spray-freezing into liquid-emulsion process.

The purpose of this paper is to investigate the influence of the emulsion composition of the feed liquid on physicochemical characteristics of drug-loaded powders produced by spray-freezing into liquid (SFL) micronization, and to compare the SFL emulsion process to the SFL solution process. Danazol was formulated with polyvinyl alcohol (MW 22,000), poloxamer 407, and polyvinylpyrrolidone K-15 in a 2:1:1:1 weight ratio (40% active pharmaceutical ingredient (API) potency based on dry weight). Emulsions were formulated in ratios up to 20:1:1:1 (87% API potency based on dry weight). Ethyl acetate/water or dichloromethane/water mixtures were used to produce o/w emulsions for SFL micronization, and a tetrahydrofuran/water mixture was used to formulate the feed solutions. Micronized SFL powders were characterized by X-ray diffraction, surface area, scanning and transmission electron microscopy, contact angle and dissolution. Emulsions containing danazol in the internal oil phase and processed by SFL produced micronized powders containing amorphous drug. The surface area increased as drug and excipient concentrations were increased. Surface areas ranged from 8.9 m(2)/g (SFL powder from solution) to 83.1 m(2)/g (SFL powder from emulsion). Danazol contained in micronized SFL powders from emulsion and solution was 100% dissolved in the dissolution media within 2 min, which was significantly faster than the dissolution of non-SFL processed controls investigated (<50% in 2 min). Micronized SFL powders produced from emulsion had similar dissolution enhancement compared to those produced from solution, but higher quantities could be SFL processed from emulsions. Potencies of up to 87% yielded powders with rapid wetting and dissolution when utilizing feed emulsions instead of solutions. Large-scale SFL product batches were manufactured using lower solvent quantities and higher drug concentrations via emulsion formulations, thus demonstrating the usefulness of the SFL micronization technology in pharmaceutical development.     

Comparison of α-tocopherol microparticles produced with different wall materials: pea protein a new interesting alternative

α-Tocopherol is a radical chain breaking antioxidant that can protect the integrity of tissues and play an important role in life process. Microparticles containing α-tocopherol were produced by spray drying technique using pea protein (PP), carboxymethylcellulose(CMC) and mixtures of these materials with maltodextrin (PP-M and CMC-M) as wall materials. The microparticles produced were characterised as regards the core retention (high performance liquid chromatography), the morphology (scanning electron microscopy) and size distribution (laser diffraction). The retention of α-tocopherol within all microparticles was above 77%. They showed a spherical shape and roughness at varied degrees. Their mean particles size remained below 7?µm, and the smallest sizes were found in PP and CMC-M microparticles. The results obtained in this work show that the pea protein use for α-tocopherol microencapsulation is a promising system for further application in food.     

Microencapsulation of probiotics by efficient vibration technology

The target site of action of probiotics is the intestine. They must be surviving the stomach acidic condition before reaching the target site. Three probiotic bacteria were microencapsulated in sodium alginate beads using a sophisticated microencapsulation technology provided by BÜCHI B-390. This study reports the tolerance of the different microencapsulated Lactobacillus at low pH using simulated gastric juice, comparing it with the tolerance of free bacteria. The three microencapsulated strains displayed time-dependent acid sensitivity at pH values under 3.0. At pH 2.0, a dramatic reduction in bacterial survival occurred after 5?min, with only L. casei surviving after 30?min, with 75% survival. At pH 2.5 microencapsulated L. casei survived for 90?, L. reuteri survived for 60?and L. bulgaricus survived for only 30?min, respectively. The microencapsulation technology used in this study may effectively protect Lactobacillus from gastric conditions and permit comparisons between strains.     

复方鸦胆子油亚微乳注射液中油酸在大鼠体内的药物动力学

目的研究复方鸦胆子油亚微乳静脉给药在大鼠体内的药物动力学特征,并与鸦胆子油和薏苡仁油单方乳剂进行比较。方法大鼠尾静脉注射2 mL.kg-1复方鸦胆子油亚微乳、鸦胆子油乳及薏苡仁油乳,建立柱前衍生化HPLC-UV法测定血浆中的油酸浓度。结果油酸质量浓度在52.08~868.0 mg.L-1内线性良好(r=0.999 2),方法回收率大于95%,日内、日间精密度RSD<15%。采用统计矩的非隔室动力学理论对复方鸦胆子油亚微乳、鸦胆子油乳及薏苡仁油乳的血药数据进行处理,ρmax分别为(1.749±0.240)、(1.568±0.470)和(1.222±0.388)g.L-1,t1/2分别为(23.43±6.13)(、25.56±4.10)和(21.30±7.34)min,AUC分别为(61.2±15.2)、(55.2±12.7)和(41.1±15.1)min.g.L-1。结论方法灵敏度高、准确、可靠。3种乳剂在大鼠体内生物学过程主要以乳滴的分布、消除为主,三者的药物动力学参数之间无显著性差异。     

New microencapsulation system for ascorbic acid using pea protein concentrate as coat protector

Microencapsulation is essential to preserve biological activity of ascorbic acid (AA) and pea protein has not been used as a carrier in such processes. This work aimed to produce microparticles by a spray-drying process using pea protein (PPC) as wall material of AA and evaluate the retention of the core by HPLC, overall morphology SEM, size distribution by light scattering and release kinetics. Carboxymethylcellulose (CMC) and blends with maltodextrin (M) were produced for comparative analyses. The yields were compatible with the applied technology and the retention was above 84% for all materials. The PPC microparticles presented irregular and rough surfaces, CMC produced a regular and smooth surface and agglomeration was more intense in microparticles with M. Mean particle diameters were all below 8?µm. The microparticle release rates were lower than those with free AA, being best correlated to the Higuchi kinetic model. These results support the utilization of PPC for microencapsulation of AA.     

Oil bodies as a potential microencapsulation carrier for astaxanthin stabilisation and safe delivery

Abstract

Astaxanthin (AST) is a valued molecule because of its high antioxidant properties. However, AST is extremely sensitive to oxidation, causing the loss of its bioactive properties. The purposes of this study were to define conditions for microencapsulating AST in oil bodies (OB) from Brassica napus to enhance its oxidative stability, and to test the bioactivity of the microencapsulated AST (AST-M) in cells. Conditions for maximising microencapsulation efficiency (ME) were determined using the Response Surface Methodology, obtaining a high ME (>99%). OB loaded with AST showed a strong electrostatic repulsion in a wide range of pH and ionic strengths. It was found that AST-M exposed to air and light was more stable than free AST. In addition, the protective effect of AST against intracellular ROS production was positively influenced by microencapsulation in OB. These results suggest that OB offer a novel option for stabilising and delivering AST.     

Impact of the type of emulsifier on the physicochemical characteristics of the prepared fish oil-loaded microcapsules

Fish oil microcapsules were successfully prepared from fish oil-in-water emulsions using chitosan as shell material and anionic surfactants sodium dodecyl sulphate (SDS), sodium dodecylbenzenesulfonate (SDBS), sodium cholate (cholate), and sodium deoxycholate (DOC) as emulsifiers. The type of emulsifier influenced the physicochemical characteristics of the prepared microcapsules to different extents. The microcapsules formed with DOC showed the least mean effective diameter (MED) of 500?nm. Emulsion formed with DOC exhibited the smallest MED of 100?nm. The emulsions showed negative zeta potential values which became positive after encapsulation with chitosan. The surfactants showed little influence on thermal stability. Microcapsule suspensions showed creaming over storage. Fish oil at higher loading in SDS microcapsules showed higher primary and secondary oxidation. All microcapsules showed sustained release but the values varied depending upon the surfactants. The emulsion and microcapsules formed with DOC showed better morphology and stability despite its lower loading and encapsulation efficiency.     

Hot-melt extrusion microencapsulation of quercetin for taste-masking

Besides its poor dissolution rate, the bitterness of quercetin also poses a challenge for further development. Using carnauba wax, shellac or zein as the shell-forming excipient, this work aimed to microencapsulate quercetin by hot-melt extrusion for taste-masking. In comparison with non-encapsulated quercetin, the microencapsulated powders exhibited significantly reduced dissolution in the simulated salivary pH 6.8 medium indicative of their potentially good taste-masking efficiency in the order of zein?>?carnauba wax?>?shellac. In vitro bitterness analysis by electronic tongue confirmed the good taste-masking efficiency of the microencapsulated powders. In vitro digestion results showed that carnauba wax and shellac-microencapsulated powders presented comparable dissolution rate with the pure quercetin in pH 1.0 (gastric) and 6.8 (intestine) medium; while zein-microencapsulated powders exhibited a remarkably slower dissolution rate. Crystallinity of quercetin was slightly reduced after microencapsulation while its chemical structure remained unchanged. Hot-melt extrusion microencapsulation could thus be an attractive technique to produce taste-masked bioactive powders.     

Physicochemical properties of lipid emulsions formulated with high-load all-trans-retinoic acid

The objective of this study was to formulate high loading with good stability of all-trans retinoic acid (ATRA) lipid emulsion. Lipid emulsions loaded with ATRA were composed of lecithin, medium chain triglyceride and poloxamer-188 or polysorbate-80. The formulation factors in a particular type and amount of oil, emulsifier, and co-emulsifier on the physicochemical properties (i.e., particle size, size distribution, droplets surface charge, pH, percentage yield, drug release, and stability of lipid emulsions) were studied. The particle size of ATRA-loaded lipid emulsions was in the nano-size range of 124.4-378.2 nm with the narrow polydispersity index of 0.04-0.09, which decreased as the amount of co-emulsifiers was increased. The amount of ATRA released from lipid emulsions was operated using a dialysis bag. The receptor medium was ethanol:polysorbate-80:water (10:15:75), adjusted to pH 8.5. ATRA release kinetics in this study were found to follow zero-order kinetics. As the concentration of co-emulsifiers increased, the flux of ATRA released from the lipid emulsions increased. In stability studies, the higher the amount of co-emulsifiers added, the lower the crystallization of ATRA was found. The percentage yield of ATRA was retained at about 70-90% and 60-72% after storage for 60 days at 4 degrees C and 25 degrees C, respectively. These results show a successful incorporation of ATRA into lipid emulsions with high loading capacity and good stability.