Microencapsulation of beta-galactosidase with fatty acid esters

Encapsulation of isoflavone with milk, maltodextrin and gum acacia improves its stability

This study was carried out for extraction of soy isoflavones and entrapment of the isoflavones so obtained into whole milk via encapsulation techniques. Three different solvent (ethanol, methanol and acetonitrile) were used for the extraction of isoflavone using three stage of extraction. The extracted isoflavone was encapsulated into 200 ml of whole milk by spray drying using different concentrations of gum acacia (4, 6 and 8% w/v) and 10% w/v maltodextrin DE 18. The ratio between cores to coating materials was 1:10. Though acetonitrile extracted higher amount of isoflavone, ethanol was selected for subsequent studies of extraction of isoflavone, as per the legislations regarding use of Food-grade solvents. There was no significant difference (p > 0.5) among all three samples 4% gum acacia+10% maltodextrin (A), 6% gum acacia+10% maltodextrin (B) and 8% gum acacia+10% maltodextrin (C) in terms of moisture content and hygroscopicity. However, insolubility index showed that sample A possessed a higher solubility index. Encapsulation techniques suggested that sample A showed higher encapsulation efficiency than others. Statistical analysis suggested that there was no significant difference among samples A, B and C during storage at 4°C for the time period (30 days) studied, in terms of isoflavone retention rate. However, samples stored at 25 and 37°C showed significant difference in the retention rate. Among all the three samples, sample B showed significantly lower isoflavone degradation rate of 3.80, 4.07 and 4.70 × 10-3/day at 4, 25 and 37°C, respectively. The highest amount of isoflavone degradation was observed at 37°C. Results indicate that isoflavone can be encapsulated using a combination of gum acacia either 4 or 6% w/v and 10% maltodextrin along with milk proteins at 4°C for longer shelf life.

Carboxymethylpachymaran entrapped plant-based hollow microcapsules for delivery and stabilization of β-galactosidase

β-Galactosidase (β-Gal) as a dietary supplement can alleviate symptoms of lactose intolerance. However, β-Gal is deactivated due to the highly acidic conditions and proteases in the digestive tract. In this work, β-Gal was encapsulated into L. clavatum sporopollenin exine capsules (SECs) to fabricate an oral-controlled release system and increase the stability of β-Gal in the digestive tract. The SEC extraction process was optimized. A 3-hour vacuum loading was determined as the optimal loading time. Five different initial ratios of SECs : β-Gal were optimized with the maximum enzyme retention rate reaching 79.40 ± 1.96%. Furthermore, β-Gal-loaded SECs entrapped in carboxymethylpachymaran (CMP) could control the release of β-Gal under simulated gastrointestinal conditions (SGC). The optimal enzyme retention rate reached 65.33 ± 1.46% within 24 h under SGC. Collectively, these results indicated that the entrapped SECs could be used as an effective oral delivery vehicle of β-Gal to improve its performance as a dietary supplement in the digestion of lactose.

Physicochemical and sensory properties of milk supplemented with lactase microcapsules coated with enteric coating materials

In this paper, we report the physicochemical and sensory properties of milk supplemented with a powder of microencapsulated lactase. The core material was lactase (β-galactosidase), the primary coating material was medium-chain triglyceride (MCT), and the secondary (enteric) coating material was either hydroxypropyl methylcellulose phthalate (HPMCP) or shellac, comparing both against market milk as a control. The physicochemical properties of both types of microcapsules were analyzed, including the particle size, zeta potential, and in vitro release behavior. To survey the stability of the microcapsules in milk during storage, we studied the residual lactose content and pH. Furthermore, to determine the properties of milk supplemented with the microcapsules, changes in color and sensory properties were evaluated during storage. The particle sizes (volume-weighted mean; D[4,3]) of the microcapsules coated with HPMCP or shellac were 2,836 and 7,834 nm, respectively, and the zeta potential of the capsules coated with shellac was higher than the zeta potential of those coated with HPMCP. The pH levels of milk supplemented with the lactase microcapsules were similar to those of the control (unsupplemented market milk); however, for milk supplemented with HPMCP-coated microcapsules, the pH was slightly lower. The core material, lactase, was released from the microcapsules during 12-d storage, and 18.82 and 35.09% of lactose was hydrolyzed in the samples for HPMCP- and shellac-coated microcapsules, respectively. The sensory characteristics of milk containing microcapsules coated with HPMCP did not show significant differences from the control, in terms of sweetness or off-taste, until 8 d of storage. However, shellac-coated microcapsules showed significant difference in sweetness and off-taste at d 8 and 6 of storage, respectively. The color of milk containing HPMCP-coated microcapsules did not show a significant difference during storage. However, that containing shellac-coated microcapsules was somewhat higher in color values than others. In particular, it showed significance from 0 to 4 d storage in L* and C* values. In conclusion, a powder of lactase microcapsules coated with HPMCP can be suitable as a supplement for milk.

Solid-in-Oil-in-Water Emulsions for Delivery of Lactase To Control in Vitro Hydrolysis of Lactose in Milk

There is an established need to deliver lactase in milk to retain activity during storage and hydrolyze lactose after ingestion. In this work, spray-dried lactase powder was encapsulated in solid-in-oil-in-water (S/O/W) emulsions to fabricate delivery systems. The adoption of Span 80 in milk fat and lecithin in protein solution enabled the encapsulation of ∼76% lactase and <400 nm droplets. Additional cross-linking of proteins on droplets by transglutaminase and addition of sodium caseinate effectively reduced the amount of free lactase after spray drying emulsions. Compared to the data for free lactase, encapsulation significantly improved the thermal stability of lactase, reduced the level of lactose hydrolysis during a 14 day refrigeration (from ∼70 to <20%), enabled the gradual release of lactose during the simulated gastric and intestinal digestions, and resulted in the hydrolysis of most lactose during the simulated digestions. Therefore, the studied S/O/W emulsions have the potential to deliver lactase in milk for lactose-intolerant consumers.

Freeze-dried capsules prepared from emulsions with encapsulated lactase as a potential delivery system to control lactose hydrolysis in milk

The objective of this work was to study solid/oil/water (S/O/W) emulsions as delivery systems with retained lactase in milk and controlled release during in vitro digestion. Spray-dried lactase powder was suspended in anhydrous milk fat/Span® 80 emulsified by sodium caseinate and lecithin (5:1). The S/O/W emulsion had an encapsulation efficiency of 75%, a hydrodynamic diameter of 292nm, and a zeta potential of -17.37mV. Cross-linking the dialyzed emulsion with transglutaminase eliminated the detection of free lactase after freeze-drying emulsions and the addition of sodium caseinate further preserved lactase activity. The hydrolysis of lactose in full-fat or skim milk after 3-week storage reduced from>75% for free lactase to<15% for encapsulated lactase. The encapsulated lactase was released gradually during the simulated digestions to hydrolyze lactose in milk more efficiently than free lactase. The present findings suggest S/O/W emulsions are potential delivery systems to incorporate lactase in milk products.

Production and characterization of lipid microparticles produced by spray cooling encapsulating a low molar mass hydrophilic compound

The objective of this research was to produce and characterize lipid particles (MpLs) that may be used as carriers of high amounts of hydrophilic core and evaluate the influence of the core amount on the performance of lipid microparticles. The MpLs were produced by spray cooling from solid and liquid lipid mixtures (stearic and oleic fatty acids and partly hydrogenated vegetable fat) containing glucose solution as core and soy lecithin as surfactant. The performance of MpLs was evaluated by means of the effective amount of encapsulated core, the core amount present on the surface of MpLs (superficial glucose) and the core release profile in aqueous solution. Morphological observations showed that MpLs presented spherical shape and a rugged and continuous surface, and an average diameter between 25 and 32 µm. The effective amount of encapsulated core was greater than 78% for all formulations evaluated. Larger amounts of superficial glucose were found in formulations in which more concentrated glucose solutions were used, regardless of the glucose lipid-solution ratio. The release results showed that core retention was significantly influenced by the glucose solution concentration, whereas release modulation was influenced by the glucose lipid-solution ratio.

Application of microencapsulated isoflavone into milk

This study was designed to develop a microencapsulated, water-soluble isoflavone for application into milk and to examine the hypocholesterolemic effect of such a milk product in a rat diet. The coating material was medium-chain triglyceride (MCT) and the core material was water-soluble isoflavone. The microencapsulation efficiency was 70.2% when the ratio (w/w) of coating material to core material was 15:1. The isoflavone release from the microcapsules was 8% after 3-day storage at 40 degrees C. In in vitro study, 4.0-9.3% of water-soluble isoflavone in simulated gastric fluid was released in the pH range of 2 to 5 after 60 min incubation; however, in simulated intestinal fluid at pH 8, 87.6% of isoflavone was released from the capsules after 40 min incubation time. In sensory analysis, the scores of bitterness, astringency, and off-taste in the encapsulated isoflavone-added milk were slightly, but not significantly, different from those in uncapsulated, isoflavone-added milk. In blood analysis, total cholesterol was significantly decreased in the isoflavone-added group compared with that in the control after 6-week feeding. Therefore, this study confirmed the acceptability of MCT as a coating material in the microencapsulation of water-soluble isoflavone for application into milk, although a slight adverse effect was found in terms of sensory attributes. In addition, blood total cholesterol was lowered in rats which had been fed a cholesterol-reduced and microencapsulated, isoflavone-added milk for 6 weeks.

The microencapsulated ascorbic acid releasein vitro and its effect on iron bioavailability

The present study was carried out to examine the stability of microencapsulated ascorbic acid in simulated-gastric and intestinal situation in vitro and the effect of microencapsulated ascorbic acid on iron bioavailability. Coating materials used were polyglycerol monostearate (PGMS) and medium-chain triacylglycerol (MCT), and core materials were L-ascorbic acid and ferric ammonium sulfate. When ascorbic acid was microencapsulated by MCT, the release of ascorbic acid was 6.3% at pH 5 and 1.32% at pH 2 in simulated-gastric fluids during 60 min. When ascorbic acid was microencapsulated by PGMS, the more ascorbic acid was released in the range of 9.5 to 16.0%. Comparatively, ascorbic acid release increased significantly as 94.7% and 83.8% coated by MCT and PGMS, respectively, for 60 min incubation in simulated-intestinal fluid. In the subsequent study, we tested whether ascorbic acid enhanced the iron bioavailability or not. In results, serum iron content and transferring saturation increased dramatically when subjects consumed milks containing both encapsulated iron and encapsulated ascorbic acid, compared with those when consumed uncapsulated iron or encapsulated iron without ascorbic acid. Therefore, the present data indicated that microencapsulated ascorbic acid with both PGMS and MCT were effective means for fortifying ascorbic acid into milk and for enhancing the iron bioavailability.

Microencapsulated ascorbic acid for milk fortification

The present study was designed to develop a microencapsulated L-ascorbic acid and iron that could be used to fortify milk and to determine the sensory properties of milk fortified with microencapuslation. Coating material was medium-chain triacylglycerol (MCT), and selected core material was ferric ammonium sulfate and L-ascorbic acid. The highest efficiency of microencapsulation was 95.0% in the ratio of 15:1 as coating to core material. Ascorbic acid release was increased sharply up to 5 d storage as 6.5%. TBA value was the lowest when both capsulated iron and ascorbic acid were added during 12 d storage, compared with other treatments. In sensory analysis, most aspects were not significantly different between control and capsulated ascorbic acid fortified milk at 5 d storage. The present study indicated that the use of microencapsulated ascorbic acid with MCT is effective for fortifying milk. In addition, these results suggest that acceptable milk products can be prepared with microencapsulated ascorbic acid and iron.

Microencapsulation of water-soluble isoflavone and physico-chemical property in milk

This study was carried out to investigate the addition of water-soluble isoflavone into milk by means of microencapsulation technique. The yield of microencapsulation, sensory attributes, and capsule stability of water-soluble isoflavone microcapsules in milk were measured. Coating materials used was polyglycerol monostearate (PGMS), and core material was water-soluble isoflavone. The encapsulation yield of water-soluble isoflavone with PGMS was 67.2% when the ratio of coating material to core material was 15:1. The rate of water-soluble isoflavone release from capsules was 18, 19, and 25% when stored at 4, 20, and 30 degrees C for 12 days in milk, respectively. In sensory evaluation, beany flavor and color of microencapsuled water-soluble isoflavone added milk were significantly different from uncapsuled water-soluble isoflavone added milk, however, bitterness was not significantly different. In vitro study, micro-capsules of water-soluble isoflavone in simulated gastric fluid with the range of 3 to 6 pHs were released 3.0-15.0%, however, the capsules in simulated intestinal fluid with pH 7 were released 95.7% for 40 min incubation time. In conclusion, this study provided that PGMS as coating materials was suitable for the microencapsulation of water-soluble isoflavone, and the capsule containing milk was almost not affected with sensory attribute.