Wall Material For Microencapsulation Research Articles

Enhanced survival of spray-dried microencapsulated Lactobacillus casei in the presence of mix-prebiotic

In this study, the effect of Galactooligosaccharide (GOS) (0% và 2% w/v) on microencapsulated L.casei in whey protein 10% (w/v) and maltodextrin 5% (w/v) by spray dry method were investigated. The physical characterization included analysis of morphology, particle size. The viable cell counts of the microcapsule were determined during storage for 50 days at 10oC and in simulated gastric fluid (SGF) and intestinal fluid (SIF). All microcapsules with (WMG sample) or without GOS (WM sample) in this study showed similar morphology and particle size, between 3 to 11µm. There no differences between WMG and WM sample in cell viability were observed. For spray dry conditions tested in this work the cell viable yield with WM sample about 86.14% whereas for WMG sample about 86.78%. The viability of the microcapsules in WMG and WM were reduced about 0.44 and 0.63 log(CFU/g), respectively and remained > 6 log(CFU/g) after 2 hour in SGF or 4 hour in SIF incubating. Microcapsules made by spray dry method with whey protein 10% (w/v) and maltodextrin 5% (w/v) as encapsulating which enhancing L.casei survival, maltodextrin’s role not only as a wall material in microencapsulation but also as a prebiotic potential, eventually leading to added GOS was not necessary.

Skipjack roe protein hydrolysate combined with tannic acid increases the stability of fish oil upon microencapsulation

AbstractMicroencapsulation of fish oil was achieved by spray drying the micro‐emulsion, in which skipjack roe protein hydrolysate (SRPH: degree of hydrolysis, 5%) was used as the wall material in the absence or presence of tannic acid (TA) or oxidized tannic acid (OTA). Microcapsule using SRPH had a lower encapsulation efficiency (EE) than those having sodium caseinate‐whey protein concentrate (Ca‐WPC) as the wall materials (p < 0.05). The incorporation of TA or OTA in combination with SRPH yielded spherical encapsulated fish oil with higher EE but lower particle size (p < 0.05) than achieved with SRPH alone. Furthermore, the addition of TA retarded lipid oxidation of microcapsule more effectively as indicated by lower peroxide value and thiobarbituric acid reactive substances (TBARS) value during storage at 30°C for 4 weeks, compared with those using only SRPH (p < 0.05). Nevertheless, OTA in conjunction with SRPH yielded the higher EE than TA. Therefore, SRPH could serve as an alternative wall material for microencapsulation of fish oil, especially with the aid of TA or OTA.Practical application: SRPH having 5% DH in the presence of TA as wall materials could be alternatively used to encapsulate fish oil. The use of SRPH‐TA could improve EE and oxidative stability of the obtained fish oil microcapsule. The fish oil microcapsule prepared using SRPH and TA could be incorporated in food products for increasing nutritive value. Additionally, the utilization of skipjack roe, which is a by‐product of the tuna canning industry, can be maximized.Scanning electron micrographs of fish oil microencapsules prepared using different wall materials. SRPH: Skipjack roe protein hydrolysate, TA: Tannic acid, OTA: Oxidized tannic acid, Ca‐WPC: Sodium caseinate‐whey protein concentrate. Magnification at 3,000×.

Oxidative stability of walnut (Juglans regia L.) and chia (Salvia hispanica L.) oils microencapsulated by spray drying

This work was primarily aimed to evaluate the use of maltodextrin in combination with hydroxypropyl methylcellulose as wall materials for microencapsulation of both walnut and chia oils by spray drying. The effect of rosemary extract on the oxidative stability of the microencapsulated oils was examined under prolonged storage conditions. After a 45-day storage, the microencapsulated chia oil with rosemary extract showed lower formation of primary oxidation compounds than the control without additives, highlighting a protective effect of the antioxidant. Nevertheless, during the entire storage period the unencapsulated chia oil reported lower oxidative damage than their encapsulated counterparts, showing that the spray drying process affected its stability negatively. Walnut oil microencapsulation protected the oil from oxidation in comparison with its unencapsulated counterpart which was further apparent from the 30th day of storage. The addition of 1600ppm of rosemary extract effectively protected microencapsulated walnut oil, showing – throughout the storage period – lower oxidation values in comparison with its analogous unencapsulated oil. The microcapsule surface oil and the images obtained by scanning electron microscopy at the beginning and at the end of the assay showed that the wall material has not been altered during storage.

Effect of Coating Method on the Survival Rate of L. plantarum for Chicken Feed.

This study was designed to find the most suitable method and wall material for microencapsulation of the Lactobacillus plantarum to maintain cell viability in different environmental conditions. To improve the stability of L. plantarum, we developed an encapsulation system of L. plantarum, using water-in-oil emulsion system. For the encapsulation of L. plantarum, corn starch and glyceryl monostearate were selected to form gel beads. Then 10% (w/v) of starch was gelatinized by autoclaving to transit gel state, and cooled down at 60ºC and mixed with L. plantarum to encapsulate it. The encapsulated L. plantarum was tested for the tolerance of acidic conditions at different temperatures to investigate the encapsulation ability. The study indicated that the survival rate of the microencapsulated cells in starch matrix was significantly higher than that of free cells in low pH conditions with relatively higher temperature. The results showed that corn starch as a wall material and glycerol monostearate as a gelling agent in encapsulation could play a role in the viability of lactic acid bacteria in extreme conditions. Using the current study, it would be possible to formulate a new water-in-oil system as applied in the protection of L. plantarum from the gastric conditions for the encapsulation system used in chicken feed industry.

Esterification of guar gum hydrolysate and gum Arabic with n-octenyl succinic anhydride and oleic acid and its evaluation as wall material in microencapsulation

The present study was undertaken to introduce hydrophobicity in guar gum hydrolysate (GGH) with a view to develop a suitable alternative to gum Arabic (GA) as wall material for microencapsulation. This was done by esterification with n-octenyl succinic anhydride (OSA) and oleic acid. The study was carried out by optimizing three parameters in the esterification process, viz. concentration of the acid, temperature, and time of reaction by response surface methodology (RSM). The reaction was monitored in terms of degree of substitution (DS), and optimized for maximal DS. The maximum DS of GGH oleate, GGH-OSA, and GA-OSA was found to be 0.061, 0.072, and 0.070, respectively. These derivatives were evaluated for their ability to be used as wall materials in microencapsulation with respect to emulsion stability, viscosity and particle size. Our results indicate the wall materials to follow the order GA-OSA>GGH-OSA>GA>GGH-oleate.

In‐vitro Zero‐order Release of Anti‐inflammatory Drugs From Pullulan Acetate Phthalate Microspheres

Pullulan acetate phthalate (PAP) was synthesized, and applied as a wall material for microencapsulation of anti-inflammatory drugs, alclofenac, ketoprofen and ibuprofen using an oil-in-oil (%) emulsion solvent evaporation process. In relation to all drugs, the dissolution pattern from microspheres prepared with PAP which contains a phthalyl content between 13 and 16% and an acetyl content between 30 and 33%, showed an apparent zero-order release until almost 80% drug was released into the pH 6.8 medium described in the disintegration test in JP XIII. The dissolution mechanism of such an apparent zero-order dissolution profile could be explained by the Case-II transport mechanism in the category of swelling controlled system in the classification related to controlled polymeric systems.

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.

Preparation of calcium–alginate microcapsuled microbial fertilizer coating Klebsiella oxytoca Rs-5 and its performance under salinity stress

Preparation of microcapsules for microbial fertilizer containing Klebsiella oxytoca Rs-5 was performed by the method of pore-coagulation bath in order to enhance the bacterial survival rate under salinity stress. In this study, sodium alginate (SA) and calcium chloride (CC) were used as wall materials for microencapsulation. The results showed that the microcapsules activity was best when the concentrations of SA and CC were 1.5–2.0% and 2.0%, respectively, and the volumetric ratio of SA and Rs-5 culture was 3:1. The particles sizes of microcapsules were concentrated in the range of 0.85–1.10 mm, measured by laser particle size analyzer. While the expansion coefficients of diameter and weight of these microcapsules were 1.35 and 1.80, respectively. The content of Rs-5 in microcapsules reached 1014 cfu/g, the embed rate was almost 100%. The bacteria released from microcapsules reached upto 1010 cfu/g when immersed in physiological saline for three weeks and kinetic release of viable cells was studied and simulated. It was found that some depressions and many small cracks on microcapsules surface observed by scanning electron microscopy contributed to bacteria release from microcapsules. The microcapsuled microbial fertilizers could promote the cotton growth better than the free cells under the same salty conditions in pot experiments.

Characterization of yeast cells as a microencapsulation wall material by Fourier-transform infrared spectroscopy

The chemically induced structural changes of yeast cells as a wall material for the microencapsulation of chlorogenic acid (CGA) were investigated by the Fourier-transform infrared (FT-IR) spectroscopy. Results indicate that the encapsulation performance of S. cerevisiae cells was largely affected by the composition of the culture medium, and the optimal composition of the culture medium was obtained in terms of the encapsulation yield of CGA. The yeast cells cultured under optimal conditions were subject to chemical treatment by sodium chloride, cetyltrimethylammonium bromide (CTAB), Triton X-100, sodium dodecyl sulfate (SDS) or ethanol. The chemical treatments notably changed the encapsulation properties of S. cerevisiae cells for CGA, with the highest encapsulation yield in the CTAB case. All the chemical treatments decreased the FT-IR absorption bands for proteins and nucleic acids of S. cerevisiae cells but increased those for lipids and fatty acids, and it is thus rather difficult to discuss the relationship between the encapsulation yield and the wall structures derived from the original FT-IR spectra. In contrast, multivariate analyses on the second derivative transformation FT-IR spectra of the yeast cell wall materials indicate that under various culture and chemical treatment conditions, the encapsulation yield of yeast cells for CGA was positively correlated with its IR absorption ratios of 1157 cm −1 to 1043 cm −1 (D1157/D1043) and of 1537 cm −1 to 1043 cm −1 (D1537/D1043) significantly ( p < 0.05), whereas negatively correlated with those of 1080 cm −1 to 1043 cm −1 (D1080/D1043), 1458 cm −1 to 1043 cm −1 (D1458/D1043) and 1740 cm −1 to 1043 cm −1 (D1740/D1043) significantly ( p < 0.05). The five absorption ratios proposed here from the second derivative transformation FT-IR spectra may be a rapid gauge for predicting the encapsulation properties of yeast cells and screening out optimal yeast cells for encapsulation of other species.

Preparation of hydroxypropyl corn and amaranth starch hydrolyzate and its evaluation as wall material in microencapsulation

Hydroxypropylation of starches lends it useful physicochemical and functional properties that are industrially important. The literature on hydroxypropylation using organic solvents for obtaining higher molar substitution (MS) is scantily available. The present work reports on hydroxypropylation of corn and a waxy amaranth starch to different MS with propylene oxide in an alkaline-organic medium (isopropanol). The synthesis was followed in terms of MS. The parameters optimized were starch:isopropanol ratio (w/w), reaction temperature, reaction time and the quantity of alkali required in the process. A maximal MS of 0.180 and 0.162 were obtained for hydroxypropyl corn starch (HPSC) and hydroxypropyl amaranth starch (HPSA), respectively. Enzymatic hydrolysis of the HPSC and HPSA of the above MS was carried out on a 30% (w/v) solution at a pH of 6.5 and 95°C for varying time periods using 0.1% (w/w based on starch) bacterial α-amylase, termamyl. The hydrolysis was terminated by adjusting the pH to 3.5 using 0.1N HCl. The hydrolyzates were characterized in terms of dextrose equivalent and viscosity. The hydrolyzate obtained after 3h of hydrolysis was spray dried and compared to gum arabic with respect to encapsulation of model flavourings, orange oil and lemon oil.

Optimization of starch oleate derivatives from native corn and hydrolyzed corn starch by response surface methodology

Conditions for the preparation of starch oleates of native and hydrolyzed corn starch were compared with the aim of developing a hydrophobic starch as gum arabic substitute for use as a wall material in microencapsulation. Optimization of the reaction parameters for maximization of degree of substitution (DS) of starch oleate was carried out using response surface methodology (RSM). Corn starch and maltodextrins of dextrose equivalent (DE) 12 and 18 were used in the study. A central composite rotatable experimental design (CCRD) was chosen to explain the combined effects of the three parameters, viz., oleic acid concentration, reaction time and reaction temperature to design minimum number of experiments. The optimal levels of the three parameters for corn starch (50 g) were an oleic acid concentration of 1.2 g, a reaction time of 201 min at 160 °C, wherein a maximum DS of 0.021 was obtained. For maltodextrin of 12 DE, 1.53 g oleic acid concentration, a reaction time of 334 min at 150 °C gave a corresponding DS of 0.0353. Similarly, for 18 DE, 1.36 g oleic acid concentration, a reaction time of 300 min at 129 °C gave a DS of 0.053. The optimized samples were compared to gum arabic with respect to emulsifying capacity.

Physicochemical characterization and oxidative stability of fish oil encapsulated in an amorphous matrix containing trehalose

Fish oil with 33% omega-3 fatty acids was microencapsulated by spray-drying in a matrix of n-octenylsuccinate-derivatized starch and either glucose syrup or trehalose. Samples showed no difference in physicochemical properties as determined by measurement of particle size, oil droplet size, true density and BET surface. Upon storage at low relative humidity, lipid oxidation was decreased in trehalose containing samples indicating that in the amorphous state trehalose is a more suitable wall material for microencapsulation than glucose syrup. The retarded oxidation of trehalose containing samples may be attributed to the unique binding properties of trehalose to dienes. At 54% relative humidity, a rapid oxidation of the microencapsulated oil was observed upon crystallization of trehalose, which limits the range of applications to products to be stored at low humidity.

Stability of Lactobacillus reuteri in Different Types of Microcapsules

ABSTRACT:This study was designed to find the most suitable method and wall material for microencapsulation of the probiotic bacterium Lactobacillus reuteri to maintain cell viability during gastric challenge. Five L. reuteri strains were individually encapsulated using alginate, alginate plus starch, K‐carrageenan with locust bean gum, or xanthan with gellan by extrusion or phase separation (emulsion). The morphology of the microcapsules was studied using phase contrast and cryo‐scanning electron microscopy (cryo‐SEM). The resistance of these microcapsules and the viability of contained L. reuteri to simulated gastric juice were studied. The shape and size of the microcapsules produced varied with the preparation method and type of wall material. Extruded microcapsules were larger and more uniformly shaped. Survival of microencapsulated L. reuteri was significantly better than that of planktonic cells and varied with the strain, method of microencapsulation, and wall material used. In general, microencapsulation using alginate and alginate with starch by both extrusion and phase separation were found to provide bacteria significantly greater protection (P &lt; 0.05) against simulated gastric juice.

The suitability of barley and corn starches in their native and chemically modified forms for volatile meat flavor encapsulation

In order to minimize the evaporative flavor loss and to improve flavor stability, the encapsulation potential of native corn and barley starches [waxy corn starch (CW), regular corn starch (CR), waxy barley starch (BW), regular barley starch (BR)] and their chemically modified counterparts (succinylated starches: CWS; CRS; BWS; BRS and octenyl succinylated starches: CWOS; CROS; BWOS; BROS) were investigated. Four different types of synthetic flavors, namely benzaldehyde, dimethyl trisulfide, 2-mercaptopropionic acid and benzothiazole, were selected. Succinylated corn and barley starches were more effective than the native starches and octenyl succinylated starches in the flavor retention. Succinylated regular starches (CRS and BRS), in particular, showed better retention ability than waxy starches. As compared to β-cyclodextrin (βCD, which is a widely used wall material in the microencapsulation of essential oils or flavors), the succinylated regular starches showed better flavor retention capabilities. Benzaldehyde and benzothiazole were retained to a higher extent by all starches (native and modified) as compared to dimethyl trisulfide and 2-mercaptopropionic acid (as measured just after preparation). None of the starches (native or modified) showed substantial decreases in flavor retention during their 4-week storage at 50 °C. In contrast, βCD showed a rapid decrease in flavor retention during the first 2 weeks of storage (from 88 to 49%) and the amount reached ∼45% at the end of 4 weeks. Also, the flavor retained by succinylated starches, based on extraction of volatile flavors in headspace, were higher than those of native and octenyl succinylated starches. CRS and BRS were noticeably superior to others. Findings showed that all starches investigated are potential wall materials for microencapsulation of volatile flavors with CRS and BRS being the best.