Wall Material For Microencapsulation Research Articles

Microencapsulation of camellia seed oil by spray drying with pea protein and maltodextrin

The purpose of this study was to extend the shelf life and enhance the oxidative stability of camellia seed oil through microencapsulation. To 2achieve this, we chose pea peptide (PP) and maltodextrin (MD) as the wall materials for microencapsulation and successfully transformed camellia oil into powdered oil using the spray drying method. The preparation conditions were optimized using a univariate method. The preparation conditions were optimized using a univariate method. The best encapsulation effect was achieved when the wall ratio (PP: MD) was 1:1, the wall-to-core ratio was 1.5:1, and the spray drying temperature was 180 °C. The results showed that the embedding rate of camellia seed oil microcapsule (CSOM) could reach 79.69 %, with a particle size below 600 nm. Additionally, the characterization results indicated that the microcapsule products were spherical, with most particles having a smooth surface and no ruptures. CSO was effectively encapsulated within the microcapsules. Furthermore, the oxidative stability of CSOM was superior to that of CSO, and the shelf lives of CSO and CSOM were 35 days and 64 days, respectively. These results demonstrate that microencapsulation technology can effectively extend the shelf life of CSO.

Encapsulation of Lactiplantibacillus plantarum CRD7 in sub-micron pullulan fibres by spray drying: Maximizing viability with prebiotic and thermal protectants

Pullulan was used as the wall material for microencapsulation of L. plantarum CRD7 by spray drying, while isomalto-oligosaccharides (IMO) was used as prebiotic. Also, the effect of different thermal protectants on survival rate during microencapsulation was evaluated. Taguchi orthogonal array design showed that pullulan at 14 % concentration, IMO at 30 % concentration and whey protein isolate at 20 % rate were the optimized wall material, prebiotic and thermal protectant, respectively for microencapsulation of L. plantarum. FESEM images revealed that the spray-dried encapsulates were fibrous similar to those produce by electrospinning, while fluorescence microscopy ascertained that most of the probiotic cells were alive and intact after microencapsulation. The adsorption-desorption isotherm was of Type II and the encapsulate had specific surface area of 1.92 m2/g and mean pore diameter of 15.12 nm. The typical amide II and III bands of the bacterial proteins were absent in the FTIR spectra, suggestive of adequate encapsulation. DSC thermogram showed shifting of melting peaks to wider temperature range due to interactions between the probiotic and wall materials. IMO at 30 % (w/w) along with WPI at 20 % concentration provided the highest storage stability and the lowest rate of cell death of L. plantarum after microencapsulation. Acid and bile salt tolerance results confirmed that microencapsulated L. plantarum could sustain the harsh GI conditions with >7.5 log CFU/g viability. After microencapsulation, L. plantarum also possessed the ability to ferment milk into curd with pH of 4.62.

Plant and animal protein mixed systems as wall material for microencapsulation of Mānuka essential Oil: Characterization and in vitro release kinetics

Combination of plant and animal protein diet is becoming a valuable source of nutrition in the modern diet due to the synergistic functional properties inherent in these protein complexes. Moreover, the synergy between animal and plant proteins can contribute to the high stability and improved solubility of the encapsulated bioactive ingredients (e.g., essential oils). Therefore, the study was designed to evaluate the plant (pea protein (PP) and lupine protein (LP)) and animal protein (whey protein, WP) mixed systems as a wall material for microencapsulation of mānuka essential oil, as an example of bioactive compound. Moreover, physicochemical properties and in vitro release profile of encapsulated mānuka essential oil were studied. Mānuka essential oil microcapsules exhibited low moisture content (5.3–7.1 %) and low water activity (0.33–0.37) with a solubility of 53.7–68.1 %. Change in wall material ratio significantly affected the color of microcapsules, while microcapsules prepared with 1:1 protein/oil ratio demonstrated a high encapsulation efficiency (90.4 % and 89.4 %) for protein mixed systems (PP + WP and LP + WP), respectively. Microcapsules further showed low values for lipid oxidation with a high oxidative stability and antioxidant activity (62.1–87.0 %). The zero order and Korsmeyer–Peppas models clearly explained the release mechanism of encapsulated oil, which was dependent on the type and concentration of the protein mixed used. The findings demonstrated that the protein mixed systems successfully encapsulated the mānuka essential oil with controlled release and high oxidative stability, indicating the suitability of the protein mixed systems as a carrier in encapsulation and application potential in development of encapsulated functional foods.

Optimization of oat protein and gum Arabic microcapsules containing juniper essential oil using Response Surface Methodology

In this study, we explored the feasibility of using oat soluble protein and gum Arabic as wall materials for microencapsulation via complex coacervation of juniper dissolved in wheat germ oil EO. The process was optimized using Response Surface Methodology (RSM), varying mixing ratios (20–80%) and pH levels (2−6), followed by freeze-drying of the coacervates. Physicochemical properties of the resulting powders, including solubility, hygroscopicity, moisture content, color, particle size distribution, and bulk and tapped density, were assessed. Encapsulation efficiency (EE) was determined through surface and total oil content calculations, supported by FT-IR spectroscopy. Characterization involved e-nose sensor analysis and differential scanning calorimetry (DSC). The study findings revealed encapsulation efficiencies (EE) ranging from 23.38 % to 26.58%, accompanied by low bulk and tapped densities (0.11–0.17 g/cm3 and 0.20–0.28 g/cm3, respectively), as well as elevated Carr Index values (36.92–46.34) and Hausner ratios (1.59–1.86). Moisture content varied between 0.07 % and 0.93 % across the samples. Additionally, the research demonstrated that employing oat protein and gum Arabic as wall materials enables the production of microcapsules with thermal stability exceeding 100 ℃, facilitating their potential application in the food industry.

Characterization of Starch from Jinicuil (Inga jinicuil) Seeds and Its Evaluation as Wall Material in Spray Drying

Jinicuil seed starch (JSS) was partially characterized and then evaluated as wall material. JSS showed higher content of proteins, lipids, and resistant starch than commercial corn starch (CCS). JSS granules presented both oval-spherical shapes and heterogeneous sizes (~1–40 µm) and exhibited a crystallinity lower than CCS with an A-type X-ray diffraction pattern. Both gelatinization peak and final viscosity values in the pasting profile were higher in JSS than in CCS. At 90 °C, the water solubility was 22% and the swelling power was 17 g g−1. Under refrigeration and freeze-thaw, the JSS gel showed high stability. JSS showed a significant presence of protein and small particles; therefore, it was evaluated as wall material in spray drying. The results showed the formation of spherical aggregates and encapsulation efficiencies of L-ascorbic acid of 14.97–81.84%, with process yields of 19.96–27.64%, under the conditions evaluated. JSS has a potential application in the food industry but also as wall material for microencapsulation by spray drying.

Use of Ora-pro-nóbis (Pereskia aculeata Miller) mucilage as a wall material in microencapsulation by complex coacervation

Innovative materials for the encapsulation of bioactive compounds are a permanent challenge. In this sense, the purpose of the study was to evaluate the use of Ora-pro-nobis mucilage (MOPN) as a wall material to replace Arabic gum (AG), in microencapsulation by complex coacervation of bocaiuva (Acrocomia aculeata) pulp oil. The MOPN was obtained from green leaves, and the pH, color, water activity, humidity, fixed mineral residue, proteins, lipids, and extraction effectiveness were determined. MOPN was employed as a partial or total replacement of AG in the microencapsulation of bocaiuva pulp oil. Dehydrated and wet mucilages were used to emulsion formation. The interaction between biopolymers, the effectiveness, efficiency of microencapsulation, and the morphological characteristics of microcapsules were confirmed. In addition, the bioactive compounds (chlorophyll and β-carotene) and antioxidant activity were evaluated. The microcapsules were produced using moist mucilage. Microcapsules obtained with AG/gelatin/ bocaiuva oil were considered as control samples. MOPN showed brown color and chlorophyll content of 72.44±5.74 mg 100 g-1. The interaction between AG and MOPN in microcapsule formation was proven for the formulations with 25 and 50% MOPN substitution. The effectiveness was 74.83 and 75.22%, and encapsulation efficiency was 79.18 and 74.59%, respectively, verified through optical micrograph. In addition, the microcapsules with 25 and 50% MOPN as wall material showed three times more antioxidant activity against ABTS, and two times more β-carotene compared to the control microcapsule.

Development and application of gelatinized starches as wall materials for Lacticaseibacillus paracasei encapsulation

The physical modification of starches by extrusion leads to changes in their physicochemical properties due to the conditions of the process, such as high temperatures and shear stress. These properties allow extruded starches to have important applications that have been scarcely explored. Therefore, the aim of this research was to physically modify starches from varied botanical sources (rice, potato, and corn) through extrusion and evaluate their application as encapsulating materials for probiotics. The modified starches showed that extrusion promoted granule structural disorganization and gelatinization. This, in turn, reduced pasting and thermal properties, so starches were viable for microencapsulation via spray drying. All starches evaluated and modified were adequate wall materials for microencapsulation of high concentrations (>9 Log CFU/g) of Lacticaseibacillus paracasei, lactic acid bacteria with probiotic potential.

Chitosan-glucose derivative as effective wall material for probiotic yeasts microencapsulation

A chitosan-glucose derivative (ChG) with lower antimicrobial activity against whey native probiotic yeast K. marxianus VM004 was synthesized by the Maillard reaction. The ChG derivative was characterized by FT-IR, 1H NMR, and SLS to determine the structure, deacetylation degree (DD), and molecular weight (Mw). In addition, we evaluated the antioxidant, cytotoxic, and antimicrobial activities of ChG. ChG was then used for microencapsulation of K. marxianus VM004 by spray drying. The microcapsules were characterized by evaluating their encapsulation yield, encapsulation efficiency, morphology, tolerance to the gastrointestinal tract, and viability during storage. The results indicated that a non-cytotoxic product with lower MW and DD and higher antioxidant activity than native chitosan was obtained by the Maillard reaction. The yeast ChG microcapsules exhibited an encapsulation efficiency >57 %, improved resistance to gastrointestinal conditions, and enhanced stability during storage. These results demonstrate that ChG may be a promising wall material for the microencapsulation of probiotic yeasts.

Comparison of Alginate Mixtures as Wall Materials of Schizochytrium Oil Microcapsules Formed by Coaxial Electrospray.

This work evaluated maltodextrin/alginate and β-glucan/alginate mixtures in the food industry as wall materials for the microencapsulation of Schizochytrium sp. oil, an important source of the omega-3 fatty acid DHA (docosahexaenoic acid). Results showed that both mixtures display a shear-thinning behavior, although the viscosity is higher in β-glucan/alginate mixtures than in maltodextrin/alginate. Scanning electron microscopy was used to assess the morphology of the microcapsules, which appeared more homogeneous for maltodextrin/alginate. In addition, oil-encapsulation efficiency was higher in maltodextrin/alginate mixtures (90%) than in β-glucan/alginate mixtures (80%). Finally, evaluating the microcapsules' stability by FTIR when exposed to high temperature (80 °C) showed that maltodextrin/alginate microcapsules were not degraded contrary to the β-glucan/alginate microcapsules. Thus, although high oil-encapsulation efficiency was obtained with both mixtures, the microcapsules' morphology and prolonged stability suggest that maltodextrin/alginate is a suitable wall material for microencapsulation of Schizochytrium sp. oil.

Application of yellow mustard mucilage in encapsulation of essential oils and polyphenols using spray drying

The current study has investigated the application of water-soluble yellow mustard mucilage (WSM) as a novel wall material in microencapsulation of essential oils (EO), thymol and carvacrol, and polyphenols (PP). Thymol (25%, w/w), carvacrol (25%, w/w) and PP (50%, w/w) were encapsulated in WSM, maltodextrin (MD) and gum Arabic (GA) at various mass ratios (e.g. 1:2:6, 2:2:5, 0:3:6) and core to wall ratios (e.g. 4:9 and 1:5, w/w) by spray drying. Results confirmed that the addition of WSM into the wall formula improved the emulsion stability, encapsulation efficiency, and assisted in modulating the release pattern of the bioactive compounds. Overall, the formula with the WSM/MD/GA ratio of 2/2/5 (w/w/w) and the core to wall ratio of 1:5 showed the best releasing performance. The emulsion has maximum stability with zeta potential of −41.5 ± 1.7 mV and highest viscosity 0.032 ± 0.04 mPa s at the shear rate 100 s−1. The Fourier-transform infrared spectrometer indicates that bioactive compounds have been entrapped physically without adverse reaction with wall materials. The scanning electron microscopy results show that microparticles are spherical with less dents and have an average particle size of 3.11 μm. The highest encapsulation efficiency of 91% and prolonged releasing time were achieved, where 72.7% of EOs and PP were delivered to the lower section of the intestinal tract. The release kinetic of EOs and PP fitted well to the Rigter Peppas model (R2 = 0.991), of which erosion is the dominant mechanism. WSM could be utilized as a superior wall material to exert synergistic effects on the encapsulation of bioactive ingredients for related food, feed, and pharmaceutical industries.

Complex coacervation and freeze drying using whey protein concentrate, soy protein isolate and arabic gum to improve the oxidative stability of chia oil.

Chia oil (CO) is popular for being the richest vegetable source of α-linolenic acid (60-66%). However, this content of polyunsaturated fatty acids(PUFA) limits the incorporation of bulk CO in food products due to its high probability of oxidation. This justifies the study of alternative wall materials for microencapsulation. No reports regarding the use of dairy protein/vegetable protein/polysaccharide blends as wall material for the microencapsulation of CO have been published. Therefore, this work analyzed the behavior of a whey protein concentrate (WPC)/soy protein isolate (SPI)/arabic gum (AG) blend as wall material. The complex coacervation (CC) process was studied: pH, 4.0; total solid content, 30% w/v; WPC/SPI/AG ratio, 8:1:1 w/w/w; stirring speed, 600 rpm; time, 30 min; room temperature. The oxidative stability index (OSI) of CO (3.25 ± 0.16 h) was significantly increased after microencapsulation (around four times higher). Furthermore, the well-known matrix-forming ability of AG and WPC helped increase the OSI of microencapsulated oils. Meanwhile, SPI contributed to the increase of the encapsulation efficiency due to its high viscosity. Enhanced properties were observed with CC: encapsulation efficiency (up to 79.88%), OSIs (from 11.25 to 12.52 h) and thermal stability of microcapsules given by the denaturation peak temperatures of WPC (from 77.12 to 86.00 °C). No significant differences were observed in the fatty acid composition of bulk and microencapsulated oils. Microcapsules developed from complex coacervates based on the ternary blend represent promising omega-3-rich carriers for being incorporated into functional foods.

Encapsulation of salmon oil using complex coacervation: Probing the effect of gum acacia on interfacial tension, coacervation and oxidative stability

The molecular characteristics of the food-grade polysaccharide gum acacia may vary depending on source, which could in turn significantly affect its behaviour as thickener, emulsifier and as a wall material in microencapsulation. In this study, five acacia gums (GA) from different sources were screened with respect to molecular weight distribution, interfacial tension, microencapsulation of salmon oil by complex coacervation and resulting oxidative stability of the oil. Bovine serum albumin (BSA) was used in combination with GA (BSA:GA = 1:1 w:w) for the coacervation. Interfacial tension was investigated for all GA alone and in combination with BSA at pH 5.5, pH 4.2 and pH 7, corresponding to the pH of emulsification, coacervation and neutral/reference conditions, respectively. Three of the five GA tested (GA from Sigma and the food grade GA Encapcia and Instant Gum BA from Nexira) resulted in stable complex coacervate microcapsules, with mean coacervate yields of the resulting microcapsules ranging from 34% to 76% depending on GA source, and a ∼100% microencapsulation yield. The food grade GA Encapcia and Instant gum BA were found to provide significantly better protection against oxidation than the Sigma GA, both as a function of the microencapsulation process and after storage for 12 months. The differences in performance of the GA are discussed in terms of molecular weight, GA variety and impurities.

Structural characterisation of two polysaccharides from white common bean (Phaseolus vulgaris L.) and the application in microencapsulation of probiotics

SummaryIncreasing attention has been focused on the application of plant polysaccharides in the area of microencapsulation of probiotic bacteria. It remained to be clarified how the chemical structure of plant polysaccharides affects their feasibility as wall materials. In this study, two structurally different polysaccharides, namely NSP‐1 (2.91 × 106 Da) and NSP‐2 (4.57 × 105 Da), were isolated from white common bean seeds. NSP‐1 was predominantly composed of Glc and Gal, and mainly linked as →4)‐Glcp‐(1→, →3,6)‐Glcp‐(1→ and →4)‐Galp‐(1→. NSP‐2 was predominantly composed of Gal and Ara, with main glycosidic bonds of →4)‐Galp‐(1→, Galp‐(1→ and →5)‐Araf‐(1→. NSP‐1 and NSP‐2 were co‐used with calcium alginate as wall materials for microencapsulation of Lactobacillus plantarum. NSP‐1 increased the encapsulation efficiency more than NSP‐2 (P < 0.05), while NSP‐2 mainly improved the survival of the probiotic during simulated gastrointestinal tract digestion and storage at 4 °C (P < 0.05). These findings will give a valuable perspective on plant polysaccharides applied in microencapsulation technology.

Optimization of fermentation medium for biocontrol strain Pantoea jilinensis D25 and preparation of its microcapsules

A newly isolated biocontrol strain, Pantoea jilinensis D25, can effectively inhibit Botrytis cinerea caused tomato gray mold. However, the short shelf-life limits its biopesticide applications. This study optimized the fermentation medium for P. jilinensis D25. Also, the best microencapsulation conditions were determined. P. jilinensis D25 microcapsules (D25Ms) were evaluated for storage stability and biofilm formation ability. The results showed that the optimal medium composition contained sucrose (19.65 g/L), tryptone (2.73 g/L), NaCl (20.71 g/L), and yeast extract (13.00 g/L) at pH 6–8. The optimal fermentation conditions were temperature 25 ℃, inoculation amount 2 %, rotation speed 150 r/min, and liquid volume 75 mL. Maltodextrin was found to be an effective microencapsulation wall material showing a great protective effect on P. jilinensis D25. The bacterial survival rate was the highest (90.83 %) for conditions: maltodextrin 80 %, air-inlet temperature 130 ℃, feed flow rate 500 mL/h, and spray pressure 0.15 MPa. D25Ms were stored at 4 ℃ for 180 days showing the bacterial survival rates of 95.1 %. Compared with free cells, the biofilm formation ability of D25Ms was 1.86 times higher. Overall, D25Ms with good stability and biofilm formation ability can be a potential biocontrol agent.

Functional Properties of Physically Pretreated Kidney Bean and Mung Bean Flours and Their Performance in Microencapsulation of a Carotenoid-Rich Oil

Microencapsulation can improve protection for compounds that degrade easily, such as β-carotene that is present in large amounts in buriti oil (Mauritia flexuosa). Encapsulating matrices are mainly composed of proteins and polysaccharides, which are often combined to improve their performance as a protective barrier. Beans, such as dark red kidney beans (Phaseolus vulgaris) and mung beans (Vigna radiata), are excellent protein sources that contain significant amounts of the essential amino acids. Bean flours are low in fat and naturally provide a blend of high-quality protein and carbohydrates that may stabilize lipophilic compounds for subsequent spray-drying. Whole bean flours, rather than refined individual biopolymers, may represent more sustainable alternative wall materials for microencapsulate bioactive compounds. This work aimed to evaluate the use of flours produced from red kidney beans and mung beans, which have been submitted to different physical pretreatments, as wall materials for microencapsulation of buriti oil by spray-drying. Different bean treatments were evaluated: untreated (control), soaked in water for 24 h, and soaked in water for 24 h followed by boiling for 30 min. The flours' proximate composition was not affected by the treatments (p < 0.05), showing similar values of carbohydrate (63.8–67.9%), protein (19.2–24.6%), and lipid (1.2–1.9%) contents. Both bean species had the water absorption capacity (WAC) increased by boiling, while the oil absorption capacity (OAC) was not altered by the treatments. Flours produced with raw or soaked beans showed emulsion activity (EA) and emulsion stability (ES) greater than 70%. Raw bean flours also showed better foaming properties, which may be indicative of higher levels of antinutritional factors. The soaked bean flours showed the best results for both type of beans, especially with regard to emulsifying properties, and were selected as wall materials for buriti oil microencapsulation. Different ratios of flour and maltodextrin were used to produce oil-in-water emulsions that were then spray-dried. Buriti oil microcapsules showed good physicochemical properties, with moisture around 3%, aw <0.3, and hygroscopicity around 5%. The carotenoid encapsulation efficiency ranged from 68.2 to 77.9%. Bean flours showed to function as a sustainable and nutrient-rich alternative wall material for microencapsulation.

Utilization of Polysaccharides Extracted from Tofu Processing Wastewater for Microencapsulation Processes in the Food Industry

The aim of this study was to extract polysaccharides from tofu processing wastewater obtained from tofu factory located at the outcast of Wuxi city, PR China. The extracted polysaccharide was used as wall material for microencapsulation processes in the food industry. This is expected to serve as an environmentally friendly research approach as it converts wastewater into useful polysaccharides that could be used in food industries. This study used vegetable oil as core material, which is used as a test case to ascertain whether a successful encapsulation process can be achieved – an indication of the possibility of the encapsulation of oil soluble minerals and vitamins.
 The polysaccharides extracted from tofu processing wastewater were used as wall materials for the encapsulation of vegetable fat load. The basic method applied in the microencapsulation process is indicative of the fact that with the addition of polysaccharides, the interfacial coacervation between the protein and the polysaccharide around the oil droplets induces the formation of microcapsules. The Seagull Model Z-Series Photomicrographic equipment was used to obtain Photomicrographs of the various phases in the development of microcapsules. Microencapsulation efficiency, the peroxide value and visual observation on spray-dried microcapsules were studied.
 Microencapsulated capsules were produced through thermal solidification of the coating to form self-sustaining entities or microcapsules. Photomicrographs were used to clearly visualize the microcapsules. The Microencapsulation efficiency of the microcapsules was studied and results showed that the highest MEE (93.04%) was obtained with a comparatively low vegetable fat load. This shows that there is a relationship between percent fat load and MEE as the higher the vegetable fat load the lower the microencapsulation efficiency. Studies conducted on the Peroxide value of the microcapsules indicated shorter shelf-life at elevated temperatures of 38ºC compared to room temperature.
 Polysaccharides extracted from tofu processing wastewater could be used as wall material for microencapsulation in food industries.

Use of hydrolysis prior to the chemical and thermomechanical modification of rice starch: alternative to traditional modification treatments

Rice starch isolated (NS), was subjected to chemical and thermomechanical modification with previous hydrolysis (MHS) and without previous hydrolysis (MS) to be evaluated on main starch properties as degree of substitution (DS), color, water absorption and solubility index (WAI, WSI), viscosity, texture, thermal properties (differential scanning calorimetry DSC) and structural properties (infrared-IR, Xray-Rx analysis, and relative crystallinity index-ICR). The modified starches were compared to native starch (NS). The DS obtained in both starches was within the range allowed by the FDA for its safety use as food ingredient (0.01-0.2). The modification showed an increase in WAI and WSI values, being WAI value higher in MS (4.80) and WSI value higher in MHS (32.06). The viscosity of retrogradation showed a significant decrease (P<0.05) in both starches (HMS 0.013 and MS 5.613), obtaining gels with greater stability, however, the hardness of starch gels decreased (60 %) while the adhesiveness decreased only in MS (66 %). The crystallinity index (ICR) of the modified starches increased with regard to the native starch indicating a depolymerization of the molecule due to the modification. The presence of the acetyl group in the starch molecule was observed in the signals between 1650 to 1744 cm-1 confirming the esterification. The starches showed a high potential for its application as edible coatings and as wall material for microencapsulation.

Application of argun fruit polysaccharide in microencapsulation of Citrus aurantium L. essential oil: preparation, characterization, and evaluating the storage stability and antioxidant activity

The aim of this study was to evaluate the influences of the partial replacement of the maltodextrin (MD) as primary wall material by argun fruit polysaccharide (AFPS) as a new promising wall material in microencapsulation of Citrus aurantium L. essential oil (CAEO). The emulsions properties, yield, microencapsulation efficiency (MEE), structural and physicochemical characteristics, thermo-gravimetric analysis (TGA), glass transition temperatures by differential scanning calorimetry (DSC), crystallinity, oxidative and antioxidant stability of the freeze-dried CAEO microcapsules were investigated. The highest values of viscosity and droplet size were achieved by CAEO emulsion stabilized with GMA100 formulation. The yield and MEE of CAEO microcapsules were significantly enhanced with increasing of AFPS in the formulations. The partial replacement treatments by AFPS increased solubility, bulk density, tapped density, particle density, and porosity of the obtained microcapsules. FTIR, X-ray, DSC, and TGA techniques were confirmed that the encapsulation of CAEO was perfectly successful. The partial replacement of MD with AFPS improved the oxidative stability and antioxidant activity of microencapsulated CAEO during the storage. Depending on physicochemical properties, thermal stability, and antioxidant activity, it could be considered these microcapsules have promising applications in the functional food and medicine industry.

Effect of pullulan concentration and pH on the interactions between whey protein concentrate and pullulan during gelation.

Whey protein concentrate (WPC)/pullulan (PUL) hydrogel is applied as a microencapsulation wall material to protect probiotics. However, the interactions between WPC and PUL during gelation have not been clarified. In the present study, the effects of PUL concentration and pH on the interactions between WPC and PUL during gelation were evaluated with respect to appearance, zeta-potential, sulfhydryl group amount, surface hydrophobicity and infrared spectroscopy measurements. The rheological properties of WPC/PUL gels were also determined. The results obtained showed that a proper concentration (0.40 g mL-1 ) of PUL could improve the gel by enhancing the strength of hydrogen bonding, electrostatic interactions and exposure of hydrophobic groups, whereas too much PUL inhibited the formation of disulfide bonds. Furthermore, hydrophobic interactions, disulfide bonds and hydrogen bonds were destroyed in varying degrees under an alkaline environment. The rheological results also demonstrated a similar effect of PUL concentration and pH on the storage modulus (G') of WPC/PUL gels. When the WPC/PUL gel was formed at PUL concentration of 0.40 g mL-1 and pH 7.0, the interaction between WPC and PUL could be enhanced, which is beneficial for the future application of WPC/PUL gels in the food industry. © 2020 Society of Chemical Industry.

Gum arabic and collagen hydrolysate extracted from hide fleshing wastes as novel wall materials for microencapsulation of Origanum onites L. essential oil through complex coacervation.

Renewable resource-based biodegradable materials attract more attention than petroleum-based biodegradable materials to support the sustainable development of ecology. Obtaining collagen hydrolysate (CH) from hide fleshing wastes of leather industry is an environmentally friendly way to develop multifunctional materials that can contribute to technological advances in different industries. In this study, 2:1, 1:1, and 1 2 ratios of gum arabic (GA) and CH extracted from hide fleshing waste were used as wall materials to encapsulate Origanum onites L. essential oil (OOEO) using the complex coacervation method. The encapsulation yield and efficiency, functional group composition, particle size, morphology, and thermal stability of the obtained OOEO microcapsules were characterized. The results showed that the obtained microcapsules had high encapsulation yield and efficiency, as well as good functional properties such as uniform morphology and low water activity. The best mass ratio for the biopolymers (GA:CH) was 1:1. Scanning electron microscopy analysis showed that OOEO microcapsule samples had a spherical shape. FTIR analysis was performed on obtained microcapsules, confirming the molecular interactions between GA and CH. These findings can be useful in designing an ideal wall material using GA and CH for microencapsulation of essential oils by the complex coacervation method.