Incorporation of microencapsulated polyphenols from jabuticaba peel (Plinia spp.) into a dairy drink: stability, in vitro bioaccessibility, and glycemic response.

This work incorporated bioactives extracted from jabuticaba peel in the form of concentrated extract (JBE) and microencapsulated powders with maltodextrin (MDP) and gum arabic (GAP) in a dairy drink, evaluating its stability, in vitro bioaccessibility, and glycemic response. We evaluated the pH, acidity, colorimetry, total phenolics and anthocyanins, antioxidant capacity, degradation kinetics and half-life of anthocyanins, bioaccessibility, and postprandial glycemic physicochemical characteristics response in healthy individuals. The drinks incorporated with polyphenols (JBE, GAP, and MDP) and the control dairy drink (CDD) maintained stable pH and acidity over 28 days. In color, the parameter a*, the most relevant to the study, was reduced for all formulations due to degradation of anthocyanins. Phenolic and antioxidant content remained constant. In bioaccessibility, we found that after the gastrointestinal simulation, there was a decrease in phenolics and anthocyanins in all formulations. In the glycemic response, we observed that the smallest incremental areas of glucose were obtained for GAP and JBE compared to CDD, demonstrating that polyphenols reduced glucose absorption. Then, the bioactives from jabuticaba peel, incorporated into a dairy drink, showed good storage stability and improved the product's functional aspects.

Microencapsulation of highly concentrated polyphenolic compounds from purple corn pericarp by spray-drying with various biomacromolecules.

Colored corn pericarp contains unusually high amounts of industrially valuable phytochemicals, such as anthocyanins, flavanols, flavonoids, and phenolic acids. Polyphenols were extracted in an aqueous solution and spray-dried to produce microencapsulates using four carrier materials, namely, maltodextrin (MD), gum arabic (GA), methylcellulose (MC), and skim milk powder (SMP) at three concentrations (1, 2, and 3 %, respectively). The encapsulates were evaluated for their polyphenolic contents using spectrophotometric techniques and HPLC analyses, and their antioxidant properties were evaluated using four different assays. The physicochemical properties of encapsulates were analyzed by measuring the zeta potential (ZP), particle size distribution, water solubility index (WSI), water absorption index (WAI), and color parameters. Structural and thermal properties were evaluated using Fourier transform infrared spectroscopy (FTIR), optical profilometry, and differential scanning calorimetry (DSC) analyses. Comparative analysis of structural characteristics, particle size distribution, zeta potential, WSI, WAI, and aw of the samples confirmed the successful formulation of encapsulates. The microencapsulates embedded with 1 % concentrations of MD, MC, GA, or SMP retained polyphenolic compounds and exhibited noteworthy antioxidant properties. The samples encapsulated with GA or MD (1 %) demonstrated superior physicochemical, color, and thermal properties. Comprehensive metabolomic analysis confirmed the presence of 38 phytochemicals in extracts validating the spray-drying process.

Rice proteins - Gum arabic coacervates: Effect of pH and polysaccharide concentration in oil-in-water emulsion stability.

In the context of replacing animal proteins in food matrices, rice proteins (RP) become promised because they come from an abundant plant source, are hypoallergenic, and have high digestibility and nutritional value. However, commercial protein isolates obtained by spray drying have low solubility and poor functionality, especially in their isoelectric point. One way to modify these properties is through interaction with polysaccharides, such as gum arabic (GA). Therefore, this work aims to evaluate the effects of pH and GA concentration on the interaction and emulsifying activity of RP:GA coacervates. First, the effects of pH (2.5 to 7.0) and GA concentrations (0.2 to 1.0 wt%, giving rise to RP:GA mass ratios of 1:0.2 to 1:1.0) in RP:GA blends were evaluated. The results demonstrated that biopolymers present opposite net charges at pH between 2.5 and 4.0. At pH 3.0, insoluble coacervates with complete charge neutralization were formed by electrostatic interactions, while at pH 5.0 it was observed that the presence of GA prevented the RP massive aggregation. Second, selected blends with 0.4 or 1.0 wt% of GA (RP:GA mass ratios of 1:0.4 or 1:1.0) at pH 3.0 or 5.0 were tested for their ability to stabilize oil-in-water emulsions. The emulsions were characterized for 21 days. It was observed that the GA increased the stability of RP emulsions, regardless of the pH and polysaccharide concentration. Taken together, our results show that it is possible to combine RP and GA to improve the emulsifying properties of these plant proteins at pH conditions close to their isoelectric point, expanding the possibility of implementation in food systems.

Fabrication of biopolymer stabilized microcapsules for enhancing physicochemical stability, antioxidant and antimicrobial properties of cinnamon essential oil.

The current study entails the encapsulation validity to enclose naturally occurring food preservatives, such as cinnamon essential oil (CM), within various wall materials. This approach has demonstrated enhanced encapsulated compounds' stability, efficiency, and bioactivity. The base carrier system consisted of a solid lipid (Berry wax, RW) individually blended with whey protein (WYN), maltodextrin (MDN), and gum Arabic (GMC) as wall materials. The resulting formulations were freeze-dried: WYN/RW/CM, MDN/RW/CM, and GMC/RW/CM. The study comprehensively analyzed encapsulation efficiency, morphology, crystallinity, thermal, and physiochemical properties. When RW was combined with WYN, MDN, and GMC, the microcapsule WYN/RW/CM showed the highest efficiency at 93.4 %, while the GMC/RW/CM exhibited the highest relative crystallinity at 46.54 %. Furthermore, the investigation assessed storage stability, release of bioactive compounds, and oxidative stability during storage at 4 °C/ 25 % RH ± 5 % and 25 °C/40 % RH ± 5 % for 55 days, revealing optimal stability in the WYN/RW/CM microcapsule. Additionally, the antimicrobial activity was assessed at various concentrations of microcapsules, revealing their inhibitory effect against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) bacteria. The WYN/RW/CM microcapsule exhibited the highest inhibition activity in both strains, reaching 40 mm. This study demonstrates that combining WYN with RW as a wall material has greater efficiency in encapsulation and potential uses in various industrial sectors.

Microencapsulation of flaxseed oil in pea protein-gum arabic complex coacervates delays lipid digestion in liquid yoghurt.

Flaxseed oil coacervates were produced by complex coacervation using soluble pea protein and gum arabic as shell materials, followed by either spray or electrostatic spray drying and their incorporation to yoghurt. Three yoghurt formulations were prepared: yoghurt with spray-dried microcapsules (Y-SD); with electrospray-dried microcapsules (Y-ES); with the encapsulation ingredients added in free form (Y). The standardised semi-dynamicin vitrodigestion method (INFOGEST) was employed to study the food digestion. The structure was analysed by confocal laser scanning microscopy and particle size distribution. Protein and lipid digestion were monitored by cumulated protein/free NH2 release and cumulated free fatty acids release, respectively. Stable microcapsules were observed during gastric digestion, but there was no significant difference in protein release/hydrolysis among samples until 55 min of gastric digestion. Formulation Y showed less protein release after 74 min (40.46 %) due to the free SPP being available and positively charged at pH 2-4, resulting in interactions with other constituents of the yoghurt, which delayed its release/hydrolysis. The total release of protein and free NH2 by the end of intestinal digestions ranged between 46.56-61.15 % and 0.83-1.57 µmol/g protein, respectively. A higher release of free fatty acids from formulation Y occurred at the end of intestinal digestion, implying that coacervates promoted the delayed release of encapsulated oil. In summary, incorporating protein-polysaccharides-based coacervates in yoghurt enabled the delay of the digestion of encapsulated lipids but accelerated the digestion of protein, suggesting a promising approach for various food applications.

Fabrication of curcumin-loaded oleogels using camellia oil bodies and gum arabic/chitosan coatings for controlled release applications.

This study has explored the potential of plant-derived oil bodies (OBs)-based oleogels as novel drug delivery systems for in vitro release under simulated physiological conditions. To obtain stable OBs-based oleogels, gum arabic (GA) and chitosan (CH) were coated onto the curcumin-loaded OBs using an electrostatic deposition technique, followed by 2,3,4-trihydroxybenzaldehyde (TB) induced Schiff-base cross-linking. Microstructural analyses indicated successful encapsulation of curcumin into the hydrophobic domain of the OBs through a pH-driven method combined with ultrasound treatment. The curcumin encapsulation efficiency of OBs increased up to 83.65 % and 92.18 % when GA and GA-CH coatings were applied, respectively, compared to uncoated OBs (63.47 %). In addition, GA-CH coatings retained the structural integrity of oleogel droplets with superior oil-holding capacity (99.07 %), while TB addition induced interconnected 3D-network structures with excellent gel strength (≥4.8 × 105 Pa) and thermal stability (≥80 °C). GA-CH coated oleogels appeared to provide the best protection for loaded bioactive against UV irradiation and high temperature-induced degradation during long-term storage. The combination of biopolymer coatings and TB-induced Schiff-base cross-linking synergistically hindered the simulated gastric degradability of oleogels, releasing only 23.35 %, 12.46 % and 7.19 % of curcumin by GA, GA-CH and GA-CH-TB stabilized oleogels, respectively, while also resulting in sustained release effects during intestinal conditions.

Brachytherapy at the nanoscale with protein functionalized and intrinsically radiolabeled [169Yb]Yb2O3 nanoseeds.

PURPOSE: Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy. METHODS: 169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model. RESULTS: The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed. CONCLUSIONS: These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.

Study on the mechanism of natural polysaccharides on the deastringent effect of Triphala extract.

This present study investigated the masking effect of high methoxyl pectin, xanthan gum, and gum Arabic on the astringency of the traditional herbal formula Triphala and further examined the mechanism of polysaccharide reducing astringency. Results of sensory evaluation and electronic tongue illustrated that 0.6 % pectin, 0.3 % xanthan gum, and 2 % gum Arabic had a substantial deastringent effect. The polyphenols in Triphala are basically hydrolysable tannins, which with high degree of gallic acylation may be the main astringent component of Triphala. Moreover, the three polysaccharides can combine with ß-casein through CO and NH groups to form soluble binary complexes and decrease the secondary structure of ß-casein. When polysaccharides were added to the Triphala-protein system, polyphenol-protein precipitation was also diminished, and they were capable of forming soluble ternary complexes. Consequently, the competition between polysaccharides and polyphenols for binding salivary proteins and the formation of ternary complexes help decrease the astringency of Triphala.

Effect of Inlet Air Temperature and Quinoa Starch/Gum Arabic Ratio on Nanoencapsulation of Bioactive Compounds from Andean Potato Cultivars by Spray-Drying.

Nanoencapsulation of native potato bioactive compounds by spray-drying improves their stability and bioavailability. The joint effect of the inlet temperature and the ratio of the encapsulant (quinoa starch/gum arabic) on the properties of the nanocapsules is unknown. The purpose of this study was to determine the best conditions for the nanoencapsulation of these compounds. The effects of two inlet temperatures (96 and 116 °C) and two ratios of the encapsulant (15 and 25% w/v) were evaluated using a factorial design during the spray-drying of native potato phenolic extracts. During the study, measurements of phenolic compounds, flavonoids, anthocyanins, antioxidant capacity, and various physical and structural properties were carried out. Higher inlet temperatures increased bioactive compounds and antioxidant capacity. However, a higher concentration of the encapsulant caused the dilution of polyphenols and anthocyanins. Instrumental analyses confirmed the effective encapsulation of the nuclei in the wall materials. Both factors, inlet temperature, and the encapsulant ratio, reduced the nanocapsules' humidity and water activity. Finally, the ideal conditions for the nanoencapsulation of native potato bioactive compounds were determined to be an inlet temperature of 116 °C and an encapsulant ratio of 15% w/v. The nanocapsules obtained show potential for application in the food industry.

All-natural wheat gliadin-gum arabic nanocarriers for encapsulation and delivery of grape by-products phenolics obtained through different extraction procedures.

Grape pomace (GP), the major winery by-product, is still rich in phenolic compounds, scarcely applied in food systems due to physicochemical instability issues. This work aimed at fabricating gliadin (G)-based nanoparticles through antisolvent precipitation, for delivery of GP extracts, investigating different extraction strategies with ethanol/water solution (70:30 v/v). Interestingly, the fabricated nanoparticles were characterized by a nanometric size range with hydraulic diameter values around 100 nm and ζ-potential of 18-22 mV. The addition of gum arabic (GA), at the optimized G/GA ratio 1:1, improved particle stability and encapsulation efficiency of GP polyphenols. The two-step extraction of GP in the G-rich solvent retrieved from G extraction, as evidenced by total phenolics (1.24 times higher than the two separately obtained extracts G/GP10:10), HPLC-PDA analysis, encapsulation efficiency (62.9% in terms of epicatechin), and simulated digestion (95.6% release of epicatechin), represented the most promising approach to obtain G nanoparticles for efficient delivery of GP extracts.

Spray dried date fruit extract with a maltodextrin/gum arabic binary blend carrier agent system: Process optimization and product quality.

Bioactive compounds can be protected from degradation through encapsulation, increasing their bioavailability and shelf life. Spray drying is an advanced encapsulation technique mainly used for the processing of food-based bioactives. In this study, Box-Behnken design (BBD)-based response surface methodology (RSM) was used to study the effects of combined polysaccharide carrier agents and other spray drying parameters on encapsulating date fruit sugars obtained from a supercritical assisted aqueous extraction. The spray drying parameters were set at various levels: Air inlet temperature (150-170 °C), feed flow rate (3-5 mL/min), and carrier agent concentration (30-50 %). Under the optimized conditions (inlet temperature of 170 °C, the feed flow rate of 3 mL/min, and carrier agent concentration of 44 %), a maximum sugar powder yield of 38.62 % with 3.5 % moisture, 18.2 % hygroscopicity and 91.3 % solubility was obtained. The tapped density and particle density of the dried date sugar were estimated as 0.575 g cm-3 and 1.81 g cm-3, respectively, showing its potential for easy storage. In addition, scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis revealed better microstructural stability of the fruit sugar product, which is essential for commercial applications. Thus, the hybrid carrier agent system (maltodextrin and gum arabic) can be considered a potential carrier agent for producing stable date sugar powder with longer shelf-life and desirable characteristics in the food industry.

Gum arabic/guar gum stabilized Hydnocarpus wightiana oil nanohydrogel: Characterization, antimicrobial, anti-inflammatory, and anti-biofilm activities.

Hydnocarpus wightiana oil has proven to inhibit the growth of pathogenic microorganisms; however, the raw form is highly susceptible to oxidation, and thus it becomes toxic when uptake is in high amounts. Therefore, to minimize the deterioration, we formulated Hydnocarpus wightiana oil-based nanohydrogel and studied its characteristics as well biological activity. The low energy-assisted hydrogel was formulated by including gelling agent, connective linker, and cross-linker and it resulted in internal micellar polymerization of the milky white emulsion. The oil showed the presence of octanoic acid, n-tetradecane, methyl 11-(2-cyclopenten-1-yl) undecanoate (methyl hydnocarpate), 13-(2-cyclopenten-1-yl) tridecanoic acid (methyl chaulmoograte), and 10,13-eicosadienoic acid. The amount of caffeic acid was 0.0636 mg/g, which was higher than the amount of gallic acid (0.0076 mg/g) in the samples. The formulated nanohydrogel showed an average droplet size of 103.6 nm with a surface charge of -17.6 mV. The minimal inhibitory bactericidal, and fungicidal concentrations of nanohydrogel against pathogenic bacteria and fungi were ranging from 0.78 to 1.56 µl/mL with 70.29-83.62 % antibiofilm activity. Also, nanohydrogel showed a significantly (p < 0.05) higher killing rate for Escherichia coli (7.89 log CFU/mL) than Staphylococcus aureus (7.81 log CFU/mL) with comparable anti-inflammatory activity than commercial standard (49.28-84.56 %). Therefore, it can be concluded that being hydrophobic, and having the capability of target-specific drug absorption as well as biocompatibility nanohydrogels can be utilized to cure various pathogenic microbial infections.

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

BACKGROUND: 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. RESULTS: 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. CONCLUSION: Microcapsules developed from complex coacervates based on the ternary blend represent promising omega-3-rich carriers for being incorporated into functional foods.

In vitro oxidation and digestibility profiles of iron-loaded whey protein isolate/gum Arabic complexes with different morphologies.

This study was designed to investigate the promotion of oxidation of lipids in oil-in-water (o/w) emulsions and digestive properties of the bionic dynamic gastrointestinal system of whey protein isolate (WPI) and gum arabic (GA) complexes loaded with iron ions, which were fabricated previously and shown as WPI/GAFe3+ nanoparticles (WGS) and WPI/GAFe3+ fibers (WGF). Compared with emulsions containing Fe3+ and GA-loaded complex (GAFe3+), WGS and WGF greatly improved the oxidative stability of lipids along with the reduced lipid oxidation products and volatile compounds, attributed to the encapsulation of iron ions. During the bionic dynamic gastrointestinal digestion, the iron ion release of WGF was significantly higher than that of WGS, probably due to different assembled internal structures. Accordingly, two proposed WPI/GAFe3+ complexes with different morphologies are expected to be developed as novel stable iron fortifiers with delayed lipid oxidation and controlled iron-ion release in food emulsions.

Effect of excipient wall materials on the development of ginger oleoresin microcapsules: assessing the physicochemical, antioxidant and structural properties.

BACKGROUND: Ginger oleoresin is prone to destruction from air, light and high temperatures and has a limited shelf life if kept improperly. Its viscous and sticky characteristics also make it difficult to handle and utilize. These issues can be solved via microencapsulation. The goal of this research was to evaluate how different wall materials affect the properties of microencapsulated ginger oleoresin powder. RESULTS: Ginger oleoresin microcapsules were developed through spray drying technique using gum acacia (GA) and whey protein isolate (WPI) as wall materials. The characteristics of the obtained powder, including water activity, wettability and encapsulation efficiency, were evaluated, corresponded to values of 0.20, 90.54 s and 84.15% for whey protein isolate-based ginger oleoresin powder. Whey protein isolate microcapsules also exhibited higher phenolic content (27.26 mg gallic acid equivalents g-1 ), total flavonoid (2.94 mg quercetin equivalents g-1 ) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (68.71%) than GA microcapsules. Both WPI- and GA-based oleoresin microcapsules displayed poor flowability, but possessed a metastable amorphous state as indicated by X-ray diffraction. GA-encapsulated oleoresin microcapsules showed a significant increase in particle size (1983 nm) compared to WPI oleoresin microcapsules. Fourier transform infrared analysis of the developed oleoresin microcapsules indicated no change in molecular structure except for a variation in peak intensity. CONCLUSION: Whey protein isolate proved to be more efficient in maintaining the physicochemical and antioxidant activity of spray-dried ginger oleoresin powder. The present study revealed whey protein-based oleoresin powder could be used as a therapeutic agent in various nutraceutical applications. © 2022 Society of Chemical Industry.

Quinoa protein isolate-gum Arabic coacervates cross-linked with sodium tripolyphosphate: Characterization, environmental stability, and Sichuan pepper essential oil microencapsulation.

Quinoa protein isolate-gum Arabic coacervates (QPI-GA coacervates) was cross-linked with sodium tripolyphosphate (STPP) to enhance their physicochemical properties. The optimum concentration of STPP for cross-linking was determined experimentally to be 0.2 g/g of QPI-GA mixture. After cross-linking, QPI-GA coacervates changed to the more ordered structure, and showed higher pH, ionic, and thermal stability. The STPP cross-linked coacervates were used as wall materials for Sichuan pepper essential oil (SPEO) encapsulation with encapsulation efficiency of 87.25 %. Compared with uncross-linked microcapsules, cross-linked microcapsules showed higher SPEO retention at high temperature, different pH, and high ionic concentration. Meanwhile, STPP cross-linked microcapsules improved the stability of SPEO during oral and gastric digestion as indicated by the lower SPEO release, which guaranteed the higher release and absorption in intestinal digestion of SPEO. Consequently, STPP cross-linked QPI-GA coacervates can be an ideal carrier for flavors or active ingredients, protecting them against harsh environment conditions during food processing and digestion.

Microplastic-Free Microcapsules to Encapsulate Health-Promoting Limonene Oil.

Fast-moving consumer goods (FMCG) industry has long included many appealing essential oils in products to meet consumers' needs. Among all, the demand for limonene (LM) has recently surged due to its broad-spectrum health benefits, with applications in cosmetic, detergent, and food products. However, LM is extremely volatile, hence has often been encapsulated for a longer shelf-life. To date, mostly non-biodegradable synthetic polymers have been exploited to fabricate the microcapsule shells, and the resulting microcapsules contribute to the accumulation of microplastic in the environment. So far, information on LM-entrapping microcapsules with a natural microplastic-free shell and their mechanism of formation is limited, and there is lack of an in-depth characterisation of their mechanical and adhesive properties, which are crucial for understanding their potential performance at end-use applications. The present research aims towards developing safe microcapsules with a core of LM fabricated via complex coacervation (CC) using gum Arabic (GA) and fungally sourced chitosan (fCh) as shell precursors. The encapsulation efficiency (EE) for LM was quantified by gas chromatography (GC) separation method. The morphology of microcapsules was investigated via bright-field optical microscopy and scanning electron microscopy, and their mechanical properties were characterised using a micromanipulation technique. Moreover, the adhesive properties of the resulting microcapsules were studied via a bespoke microfluidic device fitted with a polyethylene-terephthalate (PET) substrate and operating at increasingly hydrodynamic shear stress (HSS). Spherical core-shell microcapsules (EE ~45%) with a mean size of 38 ± 2 µm and a relatively smooth surface were obtained. Their mean rupture force and nominal rupture stress were 0.9 ± 0.1 mN and 2.1 ± 0.2 MPa, respectively, which are comparable to those of other microcapsules with synthetic shells, e.g., urea- and melamine-formaldehyde. It was also found that the fCh-GA complexed shell provided promising adhesive properties onto PET films, leading to a microcapsule retention of ~85% and ~60% at low (≤50 mPa) and high shear stress (0.9 Pa), respectively. Interestingly, these values are similar to the adhesion data available in literature for microplastic-based microcapsules, such as melamine-formaldehyde (50-90%). Overall, these findings suggest that microplastics-free microcapsules with a core of oil have been successfully fabricated, and can offer a potential for more sustainable, consumer- and environmentally friendly applications in FMCGs.

Stability evaluation of gardenia yellow pigment in the presence of different antioxidants or microencapsulating agents.

The chemical instability of gardenia yellow pigment (GYP) limits its utilization in the food industry. In this study, the effects of different antioxidants (0.2% of tea polyphenols, sodium phytate, potassium citrate, and ascorbic acid) and microencapsulating agents (gum Arabic, maltodextrin, inulin, and gum Arabic/maltodextrin) on the degradation of GYP under different conditions (heat, light, and ferric iron) were evaluated. Then, the characteristic properties of microcapsules coated with gum Arabic/maltodextrin, gum Arabic/maltodextrin/tea polyphenols, maltodextrin, and maltodextrin/tea polyphenols were investigated. Furthermore, food models were simulated to evaluate the GYP stability of the microcapsules. The results showed that tea polyphenols, maltodextrin, and gum Arabic/maltodextrin significantly improved the GYP stability. Moreover, the presence of GYP in microcapsules was confirmed by nuclear magnetic resonance and Fourier transform infrared spectroscopy. In addition, GYP-MD/TP possessed high thermal stability under different cooking methods. PRACTICAL APPLICATION: Gardenia yellow pigment (GYP) is easily degraded under light and high-temperature conditions, which limits its applications in the food industry. This study will provide effective clues for expanding the practical applications of GYP in the natural pigment industry.

Green synthesis of gold nanoparticles in Gum Arabic using pulsed laser ablation for CT imaging.

Laser ablation synthesis in liquid solution (PLAL) is a green technique that allows for the physical formation of nanomaterials. This study indicates the preparation of stable gold nanoparticles (AuNPs) in Gum Arabic (GA) solution via laser ablation as a CT contrast agent. The optical properties were achieved using the absorption spectroscopic technique whereas the morphology and size distribution were investigated by TEM and ImageJ software. TEM image shows greater stability and spherical shape of GA-AuNPs with smaller size at 1.85 ± 0.99 nm compared to AuNPs without GA. The absorption spectrum of pure AuNPs has a lower absorption peak height in the visible range at λ = 521 nm, while the spectrum of GA-AuNPs has a higher plasmon peak height at λ = 514 nm with a blue shift towards lower wavelengths. The concentration of GA that dissolved in 10 mL of DI water via laser ablation is set at 20 mg. Increasing the number of pulses has only a minor effect on particle size distribution, which remains tiny in the nanometer range (less than 3 nm). For energies greater than 200 mJ, there is a blue shift toward shorter wavelengths. As the concentration of GA-AuNPs increases, the CT number is also increased indicating good image contrast. It can be concluded that there is a positive and significant influence of GA as a reducing agent for AuNPs, and a contrast agent for CT imaging which highlights its superiority in future medical applications.

Effect of enzymatic hydrolysis conditions on structure of soy protein isolate/gum arabic complex and stability of oil-in-water emulsion.

BACKGROUND: The emulsifying, antioxidant and foaming properties of soy protein isolate hydrolysates (SPH) can be improved by the addition of gum arabic (GA). We investigated the effects of different hydrolysis conditions on the complexation of SPH and GA, and the effects of the complex on the properties of emulsions. RESULTS: Fluorescence spectroscopy showed that the addition of GA had a stronger effect on bromelain and pepsin hydrolysates than trypsin hydrolysate, and therefore had a higher binding constant (KA ) and a larger number of binding sites (n). The addition of GA could also improve protein solubility and emulsifying ability. The emulsions prepared with complexes, especially the complex of GA and SPH obtained by pepsin hydrolysis for 3 h, had a high absolute charge value, uniform particle size distribution, stable morphology, and good storage stability. After storage, the emulsification index (CI) of the emulsion only increased to 23.08%; its 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity was 24.37 ± 1.22% and its 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS+ ) free radical scavenging activity was largely retained. CONCLUSION: During long-term storage, pepsin-treated protein (especially protein treated for 3 h) and GA can form a stable emulsion with antioxidant properties. This work provides new ideas for the development of natural and safe emulsifiers that have antioxidant properties and can be stored long-term and used in the food industry. © 2022 Society of Chemical Industry.