Spray dried microparticles of chia oil using emulsion stabilized by whey protein concentrate and pectin by electrostatic deposition

A superior binary matrix of maltodextrin and whey protein concentrate for chia seed oil encapsulation through freeze-drying

The present study was designed to evaluate and compare the efficiency of two wall material (WM) matrices-maltodextrin (MD) and gum Arabic (GA) in combination with whey protein concentrate (WPC) for encapsulating chia seed oil (CSO). RSM, a robust and widely recognized optimization tool, was employed to optimize independent parameters: WM ratio (MD-WPC or GA-WPC) (0 to 100%), homogenization pressure (69-207 MPa), and oil content (6-10%). A modified rotatable central composite design with replicated factorial points ensured non-fractional factor levels to study variable interactions on encapsulation efficiency (EE) and α-Linolenic acid (ALA) retention. Optimized CSO microcapsule [OCSO I (MD-WPC)] exhibited EE (81.23%), higher ALA (61.85%) and Ω-3: Ω-6 ratio (3.44) than OCSO II (GA-WPC) under the same optimized conditions. The optimal conditions were; MD/GA:WPC ratio (25%), pressure (172.5 MPa), and oil content (9%). Microcapsule OCSO I demonstrated superior oxidative stability with a significantly (p < 0.05) longer shelf life (24-26 days) compared to OCSO II (16-18 days) and achieved significantly (p < 0.05) higher CSO delivery in the intestinal phase. FTIR analysis confirmed encapsulation integrity, showing low or no peaks associated with free CSO. These findings provide valuable insights for the industry in selecting innovative, economical, and effective WMs for encapsulating bioactive CSO.

Xanthan gum ink based on Lycium ruthenicum anthocyanin as an indicator of color change for monitoring freshness of cold fresh meat

The continuous development of intelligent food packaging has led to an increased focus on using freshness-indicating inks, which could provide a high level of quality control and consumer experience. This study aimed to further promote the application of xanthan gum ink in food freshness indication by optimizing its performance in screen printing. A novel freshness-indicating ink was prepared using Lycium ruthenicum anthocyanin (LRA) as the core indicator, glucose as the pigment carrier, soybean oil as the linker, and xanthan gum (XG) as the thickener. Scanning electron microscopy (SEM) demonstrated that the ink was uniformly distributed on paper using screen printing. Rheological and particle size analyses revealed that the incorporation of XG significantly enhanced the interaction force between droplets in the ink system. Further tests on viscosity, fineness, and initial dryness indicated that XG, a natural microbial polysaccharide with excellent stability, could effectively improve the flowability of the ink. Specifically, at a 0.3 % XG content, the ink exhibited a unimodal particle size distribution with an average particle size of 851.02 nm and a zeta potential of -27 mV. This indicated the ink system was stable and uniform, with optimal rheological properties and printing suitability. Furthermore, the printed freshness indication labels exhibited a significant change in color as the freshness of the refrigerated meat changed. This study develops a natural and safe method for monitoring the freshness of refrigerated meat and provides an optimized idea for applying indicator inks.

Enhancing Encapsulation Efficiency of Chavir Essential Oil via Enzymatic Hydrolysis and Ultrasonication of Whey Protein Concentrate-Maltodextrin

This study focused on the characterization of emulsions and microparticles encapsulating Chavir essential oil (EO) by application of modified whey protein concentrate-maltodextrin (WPC-MD). Different physical, chemical, morphological, thermal, and antioxidant properties and release behavior of spray-dried microparticles were assessed. Antioxidant, solubility, emulsifying, and foaming activities of modified WPC were increased compared to those of primary material. The results indicated that the particle size distribution varied depending on the type of carriers used, with the smallest particles formed by hydrolyzed WPC (HWPC). Binary blends of modified WPC-MD led to improved particle sizes. The spray-drying yield ranged from 64.1% to 85.0%, with higher yields observed for blends of MD with sonicated WPC (UWPC). Microparticles prepared from primary WPC showed irregular and wrinkled surfaces with indentations and pores, indicating a less uniform morphology. The UWPC as a wall material led to microparticles with increased small cracks and holes on their surface. However, HWPC negatively affected the integrity of the microparticles, resulting in broken particles with irregular shapes and surface cracks, indicating poor microcapsule formation. Encapsulating EO using WPC-MD increased the thermal stability of EO significantly, enhancing the degradation temperature of EO by 2 to 2.5-fold. The application of primary WPC (alone or in combination with MD) as wall materials produced particles with the lowest antioxidant properties because the EO cannot migrate to the surface of the particles. Enzymatic hydrolysis of WPC negatively impacted microparticle integrity, potentially increasing EO release. These findings underscore the crucial role of wall materials in shaping the physical, morphological, thermal, antioxidant, and release properties of spray-dried microparticles, offering valuable insights for microencapsulation techniques.

Ferrous sulfate microparticles obtained by spray chilling: characterization, stability and in vitro digestion simulation

The use of microencapsulated ferrous-sulfate is among the various options recommended for food fortification, as the protective wall material surrounding the compound can preserve it from undesirable alterations and also protect the food. Microencapsulated iron can be produced using different wall materials and encapsulation methods. Thus, a microparticle was developed through spray chilling, containing ferrous sulfate (FS), as active compound, and a fat mixture as the coating material. The resulting samples analyzed to determine encapsulation efficiency, particle size distribution, and morphology. Furthermore, the oxidative stability and bioaccessibility of FS microparticles were investigated by simulating in vitro digestion. The findings indicated that the encapsulation technique effectively retained FS, resulting in microparticles physically stable at room temperature with typical morphology. The encapsulation efficiency revealed that lower concentrations of FS led to reduced superficial iron content. However, the oxidative stability demonstrated that the presence of iron in the microparticles accelerated the lipid oxidation process. The in vitro digestion test demonstrated that the microparticles with lower iron content exhibited a higher percentage of bioaccessibility, even when compared to non-encapsulated FS. Additionally, the coating material successfully released FS during the simulation of gastrointestinal digestion, resulting in a bioaccessibility of 7.98%.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05820-1.

Investigating the effect of wall material and pressure homogenisation on encapsulation parameters and thermal stability in chia seed oil microcapsules

AIM

To evaluate the effect of different wall material (WM) matrices followed by homogenisation to encapsulate chia seed oil (CSO) using freeze drying technology.

METHODS

CSO was encapsulated using three ratios (100/0, 50/50, and 100/0) of two WM matrices: MTS/WPC (modified tapioca starch-whey protein concentrate) and MD/WPC (maltodextrin-whey protein concentrate). The evaluation included encapsulation efficiency (EE), oxidative stability, and α-linolenic acid (ALA) retention. Homogenised microcapsules (-H) were then assessed for storage and thermal stability, along with cumulative oil release.

RESULTS

The MD-WPC-H 50/50 microcapsules had superior EE (97.32%), higher ALA retention (60.2%), storage stability (up to 30 days), higher thermal stability (up to 700 °C), and desirable oil release in simulated condition.

CONCLUSION

Selecting suitable WM and homogenisation is key for improving EE, storage, thermal stability, and targeted release. The CSO microcapsule can serve as a functional ingredient to improve the quality of diverse food products.

Structural modification of poppy-pollen protein as a natural antioxidant, emulsifier and carrier in spray-drying of O/W-emulsion: Physicochemical and oxidative stabilization

This study was aimed to investigate the efficiency of poppy-pollen (PP) protein and peptides as carrier for spray-drying encapsulation of grape-seed oil (GSO). The composition of amino acids, functional properties and bioactivity (scavenging of DPPH, ABTS, OH, and nitric-oxide radicals, reducing power, total antioxidant, TBARS levels in O/W-emulsion, and chelation of Fe2+ and Cu2+ ions) of PP-protein were affected by the enzymolysis time. Partial enzymolysis (30 min) led to improved solubility, protein surface activity and increased physical stability of GSO/W emulsion (relative to creaming, aggregation and flocculation) during storage. Also, spray-dried emulsions with this type of carrier (H-30) had the highest production yield (~67 %), solubility (~92 %), flowability, encapsulation efficiency (~96 %), reconstitution ability (least size and EE changes), physical and oxidative stability. The evaluation of the chemical structures (FTIR) indicated the formation of hydrogen bonds between the cis-alkene groups of fatty acids and the hydroxyl groups of the amide A and B regions, as well as the trapping of oil in the carrier matrix. SEM images illustrated the effect of native protein carriers (particles with smooth, dents, and hollow surfaces with surface pores), partially (wrinkled and reservoir-type), and strongly (irregular structures, sticky and amorphous agglomerates) hydrolyzed peptides on the morphology of oily-particles. The results of this research indicate the usability of partially hydrolyzed poppy-pollen protein as a source of natural antioxidant, emulsifier, and carrier in the production, stabilization, and encapsulation of oxidation-sensitive bioactive components and emulsions.

Strategies for improving loading of emulsion-based functional oil powder

Functional oil is type of oil that is beneficial to human health and has nutritional value, however, functional oils are rich in bioactive substances such as polyunsaturated fatty acids which are sensitive to environmental factors and are susceptible to oxidation or decomposition. Construction of emulsion-based oil powder is a promising approach for improving the stability and solubility of functional oils. However, the low effective loading of oil in powder is the main challenge limiting encapsulation technology. This manuscript focuses on reviewing the current research progress of emulsion-based functional oil powder construction and systematically summarizes the processing characteristics of emulsion-based oil powder with high payload and summarizing the strategies to enhance the payload of powder in term of emulsification and drying, respectively. The impact of emulsion formation on oil powder production is discussed from different characteristics of emulsions, including emulsion composition, emulsification methods and emulsion types. In addition, the current status of improving material loading performance by various modifications to the drying technology is discussed, including the addition of drying processing additives, changes in drying parameters and the effect of innovative technological means.

Effect of ultrasonication on emulsion formulation, encapsulation efficiency, and oxidative stability of spray dried chia seed oil

Present study was conducted to develop a stable chia oil emulsion using an ultrasound emulsification technique. Whey protein concentrate, gum Arabic, and xanthan gum stabilized layer by layer chia oil emulsion was developed using an electrostatic deposition. Single-layer and multilayer emulsion of chia oil was developed and their stability is compared. Developed emulsions were characterized by viscosity, stability, surface charge, and droplet size. Layer-by-layer emulsion showed the highest stability (98%) among all the formulations developed. Formulated single-layer and double-layer emulsions were spray dried and the respective powders were characterized for bulk density, tapped density, Hausner ratio, Carr's index, moisture content, color values, encapsulation efficiency, peroxide value, XRD, and SEM. Multilayer emulsion-based powder showed better flowability properties. The encapsulation efficiency of multilayer microparticles was found to be 93% with the lowest peroxide value of 1.08 mEq O2/kg fat. XRD diffractogram of the developed microparticles revealed amorphous nature. The developed ultrasound layer-by-layer emulsification technique is an efficient technique for developing chia oil-loaded microparticles.

Constitution and reconstitution of microcapsules with high diacylglycerol oil loading capacity based on whey protein isolate / octenyl succinic anhydride starch/ inulin matrix

The aim of this study was to constitute microcapsule systems with high oil loading capacity by octenyl succinic anhydride (OSA) starch, whey protein isolate (WPI) and inulin (IN) substrates to provide a new method for encapsulating diacylglycerol oil. Specifically, this study characterizes the physicochemical properties and reconstitution capacity of highly oil loading diacylglycerol microcapsules by comparing the wall encapsulation capacity of the binary wall system OSA-IN, WPI-IN and the ternary wall system WPI-OSA (1:9, 5:5, 9:1)-IN for diacylglycerol oil. It was found that WPI-OSA (5:5)-IN significantly improved the water solubility of microcapsules (86.11 %) compared to OSA-IN microcapsules, and the addition of WPI made the surface of microcapsules smoother and increased the thermal stability and solubility of microcapsules; the addition of OSA enhanced the wettability of microcapsules compared to WPI-IN. In addition, WPI-OSA (5:5)-IN microcapsules have the highest encapsulation efficiency (96.03 %), high emulsion stability after reconstitution, and the smallest droplet size (212.83 nm) after 28 d. Therefore, the WPI-OSA-IN composite system is suitable for the production of highly oil-loaded microencapsulated systems with excellent reconstitution ability to expand the application of diacylglycerol oil.

Assessment of the Oxidative Damage and Genotoxicity of Titanium Dioxide Nanoparticles and Exploring the Protective Role of Holy Basil Oil Nanoemulsions in Rats

This study was designed to evaluate the oxidative damage, genotoxicity, and DNA damage in the liver of rats treated with titanium nanoparticles (TiO2-NPs) with an average size of 28.0 nm and ξ-potential of - 33.97 mV, and to estimate the protective role of holy basil essential oil nanoemulsion (HBEON). Six groups of Male Sprague-Dawley rats were treated orally for 3 weeks as follows: the control group, HBEO or HBEON-treated groups (5 mg/kg b.w), TiO2-NPs-treated group (50 mg/kg b.w), and the groups treated with TiO2-NPs plus HBEO or HBEON. Samples of blood and tissues were collected for different analyses. The results revealed that 55 compounds were identified in HBEO, and linalool and methyl chavicol were the major compounds (53.9%, 12.63%, respectively). HBEON were semi-round with the average size and ζ-potential of 120 ± 4.5 nm and - 28 ± 1.3 mV, respectively. TiO2-NP administration increased the serum biochemical indices, oxidative stress markers, serum cytokines, DNA fragmentation, and DNA breakages; decreased the antioxidant enzymes; and induced histological alterations in the liver. Co-administration of TiO2-NPs plus HBEO or HBEON improved all the tested parameters and the liver histology, and HBEON was more effective than HBEO. Therefore, HEBON is a promising candidate able to protect against oxidative damage, disturbances in biochemical markers, gene expression, DNA damage, and histological changes resulting from exposure to TiO2-NPs and may be applicable in the food and pharmaceutical sectors.

Modification of Whey Proteins by Sonication and Hydrolysis for the Emulsification and Spray Drying Encapsulation of Grape Seed Oil

In this study, whey protein concentrate (WPC) was sonicated or partially hydrolyzed by Alcalase, then examined as an emulsifier and carrier for the emulsification and spray drying of grape seed oil (GSO)-in-water emulsions. The modification treatments increased the free amino acid content and antioxidant activity (against DPPH and ABTS free radicals), as well as, the solubility, emulsifying, and foaming activities of WPC. The modified WPC-stabilized emulsions had smaller, more homogeneous droplets and a higher zeta potential as compared to intact WPC. The corresponding spray-dried powders also showed improved encapsulation efficiency, oxidative stability, reconstitution ability, flowability, solubility, and hygroscopicity. The morphology of particles obtained from the primary WPC (matrix type, irregular with surface pores) and modified WPC (reservoir type, wrinkled with surface indentations), as well as the oxidative stability of the GSO were influenced by the functional characteristics and antioxidant activity of the carriers. Changes in the secondary structures and amide regions of WPC, as well as the embedding of GSO in its matrix, were deduced from FTIR spectra after modifications. Partial enzymolysis had better results than ultrasonication; hence, the WPC hydrolysates are recommended as emulsifiers, carriers, and antioxidants for the delivery and protection of bioactive compounds.

The influence of beet pectin concentrate and whole-ground corn flour on the quality and safety of hardtacks

Currently, the main task of food manufacturers is to continuously improve quality while complying with legal regulations primarily related to ensuring product safety for consumers. In this regard,  using pectin substances as natural detoxifiers and wholemeal flour in the production of hardtacks will solve the problem of meeting the population's needs for safe food products with high nutritional and biological value. The article substantiates the sequence and parameters of technological operations for producing pectin concentrate from ‘Ardan’ sugar beet. The effectiveness of the use of beet pectin concentrate and whole-ground corn flour in the production of hardtacks has been substantiated experimentally based on a study of their qualitative characteristics, chemical composition and safety. The optimal dosage of pectin concentrate was determined at 10% and whole-ground corn flour at 15% in the production of hardtacks from first-grade wheat flour, where the properties of the gluten and the quality of finished products were similar to the control samples. The use of ‘Ardan’ sugar beet pectin concentrate made it possible to alter the dough's properties to increase its firmness and elasticity. It was found that the food and biological value of the developed hardtacks was higher than that of the control samples. The products obtained complied with the safety requirements of TR CU 021/2011 Technical Regulations of the Customs Union ‘On Food Safety’.

Microencapsulation of curcumin by spray drying: Characterization and fortification of milk

Curcumin, the major bioactive component of turmeric (Curcuma longa), was microencapsulated by spray drying in the matrix of HI-CAP 100 (resistant starch)/ maltodextrin and whey protein isolate to improve its oral bioavailability and solubility. Taguchi orthogonal array design (L₁₈) was used to optimize the spray drying conditions. The optimal conditions for microencapsulation were inlet drying air temperature of 185 °C, feed rate of 6 mL/min and HI-CAP 100 as wall material. The moisture content, encapsulation efficiency and bulk density at these conditions were 4.65%, 82.42% and 358.40 kg/m³, respectively. The spray-dried microcapsules were spherical-shaped with folds and vacuoles. The yellowness index and a^* value of curcumin decreased after microencapsulation. FTIR spectroscopy indicated that the curcumin after microencapsulation presumably retained its chemical structure. DSC thermograms confirmed that the microcapsules were heat stable up to 200 °C. The microcapsules had better heat stability and sustained in-vitro release as compared to that of pure curcumin. The DPPH free radical scavenging activity of curcumin was 61.43%, which was largely unaffected after microencapsulation. Fortification of milk with HI-CAP 100-based microcapsules at the selected dose had no adverse effect on organoleptic properties as compared to normal milk.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05142-0.

Pectin Microspheres: Synthesis Methods, Properties, and Their Multidisciplinary Applications

There is great contemporary interest in using cleaner technologies through green chemistry and utilizing biopolymers as raw material. Pectin is found on plant cell walls, and it is commonly extracted from fruit shells, mostly apples or citrus fruits. Pectin has applications in many areas of commercial relevance; for this reason, it is possible to find available information about novel methods to transform pectin and pursuing enhanced features, with the structuring of biopolymer microspheres being highly cited to enhance its activity. The structuring of polymers is a technique that has been growing in recent decades, due to its potential for diverse applications in various fields of science and technology. Several techniques are used for the synthesis of microspheres, such as ionotropic gelation, extrusion, aerosol drying, or emulsions, with the latter being the most commonly used method based on its reproducibility and simplicity. The most cited applications are in drug delivery, especially for the treatment of colon diseases and digestive-tract-related issues. In the industrial field, it is used for protecting encapsulated compounds; moreover, the environmental applications mainly include the bioremediation of toxic substances. However, there are still many possibilities for expanding the use of this biopolymer in the environmental field.

Influence of the particle size of encapsulated chia oil on the oil release and bioaccessibility during in vitro gastrointestinal digestion

Among vegetable oils, chia oil has been gaining interest in recent years due to its high linolenic acid content (ALA, 18:3 ω3). The aim of this work was to study the influence of the particle size of encapsulated purified chia oil (PCO) on the encapsulation efficiency and PCO release during in vitro digestion. PCO micro- and nano-sized particles with sodium alginate (SA) as an encapsulating agent (ME-PCO-SA and NE-PCO-SA) were designed by micro and nano spray-drying, respectively, applying a central composite plus star point experimental design. NE-PCO-SA showed a smaller particle size and higher encapsulation efficiency of PCO than ME-PCO-SA (0.16 μm vs. 3.5 μm; 98.1% vs. 92.0%). Emulsions (NE-PCO and ME-PCO) and particles (NE-PCO-SA and ME-PCO-SA) were subjected to in vitro static gastrointestinal digestion. ME-PCO and NE-PCO showed sustained oil release throughout the three phases of digestion (oral, gastric and intestinal phases), whereas the PCO release from ME-PCO-SA and NE-PCO-SA occurred mainly in the intestinal phase, showing the suitability of sodium alginate as an intestine-site release polymer. Nano-sized particles showed a significantly higher PCO release after in vitro digestion (NE-PCO-SA, 78.4%) than micro-sized particles (ME-PCO-SA, 69.8%), and also higher bioaccessibility of individual free fatty acids, such as C18:3 ω-3 (NE-PCO-SA, 23.6%; ME-PCO-SA, 7.9%), due to their greater surface area. However, when ME-PCO-SA and NE-PCO-SA were incorporated into yogurt, the PCO release from both particle systems after the digestion of the matrix was similar (NE-PCO-SA, 58.8%; ME-PCO-SA-Y, 61.8%), possibly because the calcium ions contained in the yogurt induced partial ionic gelation of SA, impairing the PCO release. Sodium alginate spray-dried micro and nanoparticles showed great potential for vehiculation of omega-3 rich oils in the design of functional foods.

Effect of crosslinking and drying method on the oxidative stability of lipid microcapsules obtained by complex coacervation

The crosslinking and drying method of microcapsules prepared by complex coacervation has been investigated in order to reach a better control of the oxidative stability of final powder product. Methyl...

Influence of Whey Protein Micro-Gel Particles and Whey Protein Micro-Gel Particles-Xanthan Gum Complexes on the Stability of O/W Emulsions

Appropriate pretreatment of proteins and addition of xanthan gum (XG) has the potential to improve the stability of oil-in-water (O/W) emulsions. However, the factors that regulate the enhancement and the mechanism are still not clear, which restricts the realization of improving the emulsion stability by directional design of its structure. Therefore, the effects of whey protein micro-gel particles (WPMPs) and WPMPs-XG complexes on the stability of O/W emulsion were investigated in this article to provide theoretical support. WPMPs with different structures were prepared by pretreatment (controlled high-speed shear treatment of heat-set WPC gels) at pH 3.5–8.5. The impact of initial WPC structure and XG addition on Turbiscan Indexes, mean droplet size and the peroxide values of O/W emulsions was investigated. The results indicate that WPMPs and XG can respectively inhibit droplet coalescence and gravitational separation to improve the physical stability of WPC-stabilized O/W emulsions. The pretreatment significantly enhanced the oxidative stability of WPC-stabilized O/W emulsions. The addition of XG did not necessarily enhance the oxidative stability of O/W emulsions. Whether the oxidative stability of the O/W emulsion with XG is increased or decreased depends on the interface structure of the protein-XG complex. This study has significant implications for the development of novel structures containing lipid phases that are susceptible to oxidation.

Nanoencapsulation of basil essential oil alleviates the oxidative stress, genotoxicity and DNA damage in rats exposed to biosynthesized iron nanoparticles

The application of essential oils in food and pharmaceutical sectors face several challenges due to their sensitivity to oxidation process. Additionally, the biosynthesis of nanometals is growing rapidly; however, the toxicity of these particles against living organisms did not well explore yet. This study aimed to determine the bioactive compounds in basil essential oil (BEO) using GC-MS, to encapsulate and characterize BEO and to evaluate its protective role against the oxidative stress and genotoxicity of biosynthesized iron nanoparticles (Fe-NPs) in rats. Six groups of male Sprague-Dawley rats were treated orally for 4 weeks included the control group, Fe-NPs-treated group (100 mg/kg b.w.); EBEO-treated groups at low (100 mg/kg b.w.) or high (200 mg/kg b.w.) dose and the groups treated with Fe-NPs plus the low or the high dose of EBEO. The GC-MS analysis revealed the identification of 48 compounds and linalool was the major compound. The average sizes and zeta potential of the synthesized Fe-NPs and EBEO were 60 ± 4.76 and 120 ± 3.2 nm and 42.42 mV and -6.4 mV, respectively. Animals treated with Fe-NPs showed significant increase in serum biochemical analysis, oxidative stress markers, cytokines, lipid profile, DNA fragmentation and antioxidant enzymes and their gene expression and severe changes in the histology of liver and kidney tissues. Administration of Fe-NPs plus EBEO alleviated these disturbances and the high dose could normalize most of the tested parameters and improved the histology of liver and kidney. It could be concluded that caution should be taken in using the biosynthesized metal nanoparticles in different application. EBEO is a potent candidate to protect against the hazards of metal nanoparticles and can be applied in food and medical applications.

Encapsulation of chia seed oil with curcumin and investigation of release behaivour & antioxidant properties of microcapsules during in vitro digestion studies

In this study, it was aimed to investigate the effects of both using curcumin and microencapsulation method on in vitro release behaivour of chia seed oil and its antioxidant potential during simulated gastrointestinal (GI) tract. Maltodextrin (MD) and gum Arabic (GA) was used as wall materials for freeze dried capsules. Sample 6, having 1:3 MD to GA ratio, 1:5 chia seed oil to wall material ratio and 40% total dry matter content, was found to have the optimum results in terms of emulsion stability (CI% = 0), zeta potential (-32.2 ± 0.8 mV) and size distribution (600 ± 8 nm). Moreover, release profiles of encapsulated chia seed oil samples were evaluated to determine if curcumin addition has any significant effect. The results revealed that curcumin addition decreased the release of chia seed oil from 44.6% to 37.2%. On contrary, it increased total phenolic content of in fraction of intestine to 22 mg gallic acid equivalents (GAE)/L.

Effect of natural antioxidants on the physicochemical properties and stability of freeze-dried microencapsulated chia seed oil

BACKGROUND

Chia oil possesses a very high content of polyunsaturated fatty acids, mainly α-linolenic acid. This characteristic makes this oil possess beneficial properties to health but gives it a high susceptibility to the oxidation process. Microencapsulation and the addition of natural antioxidants are alternatives to protect chia oil against oxidative deterioration. The aim of this study was to investigate the physicochemical characteristics and the oxidative stability of chia seed oil microencapsulated with different natural antioxidants (Guardian Chelox, which is a commercial blend of extracts from chamomile and rosemary, and essential oils from Origanum vulgare, Origanum x majoricum, and Mentha spicata) by freeze-drying using sodium caseinate and lactose as wall materials.

RESULTS

The main physicochemical properties of the microencapsulated chia oil were similar regardless of the presence of antioxidant. The moisture content was 38.1 ± 4.0 g kg^-1 ; the microencapsulation efficiency was higher than 85% in all cases. The freeze-drying microencapsulation significantly enhanced (P ≤ 0.05) the oxidative stability of the chia oil. The addition of natural antioxidants conferred chia oil additional protection against lipid oxidation, depending on the type and concentration (500 or 1000 mg kg^-1 of the emulsion previous to freeze-drying) of the antioxidant. Among them, Guardian Chelox (1000 mg kg^-1 ), presented the highest induction time obtained by the Rancimat accelerated oxidative stability test and the lowest peroxide values after 90 days of storage (33% relative humidity, 25 ± 2 °C). Overall, the microparticles with antioxidants presented a lower degree of yellowing during storage than the control system.

CONCLUSION

The use of different natural antioxidants confers freeze-dried microencapsulated chia seed oil additional protection against lipid oxidation. This information is relevant for the application of this oil, which is a rich source of omega-3 fatty acids, in the food industry. © 2018 Society of Chemical Industry.

High solids emulsions produced by ultrasound as a function of energy density

The use of emulsifying methods is frequently required before spray drying food ingredients, where using high concentration of solids increases the drying process yield. In this work, we used ultrasound to obtain kinetically stable palm oil-in-water emulsions with 30g solids/100g of emulsion. Sodium caseinate, maltodextrin and dried glucose syrup were used as stabilizing agents. Sonication time of 3, 7 and 11min were evaluated at power of 72, 105 and 148W (which represents 50%, 75% and 100% of power amplitude in relation to the nominal power of the equipment). Energy density required for each assay was calculated. Emulsions were characterized for droplets mean diameter and size distribution, optical microscopy, confocal microscopy, ζ-potential, creaming index (CI) and rheological behavior. Emulsions presented bimodal size distribution, with D_[3,2] ranging from 0.7 to 1.4μm and CI between 5% and 12%, being these parameters inversely proportional to sonication time and power, but with a visual kinetically stabilization after the treatment at 148W at 7min sonication. D_[3,2] showed to depend of energy density as a power function. Sonication presented as an effective method to be integrated to spray drying when emulsification is needed before the drying process.