Microencapsulation of linseed oil by spray drying for functional food application

Improving the storage and oxidative stability of essential fatty acids by different encapsulation methods; a review

Linoleic acid and α-linolenic acid are the only essential fatty acids (EFAs) known to the human body. Other fatty acids (FAs) of the omega-6 and omega-3 families originate from linoleic acid and α-linolenic acid, respectively, by the biological processes of elongation and desaturation. In diets with low fish consumption or vegetarianism, these FAs play an exclusive role in providing two crucial FAs for maintaining our body's vital functions; docosahexaenoic acid and arachidonic acid. However, these polyunsaturated FAs are inherently sensitive to oxidation, thereby adversely affecting the storage stability of oils containing them. In this study, we reviewed encapsulation as one of the promising solutions to increase the stability of EFAs. Accordingly, five main encapsulation techniques could be classified: (i) spray drying, (ii) freeze drying, (iii) emulsification, (iv) liposomal entrapment, and (v) other methods, including electrospinning/spraying, complex coacervation, etc. Among these, spray drying was the frequently applied technique for encapsulation of EFAs, followed by freeze dryers. In addition, maltodextrin and gum Arabic were the main wall materials in carriers. Paying attention to industrial scalability and lower cost of the encapsulation process by the other methods are the important aspects that should be given more attention in the future.

Role of encapsulation on the bioavailability of omega-3 fatty acids

Omega-3 fatty acids (omega-3 FAs) have been widely recognized for their therapeutic advantages, including anti-inflammatory and cardioprotective properties. They have shown promise in enhancing regulatory function, promotingdevelopment and mitigating the progression of diabetes and cancer. The scientific communities, along with industries, are actively endorsing initiatives aimed at increasing the daily intake of lipids rich in omega-3 FAs. Nevertheless, incorporating polyunsaturated FAs (PUFAs) into food products poses several challenges due to their susceptibility to oxidation when exposed to oxygen, high temperatures, and moisture. This oxidative deterioration results in undesirable flavours and a loss of nutritional value. Various methods, including physical blending, interesterification, and encapsulation, have been utilized as ways to enhance the stability of edible oils rich in PUFA against oxidation. Encapsulation has emerged as a proven strategy for enhancing the oxidative stability and functional properties of omega-3 FA-rich oils. Multiple encapsulation methods have been developed to stabilize and improve the delivery of omega-3 FAs in food products. The selection of an appropriate encapsulation method depends on the desired application of the encapsulated oil. In addition, encapsulation enhances the bioavailability of omega-3 FAs by promoting increased absorption of the encapsulated form in the intestinal epithelium. This review discusses the techniques and principles of omega-3 FA-rich oil encapsulation and its role in improving stability and bioavailability. Furthermore, it also investigates the potential health benefits of these encapsulated oils. This review explores the variations in bioavailability based on encapsulation techniques and processing, offering vital insights for nutrition and product development.

Potential use of red hibiscus flower extract for the production of spray-chilled microparticles: Characterization, stability, and bioaccessibility in vitro of anthocyanins

Microparticles (MLP) containing red hibiscus flower (Hibiscus rosa-sinensis) anthocyanins were produced by spray chilling, and characterized for physicochemical parameters, accelerated stability, and gastrointestinal release profile. Fully hydrogenated palm oil and cocoa butter were used as wall materials, at a lipid blend to hibiscus extract ratio of 70:30 (w/w). The lipid blends containing fully hydrogenated palm oil (FHPO) and cocoa butter (CB) were produced by ultrasound-assisted technique in the following FHPO to CB ratios: 100:0 (Control), 75:25, 50:50, 60:40, and 40:60. Increasing the cocoa butter content reduced the melting temperature and increased the unstable polymorphic behavior of the microparticles, resulting in amorphous characteristics. The microparticles exhibited higher viscosity, more agglomerates, and holes on the surface, and greater diameters. Characteristic peaks corresponding to the hibiscus extract were observed in the infrared spectra of the spray-chilled microparticles, indicating that the microencapsulation did not affect the anthocyanins. The antioxidant capacity of the red hibiscus anthocyanins ranged from 75 % to 79 %, with the best result observed for the treatment MLP_75:25. Higher antioxidant activities were observed for the lipid blends containing lower cocoa butter concentrations. Concerning the release profile of anthocyanins, the simulated GI digestion in vitro showed reduced release in the gastric tract and more intense release in the intestinal tract for an effective absorption of the antioxidant compounds in the small intestine. Furthermore, the treatment MLP_75:25 showed the highest encapsulation retention and lower total color difference in the accelerated stability study. Overall, the microparticles from all treatments were light-sensitive and thermosensitive at 35 °C. Thus, it is recommended to store the particles in a dark environment at temperatures below 35 °C for an effective use of the microparticles as natural food colorants.

Trends and advances in pre- and post-harvest processing of linseed oil for quality food and health products

Linseed is an ancient crop used for diverse purposes since the beginning of civilization. In recent times, linseed has emerged as a superfood due to its high content of health-promoting omega-3 fatty acids and other bioactive compounds. Among primary health effects, it has potential to manage hypertension, diabetes, osteoporosis, atherosclerosis, cancer, arthritis, neurological, cardiovascular diseases including blood cholesterol levels, constipation, diarrhea, and autoimmune disorders etc. due to the presence of omega-3 fatty acid, lignans, high dietary fibers, and proteins, whereas, secondary health effects comprise of relieving from various skin disorders. Due to these health-beneficial properties, interest in linseed oil necessitates the intensification of research efforts on various aspects. These include cultivation technology, varietal and genetic improvement, post-harvest processing, profiling of nutrients and bioactive compounds, pre-clinical and clinical studies, etc. The present review discussed the advances in linseed research including pre- and post-harvest processing. However, focus on the bioactive compounds present in linseed oil and their health effects are also presented. Linseed cultivation, pre- and post-harvest processing aspects are covered including climatic, edaphic, agronomic factors, type of cultivar and storage conditions etc, which impact the overall oil yield and its nutritional quality. Various emerging applications of linseed oil in functional food, nutraceutical, pharmaceutical, and cosmeceutical preparations were also presented in detail. Further, recommendations were made on linseed oil research in the field of genetics, breeding germplasm resources and genome editing for exploring its full applications as a nutrition and health product.

Spray Drying Enzyme-Treated Cellulose Nanofibrils

Enzyme-treated cellulose nanofibrils (CNFs) were produced via a lab-scale mass colloider using bleached kraft pulp (BKP) to evaluate their processability and power requirements during refining and spray-drying operations. To evaluate the energy efficiency in the CNF refining process, the net energy consumption, degree of polymerization (DP), and viscosity were determined. Less energy was consumed to attain a given fines level by using the endoglucanase enzymes. The DP and viscosity were also decreased using the enzymes. The morphological properties of the enzyme-pretreated spray-dried CNF powders (SDCNFs) were measured. Subsequently, the enzyme-pretreated SDCNFs were added to a PP matrix with MAPP as a coupling agent. The mixture was then compounded through a co-rotating twin-screw extruder to determine whether the enzyme treatment of the CNFs affects the mechanical properties of the composites. Compared to earlier studies on enhancing PMCs with SDCNF powders, this research investigates the use of enzyme-pretreated SDCNF powders. It was confirmed that the strength properties of PP increased by adding SDCNFs, and the strength properties were maintained after adding enzyme-pretreated SDCNFs.

Ultrasonic-Assisted Extraction of Astaxanthin from Shrimp By-Products Using Vegetable Oils

BACKGROUND

The use of conventional astaxanthin extraction methods, typically involving organic solvents, leads to a heightened environmental impact. The aim of this study was to explore the potential use of environmentally friendly extraction solvents, such as vegetable oils, for recovering the shrimp by-product astaxanthin.

METHODS

Ultrasound-assisted extraction (UAE) in vegetable oils, including olive oil (OO), sunflower oil (SO), and flaxseed oil (FO), was employed to extract astaxanthin. The astaxanthin antioxidant activity was evaluated using an ABTS assay, and a mixture of gum Arabic and soy lecithin was used to form coacervates to produce astaxanthin encapsulation.

RESULTS

A by-product-vegetable oil ratio of 1:60, extraction time of 210 min, 60% amplitude of the extraction process, and the use of OO as the extracting medium resulted in an astaxanthin yield of 235 ± 4.07 μg astaxanthin/g by-products. The astaxanthin encapsulation efficiency on day 0 and astaxanthin recovery on day 1 were recorded at 66.6 ± 2.7% and 94.4 ± 4.6%, respectively.

CONCLUSIONS

The utilization of OO as an extraction solvent for astaxanthin from shrimp by-products in UAE represents a novel and promising approach to reducing the environmental impact of shrimp by-products. The effective astaxanthin encapsulation efficiency highlights its potential application in food industries.

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.

Functional nanoemulsion and nanocomposite microparticles as an anticolorectal cancer and antimicrobial agent: applied in yogurt

Great concern for human health has led the food industry to focus on functional products. Microparticles based on nanoemulsions (M1) and nanocomposites (M2) were developed to deliver vital agents against colorectal cancer and microbial infection. The functional microparticles were prepared by coating extra virgin olive oil (EVOO), probiotics, and fig leaves extract with sodium alginate (SA) and whey protein concentrate (WPC) using the freeze drying technique. The antimicrobial, cytotoxic, apoptotic, encapsulation efficiency (EE %), release rate, and antioxidant activity were investigated. The yogurt was loaded with microparticles and evaluated microbiology, chemically, and sensory during storage. The results showed that the size of nanoemulsion and nanocomposite was between 476.1 and 517.7 nm, while the zeta potentials were −30.1 and −34.5 mV, respectively. M2 microparticles recorded the lowest IC50 values against human colorectal cancerous Caco-2 and HCT 116 cell lines: 1.10 μg/mL and 15.34 μg/mL, respectively. The inhibition zones were between 11 to 20 and 9 to 18 mm for M1 and M2, respectively. The highest EE% was 89.20% for EVOO and 91.34% for probiotics in M2 microparticles. The induction period of the EVOO from M1 and M2 microparticles was 15.37 h and 13.09 h, respectively. The antioxidant activity was between 78 and 65.8% for M1 and M2 microparticles, respectively. The probiotics in yogurt with microparticles were more than un-coated cells, and the taste of these samples was acceptable during storage. This study suggests that microencapsulation could be considered an interesting therapeutic tool when EVOO and probiotics are used in functional food.

Amelioration for oxidative stability and bioavailability of N-3 PUFA enriched microalgae oil: an overview

Technological improvements in dietary supplements and nutraceuticals have highlighted the significance of bioactive molecules in a healthy lifestyle. Eicosapentaenoic acid and Cervonic acid (DHA), omega-3 polyunsaturated fatty acids seem to be famed for their ability to prevent diverse physiological abnormalities. Selection of appropriate pretreatments and extraction techniques for extraction of lipids from robust microalgae cell wall are very important to retain their stability and bioactivity. Therefore, extraction techniques with optimized extraction parameters offer an excellent approach for obtaining quality oil with a high yield. Oils enriched in omega-3 are particularly imperiled to oxidation which ultimately affects customer acceptance. Bio active encapsulation could be one of the effective approaches to overcome this dilemma. This review paper aims to give insight into the cultivation methods, and downstream processes, various lipid extraction approaches, techniques for retaining oxidative stability, bioavailability and food applications based on extracted or encapsulated omega-3.

A Narrative Review on Various Oil Extraction Methods, Encapsulation Processes, Fatty Acid Profiles, Oxidative Stability, and Medicinal Properties of Black Seed (Nigella sativa)

The current review investigates the effects of black seed (Nigella sativa) on human health, which is also used to encapsulate and oxidative stable in different food products. In recent decades, many extraction methods, such as cold pressing, supercritical fluid extraction, Soxhlet extraction, hydro distillation (HD) method, microwave-assisted extraction (MAE), ultrasound-assisted extraction, steam distillation, and accelerated solvent extraction (ASE) have been used to extract the oils from black seeds under optimal conditions. Black seed oil contains essential fatty acids, in which the major fatty acids are linoleic, oleic, and palmitic acids. The oxidative stability of black seed oil is very low, due to various environmental conditions or factors (temperature and light) affecting the stability. The oxidative stability of black seed oil has been increased by using encapsulation methods, including nanoprecipitation, ultra-sonication, spray-drying, nanoprecipitation, electrohydrodynamic, atomization, freeze-drying, a electrospray technique, and coaxial electrospraying. Black seed, oil, microcapsules, and their components have been used in various food processing, pharmaceutical, nutraceutical, and cosmetics industries as functional ingredients for multiple purposes. Black seed and oil contain thymoquinone as a major component, which has anti-oxidant, -diabetic, -inflammatory, -cancer, -viral, and -microbial properties, due to its phenolic compounds. Many clinical and experimental studies have indicated that the black seed and their by-products can be used to reduce the risk of cardiovascular diseases, chronic cancer, diabetes, oxidative stress, polycystic ovary syndrome, metabolic disorders, hypertension, asthma, and skin disorders. In this review, we are focusing on black seed oil composition and increasing the stability using different encapsulation methods. It is used in various food products to increase the human nutrition and health properties.

The Physicochemical Properties and Antioxidant Activity of Spirulina (Artrhospira platensis) Chlorophylls Microencapsulated in Different Ratios of Gum Arabic and Whey Protein Isolate

Spirulina (Artrhospira platensis) is rich in chlorophylls (CH) and is used as a potential natural additive in the food industry. In this study, the CH content was extracted from spirulina powder after ultrasound treatment. Microcapsules were then prepared at different ratios of gum Arabic (GA) and whey protein isolate (WPI) through freeze-drying to improve the chemical stability of CH. As a result, a* and C* values of the microcapsules prepared from GA:WPI ratios (3:7) were −8.94 ± 0.05 and 15.44 ± 0.08, respectively. The GA fraction increased from 1 to 9, and encapsulation efficiency (EE) of microcapsules also increased by 9.62%. Moreover, the absorption peaks of CH at 2927 and 1626 cm⁻¹ in microcapsules emerged as a redshift detected by FT-IR. From SEM images, the morphology of microcapsules changed from broken glassy to irregular porous flake-like structures when the GA ratio increased. In addition, the coated microcapsules (GA:WPI = 3:7) showed the highest DPPH free radical scavenging activity (SA_DPPH) (56.38 ± 0.19) due to low moisture content and better chemical stability through thermogravimetric analysis (TGA). Conclusively, GA and WPI coacervates as the wall material may improve the stability of CH extracted from spirulina.

Effects of Wall Material on Medium-Chain Triglyceride (MCT) Oil Microcapsules Prepared by Spray Drying

A medium-chain triglyceride (MCT) oil microcapsule was prepared by spray drying. The effects of the wall-material parameters of wall-to-oil ratio (1:1 to 3:1) and type of wall material (gum arabic (GA), whey protein isolate (WPI), and octenyl succinic anhydride (OSA) starch) on the microcapsules were evaluated. The droplet size, size distribution, viscosity, zeta potential, and stability of the emulsions were measured. The spray-dried powder was characterized by its morphology, yield, encapsulation efficiency, and moisture content. The wall material influenced the characteristics of the emulsions and microcapsules. The formulation with a 2:1 wall-to-oil ratio and OSA starch/maltodextrin as the wall material resulted in a small droplet size (0.177 ± 0.002 µm) with high encapsulation efficiency (98.38 ± 0.01%). This formulation had good physical stability over three months under accelerated conditions. Thus, OSA starch/maltodextrin is an appropriate wall material for encapsulating MCT oil.

Stirred Yogurt as a Delivery Matrix for Freeze-Dried Microcapsules of Synbiotic EVOO Nanoemulsion and Nanocomposite

Nowadays, dairy products are considered a good matrix to deliver many functional substances either vital oils or probiotic cells. Two models of microcapsules were produced from co-encapsulation of extra virgin olive oil (EVOO) nanoemulsion or nanocomposite and synbiotic bacteria (maltodextrin with Lactobacillus acidophilus and Bifidobacterium bifidum) using the freeze-drying technique. These models of microcapsules were added to stirred yogurt, and then its storage effect on microbiology, chemically, and sensory properties were evaluated for 21 days. The average droplet size and zeta potential distribution of EVOO nanoemulsion and nanocomposite were investigated. Also, oxidative stability, microencapsulation efficiency, release profile, and antioxidant activity were studied. The results showed that the average particle size of EVOO nanoemulsion and nanocomposite ranged between 416 and 475 nm, while zeta potential was -39.6 and -33.6 mV, respectively. The induction period of EVOO extracted from nanoemulsion and nanocomposite microcapsules models was 11.30 and 8 h. The microencapsulation efficiency of probiotic and EVOO was determined at 88.84 and 65.61% for the nanoemulsion microcapsules model, while the nanocomposite microcapsules model showed 98.49 and 72%. The two models of microcapsules have boosted the viability of probiotic bacteria inside stirred yogurt than free cells. Also, the presence of microcapsules did not affect the viability of stirred yogurt starter cultures, and high values for the total solid and protein were detected. Therefore, the results recommended that stirred yogurt is a good delivery carrier for highly antioxidant and healthy microcapsules of synbiotic EVOO nanoemulsion and nanocomposite.

Cod Liver Oil’s Encapsulation into Sodium Alginate/Lupin Protein Beads and Its Application in Functional Meatballs’ Preparation

Cod liver oil (CLO) is an essential source of healthy ω-3 fatty acids to be employed in functional meals. However, its autoxidation sensitivity, solubility, and odour present it as challenging to handle. Its encapsulation might mitigate these problems. This research studied using alginate/lupine protein as a wall material for CLO encapsulation as well as to characterise CLO microcapsules for their size, sphericity factor, encapsulation efficiency, morphology (scanning electron microscopy), in vitro release, and thermal stability. In this study, the oxidative stability, quality parameters, and sensory attributes of meatballs enriched with free CLOs and encapsulated CLOs throughout storage at 4 ± 1 °C for 16 days were assessed. The CLO microspheres had a homogeneous round shape, a diameter of 0.82 ± 0.06 mm, a sphericity factor of 0.092 ± 0.01, an encapsulation efficiency of 95.62% ± 1.13%, and an accumulative release rate of 87.10% after 270 min in the stimulated gastrointestinal conditions. Additionally, it was discovered that encapsulated oil was more stable than free CLOs to heat treatments (70–100 °C, 24 h). pH, thiobarbituric acid-reactive substances, peroxide value, conjugated dienes value, and carbonyl content of meatballs enriched with microencapsulated CLOs were significantly lower when compared to free CLOs and/or control samples. CLO microcapsules improved the sensory characteristics of meatballs throughout storage; however, meatballs directly containing CLOs were rejected. Thus, the viability of alginate/LPI complex microcapsules containing CLOs to enrich meat products subjected to storage with refrigeration could be indicated without any change in the characteristics.

Polysaccharides as wall materials in spray-dried microencapsulation of bioactive compounds: Physicochemical properties and characterization

Natural bioactive compounds (BCs) are types of chemicals found in plants and certain foods that promote good health, however they are sensitive to processing and environmental conditions. Microencapsulation by spray drying is a widely used and cost-effective approach to create a coating layer to surround and protect BCs and control their release, enabling the production of high functional products/ingredients with extended shelf life. In this process, wall materials determine protection efficiency, and physical properties, bioavailability, and storage stability of microencapsulated products. Therefore, an understanding of physicochemical properties of wall materials is essential for the successful and effective spray-dried microencapsulation process. Typically, polysaccharide-based wall materials are generated from more sustainable sources and have a wider range of physicochemical properties and applications compared to their protein-based counterparts. In this review, we highlight the essential physicochemical properties of polysaccharide-based wall materials for spray-dried microencapsulation of BCs including solubility, thermal stability, and emulsifying properties, rheological and film forming properties. We provide further insight into possibilities for the chemical structure modification of native wall materials and their controlled release behaviors. Finally, we summarize the most recent studies involving polysaccharide biopolymers as wall materials and/or emulsifiers in spray-dried microencapsulation of BCs.

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...

Fabrication and characterization of gum arabic- and maltodextrin-based microcapsules containing polyunsaturated oils

BACKGROUND

Polyunsaturated oils have various health-promoting effects, however, they are highly prone to oxidation. Encapsulation using biopolymers is one of the most effective strategies to enhance oil stability. This research examined the potential of gum arabic and maltodextrin for microencapsulation of omega-3 rich oils, aiming to enhance encapsulation efficiency and stability of encapsulated oil.

RESULTS

We encapsulated fish and flaxseed oils by emulsification-spray drying. Spray-dried microcapsules were prepared by oil-in-water emulsions consisting of 10 wt% oil and 30 wt% biopolymer (gum arabic, maltodextrin, or their mixture). Results showed that both microcapsules were spherical in shape with surface shrinkage, and exhibited amorphous structures. Gum arabic-based microcapsules had higher encapsulation efficiency as well as better storage stability for both types of oil. Flaxseed oil microcapsules generally had higher oxidative stability regardless of the type of wall material.

CONCLUSIONS

Through a comprehensive characterization of the physical and chemical properties of the emulsions and resulting microcapsules, we proved gum arabic to be a more effective wall material for polyunsaturated oil microencapsulation, especially flaxseed oil. This study provides a promising approach to stabilize oils which are susceptible to deterioration, and facilitates their wider uses as food and nutraceutical products. © 2021 Society of Chemical Industry.

Interactions of the molecular assembly of polysaccharide-protein systems as encapsulation materials. A review

Studying the interactions of biopolymers like polysaccharides and proteins is quite important mainly due to the wide number of applications such as the stabilization and encapsulation of active compounds in complex systems. Complexation takes place when materials like proteins and polysaccharides are blended to promote the entrapment of active compounds. The interaction forces between the charged groups in the polymeric chains allow the miscibility of the components in the complex system. Understanding the interactions taking place between the polymers as well as between the wall material and the active compound is important when designing delivery systems. However, some features of the biopolymers like structure, functional groups, or electrical charge as well as extrinsic parameters like pH or ratios might affect the structure and the performance of the complex system when used in encapsulation applications. This work summarizes the recent progress of the polysaccharide/protein complexes for encapsulation and the influence of the pH on the structural modifications during the complexation process.

Encapsulated Food Products as a Strategy to Strengthen Immunity Against COVID-19

In December 2019, the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2)-a novel coronavirus was identified which was quickly distributed to more than 100 countries around the world. There are currently no approved treatments available but only a few preventive measures are available. Among them, maintaining strong immunity through the intake of functional foods is a sustainable solution to resist the virus attack. For this, bioactive compounds (BACs) are delivered safely inside the body through encapsulated food items. Encapsulated food products have benefits such as high stability and bioavailability, sustained release of functional compounds; inhibit the undesired interaction, and high antimicrobial and antioxidant activity. Several BACs such as ω-3 fatty acid, curcumin, vitamins, essential oils, antimicrobials, and probiotic bacteria can be encapsulated which exhibit immunological activity through different mechanisms. These encapsulated compounds can be recommended for use by various researchers, scientists, and industrial peoples to develop functional foods that can improve immunity to withstand the coronavirus disease 2019 (COVID-19) outbreak in the future. Encapsulated BACs, upon incorporation into food, offer increased functionality and facilitate their potential use as an immunity booster. This review paper aims to target various encapsulated food products and their role in improving the immunity system. The bioactive components like antioxidants, minerals, vitamins, polyphenols, omega (ω)-3 fatty acids, lycopene, probiotics, etc. which boost the immunity and may be a potential measure to prevent COVID-19 outbreak were comprehensively discussed. This article also highlights the potential mechanisms; a BAC undergoes, to improve the immune system.

Plant oils: From chemical composition to encapsulated form use

The last decade has witnessed a burgeoning global movement towards essential and vegetable oils in the food, agriculture, pharmaceutical, cosmetic, and textile industries thanks to their natural and safe status, broad acceptance by consumers, and versatile functional properties. However, efforts to develop new therapy or functional agents based on plant oils have met with challenges of limited stability and/or reduced efficacy. As a result, there has been increased research interest in the encapsulation of plant oils, whereby the nanocarriers serve as barrier between plant oils and the environment and control oil release leading to improved efficacy, reduced toxicity and enhanced patient compliance and convenience. In this review, special concern has been addressed to the encapsulation of essential and vegetable oils in three types of nanocarriers: polymeric nanoparticles, liposomes and solid lipid nanoparticles. First, the chemical composition of essential and vegetable oils was handled. Moreover, we gather together the research findings reported by the literature regarding the different techniques used to generate these nanocarriers with their significant findings. Finally, differences and similarities between these nanocarriers are discussed, along with current and future applications that are warranted by their structures and properties.

Extraction of pumpkin peel extract using supercritical CO2 and subcritical water technology: Enhancing oxidative stability of canola oil

In this study, subcritical water extraction (SWE) and the supercritical fluid extraction (SFE) methods were used for the extraction of pumpkin peel extract. Total phenolic content and carotenoid compounds of extracts were measured. The extracts were added to canola oil at a concentration of 400 ppm and were stored at 30 °C for 60 days. The peroxide, carbonyl and acid values of the oil samples were measured, then compared with 100 ppm of tert-butylhydroquinone (TBHQ) synthetic antioxidants. The results showed that the total phenol content of obtained extract by SFE (353.5 mg GA/100 g extract) was higher than by SWE (213.6 mg GA/100 g extract), while the carotenoid content was higher for obtained extract by SWE (15.22 mg/100 g extract) compared to SFE (11.48 mg/100 g extract). The result of oil oxidation showed that the oxidative stability of the oil containing the mixed extract (SFE-SWE) is higher than the separate extract, consequently showing higher performance in preventing oil oxidation compared to TBHQ.

Microencapsulation of Flaxseed Oil—State of Art

Microencapsulation is a well-known technology for the lipid delivery system. It prevents the oxidation of fatty acids and maintains the quality of lipid after extraction from oil seed and processing. In flaxseed oil, the amount of ω-3 and ω-6 polyunsaturated fatty acids are 39.90–60.42% and 12.25–17.44%, respectively. A comprehensive review article on the microencapsulation of flaxseed oil has not been published yet. Realizing the great advantages of flaxseed oil, information about different technologies related to the microencapsulation of flaxseed oil and their characteristics are discussed in a comprehensive way, in this review article. To prepare the microcapsule of flaxseed oil, an emulsion of oil-water is performed along with a wall material (matrix), followed by drying with a spray-dryer or freeze-dryer. Different matrices, such as plant and animal-based proteins, maltodextrin, gum Arabic, and modified starch are used for the encapsulation of flaxseed oil. In some cases, emulsifiers, such as Tween 80 and soya lecithin are used to prepare flaxseed oil microcapsules. Physico-chemical and bio-chemical characteristics of flaxseed oil microcapsules depend on process parameters, ratio of oil and matrix, and characteristics of the matrix. As an example, the size of the microcapsule, prepared with spray-drying and freeze-drying ranges between 10–400 and 20–5000 μm, respectively. It may be considered that the comprehensive information on the encapsulation of flaxseed oil will boost the development of functional foods and biopharmaceuticals.

Effects of wheat fiber addition on emulsion and lipid/protein stabilities of an omega-3 fatty acid-fortified chicken surimi product

Meat, except marine sources, is a highly nutritious food but generally lacks some healthy ingredients, such as omega-3 fatty acids (ω-3 FA) and dietary fiber. However, ω-3 FA and dietary fiber could be incorporated during the manufacture of surimi-like products. In our previous study, chicken surimi was successfully developed from spent-hen breast. Although there was no (P > 0.05) difference in water-holding capacity between wheat fiber and carrageenan, an increased (P < 0.05) flaxseed oil–holding capacity was observed in wheat fiber samples. Furthermore, an addition of 5% wheat fiber resulted in optimal emulsification capacity and less cooking loss at 4°C for 14 d and at −20°C for 60 d (P < 0.05). Because of the lower (P < 0.05) purge and centrifugation losses, thiol group content, and thiobarbituric acid reactive substance value than those formulated with more flaxseed oil, 12% flaxseed oil was an optimal level in chicken surimi with 5% wheat fiber. Scanning electron microscopy results also showed better emulsification of surimi batters with wheat fiber compared with those without wheat fiber, and meanwhile, the formulation with 5% wheat fiber could hold up to 12% flaxseed oil as well. To enhance flaxseed-oil addition, semi-manufactured chicken surimi batter was successfully fortified with a combination of 12% flaxseed oil and 5% wheat fiber. This surimi-like product with dietary fiber and ω-3 FA would fit the need in the current market regarding consumers' demands for high nutritional value and improved processing characteristics.

The Influence of Flaxseed Oil Cake Extract on Oxidative Stability of Microencapsulated Flaxseed Oil in Spray-Dried Powders

The objective of the study was to investigate the application of flaxseed oil cake extract (FOCE) for oxidative stabilization of flaxseed oil in spray-dried emulsions. Two variants of powders with 10% and 20% of flaxseed oil (FO), FOCE, and wall material (maltodextrin and starch Capsul^®) were produced by spray-drying process at 180 °C. The oxidative stability of FO was monitored during four weeks of storage at 4 °C by peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) measurements. Additionally, the fatty acids content (especially changes in α-linolenic acid content), radical scavenging activity, total polyphenolics content, color changes and free amino acids content were evaluated. Obtained results indicated that FOCE could be an adequate antioxidant dedicated for spray-dried emulsions, especially with a high content of FO (20%). These results have important implications for the flaxseed oil encapsulation with natural antioxidant agents obtained from plant-based agro-industrial by product, meeting the goals of circular economy and the idea of zero waste.

Physicochemical characterization and oxidative stability of microencapsulated edible sacha inchi seed oil by spray drying

The aim of this work was to obtain sacha inchi oil (SIO) microcapsules from two different species, Plukenetia volubilis L. (SIVO) and Plukenetia huayllabambana L. (SIHO), using different biopolymers as wall materials and spray drying technology. The physicochemical characteristics such as encapsulation efficiency, particle size, morphology and oxidative stability were analyzed in order to select the best formulation that could potentially be used as an ingredient in the development of functional food. Bulk SIO and four formulations were tested for each oil ecotype, using different encapsulating agents: maltodextrin (MD), Arabic gum (AG), whey protein concentrate (WPC) and modified starch HI-CAP®-100 (H). Microcapsules made of H presented the highest oxidative stability and encapsulation efficiency compared to AG, AG:MD or AG:MD:WPC formulations.

Influence of the Location of Ascorbic Acid in Walnut Oil Spray-Dried Microparticles with Outer Layer on the Physical Characteristics and Oxidative Stability

Purified walnut oil (PWO) microparticles with Capsul® (C, encapsulating agent), sodium alginate (SA) as outer layer and ascorbic acid (AA) as oxygen scavenger were obtained by spray drying using a three-fluid nozzle. AA was incorporated in the inner infeed (PWO-C(AA)/SA), in the outer infeed (PWO-C/SA(AA)) and in both infeed (PWO-C(AA)/SA(AA)). PWO-C(AA)/SA (4.56 h) and POW-C(AA)/SA(AA) (2.60 h) microparticles showed higher induction period than POW-C/SA(AA) (1.17 h), and lower formation of triacylglycerol dimers and polymers during storage (40 °C). Therefore, AA located in the inner infeed improved the oxidative stability of encapsulated PWO by removing the residual oxygen. AA in the SA outer layer did not improve the oxidative stability of encapsulated PWO since oxygen diffusion through the microparticles was limited and/or AA weakened the SA layer structure. The specific-location of AA (inner infeed) is a strategy to obtain stable spray-dried polyunsaturated oil-based microparticles for the design of foods enriched with omega-3 fatty acids.

Microencapsulation of sea buckthorn (Hippophae rhamnoides L.) pulp oil by spray drying

The aim of this work was to encapsulate sea buckthorn (Hippophae rhamnoides L.) pulp oil (SBPO) by spray drying. Gum Arabic (GA) and maltodextrins (MD) were used as wall materials. The effects of several factors, including GA to MD ratio, total solids content of emulsion, wall to core ratio, and inlet air temperature, on the microencapsulation efficiency (ME) were investigated. The optimization of operation conditions was realized by response surface methodology (RSM). The optimal conditions were as follows: GA to MD ratio 2.38, total solids content 39%, wall to core ratio 5.33, and inlet air temperature 154°C. Under the optimal conditions, the ME of SBPO microcapsules was 94.96 ± 1.42%. The physicochemical properties of microcapsules were also invested. SBPO microcapsules obtained had low water activity, low moisture content, high water solubility, and high bulk density. For the morphological characteristics, cracks and pores were not observed in most microcapsules, which was beneficial for the protection of ingredients in microcapsules. The particle size of SBPO microcapsules ranged from 0.01 to 5 μm, and the mean diameter d 4,3 was 2.55 μm. The analysis results of fourier transform infrared spectroscopy (FTIR) informed the presence of SBPO in microcapsules. There were no significant differences in the content of the main fatty acids in SBPO before and after spray drying. The results of oxidative stability showed that the microencapsulation by spray drying could effectively protect SBPO from oxidation and extend the shelf life of SBPO.