Controlled release of microencapsulated docosahexaenoic acid (DHA) by spray-drying processing

Oxidative Stability of Fish Oil-Loaded Nanocapsules Produced by Electrospraying Using Kafirin or Zein Proteins as Wall Materials

The encapsulation of fish oil by monoaxial electrospraying using kafirin or zein proteins as hydrophobic wall materials was investigated. Kafirin resulted in spherical fish oil-loaded nanocapsules (>50% of capsules below 1 µm), whereas zein led to fish oil-loaded nanocapsules with non-spherical morphology (>80% of capsules below 1 µm). Both hydrophobic encapsulating materials interacted with fish oil, successfully entrapping the oil within the protein matrix as indicated by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy results. FTIR also suggested hydrogen bonding between fish oil and the proteins. Trapped radicals in the encapsulation matrix that were detected by electron paramagnetic resonance (EPR), indicated oxidation during electrospraying and storage. Results from isothermal (140 °C) differential scanning calorimetry (DSC) denoted that the encapsulation of fish oil by electrospraying using both kafirin or zein as wall materials protected fish oil from oxidation. In particular, the zein-based nanocapsules were 3.3 times more oxidatively stable than the kafirin-based nanocapsules, which correlates with the higher oil encapsulation efficiency found for zein-based capsules. Thus, this study shows that kafirin might be considered a hydrophobic wall material for the encapsulation of fish oil by electrospraying, although it prevented lipid oxidation to a lower extent when compared to zein.

Impact of wall materials and DHA sources on the release, digestion and absorption of DHA microcapsules: Advancements, challenges and future directions

Docosahexaenoic acid (DHA), an essential omega-3 fatty acid, offers significant health benefits but faces challenges such as distinct odor, oxidation susceptibility, and limited intestinal permeability, hindering its broad application. Microencapsulation, widely employed, enhances DHA performance by facilitating controlled release, digestion, and absorption in the gastrointestinal tract. Despite extensive studies on DHA microcapsules and related delivery systems, understanding the mechanisms governing encapsulated DHA release, digestion, and absorption, particularly regarding the influence of wall materials and DHA sources, remains limited. This review starts with an overview of current techniques commonly applied for DHA microencapsulation. It then proceeds to outline up-to-date advances in the release, digestion and absorption of DHA microcapsules, highlighting the roles of wall materials and DHA sources. Importantly, it proposes strategies for overcoming challenges and exploiting opportunities to enhance the bioavailability of DHA microcapsules. Notably, spray drying dominates DHA microencapsulation (over 90 % usage), while complex coacervation shows promise for future applications. The combination of proteins and carbohydrates or phospholipids as wall material exhibits potential in controlling release and digestion of DHA microcapsules. The source of DHA, particularly algal oil, demonstrates higher lipid digestibility and absorptivity of free fatty acids (FFAs) than fish oil. Future advancements in DHA microcapsule development include formulation redesign (e.g., using plant proteins as wall material and algal oil as DHA source), technique optimization (such as co-microencapsulation and pre-digestion), and creation of advanced in vitro systems for assessing DHA digestion and absorption kinetics.

Optimized spray-dried conditions' impact on fatty acid profiles and estimation of in vitro digestion of spray-dried chia/fish oil microcapsules

Long-chain polyunsaturated fatty acids (LCPUFA) are of interest due to their potential health properties and have a significant role in reducing the risk of various chronic diseases in humans. It is commonly used as a supplement. However, lipid oxidation is an important negative factor caused by environmental, processing, and limited water solubility of LCPUFA, making them difficult to incorporate into food products. The objective of this research work was to prevent oxidation, extend shelf life, enhance the stability of fatty acids, and to achieve controlled release by preparing spray-dried powder (SDM). For spray-drying, aqueous emulsion blends were formulated using a 1:1 ratio of chia seed oil (CSO) and fish oil (FO) and using a laboratory-scale spray-dryer with varying conditions: inlet air temperature (IAT, 125-185 °C), wall material (WM, 5-25%), pump speed (PS, 3-7 mL/min), and needle speed (NS, 3-11 s). The maximum alpha-linolenic acid (ALA) content was 33 ± 1%. The highest values of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the microcapsules were 8.4 ± 0.4 and 13 ± 1%, respectively. Fourier transform infrared and X-Ray diffraction analysis results indicated that SDM was successfully formulated with Gum Arabic and maltodextrin (MD). The blending without encapsulation of CSO and FO was digested more efficiently and resulted in more oil being released with simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and SGF + SIF conditions without heating. No significant changes were observed for saturated, monounsaturated, and LCPUFA, whether exposed or not to gastrointestinal conditions. However, compared to the release of SDM, it can be useful for designing delivery systems for the controlled release of essential fatty acids.

Recent Developments in the Microencapsulation of Fish Oil and Natural Extracts: Procedure, Quality Evaluation and Food Enrichment

Due to the beneficial health effects of omega-3 fatty acids and antioxidants and their limited stability in response to environmental and processing factors, there is an increasing interest in microencapsulating them to improve their stability. However, despite recent developments in the field, no specific review focusing on these topics has been published in the last few years. This work aimed to review the most recent developments in the microencapsulation of fish oil and natural antioxidant compounds. The impact of the wall material and the procedures on the quality of the microencapsulates were preferably evaluated, while their addition to foods has only been studied in a few works. The homogenization technique, the wall-material ratio and the microencapsulation technique were also extensively studied. Microcapsules were mainly analyzed for size, microencapsulation efficiency, morphology and moisture, while in vitro digestion, flowing properties, yield percentage and Fourier transform infrared spectroscopy (FTIR) were used more sparingly. Findings highlighted the importance of optimizing the most influential variables of the microencapsulation procedure. Further studies should focus on extending the range of analytical techniques upon which the optimization of microcapsules is based and on addressing the consequences of the addition of microcapsules to food products.

Encapsulated Microstructures of Beneficial Functional Lipids and Their Applications in Foods and Biomedicines

Beneficial functional lipids are essential nutrients for the growth and development of humans and animals, which nevertheless possess poor chemical stability because of heat/light-sensitivity. Various encapsulation technologies have been developed to protect these nutrients against adverse factors. Different microstructures are exhibited through different encapsulation methods, which influence the encapsulation efficiency and release behavior at the same time. This review summarizes the effects of preparation methods and process parameters on the microstructures of capsules at first. The mechanisms of the different microstructures on encapsulation efficiency and controlled release behavior of core materials are analyzed. Next, a comprehensive overview on the beneficial functional lipids capsules in the latest food and biomedicine applications are provided as well as the matching relationship between the microstructures of the capsules and applications are discussed. Finally, the remaining challenges and future possible directions that have potential interest are outlined. The purpose of this review is to convey the construction of beneficial functional lipids capsules and the function mechanism, a critical analysis on its current status and challenges, and opinions on its future development. This review is believed to promote communication among the food, pharmacy, agronomy, engineering, and nutrition industries.

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.

Preparation of deer oil powder and its effect on acute gastric mucosal injury in rats

In this paper, deer oil was used as a raw material to prepare deer oil powder by microencapsulation technology to study the potential protective activity of deer oil powder on ethanol-induced acute gastric mucosal injury in rats. The results show that the best process for preparing deer oil powder is: the solids account for 25% of the system content, the wall material Whey Milk Protein Isolate-Maltodextrin ratio is 1:5, the Sodium Stearyl Lactate-Glycerides of Monostearate and Distearate compound emulsifier content is 0.8%, the ratio is 1:1, and the deer oil accounts for 30% of the solid content, and the spray drying inlet temperature is 180°C. Deer oil powder can reduce total stomach injury, gastric mucosal congestion area, and injury score index. Without affecting the blood lipid level, it can reduce the content of Myeloperoxidase, enhance the activity of Superoxide Dismutase and Glutathione Peroxidase, and has good antioxidant activity. Enhance the expression of defense factors Estradiol, Epidermal Growth Factor, and Somatostatin. At the same time, it reduces the levels of Interleukin-1β and Interleukin-6 pro-inflammatory cytokines in gastric tissue and enhances the expression of anti-inflammatory factors Interleukin-4 and Interleukin-10. These results indicate that the gastric protection mechanism of deer oil powder may be related to the enhancement of mucosal defense factors, inhibition of inflammation, and oxidative stress. PRACTICAL APPLICATIONS: This study screened the optimal formula for preparing microencapsulated deer oil powder and proved for the first time that deer oil powder has a strong gastroprotective effect on ethanol-induced acute gastric injury in rats. The gastric protective mechanism of deer oil powder is mainly to reduce oxidative stress, inflammatory cytokine accumulation and to increase the content of defense factors. Therefore, deer oil powder can be used as a new source of gastric treatment drugs.

Preparation of Human Milk Fat Substitutes: A Review

Human milk is generally regarded as the best choice for infant feeding. Human milk fat (HMF) is one of the most complex natural lipids, with a unique fatty acid composition and distribution and complex lipid composition. Lipid intake in infants not only affects their energy intake but also affects their metabolic mode and overall development. Infant formula is the best substitute for human milk when breastfeeding is not possible. As the main energy source in infant formula, human milk fat substitutes (HMFSs) should have a composition similar to that of HMF in order to meet the nutritional needs of infant growth and development. At present, HMFS preparation mainly focuses on the simulation of fatty acid composition, the application of structured lipids and the addition of milk fat globule membrane (MFGM) supplements. This paper first reviews the composition and structure of HMF, and then the preparation development of structured lipids and MFGM supplements are summarized. Additionally, the evaluation and regulation of HMFSs in infant formula are also presented.

Emerging drying techniques for food safety and quality: A review

The new trends in drying technology seek a promising alternative to synthetic preservatives to improve the shelf-life and storage stability of food products. On the other hand, the drying process can result in deformation and degradation of phytoconstituents due to their thermal sensitivity. The main purpose of this review is to give a general overview of common drying techniques with special attention to food industrial applications, focusing on recent advances to maintain the features of the active phytoconstituents and nutrients, and improve their release and storage stability. Furthermore, a drying technique that extends the shelf-life of food products by reducing trapped water, will negatively affect the spoilage of microorganisms and enzymes that are responsible for undesired chemical composition changes, but can protect beneficial microorganisms like probiotics. This paper also explores recent efficient improvements in drying technologies that produce high-quality and low-cost final products compared to conventional methods. However, despite the recent advances in drying technologies, hybrid drying (a combination of different drying techniques) and spray drying (drying with the help of encapsulation methods) are still promising techniques in food industries. In conclusion, spray drying encapsulation can improve the morphology and texture of dry materials, preserve natural components for a long time, and increase storage times (shelf-life). Optimizing a drying technique and using a suitable drying agent should also be a promising solution to preserve probiotic bacteria and antimicrobial compounds.

Incorporation of docosahexaenoic acid (DHA) enhances nanodelivery of antiretroviral across the blood-brain barrier for treatment of HIV reservoir in brain

Although the newer antiretroviral (ARV) drugs are highly active against the human immunodeficiency virus (HIV) in the body compartment, they often fail to effectively tackle the HIV reservoir in the brain because of inefficient penetration to the blood-brain barrier (BBB). In this study, we investigated the potential benefits of incorporating docosahexaenoic acid (DHA), an omega-3 fatty acid essential for brain development, in lipid nanocarriers for facilitating the BBB passage of an ARV darunavir. The resulting nanocarriers (nanoARVs) containing 5-15% DHA were 90-140 nm in size, had high darunavir payload (~11-13% w/w), good stability and minimal cellular toxicity, and could be further decorated with transferrin (Tf) for Tf-receptor targeting. In BBB models of hCMEC/d3 cells, nanoARVs with higher DHA content achieved increased nanocarrier uptake and up to 8.99-fold higher darunavir permeation than free darunavir. In animals, nanoARVs were able to achieve 3.38-5.93-fold increase in brain darunavir level over free darunavir. Tf-conjugated nanoARVs also achieved significantly higher anti-HIV activity than free darunavir (viral titer 2 to 2.6-fold higher in latter group). Comparison of DHA incorporation and Tf-receptor targeting showed that while both strategies could enhance the cellular uptake and brain accumulation of the nanocarriers, DHA was more effective (P < 0.05) for improving BBB permeation and brain accumulation of the darunavir payload. Substituting DHA with another oil noticeably reduced the cellular uptake of nanoARVs. Overall, this proof-of-concept study has supported the development of DHA-based nanoARVs as an effective, safe yet technically simple strategy to enhance brain delivery of darunavir and potentially other lipophilic ARVs for treatment of HIV reservoir.

Potential of Nanonutraceuticals in Increasing Immunity

Nutraceuticals are defined as foods or their extracts that have a demonstrably positive effect on human health. According to the decision of the European Food Safety Authority, this positive effect, the so-called health claim, must be clearly demonstrated best by performed tests. Nutraceuticals include dietary supplements and functional foods. These special foods thus affect human health and can positively affect the immune system and strengthen it even in these turbulent times, when the human population is exposed to the COVID-19 pandemic. Many of these special foods are supplemented with nanoparticles of active substances or processed into nanoformulations. The benefits of nanoparticles in this case include enhanced bioavailability, controlled release, and increased stability. Lipid-based delivery systems and the encapsulation of nutraceuticals are mainly used for the enrichment of food products with these health-promoting compounds. This contribution summarizes the current state of the research and development of effective nanonutraceuticals influencing the body's immune responses, such as vitamins (C, D, E, B12, folic acid), minerals (Zn, Fe, Se), antioxidants (carotenoids, coenzyme Q10, polyphenols, curcumin), omega-3 fatty acids, and probiotics.