Encapsulation of Antarctic krill oil in yeast cell microcarriers: Evaluation of oxidative stability and in vitro release

Preparation and intestinal gastrointestinal delivery performance of Malus baccata (Linn.) polyphenols loaded nanoparticles based on yeast membranes

The currently available polyphenols delivery systems require the complicated preparation process and participation of multiple food-graded materials. Yeast membranes (YMS), as unitary encapsulation material, not only can load natural products by their porous structure but also can be specifically degraded by β-glucanase in intestine. Therefore, this study fabricated Malus baccata (Linn.) polyphenols loaded nanoparticles based on yeast membranes (YMS@MBP) by hydrogen bonding and hydrophobic interaction. YMS@MBP with the lamellar aggregated morphology possessed the non-crystalline feature and excellent thermal stability, and their average particle size was 997.2 ± 22.1 nm. Through establishing the model of gastrointestinal digestion in vitro, YMS@MBP presented the sustained release and intestinal targeting release characteristics, and the maximum release rates in gastric and small intestine were 16.04 % and 79.39 %, respectively. HPLC-MS/MS analysis showed that MBP were mainly composed by quercetin and its derivatives, phloretin, catechins, anthocyanins and phenolic acids. After digestion, the phenolic composition of MBP was perfectly protected by encapsulation of YMS, which was much closer to that of undigested MBP. This study provides a new strategy for construction of polyphenols delivery system applied in functional food field.

Health promoting benefits of krill oil: mechanisms, bioactive combinations, and advanced encapsulation technologies

Krill oil, derived from Antarctic krill (Euphausia superba) species, is drawing increased attention due to its distinct composition, being rich in omega-3 fatty acids, phospholipids, and astaxanthin. Recent studies highlight the potential benefits of krill oil as a dietary supplement for enhancing various health-related factors. Research indicates that supplementing with krill oil positively affects markers of inflammation, oxidative stress, muscle function, glucose metabolism, and lipid profiles. Additionally, advancements in encapsulation technologies aim to optimize the delivery and efficacy of krill oil supplements. The review outlines the selection of emulsifiers and wall materials, along with techniques employed in creating four novel encapsulation methods for krill oil: micro/nanoemulsions, microcapsules, liposomes, and nanostructured lipid carriers. The review also provides scientific literature on the physiological impacts and underlying mechanisms of krill oil supplementation. It explores its influence on glucose homeostasis, oxidative stress responses, inflammatory pathways, lipid metabolism, and muscle physiology.

Yeast cell biocarrier for the encapsulation of ascorbic acid: effect of plasmolysis process, suspension media and ascorbic acid levels on the physicochemical, morphological and bioactive properties of microcapsules

BACKGROUND

Ascorbic acid is a water-soluble vitamin and shows weak stability against external factors such as heat, oxygen, light etc. Due to its lower stability, encapsulation is an effective process for the preservation of its activity. Although there are a wide variety of encapsulation methods, the technique of encapsulation with yeast cells has been followed with increasing interest in recent years. In this study, encapsulation possibilities of ascorbic acid by yeast cells were investigated. In this context, Saccharomycess cerevisiae yeast cells in plasmolyzed and non-plasmolyzed forms were used in two different suspension media (water and ethanol) and effect of ascorbic acid concentrations (10, 20 and 50 g per 10 g yeast) were studied. A total of 12 different yeast microcapsule samples were produced and some physicochemical, bioactive and structural characterizations were performed.

RESULTS

The ascorbic acid level of yeast microcapsule samples was determined as 206.4-713.9 and 202.8-726.1 mg g-1 for plasmolyzed and non-plasmolyzed yeast cell types, respectively. ABTS radical scavenging activity increased from 27.23 to 233.04 μg TE g-1 by increased ascorbic acid levels. Ascorbic acid capsules were used in soft candy processing against free ascorbic acid and it was found that 47.9% ascorbic acid loss was detected for control sample at the 24-day storage while the ascorbic acid loss was approximately 25% for yeast microcapsules.

CONCLUSION

It was concluded that yeast cells are capable of preserving ascorbic acid stability during storage and yeast cells can be used effectively and safely for the manufacturing of the ascorbic acid microcapsules. © 2024 Society of Chemical Industry.

Pichia pastoris-Derived β-Glucan Capsules as a Delivery System for DNA Vaccines

BACKGROUND/OBJECTIVES

DNA vaccines are rapidly produced and adaptable to different pathogens, but they face considerable challenges regarding stability and delivery to the cellular target. Thus, effective delivery methods are essential for the success of these vaccines. Here, we evaluated the efficacy of capsules derived from the cell wall of the yeast Pichia pastoris as a delivery system for DNA vaccines.

METHODS

The capsules were extracted from the yeast Pichia pastoris strain GS115, previously grown in a YPD medium. pVAX1 expression vector was adopted to evaluate the DNA vaccine insertion and delivery. Three encapsulation protocols were tested to identify the most effective in internalizing the plasmid. The presence of plasmids inside the capsules was confirmed by fluorescence microscopy, and the encapsulation efficiency was calculated by the difference between the initial concentration of DNA used for insertion and the concentration of unencapsulated DNA contained in the supernatant. The capsules were subjected to different temperatures to evaluate their thermostability and were co-cultured with macrophages for phagocytosis analysis. HEK-293T cells were adopted to assess the cytotoxicity levels by MTT assay.

RESULTS

The microscopy results indicated that the macrophages successfully phagocytosed the capsules. Among the protocols tested for encapsulation, the one with 2% polyethylenimine for internalization showed the highest efficiency, with an encapsulation rate above 80%. However, the vaccine capsules obtained with the protocol that used 5% NaCl showed better thermal stability and encapsulation efficiency above 63% without induction of cell viability loss in HEK 293T.

CONCLUSIONS

We successfully described a vaccine delivery system using yeast capsules derived from Pichia pastoris, demonstrating its potential for DNA vaccine delivery for the first time. Additional studies will be needed to characterize and improve this delivery strategy.

Overcoming Biopotency Barriers: Advanced Oral Delivery Strategies for Enhancing the Efficacy of Bioactive Food Ingredients

Bioactive food ingredients contribute to the promotion and maintenance of human health and wellbeing. However, these functional ingredients often exhibit low biopotency after food processing or gastrointestinal transit. Well-designed oral delivery systems can increase the ability of bioactive food ingredients to resist harsh environments inside and outside the human body, as well as allow for controlled or triggered release of bioactives to specific sites in the gastrointestinal tract or other tissues and organs. This review presents the characteristics of common bioactive food ingredients and then highlights the barriers to their biopotency. It also discusses various oral delivery strategies and carrier types that can be used to overcome these biopotency barriers, with a focus on recent advances in the field. Additionally, the advantages and disadvantages of different delivery strategies are highlighted. Finally, the current challenges facing the development of food-grade oral delivery systems are addressed, and areas where future research can lead to new advances and industrial applications of these systems are proposed.

Yeast cell wall capsules for delivery of oat biomarker avenanthramide-C

Avenanthramide-C (AVN-C) is the biomarker for oat with a variety of physiological functions, whereas its application is constrained by low stability and bioavailability. Avenanthramide-C is the biomarker for oat with a variety of physiological functions, whereas its application is constrained by low stability and bioavailability. This study evaluated the potential of yeast cell (YC) and yeast cell wall (YCW) capsules as delivery systems for stabilizing AVN-C. It was observed that these yeast capsules possessed the ellipsoidal morphology and intact structure without visual pores. Additionally, the YCW capsules exhibited higher encapsulation and loading capacity due to the large internal space. The interaction of yeast capsules with AVN-C involved the hydrophobic interactions and hydrogen bonding. Moreover, the loading of AVN-C induced high hydrophobicity inside the yeast capsules, which helped to protect AVN-C against degradation and release AVN-C in a slow and sustained manner in the simulated gastrointestinal tract. The YCW capsules have potential as controlled delivery system for AVN-C, which could be further used as a nutraceutical and added to functional foods.

Advances in encapsulation systems of Antarctic krill oil: From extraction to encapsulation, and future direction

Antarctic krill oil (AKO) is highly sought after by consumers and the food industry due to its richness in a variety of nutrients and physiological activities. However, current extraction methods are not sufficient to better extract AKO and its nutrients, and AKO is susceptible to lipid oxidation during processing and storage, leading to nutrient loss and the formation of off-flavors and toxic compounds. The development of various extraction methods and encapsulation systems for AKO to improve oil yield, nutritional value, antioxidant capacity, and bioavailability has become a research hotspot. This review summarizes the research progress of AKO from extraction to encapsulation system construction. The AKO extraction mechanism, technical parameters, oil yield and composition of solvent extraction, aqueous enzymatic extraction, supercritical/subcritical extraction, and three-liquid-phase salting-out extraction system are described in detail. The principles, choice of emulsifier/wall materials, preparation methods, advantages and disadvantages of four common encapsulation systems for AKO, namely micro/nanoemulsions, microcapsules, liposomes and nanostructured lipid carriers, are summarized. These four encapsulation systems are characterized by high encapsulation efficiency, low production cost, high bioavailability and high antioxidant capacity. Depending on the unique advantages and conditions of different encapsulation methods, as well as consumer demand for health and nutrition, different products can be developed. However, existing AKO encapsulation systems lack relevant studies on digestive absorption and targeted release, and the single product category of commercially available products limits consumer choice. In conjunction with clinical studies of AKO encapsulation systems, the development of encapsulation systems for special populations should be a future research direction.

Foam-templated oleogels constructed by whey protein isolate and xanthan gum: Multiple-effect delivery vehicle for Antarctic krill oil

To address the limitations of Antarctic krill oil (AKO) such as easy oxidation, unacceptable fishy flavor and low bioaccessibility of astaxanthin in it, a multiple-effect delivery vehicle for AKO is needed. In this study, whey protein isolate (WPI) and xanthan gum (XG) were utilized to construct AKO into oleogels by generating foam-templates. The effects of the concentration of XG on the properties of foam, cryogel and the corresponding oleogels were investigated, and the formation mechanism of oleogel was discussed from the perspective of the correlation between foam-cryogel-oleogel. The results demonstrated that with the increase of the concentration of XG, the foam stability was improved, the cryogel after freeze drying had a more uniform network structure and superior oil absorption ability, and the corresponding oleogel had excellent oil holding ability after oil absorption. The AKO oleogels showed superior oxidative stability compared with AKO. The in vitro digestion experiments demonstrated that the bioaccessibility of the astaxanthin in this oleogel was also considerably higher than that in AKO. In addition, this oleogel had masking effect on the odor-presenting substances in AKO, while retaining other flavors of AKO. The foam-templated oleogel can be considered as a multiple-effect vehicle for AKO to facilitate its application in food products. This study provides theoretical basis and data support for the development and utilization of novel vehicle for AKO, broadening the application of AKO in the field of food science.

Yeast glucan particles: An express train for oral targeted drug delivery systems

As an emerging drug delivery vehicle, yeast glucan particles (YGPs) derived from yeast cells could be specifically taken up by macrophages. Therefore, these vehicles could rely on the recruitment of macrophages at the site of inflammation and tumors to enable targeted imaging and drug delivery. This review summarizes recent advances in the application of YGPs in oral targeted delivery systems, covering the basic structure of yeast cells, methods for pre-preparation, drug encapsulation and characterization. The mechanism and validation of the target recognition interaction of YGPs with macrophages are highlighted, and some inspiring cases are presented to show that yeast cells have promising applications. The future chances and difficulties that YGPs will confront are also emphasized throughout this essay. YGPs are not only the "armor" but also the "compass" of drugs in the process of targeted drug transport. This system is expected to provide a new idea about the oral targeted delivery of anti-inflammatory and anti-tumor drugs, and furthermore offer an effective delivery strategy for targeted therapy of other macrophage-related diseases.

Development and characterization of self-emulsifying high internal phase emulsions using endogenous phospholipids from Antarctic krill oil

High internal phase emulsions (HIPEs) have emerged as a promising structured oil system in food industry. This study developed self-emulsifying HIPEs (SHIPEs) using Antarctic krill oil (KO) with endogenous phospholipids as surfactant and algae oil as a diluent. The influence of phospholipids self-assembly on SHIPEs formation was investigated by evaluating the microstructures, particle size, rheological properties, and water distribution. Results demonstrated that the concentration and self-assembly behavior of phospholipids dominated the SHIPEs formation. Optimized SHIPEs with desirable gel properties contained 10 wt% krill oil in the oil phase at an 80 wt% oil phase level. Furthermore, these SHIPEs exhibited excellent performance in 3D printing applications. Hydrated phospholipids formed lamellar network at the oil-water interface, enhancing gel strength by crosslinking oil droplets. These findings shed light on the self-assembly of phospholipids during HIPEs formation and highlight the potential phospholipids-rich marine lipids in SHIPEs for functional food products development.

Integrated the embedding delivery system and targeted oxygen scavenger enhances free radical scavenging capacity

World trends in oil crop growing area, yield, and production over the last 10 years exhibited an increase of 48 %, 82 %, and 240 %, respectively. Concerning reduced shelf-life of oil-containing food products caused by oil oxidation and the demand for sensory quality of oil, the development of methods the improvement oil quality is urgently required. This critical review presented a concise overview of the recent literature related to the inhibition ways of oil oxidation. The mechanism of different antioxidants and nanoparticle delivery systems on oil oxidation was also explored. The current review provides scientific findings on control strategies: (i) design oxidation quality assessment model; (ii) packaging by antioxidant coatings and eco-friendly film nanocomposite: ameliorate physicochemical properties; (iii) molecular investigations on inhibitory effects of selected antioxidants and underlying mechanisms; (iv) explore the interrelationship between the cysteine/citric acid and lipoxygenase pathway in the progression of oxidative/fragmentation degradation of unsaturated fatty acid chains.

OSA-starch stabilized EPA nanoliposomes: preparation, characterization, stability and digestion in vitro and in vivo

OSA-starch stabilized EPA nanoliposomes (OSA-EPA-NLs) were prepared by thin film rehydration/dispersion method. The physical properties and morphology of OSA-EPA-NLs were characterized. The best formulated sample was used to measure the storage stability and oxidative properties of EPA under different environmental stresses and to determine release and absorption of OSA-EPA-NLs in vitro and in vivo. The results showed that the encapsulation efficiency of OSA-EPA-NLs was 84.61%. All samples were relatively stable under different environmental stresses, and the release rate of EPA in simulated intestine stage (89.87%) was higher than that in the simulated gastric stage (5.86%). The areas under the EPA concentration-time curve of OSA-EPA-NLs group and EPA-NLs group through in vivo study were 0.42 and 0.32, respectively, which indicated that OSA-starch could improve the stability of EPA nanoliposomes and enhance EPA bioavailability in the form of ethyl esters.

Efficient encapsulation of curcumin into spent brewer's yeast using a pH-driven method

Curcumin (CUR) was encapsulated into yeast cells (YCs) through a pH-driven method with a 5.04-fold increase in loading capacity and a 43.63-fold reduction in incubation time compared to the conventional diffusion method. Optimal encapsulation was obtained when the mass ratio of CUR to YCs was 0.1, and the loading capacity and encapsulation efficiency were 8.07% and 80.66%, respectively. Encapsulation of CUR into YCs was confirmed by fluorescence microscopy, differential scanning calorimetry, and thermogravimetric analysis. Fourier transform infrared spectroscopy and X-ray diffraction further demonstrated that the encapsulated CUR was interacted with mannoprotein and β-glucan of the cell wall network through hydrophobic interaction and hydrogen bond in amorphous state. The in vitro bioaccessibility of YCs-loaded CUR was significantly increased by 6.05-fold. The enhanced encapsulation efficiency and rapid encapsulation process proposed in this study could facilitate YCs-based microcarriers to encapsulate bioactive substances with higher bioaccessibility.

Current trends in flavor encapsulation: A comprehensive review of emerging encapsulation techniques, flavour release, and mathematical modelling

Food flavors are volatile compounds that impact the human sensory perception profoundly and find extensive applications in various food products. Because of their volatility and high sensitivity to pH, temperature, oxidation, and external conditions, they require adequate protection to last for a longer duration. Encapsulation plays a critical role in preserving food flavors by enhancing their thermal and oxidative stability, overcoming volatility limitations, and regulating their rapid release with improved bioavailability in food products. The current review focuses on the recent developments in food flavor encapsulation techniques, such as electrospinning/spraying, cyclodextrin inclusion complexes, coacervation, and yeast cell micro-carriers. The review also comprehensively discusses the role of encapsulants in achieving controlled flavor release, the mechanisms involved, and the mathematical modelling for flavor release. Specific well-established nanoencapsulation techniques render better encapsulation efficiency and controlled release of flavor compounds. The review examined specific emerging methods for flavor encapsulation, such as yeast cell encapsulation, which require further exploration and development. This article provides readers with up-to-date information on different encapsulation processes and coating methods used for flavor encapsulation.

Preparation of Antarctic Krill Oil Emulsion and Its Stability under Catalase Treatment

Making Antarctic krill oil into emulsion is a good way to utilize Antarctic krill, but proliferation of microorganisms cannot be ignored. H₂O₂ is widely used in the sterilization of liquid food since its decomposition products are environmentally friendly, although residual H₂O₂ should be removed for food safety. Adding catalase (CAT) is an effective means to do this. However, the enzyme activity center of CAT is the iron porphyrin group, which has the risk of accelerating lipid oxidation in the oil emulsion. Therefore, we hypothesized that CAT might not be suitable for the removal of H₂O₂ in Antarctic krill oil emulsion. In this paper, Antarctic krill oil emulsion was prepared, and then the effect of CAT on the emulsion was studied through visual observation, microscopic morphology observation, turbidity and stability, particle size, and ζ-potential; finally, the mechanism of CAT destroying the emulsion was explored from the perspective of lipid oxidation. The results showed that a stable Antarctic krill emulsion was prepared using Tween-80 as the emulsifier, with the oil concentration of 1% (v/v) and the ratio of surfactant to oil phase of 1:5 (v/v). The emulsion treated with CAT had undergone demulsification, stratification, and coagulation after 2 days of incubation, while the emulsion treated with superoxide dismutase (SOD) and bovine serum albumin (BSA) changed little. In addition, the thiobarbituric acid reactive substances (TBARS) value and the content of hydroxyl radicals in the CAT group increased significantly. The preliminary research results indicated that the effect of CAT on the emulsion related to the lipid oxidation caused by the iron porphyrin group at the center of the enzyme activity. All these results indicated that CAT was not suitable for the removal of residual H₂O₂ in Antarctic krill oil emulsion. Moreover, it is helpful to avoid the contact of Antarctic krill oil emulsion and CAT during the processing of the krill.

Persistence Enhancement of a Promising Tick Repellent, Benzyl Isothiocyanate, by Yeast Microcarriers

Phenethyl isothiocyanate isolated from Armoracia rusticana root oil and its derivatives were tested at different doses in a bioassay designed to evaluate repellency against individual Haemaphysalis longicornis nymphs. Among the tested compounds, benzyl isothiocyanate exhibited repellency against H. longicornis nymphs at the lowest dose of 0.00625 mg/cm², followed by phenethyl isothiocyanate (0.0125 mg/cm²) and phenyl isothiocyanate (0.025 mg/cm²). The behavioral responses of H. longicornis nymphs exposed to benzyl isothiocyanate and phenethyl isothiocyanate indicated that the mode of action of these compounds can be mainly attributed to the vapor phase. Encapsulated benzyl isothiocyanate showed repellency up to 120 min post-application at 0.1 mg/cm², whereas pure benzyl isothiocyanate showed repellency up to 60 min post-application at 0.1 mg/cm². The present study suggests that benzyl isothiocyanate is a potential repellent for protection against H. longicornis nymphs, and encapsulation in yeast cells may enhance the repellency effect.

Yeast Cells in Microencapsulation. General Features and Controlling Factors of the Encapsulation Process

Besides their best-known uses in the food and fermentation industry, yeasts have also found application as microcapsules. In the encapsulation process, exogenous and most typically hydrophobic compounds diffuse and end up being passively entrapped in the cell body, and can be released upon application of appropriate stimuli. Yeast cells can be employed either living or dead, intact, permeabilized, or even emptied of all their original cytoplasmic contents. The main selling points of this set of encapsulation technologies, which to date has predominantly targeted food and-to a lesser extent-pharmaceutical applications, are the low cost, biodegradability and biocompatibility of the capsules, coupled to their sustainable origin (e.g., spent yeast from brewing). This review aims to provide a broad overview of the different kinds of yeast-based microcapsules and of the main physico-chemical characteristics that control the encapsulation process and its efficiency.

Development of a High Internal Phase Emulsion of Antarctic Krill Oil Diluted by Soybean Oil Using Casein as a Co-Emulsifier

Antarctic krill oil (AKO) with 5–30% (w/w) dilution by soybean oil was co-emulsified by phospholipids (PLs) naturally present in AKO and 2% (w/w) casein in the aqueous phase to prepare high internal phase emulsions (HIPEs). The results showed that raising the AKO level resulted in concave-up changes in the mean size of oil droplets which became more densely packed. Confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (cryo-SEM) micrographs revealed that PLs at higher concentrations expelled more casein particles from the oil droplet surface, which facilitated the formation of a crosslinked network structure of HIPEs, leading to reduced mobility of water molecules, extended physical stability, and somewhat solid-like behavior. The rheological analysis showed at lower levels of AKO promoted fluidity of emulsions, while at higher levels it increased elasticity. Lastly, increasing the AKO level slowed down the oxidation of HIPEs. These findings provide useful insights for developing HIPEs of highly viscous AKO and its application in foods.