Myofibrillar protein with κ- or λ-carrageenans as novel shell materials for microencapsulation of tuna oil through complex coacervation

Microencapsulation of ginger essential oil using mung bean protein isolate-chitosan complex coacervates: Application in the preservation of crab meatballs and the prediction of shelf life

Crab meatballs with more unsaturated fat tend to spoil. Ginger essential oil (GEO) with oxidation resistance was encapsulated into microcapsules (GM) by complex cohesion of mung bean protein isolate (MBPI) and chitosan (CS) in a ratio of 8:1 at pH = 6.4, encapsulation efficiency (EE) and payload (PL) of GM (D50 = 26.16 ± 0.45 μm) with high thermal stability were 78.35 ± 1.02% and 55.43 ± 0.64%. GM (0.6%, w/w) did not interfere with the original flavor of crab meatballs, and lowered values of pH, thiobarbituric acid reactive substances (TBARS) and total bacteria counts (TBC) of the products than those spiked with GEO and the control. The prediction accuracy of the logistic first-order growth kinetic equation in line with TBC (2.84%) was better than that of zero-order and Arrhenius coupled equation based on pH (7.48%) and TBARS (5.94%), but all of them could predict the shelf life of crab meatballs containing GM stored at 4-25 °C.

New perspective on protein-based microcapsules as delivery vehicles for sensitive substances: A review

Sensitive substances have attracted wide attention due to their rich functional activities, such as antibiosis activities, antioxidant activities and prevent disease, etc. However, the low stability of sensitive substances limits their bioavailability and functional activities. Protein-based microcapsules can encapsulate sensitive substances to improve their adverse properties due to their good stability, strong emulsifying ability and wide source. Therefore, it is necessary to fully elaborate and summarize protein-based microcapsules to maximize their potential benefits in nutritional interventions. The focus of this review is to highlight the classification of protein-based microcapsules. In addition, the principles, advantages and disadvantages of preparation methods for protein-based microcapsules are summarized. Some novel preparation methods for protein-based microcapsules are also emphasized. Moreover, the mechanism of protein-based microcapsules that release sensitive substances in vitro is elucidated and summarized. Furthermore, the applications of protein-based microcapsules are outlined. Protein-based microcapsules can effectively encapsulate sensitive substances, which improve their bioavailability, and provide protective effects during storage and gastrointestinal digestion. In addition, microcapsules can improve the sensory quality of food and enhance its stability. The performance of protein-based microcapsules for delivering sensitive substances is influenced by factors such as protein type, the ratio between protein ratio and the other wall material, the preparation process, etc. Future research should focus on the new composite protein-based microcapsule delivery system, which can be applied to in vivo research and have synergistic effects and precise nutritional functions. In summary, protein-based microcapsules have broader research prospects in the functional foods and nutrition field.

Enhancing basil essential oil microencapsulation using pectin/casein biopolymers: Optimization through D-optimal design, controlled release modeling, and characterization

A D-optimal design was employed to optimize the microencapsulation (MEC) of basil essential oil (BEO) within a biopolymer matrix using the complex coacervation technique. BEO microcapsules (BEO-MCs) obtained under the optimal conditions exhibited high yield and efficiency with 80.45 ± 0.01 % and 93.10 ± 0.18 %, respectively. The successful MEC of BEO with an average particle size of 4.81 ± 2.86 μm was confirmed by ATR-FTIR, X-RD, and SEM analyses. Furthermore, the thermal stability of BEO-MCs was assessed using TGA-DSC analysis, which provided valuable insights into the MC's thermal stability. Furthermore, the proposed model, with a high R2 value (0.99) and low RMSE (1.56 %), was the most suitable one among the tested models for the controlled release kinetics of the optimal BEO-MCs under simulated gastrointestinal conditions. The successful optimization of BEO MEC using biopolymers through the D-optimal design could be a promising avenue for food and pharmaceutical industries, providing new strategies for the development of effective products.

Development of chitosan/carrageenan macrobeads for encapsulation of Paenibacillus polymyxa and its biocontrol efficiency against clubroot disease in Brassica crops

Clubroot, caused by the obligate parasite Plasmodiophora brassicae, is one of the most important diseases of brassicas. The antagonistic bacterium Paenibacillus polymyxa ZF129 can suppress clubroot while its effectiveness is often unstable. To control clubroot more effectively, the macrobeads for controlled release of ZF129 were prepared using microencapsulation technology. Macrobeads with various ratios of chitosan (2 % w/w): carrageenan (0.3 % w/v) were prepared by an ionotropic gelation method and the bacteria ZF129 was loaded into macrobeads. The 1:1 chitosan: carrageenan showed the maximum swelling ratio (634 %), and the maximum survival rate (61.52 ± 1.12 %) after freeze-drying. Fourier transform infrared revealed the electrostatic interactions between chitosan and carrageenan. The macrobeads can efficiently release ZF129 strains into phosphate buffer solution and reach equilibrium in 48 h. The maximum number of bacteria cells to be released in the soil was observed after 25-30 days. The control efficacy of ZF129 macrobeads (chitosan: carrageenan, 1:1) and ZF129 culture against clubroot disease was 76.33 ± 3.65 % and 59.76 ± 4.43 % in greenhouse experiments, respectively and the control efficacy was calculated as 60.74 ± 5.00 % for ZF129 macrobeads and 40.94 ± 4.05 % for ZF129 culture under field experiments, respectively. The ZF129 macrobeads had significant growth-promoting effects on pak choi and Chinese cabbage. The encapsulation method described in this study is a prudent approach toward efficient biopesticides utilization with reduced environmental implications.

Advances in protein-based microcapsules and their applications: A review

Due to their excellent emulsification, biocompatibility, and biological activity, proteins are widely used as microcapsule wall materials for encapsulating drugs, natural bioactive substances, essential oils, probiotics, etc. In this review, we summarize the protein-based microcapsules, discussing the types of proteins utilized in microcapsule wall materials, the preparation process, and the main factors that influence their properties. Additionally, we conclude with examples of the vital role of protein-based microcapsules in advancing the food industry from primary processing to deep processing and their potential applications in the biomedical, chemical, and textile industries. However, the low stability and controllability of protein wall materials lead to degraded performance and quality of microcapsules. Protein complexes with polysaccharides or modifications to proteins are often used to improve the thermal instability, pH sensitivity, encapsulation efficiency and antioxidant capacity of microcapsules. In addition, factors such as wall material composition, wall material ratio, the ratio of core to wall material, pH, and preparation method all play critical roles in the preparation and performance of microcapsules. The application area and scope of protein-based microcapsules can be further expanded by optimizing the preparation process and studying the microcapsule release mechanism and control strategy.

Micro/nano-encapsulation of marine dietary oils: A review on biomacromolecule-based delivery systems and their role in preventing cardiovascular diseases

Marine-based dietary oils (MDOs), which are naturally obtained from different sources, have been scientifically recommended as potent functional bioactives owing to their therapeutic biological activities; however, they have exhibited plenty of health benefits. Though they are very sensitive to light, temperature, moisture, and oxygen, as well as being chemically unstable and merely oxidized, this may limit their utilization in food and pharmaceutical products. Miro- and nanoencapsulation techniques are considered to be the most promising tactics for enhancing the original characteristics, physiochemical properties, and therapeutic effects of entrapped MDOs. This review focuses on the biomacromolecule-stabilized micro/nanocarriers encompassing a wide range of MDOs. The novel-equipped polysaccharides and protein-based micro/nanocarriers cover microemulsions, microcapsules, nanoemulsions, and nanoliposomes, which have been proven to be encouraging candidates for the entrapment of diverse kinds of MDOs. In addition, the current state-of-the-art loading of various MDOs through polysaccharide and protein-based micro/nanocarriers has been comprehensively discussed and tabulated in detail. Biomacromolecule-stabilized nanocarriers, particularly nanoemulsions and nanoliposomes, are addressed as propitious nanocargos for protection of MDOs in response to thought-provoking features as well as delivering the successful, meticulous release to the desired sites. Gastrointestinal fate (GF) of biopolymeric micro/nanocarriers is fundamentally based on their centrifugation, dimension, interfacial, and physical properties. The external surface of epithelial cells in the lumen is the main site where the absorption of lipid-based nanoparticles takes place. MDO-loaded micro- and nanocarriers with biological origins or structural modifications have shown some novel applications that could be used as future therapies for cardiovascular disorders, thanks to today's cutting-edge medical technology. In the future, further investigations are highly needed to open new horizons regarding the application of polysaccharide and protein-based micro/nanocarriers in food and beverage products with the possibility of commercialization in the near future for industrial use.

Microencapsulation of green coffee oil by complex coacervation of soy protein isolate, sodium casinate and polysaccharides: Physicochemical properties, structural characterisation, and oxidation stability

This study developed a combination method between protein-polysaccharide complex coacervation and freezing drying for the preparation of green coffee oil (GCO) encapsulated powders. Different combinations of soy protein isolate, sodium caseinate, sodium carboxymethylcellulose, and sodium alginate were utilised as wall materials. The occurrence of complexation between the biopolymers were compared to the final emulsion of the individual protein and confirmed by fourier transform infrared spectrometry and X-ray diffraction. The mean diameter and estimated PDI of GCO microcapsules were 72.57-295.00 μm and 1.47-2.02, respectively. Furthermore, the encapsulation efficiency of GCO microcapsules was between 61.47 and 90.01 %. Finally, oxidation kinetics models of GCO and its microcapsules demonstrated that the zero-order model of GCO microcapsules was found to have a higher fit, which could better reflect the quality changes of GCO microcapsules during storage. Different combinations of proteins and polysaccharides exhibited effective oxidative stability against single proteins because of polysaccharide addition. This research revealed that soy protein isolate, sodium caseinate combined with polysaccharides can be used as a promising microencapsulating agent for microencapsulation of GCO, especially with sodium carboxymethylcellulose and sodium alginate, and provided useful information for the potential use of GCO in the development of powder food.

Current and emerging applications of carrageenan in the food industry

Carrageenan, a polysaccharide derived from red algae, has a long history of use as a food additive in food. Carrageenan comes in three classes, κ-, ι-, and λ-carrageenan, with different properties attributed to their organosulfate substitution levels, and their interactions with other food components give rise to properties such as water holding, thickening, gelling, and stabilizing. Over the years, carrageenan has been used in wide variety of food products such as meat, dairy, and flour-based products, and their mechanisms and functions in these matrices have also been studied. With the emergence of novel food technologies, carrageenan's potential applications have been extensively explored alongside, including encapsulation, edible films/coatings, plant-based analogs, and 3D/4D printing. As the food technology evolves, the required functions of food ingredients have changed, and carrageenan is being investigated for its role in these new areas. However, there are many similarities in the use of carrageenan in both classic and emerging applications, and understanding the underlying principles of carrageenan will lead to a proper use of carrageenan in emerging food products. This review focuses on the potential of carrageenan as a food ingredient in these emerging technologies mainly based on papers published within the past five years, highlighting its functions and applications to better understand its role in food products.

Understanding the structure, interfacial properties, and digestion fate of high internal phase Pickering emulsions stabilized by food-grade coacervates: Tracing the dynamic transition from coacervates to complexes

Although protein-polysaccharide complexes have shown tremendous potential in stabilizing high internal phase Pickering emulsions (HIPPEs), it is unclear whether coacervates have the same potential to be used as effective Pickering stabilizers. In this study, HIPPEs were prepared by ovalbumin (OVA)-pectin (PE) coacervates during the transition from coacervates to complexes. The results showed that enhanced OVA-PE interactions significantly affected the wettability and surface-tension reduction ability of the OVA-PE coacervates. At pH 2, the coacervate-stabilized HIPPEs exhibited smaller oil droplet sizes (21.3±2.3 μm), tighter droplet packing, and finer solid-like structures through the bridging of droplets and the generation of stronger gel-like network structures to prevent coalescence and lipid oxidation. The gastrointestinal digestion results proved that the OVA-PE coacervates promoted lipid hydrolysis and improved the bioaccessibility (from 19.7±0.7% to 36.5±2%) of curcumin-loaded HIPPEs. Our work provides new ideas for the development of biopolymer particles as effective Pickering stabilizers in the food industry.

Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Wall Materials for Encapsulating Bioactive Compounds via Spray-Drying: A Review

Spray-drying is a continuous encapsulation method that effectively preserves, stabilizes, and retards the degradation of bioactive compounds by encapsulating them within a wall material. The resulting capsules exhibit diverse characteristics influenced by factors such as operating conditions (e.g., air temperature and feed rate) and the interactions between the bioactive compounds and the wall material. This review aims to compile recent research (within the past 5 years) on spray-drying for bioactive compound encapsulation, emphasizing the significance of wall materials in spray-drying and their impact on encapsulation yield, efficiency, and capsule morphology.

Effects of pH and NaCl on the Spatial Structure and Conformation of Myofibrillar Proteins and the Emulsion Gel System—Insights from Computational Molecular Dynamics on Myosin of Golden Pompano

In this study, the effects of pH and NaCl concentrations on the structure of golden pompano myosin and emulsion gel were analyzed using SEM in combination with molecular dynamics simulations (MDS). The microscopic morphology and spatial structure of myosin were investigated at different pH (3.0, 7.0, and 11.0) and NaCl concentrations (0.0, 0.2, 0.6, and 1.0 M), and their effects on the stability of emulsion gels were discussed. Our results show that pH had a greater effect on the microscopic morphology of myosin than NaCl. The MDS results show that under the condition of pH 7.0 and 0.6 M NaCl, the myosin expanded and experienced significant fluctuations in its amino acid residues. However, NaCl showed a greater effect on the number of hydrogen bonds than pH. Although changes in pH and NaCl concentrations only slightly altered the secondary structures in myosin, they, nevertheless, significantly influenced the protein spatial conformation. The stability of the emulsion gel was affected by pH changes but not NaCl concentrations, which only affect the rheology. The best elastic modulus G″ of the emulsion gel was obtained at pH 7.0 and 0.6 M NaCl. Based on the results, we conclude that pH changes have a greater influence than NaCl concentrations on the spatial structure and conformation of myosin, contributing to the instability of its emulsion gel state. The data from this study would serve as a valuable reference for emulsion gel rheology modification in future research.

Contribution of κ-/ι-carrageenan on the gelling properties of shrimp myofibrillar protein and their interaction mechanism exploration

BACKGROUND

The contribution and mechanism of κ-/ι-carrageenan (CG) with different hydration characteristics on the gelling properties of shrimp myofibrillar protein (MP) gelation was studied.

RESULTS

The gel strength, water-holding capacity and viscoelastic properties of MP gels were significantly enhanced by 1.0% κ-/ι-CG (P < 0.05), but the microstructure showed that excessive carrageenan caused fragmentation of the gel network and a corresponding decrease in gel properties. Compared to MP-ιCG, MP-κCG showed larger breaking force and shorter breaking distance, thus enhancing the hardness and brittleness of the gel, which might be ascribed to a reinforced network skeleton and a tighter binding of κCG-myosin. However, MP-ιCG stabilized more moisture in the gel network, thereby improving the tenderness of the gel, which might be related to the electrostatic repulsion observed between the sulfate groups of ιCG and the myosin observed by molecular docking. In addition, the β-sheet content and intermolecular interactions might be positively correlated with gel properties.

CONCLUSION

In this study, a composite gel system was constructed based on the interaction of MP and CG. The quality differences of two kinds of CG-MP gels were clarified, which will provide guidance for the application of different kinds of carrageenan and the development of recombinant meat products with specific quality. © 2022 Society of Chemical Industry.

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.

Comparative Study on the Characterization of Myofibrillar Proteins from Tilapia, Golden Pompano and Skipjack Tuna

In this study, the physicochemical properties, functional properties and N-glycoproteome of tilapia myofibrillar protein (TMP), golden pompano myofibrillar protein (GPMP) and skipjack tuna myofibrillar protein (STMP) were assessed. The microstructures and protein compositions of the three MPs were similar. TMP and GPMP had higher solubility, sulfhydryl content and endogenous fluorescence intensity, lower surface hydrophobicity and β-sheet contents than STMP. The results showed that the protein structures of TMP and GPMP were more folded and stable. Due to its low solubility and high surface hydrophobicity, STMP had low emulsifying activity and high foaming activity. By N-glycoproteomics analysis, 23, 85 and 22 glycoproteins that contained 28, 129 and 35 N-glycosylation sites, were identified in TMP, GPMP and STMP, respectively. GPMP had more N-glycoproteins and N-glycosylation sites than STMP, which was possibly the reason for GPMP’s higher solubility and EAI. These results provide useful information for the effective utilization of various fish products.

Stabilization and Dispersion of OSA Starch-Coated Titania Nanoparticles in Kappa-Carrageenan-Based Solution

Titania is a white pigment used widely in papermaking, paints and cosmetic industries. Dispersion and stabilization of high concentration titania in water-based system remains a great bottleneck in industry nowadays, because aggregation of titania nanoparticles results in severe adverse effects to gloss, opacity, tint strength, color distribution and storage stability of end products. Because kappa-carrageenan (κ-CG) has excellent rheological properties such as emulsification, gelation, stability and so on, it has the ability to form gel and increase the viscosity of aqueous solution. In this work, Octenyl succinic anhydride (OSA) starch was utilized as wall material to encapsulate titania pigments using electrostatic spray drying processing. Transmission electron microscopy (TEM) showed that titania pigments were coated by OSA starch, with a final form of nanoparticle. Accelerating stability test found that around 60% OSA starch–titania particles were stably dispersed in κ-CG-based solution. All materials used in this work were natural ingredient, which would be preferred by cosmetic industry and consumers. The technique used in the present study could potentially be extended to other pigments for similar purpose.

Polymers as Encapsulating Agents and Delivery Vehicles of Enzymes

Enzymes are versatile biomolecules with broad applications. Since they are biological molecules, they can be easily destabilized when placed in adverse environmental conditions, such as variations in temperature, pH, or ionic strength. In this sense, the use of protective structures, as polymeric capsules, has been an excellent approach to maintain the catalytic stability of enzymes during their application. Thus, in this review, we report the use of polymeric materials as enzyme encapsulation agents, recent technological developments related to this subject, and characterization methodologies and possible applications of the formed bioactive structures. Our search detected that the most explored methods for enzyme encapsulation are ionotropic gelation, spray drying, freeze-drying, nanoprecipitation, and electrospinning. α-chymotrypsin, lysozyme, and β-galactosidase were the most used enzymes in encapsulations, with chitosan and sodium alginate being the main polymers. Furthermore, most studies reported high encapsulation efficiency, enzyme activity maintenance, and stability improvement at pH, temperature, and storage. Therefore, the information presented here shows a direction for the development of encapsulation systems capable of stabilizing different enzymes and obtaining better performance during application.

Low Molecular Weight Kappa-Carrageenan Based Microspheres for Enhancing Stability and Bioavailability of Tea Polyphenols

Tea polyphenols (TP) are a widely acknowledged bioactive natural product, however, low stability and bioavailability have restricted their application in many fields. To enhance the stability and bioavailability of TP under certain moderate conditions, encapsulation technique was applied. Kappa–Carrageenan (KCG) was initially degraded to a lower molecular weight KCG (LKCG) by H2O2, and was selected as wall material to coat TP. The obtained LKCG (Mn = 13,009.5) revealed narrow dispersed fragments (DPI = 1.14). FTIR and NMR results demonstrated that the main chemical structure of KCG remained unchanged after degradation. Subsequently, LK-CG and TP were mixed and homogenized to form LK-CG-TP microspheres. SEM images of the microspheres revealed a regular spherical shape and smooth surface with a mean diameter of 5–10 μM. TG and DSC analysis indicated that LK-CG-TP microspheres exhibited better thermal stability as compared to free TP. The release profile of LK-CG-TP in simulated gastric fluid (SGF) showed a slowly release capacity during the tested 180 min with the final release rate of 88.1% after digestion. Furthermore, in vitro DPPH radical scavenging experiments revealed that LK-CG-TP had an enhanced DPPH scavenging rate as compared to equal concentration of free TP. These results indicated that LK-CG-TP microspheres were feasible for protection and delivery of TP and might have extensive potential applications in other bioactive components.

Structural characteristics and emulsifying properties of myofibrillar protein-dextran conjugates induced by ultrasound Maillard reaction

In this study, we investigated the effect of the ultrasound-assisted Maillard reaction on the structural and emulsifying properties of myofibrillar protein (MP) and dextran (DX) conjugates with different molecular weights (40, 70 and 150 kDa). Compared with classical heating, mild and moderate ultrasound-assisted methods (100-200 W) could accelerate the later stage of the Maillard reaction, which increased the degree of graft (DG) and the content of advanced Maillard reaction products (MPRs). Structural analysis revealed conjugates obtained by Maillard reaction induced the loss of ordered secondary structures (α-helix, β-sheets) and red-shift of maximum emission wavelength of intrinsic fluorescence spectrum. The conjugate containing 40 kDa DX exhibited higher extent of Maillard reaction compared to those containing 70 kDa and 150 kDa DX under various treating methods. Moreover, the ultrasound-assisted Maillard reaction could effectively improve the emulsifying behaviors. 100 W ultrasound-induced conjugates grafted by 70 kDa DX produced the smallest emulsion size with optimum storage stability. Confocal laser scanning microscopy and analytical centrifugal analyzer further confirmed MP grafted by 70 kDa DX with the assistance of 100 W ultrasound field could produce the smallest and most homogeneous MP-base emulsion with no flocculation. Our study demonstrated that mild ultrasound treatment resulted in well-controlled Maillard reaction, and the related glycoconjugate grafted with 70 kDa DX showed the greatest improvements in emulsifying ability and stability. These findings provided a theoretical foundation for the development of emulsion-based foods with excellent characteristics.

Preparation and Characterization of Double-Layered Microcapsules Containing Nano-SiO2

The double-layered microencapsulation technology has been used in many fields. In this study, the double-layered microencapsulated anthocyanin of Passiflora edulis shells (APESs) was prepared via complex coacervation using gelatin and gum Arabic as the first wall materials (single-layered microcapsules (SMs)) and using gum Arabic containing nano-SiO2 as the second wall material (double-layered microcapsules (DMs)/nano-SiO2) to enhance the stability of the core material. Properties of microcapsules were analyzed on the basis of EE, morphology, scanning electron microscopy (SEM), droplet size, moisture content, and differential scanning calorimetry (DSC). The results showed that the EE values of SMs, DMs, and DMs/nano-SiO2 were 96.12%, 97.24%, and 97.85%, respectively. DMs/nano-SiO2 had the lowest moisture content (2.17%). The average droplet size of DMs/nano-SiO2 (34.93 μm) was higher than those of SMs and DMs. DSC indicated that the melting temperature of DMs/nano-SiO2 was 73.61°C and 45.33°C higher than those of SMs and DMs, respectively. SEM demonstrated that DMs/nano-SiO2 had the smoothest surface compared with the other two kinds of microcapsules. The storage stability of APESs and their microcapsules indicated that the stability of the microcapsules was improved by adding DMs/nano-SiO2 into the wall material of microcapsules. These results indicated double-layered microcapsules containing silica nanoparticles contribute to the stability of the core material.

Electric Soldering Iron Ionization Mass Spectrometry Based Lipidomics for in Situ Monitoring Fish Oil Oxidation Characteristics during Storage

An electric soldering iron ion source (ESII) coupling with rapid evaporative ionization mass spectrometry (REIMS) was developed and used for in situ monitoring the dynamic variation trend in oxidation characteristics of fish oil during storage. The lipidomics profiles of fish oil stored at various days were acquired by ESII-REIMS. The fatty acid and triacylglycerol species were structurally identified, and their abundances were analyzed according to multivariate statistical models mainly including principle component analysis as well as orthogonal partial least-squares analysis. On the shared and unique structure plot, the ions of m/z 255.23, 281.24, 877.72, and 901.72 displayed the most significant variation among the oxidized fish oil samples. Based on receiver operating characteristic curve analysis with an optimal Youden index of 0.91, these markers were further verified. The variation of viscosity and volatiles were also evaluated to further verify the oxidation characteristics of fish oil. The study demonstrated that ESII-REIMS technology used as an advanced detection method could ensure fish oil quality during storage.