Pickering emulsion gel stabilized by octenylsuccinate quinoa starch granule as lutein carrier: Role of the gel network

Recent advances of octenyl succinic anhydride modified polysaccharides as wall materials for nano-encapsulation of hydrophobic bioactive compounds

Polysaccharides can be esterified with octenyl succinic anhydride (OSA) to form derivatives with amphiphilic properties. The general preparation methods of OSA-polysaccharides are described, especially the aqueous method. The new hydrophobic groups introduced result in OSA-polysaccharides showing higher interfacial properties, better emulsifying stability, higher viscosity, and lower digestibility. There have been advances in the development of OSA-polysaccharides-based nano-encapsulation systems for hydrophobic bioactive compounds in recent years. Nano-encapsulation systems are formed through nanoemulsions, nanocapsules, nanoparticles, micelles, vesicles, molecular inclusion complexes, and so on. This review aims to describe the preparation methods, the structure characterizations, and the physicochemical properties of OSA-polysaccharides as encapsulating agents. In addition, the focus is on the different nano-encapsulation systems based on OSA-polysaccharides as wall materials. Future perspectives will concern OSA-polysaccharides-based nano-encapsulation systems with optimized functional properties for providing higher bioavailability and targeted delivery of various hydrophobic bioactive compounds. © 2022 Society of Chemical Industry.

Preparation and characterization of octenyl succinic anhydride-modified ginkgo seed starch with enhanced physicochemical and emulsifying properties

A quick preparation of octenylsuccinylated (OS)-ginkgo seed starch was proposed by lipase-coupling esterification within 30 min, and the physicochemical and emulsifying properties of OS-ginkgo seed starch were evaluated. High-performance liquid chromatography results revealed that ginkgolic acid in ginkgo seed starch was too low to be detected, which improved the biosafety and application range of OS-ginkgo seed starch. The degree of substitution (DS) of OS-ginkgo starch varied from 0.006 to 0.0169 depending on the lipase concentration increased from 0% to 1% (w/w, based on the volume of starch solution), and the reaction efficiency obtained the highest value of 68.5% at the lipase concentration of 1%. Fourier transform infrared spectra of OS-ginkgo seed starch confirmed ester carbonyl splicing in the starch molecular with the characteristic peaks at 1722 and 1567 cm^-1 . Scanning electron microscopy observations revealed that the esterification occurred mainly in the amorphous regions with slight morphological modification. X-ray diffractions suggested that no crystal change occurred on the starch granule. The thermal analysis revealed that OS-ginkgo seed starch showed a lower temperature and endothermic enthalpy for gelatinization, and presented enhanced and DS-dependent emulsifying properties and in vitro antidigestion properties. PRACTICAL APPLICATION: Results indicated that OS-ginkgo seed starch prepared by lipase-coupling esterification would be an alternative emulsion stabilizer for encapsulation and delivery of hydrophobic components. This study would provide an alternative method for the efficient and economical production of OS-ginkgo seed starch, thereby broadening its application in commercial exploitation.

Starch-lauric acid complex-stabilised Pickering emulsion gels enhance the thermo-oxidative resistance of flaxseed oil

Hydrophobic-modified starch complexes have the potential to form Pickering emulsions and improve the oxidative stability of flaxseed oil. Here, V-type starch-lauric acid complexes (SLACs) were fabricated via solid encapsulation within 0.5-12 h and applied in flaxseed oil Pickering emulsions. Complexing index, X-ray diffraction and differential scanning calorimetry analyses confirmed that the degree of complexation increased with the reaction time. Pickering emulsion gels stabilised by SLACs generated with reaction times of 6 h and 12 h exhibited good storage stability and high yield stress, G' values and apparent viscosity. Confocal laser scanning microscopy and cryo-scanning electron microscopy revealed a gelation mechanism involving increased interface roughness and enhanced droplet-droplet interaction. In comparison to pure flaxseed oil, higher thermo-oxidative resistance was observed at 130 °C, with a markedly longer oxidation induction for emulsions and emulsion gels stabilised by SLACs. Our findings could assist in the design of hydrophobic-modified starch and provide a new paradigm for delaying oil oxidation.

Construction of lipid-biomacromolecular compounds for loading and delivery of carotenoids: Preparation methods, structural properties, and absorption-enhancing mechanisms

Due to the unstable chemical properties and poor water solubility of carotenoids, their processing adaptation and oral bioavailability are poor, limiting their application in hydrophilic food systems. Lipid-biomacromolecular compounds can be excellent carriers for carotenoid delivery by taking full advantage of the solubilization of lipids to non-polar nutrients and the water dispersion and gastrointestinal controlled release properties of biomacromolecules. This paper reviewed the research progress of lipid-biomacromolecular compounds as encapsulation and delivery carriers of carotenoids and summarized the material selection and preparation methods for biomacromolecular compounds. By considering the interaction between the two, this paper briefly discussed the effect of these compounds on carotenoid water solubility, stability, and bioavailability, emphasizing their delivery effect on carotenoids. Finally, various challenges and future trends of lipid-biomacromolecular compounds as carotenoid delivery carriers were discussed, providing new insight into efficient loading and delivery of carotenoids.

Formation and stability of Pickering emulsion gels by insoluble soy peptide aggregates through hydrophobic modification

In this work, a highly stable food-grade Pickering emulsion gels was successfully prepared by hydrophobically modified insoluble soybean peptide aggregates. The relationships between the surface properties of insoluble soybean peptide aggregates and Pickering emulsion gels characteristics were clarified. After modification, the insoluble soybean peptide aggregates with high surface hydrophobicity had small particle size (377 nm), near-neutral wettability (θo/w = 92°) and strong interfacial adsorption capability. These allowed the modified insoluble soybean peptide aggregates to stabilize the oil-water interface and form continuous network surrounding oil droplets, leading to the formation of stable Pickering emulsion gels. Besides, Pickering emulsion gels prepared by insoluble soybean peptide aggregates with higher surface hydrophobicity had smaller droplet size and higher gel strength, and remained stable even after 60 days of storage. The findings suggest a preferable plant protein particle for the preparation of stable Pickering emulsion gels in food industry.

Encapsulation of indole-3-carbinol in Pickering emulsions stabilized by OSA-modified high amylose corn starch: Preparation, characterization and storage stability properties

The stability of hydrophobic bioactive compound indole-3-carbinol (I3C) is a challenge for application. In this work, Pickering emulsions were prepared to encapsulate I3C. As the emulsifier, high amylose corn starch was pretreated by acid hydrolysis, afterwards modified by different concentrations of octenyl succinic anhydride (OSA), and their emulsions were evaluated. The XRD, SEM and FTIR results indicated the successful modification. ζ-potential, mean droplet size and emulsification index (EI) of the emulsions confirmed that modified starch with a higher degree of substitution (DS) was more effective for enhancing the storage stability. The results of encapsulation efficiency (EE) and retention degree of I3C after 14 d also proved the assumption. Moreover, the Pickering emulsions protected I3C against ultraviolet light and achieved controlled release in vitro. The food-grade Pickering emulsion loading I3C is promising to be used as a nutrient or dietary supplement for food applications.

Chitosan films with tunable droplet size of Pickering emulsions stabilized by amphiphilic konjac glucomannan network

In this work, chitosan (CS) emulsion films were prepared with grapefruit essential oil (GEO) Pickering emulsions (OGEOs) stabilized by amphiphilic octenyl succinic anhydride (OSA) konjac glucomannan (OSA-KGM) network. The droplet size of emulsion was regulated by altering oil content in OGEOs (10 %, 20 %, 30 % and 40 %, w/w). The structural and physicochemical properties of CS films with tunable emulsion droplets (OGEOs) were investigated. The droplet size of OGEOs increased with the increasing content of GEO. FT-IR revealed that the formation of CS-OGEOs films was attributed to hydrogen bonding. CS-OGEOs films with large droplets presented smoother surface, enhanced water resistance, UV-shielding property, mechanical properties, but increased water vapor permeability (WVP) compared with CS-OGEOs films with small droplets. In addition, CS-OGEOs films with large droplets also presented compact film structure, controlled release of GEO, high efficiency of DPPH free radical scavenging and antibacterial activity. To sum up, incorporation of emulsion droplets was a good strategy for improving the structural and physicochemical properties of CS films.

Enzymatically modified quinoa starch-based Pickering emulsion: Effect of enzymolysis and emulsifying conditions

Both the effects of enzymolysis condition on the microstructures and emulsifying property of enzymatic modified quinoa starch (EMQS) and the effects of emulsion formulation on the EMQS based emulsions were investigated. The emulsifying capacity (EC) and stability (ES) of EMQS were positive correlated with enzyme amount (0-2.4 % w/w_starch). The particle sizes of EMQS decreased and its hydrophobicity increased with increasing enzyme amount (0-2.4 % w/w_starch), which were the main reasons for the increasing emulsifying performance of EMQS. With the increasing starch concentration, the EC of the EMQS increased, the oil droplet size of the emulsion decreased. With the oil/water ratios ranging from 1:9 to 6:4, the emulsification index (EI) and oil droplet size of the emulsion increased. EMQS based emulsion had a relatively good stability in the pH range of 2-10. This study lays the foundation for the application of EMQS as a stable clean-label Pickering emulsifier.

Pickering emulsion hydrogel based on alginate-gellan gum with carboxymethyl chitosan as a pH-responsive controlled release delivery system

Pickering emulsion hydrogels (PEHs) were developed as a pH-responsive, controlled-release delivery system to address the limitations of Pickering emulsions in some harsh processing or gastrointestinal conditions. Specifically, the PEHs were fabricated based on alginate and various concentrations of gellan gum (GG) with carboxymethyl chitosan (CMCS) matrix. The encapsulation efficiency (EE), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) results proved the successful encapsulation. Furthermore, the hydrogels remained stable in the presence of destabilizing ions (Na⁺ or phosphate ions) and high osmotic pressure mediums. The texture profile analysis (TPA) characteristics and Young's modulus of the 0.8 % GG (w/v) PEHs were superior to the others. The PEHs prevented the emulsions from being released at pH 2.0, while the emulsions were entirely released at pH 7.4 in vitro, with the rate of release controlled by CMCS and the degree by GG concentration. This work facilitates the delivery of Pickering emulsions with excellent stability and pH-responsive controlled release for hydrophobic actives in food applications.

Lipase-polydopamine magnetic hydrogel microspheres for the synthesis of octenyl succinic anhydride starch

Octenyl succinic anhydride (OSA) starch is an important edible additive in the food field, and its synthesis method has attracted much attention. Lipase as a biocatalyst can improve the synthesis efficiency of OSA starch, and significantly inhibit the occurrence of side reactions. However, free lipase has not been widely applied in the synthesis of OSA starch due to the difficulty of separation from starch and poor reusability. In this work, a promising strategy for the synthesis of OSA starch catalyzed by lipase immobilized on polydopamine magnetic hydrogel microspheres (PMHM) is reported. The prepared lipase-polydopamine magnetic hydrogel microspheres (L-PMHM) can be uniformly dispersed in starch slurry, which is conducive to the full contact between lipase and starch. L-PMHM (Km =2.6276 μmol/mL) exhibits better affinity to the substrate than free lipase (Km = 3.4301 μmol/mL). Compared with the OSA starch catalyzed by free lipase (DS = 0.0176), the degree of substitution of OSA starch catalyzed by L-PMHM is up to 0.0277 in a short reaction time. In cyclic catalysis, L-PHMM can remain about 48 % of their original activity after 20 reuses and can be quickly separated from the product. These results suggest that L-PMHM has great potential as a biocatalyst for the efficient synthesis of OSA starch.

Nano-enabled plant-based colloidal delivery systems for bioactive agents in foods: Design, formulation, and application

Consumers are becoming increasingly aware of the impact of their dietary choices on the environment, animal welfare, and health, which is causing many of them to adopt more plant-based diets. For this reason, many sectors of the food industry are reformulating their products to contain more plant-based ingredients. This article describes recent research on the formation and application of nano-enabled colloidal delivery systems formulated from plant-based ingredients, such as polysaccharides, proteins, lipids, and phospholipids. These delivery systems include nanoemulsions, solid lipid nanoparticles, nanoliposomes, nanophytosomes, and biopolymer nanoparticles. The composition, size, structure, and charge of the particles in these delivery systems can be manipulated to create novel or improved functionalities, such as improved robustness, higher optical clarity, controlled release, and increased bioavailability. There have been major advances in the design, assembly, and application of plant-based edible nanoparticles within the food industry over the past decade or so. As a result, there are now a wide range of different options available for creating delivery systems for specific applications. In the future, it will be important to establish whether these formulations can be produced using economically viable methods and provide the desired functionality in real-life applications.

Are quinoa proteins a promising alternative to be applied in plant-based emulsion gel formulation?

Emulsion gels are structured emulsion systems that behave as soft solid-like materials. Emulsion gels are commonly used in food-product design both as fat replacers and as delivery carriers of bioactive compounds. Different plant-derived proteins like soy, chia, and oat have been used in emulsion gel formulation to substitute fat in meat products and to deliver some vegetable dyes or extracts. Quinoa protein isolates have been scarcely applied in emulsion gel formulation although they seem to be a promising alternative as emulsion stabilizers. Quinoa protein isolates have a high protein content with a well-balanced amino acid profile and show good emulsifying and gelling capabilities. Unlike quinoa starch, quinoa protein isolates do not require any chemical modification before being used. The present article reviews the state of the art in food emulsion gels stabilized with vegetable proteins and highlights the potential uses of quinoa proteins in emulsion gel formulation.

Pickering Emulsion Stabilized by Tea Seed Cake Protein Nanoparticles as Lutein Carrier

To effectively deliver lutein, hydrothermally prepared tea seed cake protein nanoparticles (TSCPN) were used to fabricate Pickering emulsion, and the bioaccessibility of lutein encapsulated by Pickering emulsion and the conventional emulsion was evaluated in vitro. The results indicated that the average size and absolute value of zeta potential of TSCPN increased along with the increase in the protein concentration, and 2% protein concentration was adopted to prepare TSCPN. With the increase in the concentration of TSCPN, the size of Pickering emulsion decreased from 337.02 μm to 89.36 μm, and when the TSCPN concentration was greater than 0.6%, all emulsions exhibited good stability during the 14 days storage. Combined with the microstructure result, 1.2% TSCPN was used to stabilize Pickering emulsion. With the increase in ionic concentration (0-400 mM), the particle size of the emulsions increased while the absolute value of zeta potential decreased. TSCPN-based Pickering emulsion was superior to the conventional emulsion for both lutein encapsulation (96.6 ± 1.0% vs. 82.1 ± 1.4%) and bioaccessibility (56.0 ± 1.1% vs. 35.2 ± 1.2%). Thus, TSCPN-based Pickering emulsion in this study have the potential as an effective carrier for lutein.

Triggered and controlled release of bioactives in food applications

Bioactive compounds (e.g., nutraceuticals, micronutrients, antimicrobial, antioxidant) are added to food products and formulations to enhance sensorial/nutritional attributes and/or shelf-life. Many of these bioactives are susceptible to degradation when exposed to environmental and processing factors. Others involve in undesirable interactions with food constituents. Encapsulation is a useful tool for addressing these issues through various stabilization mechanisms. Besides protection, another important requirement of encapsulation is to design a carrier that predictably releases the encapsulated bioactive at the target site to elicit its intended functionality. To this end, controlled release carrier systems derived from interactive materials have been developed and commercially exploited to meet the requirements of various applications. This chapter provides an overview on basic controlled and triggered release concepts relevant to food and active packaging applications. Different approaches to encapsulate bioactive compounds and their mode of release are presented, from simple blending with a compatible matrix to complex multiphase carrier systems. To further elucidate the mass transport processes, selected diffusion and empirical release kinetic models are presented, along with their brief historical significance. Finally, interactive carriers that are responsive to moisture, pH, thermal and chemical stimuli are presented to illustrate how these triggered release mechanisms can be useful for food applications.

Fabrication and characterization of Pickering high internal phase emulsions stabilized by debranched starch-capric acid complex nanoparticles

High internal phase emulsions (HIPEs) stabilized by debranched starch-capric acid (DBS-CA) complex nanoparticles were fabricated and their performance was evaluated. DBS-CA was prepared through enzymatic debranching and solid encapsulation methods, and displayed V-type crystalline structure. Contact angle measurements show enhanced hydrophobicity of DBS-CA compared to native starch. The DBS-CA nanoparticles have an average size of 463.77 nm and tended to be aggregating as analyzed by scanning electron microscope and dynamic light scattering particle size analysis. When used as a particulate emulsifier, DBS-CA could stabilize HIPEs with oil volume fraction as high as 80%. The HIPEs showed pH-dependent properties; good storage stability and mechanical strength were achieved within pH range from 3 to 11, especially under alkaline conditions. It was proposed that smaller particle size and higher surface charging were responsible for the more tightly connected gel structure and thus their performance. This study demonstrates a novel approach to fabricate food-grade Pickering HIPEs, which may have many promising potential applications in the food industry.

Pickering Emulsions Stabilized by Tea Water-Insoluble Protein Nanoparticles From Tea Residues: Responsiveness to Ionic Strength

Tea water-insoluble protein nanoparticles (TWIPNs) can be applied to stabilize Pickering emulsions. However, the effect of ionic strength (0–400 mmol/L) on the characteristics of Pickering emulsions stabilized by TWIPNs (TWIPNPEs) including volume-averaged particle size (d_4,3), zeta potential, microstructure and rheological properties is still unclear. Therefore, this work researched the effect of ionic strength on the characteristics of TWIPNPEs. The d_4,3 of TWIPNPEs in the aquatic phase increased with the increase in ionic strength (0–400 mmol/L), which was higher than that in the SDS phase. Furthermore, the flocculation index of TWIPNPEs significantly (P < 0.05) increased from 24.48 to 152.92% with the increase in ionic strength. This could be verified from the microstructure observation. These results indicated that ionic strength could promote the flocculation of TWIPNPEs. Besides, the absolute values of zeta potential under different ionic strengths were above 40 mV in favor of the stabilization of TWIPNPEs. The viscosity of TWIPNPEs as a pseudoplastic fluid became thin when shear rate increased from 0.1 to 100 s⁻¹. The viscoelasticity of TWIPNPEs increased with increasing ionic strength to make TWIPNPEs form a gel-like Pickering emulsion. the possible mechanism of flocculation stability of TWIPNPEs under different ionic strengths was propose. TWIPNs adsorbed to the oil-water interface would prompt flocculation between different emulsion droplets under the high ionic strength to form gel-like behavior verified by CLSM. These results on the characteristics of TWIPNPEs in a wide ionic strength range would provide the theoretical basis for applying Pickering emulsions stabilized by plant proteins in the food industry.

Recent Advances on Pickering Emulsions Stabilized by Diverse Edible Particles: Stability Mechanism and Applications

Pickering emulsions, which are stabilized by particles, have gained considerable attention recently because of their extreme stability and functionality. A food-grade particle is preferred by the food or pharmaceutical industries because of their noteworthy natural benefits (renewable resources, ease of preparation, excellent biocompatibility, and unique interfacial properties). Different edible particles are reported by recent publications with distinct shapes resulting from the inherent properties of raw materials and fabrication methods. Furthermore, they possess distinct interfacial properties and functionalities. Therefore, this review provides a comprehensive overview of the recent advances in the stabilization of Pickering emulsions using diverse food-grade particles, as well as their possible applications in the food industry.

Pickering emulsion stabilized by composite-modified waxy corn starch particles

The starch-based Pickering stabilizer has attracted more research interest recently, however, its application in food system is limited due to the low digestibility of raw starch particles. In this study, waxy corn starches were modified with octenyl succinic anhydride and then treated by dry heating at 180 °C for 20-60 min. Pickering emulsions stabilized by the composite-modified starch particles were fabricated, the physical stability, rheology property and microstructure of the emulsions were investigated. The results showed that the composite-modified starches maintained granule structure, their gelatinization temperatures and enthalpy significantly reduced after heat treatment (p < 0.05). Compared with native starch, the composite-modified starches had bigger three-phase contact angles and higher in vitro digestibility, while the relative crystallinity decreased from 32.46% to 24.87%. Pickering emulsions stabilized by composite-modified starch particles had long-term stability up to 300 days. The rheology results showed that all emulsions exhibited pseudoplastic behaviors and had higher storage modulus than loss modulus. Moreover, the viscosities decreased when the starch was roasted for 40 and 60 min. The composite-modified starch particles and few starch macromolecules at oil-water interface stabilized the emulsions collectively. These results provide a new strategy for designing an edible Pickering stabilizer.

Characteristics and ethylene encapsulation properties of V-type linear dextrin with different degrees of polymerisation

The objective of this research was to investigate the effects of preparation method on the characteristics and ethylene loading capacity of V-type linear dextrin (LD). LD with different degrees of polymerisation were obtained from debranched starch by gradient ethanol precipitation. X-ray diffraction (XRD) patterns of samples obtained by precipitation and anti-solvent precipitation presented A + V-type crystalline structure. However, the percentage of V-type structure of samples obtained by anti-solvent precipitation was significantly higher than for samples prepared by precipitation, which was further confirmed by nuclear magnetic resonance spectroscopy (NMR), and molecular dynamics simulation supported the XRD and NMR results. The ethylene encapsulation capabilities of samples fabricated by different methods were in range of 1.15-4.68 cm³/g. Ethylene release from V-type LD was a physical process at different storage temperatures, and the higher percentage of V-type structure, the slower release rate. Thus, a higher V-type structure content was beneficial for encapsulation of gaseous molecules.

Dry heat treatment induced the gelatinization, rheology and gel properties changes of chestnut starch

The effects of continuous dry heat treatment (CT) and repeated dry heat treatment (RT) on gel and structural properties of chestnut starch (CS) were investigated. CT and RT both reduced the swelling degree of starch and showed significant variations in pasting viscosity, viscoelasticity, gel strength and hardness varying from high to low after dry heat treatment, and CT was lower than that of RT. Neither dry heat treatment nor gelatinization produced new functional groups, and both reduced short-range ordered degree. There were significant decrease in spin-spin relaxation time (T₂) with dry heat treatment (CT and RT), which made the starch in the samples closely combine with water. These results are helpful to better understand the changes of physicochemical properties of starch gel products during dry heat treatment and provide some theoretical references for the application of CS in food industry.

Proximate Composition, Physicochemical, Functional, and Antioxidant Properties of Flours from Selected Cassava (Manihot esculenta Crantz) Varieties

Cassava flour has a high potential to contribute as a raw material in the food industry. This study was aimed at characterizing flours from Sri Lankan cassava varieties with a view to explore the potential in food applications. Flours prepared from five cassava varieties, namely, Kirikawadi, MU51, Swarna, Shani, and Suranimala, were analyzed for proximate composition and physicochemical, functional, and antioxidant properties using standard methods. Flours from tested cassava varieties contained <1% crude fat and <2% crude protein. Flour from MU51 contained the highest amount of HCN (48.05 mg/kg) while flour from Suranimala contained the lowest (4.85 mg/kg). Total starch and amylose contents of flours were significantly lower (p < 0.05) than those of commercial wheat flour. Flour from Suranimala contained approximately similar amylopectin content as commercial wheat flour. Water absorption capacity, oil absorption capacity, water solubility index, swelling power, emulsion activity, and emulsion stability of flours from five cassava varieties were significantly higher (p < 0.05) than those of commercial wheat flour. Swarna was identified as the richest source of phenolic compounds (4.44 mmol GAE/100 g dry weight) among the five varieties. Results showed the promising application potential of flours from these five cassava varieties in different food applications such as weaning foods, bakery foods, and edible films.

Enhanced stability and controlled release of menthol using a β-cyclodextrin metal-organic framework

Menthol inclusion complexes (ICs) have addressed a range of opportunities in food applications due to their volatile resistance. However, previous protocols used for their synthesis give low yields and high industrial application costs. In the present investigation, metal-organic frameworks based on β-cyclodextrin (β-CD-MOF) have been prepared for the molecular encapsulation of menthol. Menthol/β-CD-MOF-IC was synthesized under the optimized parameters, after which release behavior was studied. In this optimized manner, a higher menthol capacity was obtained in which the menthol content and encapsulation efficiency were 27.1 and 30.6%, respectively. Compared with menthol/β-CD-IC, menthol/β-CD-MOF-IC is resistant to high temperature, but sensitive to moisture. In a simulated oral release experiment, the rate of menthol release from different samples followed the order of: pure menthol > β-CD > β-CD-MOF, which can be attributed to two mechanisms: non-specific binding and site preference. We propose that β-CD-MOF can be used as a promising delivery system for aroma compounds.

Comparison of Lutein Bioaccessibility from Dietary Supplement-Excipient Nanoemulsions and Nanoemulsion-Based Delivery Systems

The impact of lutein-loaded nanoemulsions and excipient nanoemulsions mixed with lutein-based dietary supplements (capsules and soft gels) on the bioaccessibility of lutein was explored using a simulated gastrointestinal tract (GIT). The particle size, particle size distribution, ζ-potential, microstructure, lipid digestibility, and lutein bioaccessibility of all the samples were measured after they were exposed to different environments (stomach and small intestine environments) within a simulated GIT. As expected, the bioaccessibility of lutein from the capsules (1.5%) and soft gels (3.2%) was relatively low when they were administered alone. However, the co-administration of excipient nanoemulsions significantly increased the bioaccessibility of lutein from both the capsules (35.2%) and soft gels (28.7%). This phenomenon was attributed to the fast digestion of the small oil droplets in the excipient nanoemulsions and the further formation of mixed micelles to solubilize any lutein molecules released from the supplements. The lutein-loaded nanoemulsions exhibited a much higher lutein bioaccessibility (86.8%) than any of the supplements, which was attributed to the rapid release and solubilization of lutein when the lipid droplets were rapidly and extensively digested within the small intestine. This study indicates that the bioaccessibility of lutein is much higher in nanoemulsion droplets than that in dietary supplements. However, consuming dietary supplements in the presence of nanoemulsion droplets can greatly increase lutein bioavailability. The results of this study have important guiding significance for the design of more effective lutein supplements.

Changes in the multi-scale structure and physicochemical properties of starch during potato growth

BACKGROUND

Growth stage contributes critically to the physicochemical properties of starches, which make achieving desired functional properties by controlling the growth period possible. Thus, this study investigated the changes in multiscale structure and physicochemical properties of potatoes starches harvested at different growth stages.

RESULTS

The amylose and phosphate content varied over the growth period, with the ranges 2.756-2.998 g kg^-1 and 0.0058-0.0077 g kg^-1 , respectively. The starch granules were round or oval, and the size increased with growth. X-Ray diffraction indicated the B-type crystalline structure of samples. Time-dependent changes in crystallinity were observed. The weight-average molecular weight (M_w ) showed a tendency to decrease first and then increase, and presented the lowest M_w (1.105 × 10⁸  g mol^-1 ) at 35 days. A higher proportion of long chains were noted in starch from earlier harvested potatoes than that in later harvested ones. Differential scanning calorimetry revealed that starch gelatinization temperature decreased, and gelatinization enthalpy decreased from 16.39 to 14.89 J g^-1 . All samples possessed weak elastic gel-like structure, and starches harvested at early stage possessed highest viscosity and stronger gel behaviour. Resistant starch showed a decreasing trend on the whole, and presented highest value (10.69%) at earliest harvest time. Starch from the potatoes harvested at 35 days after tuberization exhibited excellent light transmittance (up to 62.47%).

CONCLUSION

Potato starches harvested at different growth period presented extremely different structures and physicochemical properties. The results will provide fundamental data in terms of changes of potato starch during growth which will affect the choice of harvest time. © 2021 Society of Chemical Industry.

Pickering emulsifiers based on enzymatically modified quinoa starches: Preparation, microstructures, hydrophilic property and emulsifying property

Quinoa starch was developed as a new kind of Pickering emulsifier by enzymatic modification. The morphological structure, crystalline structure, lamellar structure, fractal structure, particle size distribution, contact angle, emulsion index (EI), and emulsion micromorphology were studied to explore the relationship between structure characteristics, hydrophilic property, and emulsifying properties of enzymatically modified (EM) quinoa starches. With the increasing enzymatic hydrolysis time in the test range of 0-9 h, particle size of EM quinoa starch decreased, and the broken starch and contact angle of EM quinoa starch increased; the EI value of emulsions with EM quinoa starch increased, and the oil droplet size of emulsions with EM quinoa starch decreased. It suggested that both the smallest particle size and the closest extent of the contact angle to 90° derived the best emulsifying property of EM-9. The EM quinoa starch had higher emulsifying capacity at higher oil volume fraction (Φ) (50%) than at lower Φ (20%), proving that the EM starch has potential to be used as Pickering emulsifiers in higher oil products, such as salad dressing.

Complexation between High-Amylose Starch and Binary Aroma Compounds of Decanal and Thymol: Cooperativity or Competition?

The use of combinations of aroma compounds is common in many food and cosmetic applications. To investigate the binding behavior between high-amylose maize starch and binary aroma combinations of decanal and thymol, starch-aroma inclusion complexes (ICs) were prepared by a one-step or two-step method with different concentrations and orders of addition. The thymol molecule induced the starch chain to form a larger helical cavity and was more likely to form hydrogen bonds with solvents. The encapsulation efficiency and loading efficiency of starch-thymol ICs were always higher than those of starch-decanal ICs, independent of the aroma concentration and addition order in binary aroma ICs. However, starch-decanal ICs prepared in the presence of thymol encapsulated more decanal than in the absence of thymol. The V_6I-type crystals formed by starch-decanal ICs and the V_6III-type crystals formed by starch-thymol ICs were both present in binary aroma ICs, resulting in a less-ordered structure and lower thermal transition temperatures. In summary, the complexation between binary aroma compounds and starch exhibited both cooperative and competitive binding behaviors. The synergistic effects between decanal and thymol provide guidance in enhancing the aroma encapsulation in starch carriers.

New insights into food O/W emulsion gels: Strategies of reinforcing mechanical properties and outlook of being applied to food 3D printing

3D printing technology has been widely used in food processing with its advantages of customized food design, personalized nutrition design, and simplified food supply chain. Food emulsion gels have application value and prospects in food 3D printing due to their promising properties, including biodegradability, biocompatibility, as well as dual characteristics of emulsions and biopolymer gels. Food emulsion gels with appropriate mechanical properties, as a new type of food inks, expand the types and functions of the inks. However, food emulsion gels without adequate reinforced mechanical properties may suffer from defects in shape, texture, mouthfeel, and functionality during 3D printing and subsequent applications. Therefore, it is necessary to summarize the strategies to improve the mechanical properties of food emulsion gels. According to the methods of characterizing the mechanical properties of emulsion gels, this article summarizes four strategies for improving the mechanical properties of emulsion gels through two ways: inside-out (reinforcement of interface and reinforcement of cross-linking) and outside-in (physical approaches and environmental regulations), as well as their basic mechanisms. The application status and future research trends of emulsion gels in food 3D printing are finally discussed.

Recent Innovations in Emulsion Science and Technology for Food Applications

Emulsion technology has been used for decades in the food industry to create a diverse range of products, including homogenized milk, creams, dips, dressings, sauces, desserts, and toppings. Recently, however, there have been important advances in emulsion science that are leading to new approaches to improving food quality and functionality. This article provides an overview of a number of these advanced emulsion technologies, including Pickering emulsions, high internal phase emulsions (HIPEs), nanoemulsions, and multiple emulsions. Pickering emulsions are stabilized by particle-based emulsifiers, which may be synthetic or natural, rather than conventional molecular emulsifiers. HIPEs are emulsions where the concentration of the disperse phase exceeds the close packing limit (usually >74%), which leads to novel textural properties and high resistance to gravitational separation. Nanoemulsions contain very small droplets (typically d < 200 nm), which leads to useful functional attributes, such as high optical clarity, resistance to gravitational separation and aggregation, rapid digestion, and high bioavailability. Multiple emulsions contain droplets that have smaller immiscible droplets inside them, which can be used for reduced-calorie, encapsulation, and delivery purposes. This new generation of advanced emulsions may lead to food and beverage products with improved quality, health, and sustainability.