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The term “superfruit” usually refers to certain fruits, which are rich in antioxidant components, therefore, are beneficial to human health. In China, there has been the concept of health preservation and dietary therapy through food intake in a long history. However, some other superfruits growing mainly in China have not attracted extensive attention, such as Cili, Goji berry, and sea buckthorn. Many studies suggested all of these superfruits showed strong antioxidant effects and anti‐inflammatory activity in common. However, there are various other advantages and functions in different fruits. This article reviewed the research findings from the existing literature published about major antioxidant bioactive compounds and the potential health benefits of these fruits. The phytochemicals from superfruits are bioaccessible and bioavailable in humans with promising health benefits. More studies are needed to validate the health benefits of these superfruits. It would provide essential information for further research and functional food development., This paper reviewed the recent studies on superfruits in China and emphasized their valuable or unique bioactive components and their nutritional and medicinal values.

Calcium carbonate (CaCO

Phytosterols are natural plant-based bioactive compounds that can lower blood cholesterol levels and help prevent cardiovascular diseases. Consequently, they are being utilized in functional foods, supplements, and pharmaceutical products designed to improve human health. This paper summarizes different approaches to isolate, purify, and characterize phytosterols. It also discusses the hypolipidemic mechanisms of phytosterols and their impact on cholesterol transportation. Phytosterols have a low water-solubility, poor chemical stability, and limited bioavailability, which limits their utilization and efficacy in functional foods. Strategies are therefore being developed to overcome these shortcomings. Colloidal delivery systems, such as emulsions, oleogels, liposomes, and nanoparticles, have been shown to be effective at improving the water-dispersibility, stability, and bioavailability of phytosterols. These delivery systems can be used to incorporate phytosterols into a broader range of cholesterol-lowering functional foods and beverages. We also discuses several issues that need to be addressed before these phytosterol delivery systems can find widespread commercial utilization.

Oil bodies (OBs) are micron- or submicron-sized sub-organelles widely found in plants seeds and nuts. The structure OBs is composed of a core of triglycerides covered by a phospholipid-protein layer, which ensures the stability of the OBs under extreme environmental conditions and further protects core lipids as energy reserves. As naturally pre-emulsified oil-in-water emulsions, OBs have been gradually applied to replace synthetically engineered oil droplets. In this paper, the recent research on the composition, extraction, stability, delivery system, digestion, food applications and future perspectives of plant OBs are reviewed. Recent studies have focused on the OBs surface protein identification and function, large-scale extraction techniques such as enzyme assisted, high pressure, ultrasound, and extrusion and the reconstituted OBs. Electrostatic deposition of polysaccharides significantly improves the stability of OBs emulsions. OBs emulsions have promising applications to encapsulate bioactive compounds, deliver targeted drugs, and prepare gels and edible functional films. The digestive behavior of OBs emulsions is similar to that of protein-stabilized emulsions, which can increase the satiety, effectively help reduce calorie intake and improve the bioavailability of functional factors. It has also promoted the development of simulated dairy, spices and meat products.

The aim was to investigate rosemary extract with different addition methods affecting the physicochemical stability of WPI-coated lutein emulsions and examine the correlations between lutein degradation and WPI oxidation during storage. First, lutein emulsions containing different concentrations of rosemary extract in the oil phase were prepared. Second, lutein emulsions containing rosemary extract in the oil phase or water phase were studied along with the kinetic reaction of lutein degradation. Moreover, the impact of rosemary extract on the oxidation of WPI and their products was also determined. It was noticed that rosemary extract at 0.05 wt.% exhibited the best protection of lutein. According to the kinetics analysis of lutein degradation, the direct addition of rosemary extract in the oil phase was more suitable for retarding the degradation of lutein in emulsion than the addition in the aqueous phase due to it being partitioned at the interface. Meanwhile, it was revealed that the addition of rosemary extract in the water phase exhibited better inhibition of the WPI oxidation than addition in the oil phase. The understanding of the association and driving forces of rosemary extract in emulsion systems may be useful for the application of rosemary extract in multicomponent food systems.

Docosahexaenoic acid (DHA) was encapsulated in caseinate/alginate microparticles by adjusting the pH based on the electrostatic complexation, in order to improve the physicochemical stability and digestibility of single caseinate-stabilized DHA emulsions. In this study, relatively stable honeycomb-shaped DHA microparticles were formed by electrostatic complexation between positively charged caseinate-coated DHA droplets, caseinate and negatively charged alginate at pH 4.5. The zeta-potential, particle size, size distribution, physical stability, microstructure, DHA oxidation and free fatty acids (FFA) release rate in a simulated gastrointestinal tract (GIT) model were determined. Dynamic light scattering (DLS) and confocal laser scanning microscopy (CLSM) measurements indicated that DHA microparticles had a particle size (1521.00 ± 39.15 nm) significantly larger than that of caseinate-stabilized DHA emulsions (243.23 ± 4.51 nm). The microparticles were much more stable near the isoelectric point (pI) of the adsorbed proteins compared with the single emulsions according to the original transmissions of LUMiSizer. The cryo-scanning electron microscopy (Cryo-SEM) images also showed that the microparticles formed a specific honeycomb-shaped network structure with more uniform distribution and without aggregation. The incorporation of DHA droplets into caseinate/alginate microparticles significantly ameliorated their chemical stability. GIT studies showed that the digestion of DHA microparticles was enhanced which was due to more open loose structures compared with the large-scale close-knit aggregation of DHA emulsion droplets. This study may provide useful information for the stabilization of functional food components and rational design of nutraceutical delivery systems.

This paper systematically compared the effects of heteroaggregation, layer-by-layer and directly mixing techniques on the physical properties of emulsions through mechanical rheology, microrheology, LUMisizer stability analyzer, Cryo-scanning electron microscopy (Cryo-SEM) and in vitro simulated gastrointestinal model. The shear rheology results showed that the viscosity of emulsions stabilized with whey protein isolate (WPI) and flaxseed gum (FG) by different techniques was in the order of heteroaggregated emulsion > layer-by-layer emulsion > directly mixing emulsion. Furthermore, it confirmed that the heteroaggregated emulsion had a best stability and the interface moving speed was the slowest compared with those of layer-by-layer and directly mixing emulsions. Cryo-SEM microstructure results showed that the three dimensional network structure of heteroaggregate was the main reason for maintaining high stability and shear rheological properties. Microrheological properties results indicated that heteroaggregated emulsion was sensitive to the shearing force due to the liquid behavior. While, the structures of WPI-FG emulsions prepared by layer-by-layer and directly mixing were not destroyed after shearing due to their high elasticity and solid behaviors. It was found that the order of released FFA content at the beginning of 30 min was directly mixing emulsion > layer-by-layer emulsion > heteroaggregated emulsion, but the released free fatty acid of heteroaggregated emulsion was the most in the end, which indicated that heteroaggregated emulsion had a certain controlled release effect. The study could be helpful for choosing proper technique to gain good emulsion delivery system.

The impact of oil content on the stability, shear rheology, microrheology and microstructure of heteroaggregated emulsions with 40% whey protein isolate (WPI)-coated droplets and 60% flaxseed gum (FG)-coated droplets at pH 3.0 was studied. The mean particle size, zeta-potential, physical stability, the mean square displacement (MSD), solid liquid balance (SLB), viscosity and Cryo-SEM microstructure of the heteroaggregated emulsions as a function of oil contents ranging from 10% to 30% were measured. It was found that the physical stability and viscosity of the heteroaggregated emulsion was decreased with increasing oil content. MSD curves showed that the particle motion of heteroaggregated emulsions with increasing oil contents was obviously accelerated at a shorter decorrelation time, which indicated that elastic behavior would be dominated with higher oil content (20% & 30%). Cryo-SEM microstructure proved that the specific three-dimensional network of the heteroaggregated emulsion could be formed at low oil content (10% & 15%) by the strong electrostatic and steric interactions between droplets and free WPI and FG. It proved that heteroaggregates formed by WPI-coated droplets and FG-coated droplets may be useful for creating specific food structures that lead to desirable viscosity at low fat content.

This study aimed to evaluate the effect of sodium caseinate (SC) on the thermal stability of Monascus pigments (MPs) under acidic conditions (pH 3.0) during heating at 100 °C at different time (0, 30, 60, 90 and 120 min). The MPs solution was precipitated after heating in an acidic condition, while it was stable in the presence of SC. Particle size results indicated the formation of MP-SC complex nanoparticles. Their values (141) were much smaller than MP and significantly improved the solubility and stability of MP in acidic conditions. The formation of covalent interactions (CC at peak 1643-1654 and NO stretching at peak (1537-1539) and hydrogen bonds (CH binding at peak 1452-1454) between MPs and SC were clear. Overall, the formation of the MP-SC complex was attributed to the covalent interactions and hydrogen bonds between MPs and SC, leading to the inhibition of MPs aggregation and improved stability in acidic solution.

In this study, two modified silica nanoparticles (SiO2-GA NPs) were successfully obtained by covalently grafting gallic acid onto silica nanoparticles. The mean particle diameters of their were 112.7 ± 0.55 nm (1-SiO2-GA NPs) and 408.7 ± 3.20 nm (4-SiO2-GA NPs), respectively. Novel antioxidant active packaging composite films were prepared by incorporation of 1-SiO2-GA NPs or 4-SiO2-GA NPs into chitosan. The structure analysis of the composite films showed that intermolecular hydrogen bonds were formed between the two modified silica nanoparticles and chitosan. Compared with the chitosan film, the mechanical properties, water vapor barrier property and UV light barrier ability of the composite films were significantly improved. Moreover, the incorporated of the two modified silica nanoparticles significantly increased antioxidant activity of the composite films. This study indicates that composite films incorporated with modified silica nanoparticles, especially the incorporation of 1-SiO2-GA NPs can be used as novel antioxidant food packaging composite films.

In this paper, we propose a facile program of preparing nanoscale γ-cyclodextrin-based metal-organic frameworks (Nano-CD-MOFs) for the encapsulation of curcumin. Such Nano-CD-MOFs not only possess excellent mono-dispersity and crystalline structure, but also perform superior loading capacity. The results of N

The removals of chlorothalonil, pyrazophos, and carbendazim residues form pakchoi by ultrasonic treatment were investigated in this study. The ultrasonic treatment has higher efficiency on the removal of pesticides compared to traditional water soaking. The removal rates of ultrasonic treatment for chlorothalonil, pyrazophos, and carbendazim residues were in the range of 13.87–74.86%, 21.74–45.68%, and 5.12–24.63%, respectively. The removal rates increased with the increase of ultrasonic power, while decreased with the increase of ultrasonic frequency. Besides, the physical damage and vitamin C loss for pakchoi leaves caused by ultrasonic treatment were also evaluated. Results showed that both the physical damage and vitamin C loss increased with the increase of ultrasonic power but decreased with the increase of ultrasonic frequency. A simple three-variable linear model was built up to estimate the loss of vitamin C according to the physical damage on leaves. In conclusion, ultrasonic treatment is an effective technique for the removal of pesticide residues from leafy vegetables. Ultrasonic condition should be considered to avoid the physical damage and the vitamin C loss for vegetables.

Monascus pigment is a natural food pigment and is commonly used for coloring and as antiseptic of cured meat products, confectionery, cakes, and beverages. However, Monascus pigment is sensitive to environmental conditions. The main aim of this study was to investigate the effect of polyglycerol polyricinoleate (PGPR) and soy protein isolate (SPI) on the particle size, zeta potential, physical stability, microstructure, and microrheological properties of Monascus pigment double emulsions. The effects of ionic strength, heating, and freeze thawing treatment on the stabilities of Monascus pigment double emulsions were also characterized. It was found that the optimum PGPR and SPI concentrations for fabricating Monascus pigment double emulsion were 3.6 and 3.0 wt%, respectively. The fabricated Monascus pigment double emulsion was composed of fine particles with narrow and uniform size distributions. Microrheological property results suggested that the elastic characteristic of the Monascus pigment double emulsion was dominated with increasing PGPR and SPI contents. It was mainly due to the increased collision and interaction between the droplets during the movement resulting in force increasing. Monascus pigment double emulsions with 2 prevented calcium to destroy the physical stability of emulsions, while Monascus pigment double emulsions with more than 10 mM CaCl2 formed creaming. After freeze thawing treatment, creaming occurred in Monascus pigment double emulsion. However, it was stable against heating treatment due to heating leading to a dense network structure. It could be contributed to the practical applications of Monascus pigment double emulsions in food products.

In this study, biopolymer microparticles were fabricated for the encapsulation and delivery of lutein by electrostatic complexation of sodium caseinate (NaCas) and sodium alginate (ALG) to improve its physicochemical stability and bioaccessibility. The construction conditions of lutein microparticles were determined by analysis of the particle size, zeta-potential, physical stability and microstructure. The formation mechanism of lutein microparticles was examined by Fourier transform infrared spectroscopy (FTIR) analysis. Moreover, the crystalline structure change of lutein was characterized by X-ray diffraction (XRD) and Differential scanning calorimetry (DSC). Bioaccessibility of lutein was also investigated in a simulated gastrointestinal tract (GIT) model. Lutein microparticles were rough irregular structures with larger mean particle size of 1750 ± 2.24 nm, higher physical stability and negative zeta-potential (−54.03 ± 0.38 mV) when the optimized concentration of NaCas and ALG were 2.0 wt%, respectively. FTIR analysis indicated the electrostatic interaction between the amino group of the caseinate and the carboxyl group of the alginate in the formation of microparticles. XRD and DSC analysis confirmed that lutein was encapsulated in microparticles as an amorphous state. Meanwhile, the microparticles effectively reduced the decomposition of lutein during 22 d storage at 37 °C. GIT studies showed that the microparticles presented higher free fatty acid (FFA) release and lutein bioaccessibility (51.27 ± 0.78%) than emulsions (12.83 ± 1.43%). This study provided a broad prospect for the formulation of lutein-fortified functional foods and beverages.

In this study, the interaction of ovalbumin with lutein dipalmitate and the effect of ovalbumin on marigold lutein esters extracts were investigated. Lutein dipalmitate quenched the fluorescence of ovalbumin by static quenching. Binding and thermodynamic parameters proved that lutein dipalmitate bound to ovalbumin spontaneously by van der Waals force and hydrogen bond, and the complex stoichiometry was 1:1. Through three-dimensional fluorescence spectroscopy, Fourier transform infrared spectroscopy and circular dichroism experiments, the conformation of ovalbumin was unfolded, and alteration in the ovalbumin secondary structure induced by lutein dipalmitate was observed. The results of transmission electron microscopy and particle size revealed that there were spherical and nano-sized aggregates in the ovalbumin-lutein dipalmitate system, indicating the lutein dipalmitate not only could bind to ovalbumin at molecular level, but also promote the aggregation of ovalbumin. Additionally, the addition of ovalbumin had a positive effect on the stability of marigold lutein esters extracts.

Spray drying is an economic technique used in preservation and production of Monascus pigment powder. This study was performed to encapsulate the Monascus pigment with maltodextrin using spray drying technique with three types of carrier agents: propylene glycol, mannitol and polyglycerol ester at different concentrations (0.5%, 1% and 1.5%). Analyses of particle size, the spattering behavior, microstructure, color value, and thermal profile were performed on the obtained powder. The addition of propanediol, mannitol and polyglycerol ester in combination with maltodextrin led to an increase of 17.5%, 45.8%, and 23.5% in the volume mean diameter of Monascus pigment powder, respectively. The decrease of spattering of Monascus pigment with maltodextrin was clearly evident in the case of formulations containing 1.5% polyglycerol ester. Scanning electronic microscopy analyses showed that Monascus pigment particle treated with maltodextrin exhibited microstructures that were smooth and dented, while the particles treated with carriers exhibited rough, irregular surface and adherence of smaller particles on their surfaces. UV–visible spectroscopy proved that the addition of carriers did not influence the molecular structure of Monascus pigment compared to the powder without carrier treatment. Differential scanning calorimeter analysis revealed that mannitol enhanced water vaporization during spray drying process as lower enthalpy change was observed in thermogram. The addition of an appropriate carrier (0.5%, 1.5% propanediol or 1% mannitol) improved the color values of Monascus pigment.

Recent studies have shown that controlled heteroaggregation of oppositely charged lipid droplets can be used to control the rheological properties of emulsion. The effect of unadsorbed emulsifier on the microstructure and rheological properties of heteroaggregate of emulsion is not clear. Therefore, the influence of unadsorbed emulsifiers (whey protein isolate-WPI & Flaxseed gum-FG) on the microstructure and rheological properties of heteroaggregate of 40% WPI-coated droplets and 60% FG-coated droplets was studied. WPI-stabilized emulsions and FG-stabilized emulsions were centrifuged to separate the aqueous phase from the oil droplets to prepare the washed emulsions, separately. Emulsions containing mixtures of droplets with washed and unwashed WPI-emulsion and FG-emulsion were prepared, respectively. Droplet size, zeta-potential, transmission-physical stability, rheological behavior, and Cryo-SEM microstructure of the heteroaggregates were measured as a function of unwashed and washed WPI & FG emulsion. It was found that the presence of unadsorbed WPI in the aqueous phase of mixed emulsion adsorbed onto the FG-coated droplets, meanwhile, the unadsorbed FG could bind WPI-droplet and FG-droplet-WPI together forming a special three-dimensional network. Rheological properties indicated that free WPI and FG played dominated roles in the heteroaggregation of mixed emulsions. The shearing viscosity of the heteroaggregates formed by washed WPI-droplets and FG-droplets was significantly decreased compared with the unwashed mixed emulsion. Microrheological analysis showed that heteroaggregate of mixed emulsion became liquid behavior after washing compared to the solid behavior of unwashed emulsion. It indicated that unadsorbed WPI and FG dominated the physical property through a specific network structure. This study proved the effect of the continuous phase on the rheological properties of heteroaggregates and provided theoretical basis for the development of reduced-fat food.

It was reported that the controlled heteroaggregation of oppositely charged lactoferrin (LF)-lutein droplets and whey protein isolate (WPI)-DHA droplets enhanced the physicochemical properties of emulsions. The effect of the unadsorbed proteins on the physicochemical properties of the heteroaggregates of emulsions has not been clear. Therefore, the effects of unadsorbed proteins on the physicochemical stability of heteroaggregates of LF-lutein droplets and WPI-DHA droplets were investigated. The particle size, zeta-potential, transmission-physical stability, microstructure were observed by confocal laser scanning microscopy (CLSM) and cryo-scanning electron microscopy (cryo-SEM) and the chemical stability (lutein degradation and DHA oxidation) of the unwashed and washed heteroaggregates were measured. The results showed that compared with unwashed emulsions, the particle sizes and instability indexes of WPI-DHA emulsions, heteroaggregated LF-lutein/WPI-DHA emulsions and LF-lutein emulsions changed after washing. The instability index of washed-1 heteroaggregated LF-lutein/WPI-DHA emulsion was 10.5 times greater compared with the unwashed samples. The microstructure images showed that the washed single and heteroaggregated emulsions resulted in creaming. The unadsorbed proteins had a great protective effect on the physical stability of the emulsions, especially for the heteroaggregated LF-lutein/WPI-DHA emulsion. The degradation rate of lutein, lipid hydroperoxides and thiobarbituric acid reactive substance (TBARS) values of DHA in washed single and heteroaggregated emulsions were higher than those of the unwashed samples. This proved that the unadsorbed proteins dominated the physicochemical stabilities of heteroaggregates. This laid the foundation for the study of a delivery system of functional component heteroaggregates.

Rice bran as a by-product of rice processing can be used to produce oil. Aqueous enzymatic extraction (AEE) of rice bran oil (RBO) was performed in this study. The physicochemical properties, fatty acid compositions, bioactive compounds, antioxidant activity and thermal behavior of AEE-extracted oil (AEEO) were evaluated and compared with those of Soxhlet-extracted oil (SEO). It was found that iodine value and saponification value in the AEEO were higher than the SEO. AEEO with lower acid value and peroxide value was considered to be a high quality. The contents of wax and phospholipid in AEEO were lower, which could simplify the refining steps. Additionally, AEEO exhibited a higher content of unsaturated fatty acids (76.31%), sum of tocopherols and tocotrienols (1004 mg/kg), sterols (7749 mg/100 g), squalene (2962 mg/kg), oryzanol (2.43 g/100 g). The antioxidant activity of AEEO (EC50 = 5.52 mg/mL) was better than that of SEO (EC50 = 8.66 mg/mL). Moreover, AEEO was found to have lower crystallization and melting points. Scanning electron microscope (SEM) results showed the destruction of cell walls and the decrease of substances in the cell by AEE. Overall, the present results showed the improvement in the quality of the AEEO for green extraction of RBO.

Grape seed procyanidin extract (GSPE) can modulate intestinal dysfunction, however; the mechanism needs to be clarified. This study aims at investigating the beneficial effect of GSPE on intestinal epithelial integrity and its regulatory mechanism. The results showed that consumption of high-fat (HF) diet for 13 weeks increased intestinal permeability. GSPE (200 mg/kg·bw) treatment reduced the concentration of lipopolysaccharide (LPS) in the circulatory system. The expression of tight junction proteins increased in GSPE-treated rats. Moreover, GSPE treatment inhibited the expression of pro-inflammatory mediators. The flow cytometry results revealed that GSPE treatment significantly increased the proportion of CD4+ CD25+ Foxp3+ Tregs in gut-associated lymphoid tissue. GSPE modulated the composition of the gut microbiota and Spearman's correlation analysis revealed that the genera Anaerotruncus, Blautia, Oscillibacter, and Ruminococcaceae_UCG-004 were related to intestinal permeability indices. In conclusion, GSPE ameliorated intestinal barrier dysfunction in HF diet-fed rats, probably via the regulation of intestinal immune balance and intestinal microbiota.

Bacteriocins are ribosomally synthesized antibacterial peptides or proteins from microorganisms. We report a novel bacteriocin producing strain, Enterococcus faecalis Gr17, that was isolated from the Chinese traditional low-salt fermented whole fish product Suan yu. E. faecalis Gr17 displayed potent antibacterial activity against foodborne pathogenic and spoilage bacteria. The complete genome of E. faecalis Gr17 contained one circular chromosome and plasmid. The gene cluster of a novel bacteriocin designated enterocin Gr17 was identified. The enterocin Gr17 structural gene encodes a precursor of the bacteriocin. Two other transporter genes and an immunity gene within two divergent operons were identified as being associated with enterocin Gr17 secretion and protection. The novel enterocin Gr17 was purified by ammonium sulfate precipitation, cation exchange, gel filtration, and reverse-phase high-performance liquid chromatography. The molecular weight of enterocin Gr17 was 4,531.01 Da as determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and its mature amino acid sequence of enterocin Gr17 was RSYGNGVYCNNSKCWVNWGEAKENIIGIVISGWATGLAGMGR. Sequence alignment revealed that enterocin Gr17 is a class IIa bacteriocin with similarities to enterocin P. The merits of bactericidal activity, sensitivity to enzymes, and pronounced stability to chemicals, temperature (60°C, 30 min and 121°C, 15 min), and pH (2-10) indicated practicality and safety of enterocin Gr17 in the food industry. The complete genome information of E. faecalis Gr17 will improve the understanding of the biosynthetic mechanism of enterocin Gr17, which has potential value as a food biopreservative.

Bovine serum albumin (BSA) is a natural protein commonly used to prepare nanoparticle to encapsulate food ingredients. The interaction between lutein dipalmitate and BSA was investigated using fluorescence, UV–vis absorption, circular dichroism (CD) spectroscopies and molecular docking. The fluorescence quenching study suggested the quenching process of BSA by lutein dipalmitate was static, which was consistent with the results of UV–vis absorption. The binding parameters proved that the binding stoichiometry between BSA and lutein dipalmitate was 1:1. Molecular docking revealed that lutein dipalmitate bound to site I on BSA, which was confirmed by site competitive experiments. Moreover, thermodynamic study and molecular docking suggested lutein dipalmitate spontaneously bound to BSA by hydrogen bond, van der Waals force, and hydrophobic interaction. The synchronous and three-dimensional fluorescence showed that the microenvironment of Tyr and Trp was changed and the protein skeleton got loosened in the presence of lutein dipalmitate. According to CD, a decrease in α-helix content of BSA was observed upon the addition of lutein dipalmitate.

The impact of flaxseed gum (FG) on the microrheological properties and physicochemical stability of whey protein isolate (WPI) stabilized β-carotene emulsions at pH 3.0 was studied. A layer-by-layer electrostatic deposition method was used to prepare multilayered β-carotene emulsions with interfacial membranes consisting of WPI and FG. The microrheological behavior of the multilayered β-carotene emulsions was measured through the diffusive wave spectroscopy technique. WPI alone and WPI-FG (concentration of FG = 0.1, 0.2, 0.3 wt%) stabilized β-carotene emulsions were purely viscous giving a mean square displacement that scaled linearly with decorrelation time (τ). The presence of 0.01, 0.02, and 0.05 wt% FG in the WPI-stabilized emulsions caused them to exhibit viscoelastic properties. Meanwhile, the increase in τ reflected the increase in the length scale of connectivity in the emulsions until a "cluster" was formed and the droplets were not free to move due to droplet-network interaction. The apparent increase in the macroscopic viscosity and elasticity index and decrease in the solid lipid balance and fluidity index of emulsions with lower concentrations (0.01, 0.02, 0.05 wt%) of FG indicated that the bridging flocculation of FG had a much more appreciable influence on the microrheological properties than depletion flocculation (higher concentrations, 0.1, 0.2, 0.3 wt%). Droplet size, zeta-potential, and transmission profiles using the centrifugal sedimentation technique and β-carotene degradation during storage were also characterized. With the addition of FG, the zeta-potential of WPI coated β-carotene droplets decreased from positive to negative, and an increase in the apparent droplet size was also noted. LUMISizer analysis exhibited an improvement in physical stability with the addition of 0.1 wt% FG. FG also helped to chemically stabilize the WPI emulsions against β-carotene degradation mainly by slowing down the mobility of the droplets.

The influence of calcium-induced droplet heteroaggregation on the formation and physicochemical stability of mixed lutein and DHA emulsions was studied. Heteroaggregation was induced by mixing oppositely charged lactoferrin (LF)-coated lutein and whey protein isolate (WPI)-coated DHA emulsions with different CaCl2 concentrations at pH 6.0. The droplet size, zeta-potential, transmission-physical stability and microstructure behavior (CLSM and Cryo-SEM) of single-protein emulsions and mixed emulsions were measured as a function of different CaCl2 concentrations. Lutein degradation and DHA oxidation by measurement of lipid hydroperoxides and thiobarbituric acid reactive substances were determined during storage. The physical stability of the mixed emulsions could be modulated by controlling CaCl2 concentrations. Microstructure behavior indicated that a mixed emulsion with 30 mM CaCl2 promoted more droplets to form a special three-dimensional network and microcluster structures. The chemical stability of the mixed lutein and DHA emulsions was obviously enhanced by the addition of 30 mM CaCl2. The decreased surface areas of the DHA and lutein droplets and the physical barrier of the network of heteroaggregates against transition metals and free radicals could mainly explain the improvement in chemical stability. Calcium-induced droplet aggregation may be useful for creating specific food structures that lead to desirable physicochemical properties of multiple functional components.

Background: Ultrasound treatment has been shown to be an effective technique for improving the activity of immobilized enzymes. However, its mechanism is unclear.; Results: The effect of ultrasonic pretreated chitosan-sodium alginate (CHI-ALG) on the enzymatic activity of papain was investigated via a single factor (temperature, time, frequency, power) experiment. The maximum relative enzyme activity of papain was observed when it was mixed with ultrasound pretreated CHI-ALG at 135 kHz, 0.25 W cm-2 and 50 °C for 20 min, during which the relative activity increased by 72.14% compared to untreated CHI-ALG. Viscosity analysis of papain mixed with CHI-ALG pretreated and untreated with ultrasound revealed that stronger association interactions between the polymers were formed compared to the untreated sample. Fluorescence and circular dichroism spectra indicated that the ultrasonic pretreatment of CHI-ALG increased the number of tryptophan on the papain surface and also increased the content of α-helix by 6.97% and decreased the content of β-sheet by 3.45% compared to the untreated solution.; Conclusion: The results of the present study indicate that papain combined with CHI-ALG pretreated with the appropriate ultrasound could be effective technique for improving the activity of immobilized enzymes as a result of changes in its structure and intermolecular interactions. It is important to extend the application of CHI-ALG gel in the immobilized enzyme industry. © 2016 Society of Chemical Industry.; © 2016 Society of Chemical Industry.

The impact of chitosan (CTS) on the physicochemical stability, microrheological property and microstructure of whey protein isolate (WPI)-flaxseed gum (FG) stabilized lutein emulsions at pH 3.0 was studied. A layer-by-layer electrostatic deposition method was used to prepare multilayered lutein emulsions. Droplet size, zeta-potential, instability index, microstructure and microrheological behavior of lutein emulsions were measured. The influences of interfacial layer, metal chelator and free radical scavenger on the chemical stability of lutein emulsions were also investigated. It was found that multilayer emulsions had better physical stability showing the pronounced effect of 1wt% CTS. The mean square displacement analysis demonstrated that CTS led to increases of macroscopic viscosity and elasticity index for WPI-FG stabilized lutein emulsions due to CTS embedding in the network. CTS also helped to chemically stabilize the lutein emulsions against degradation. The combination of interfacial membrane and prooxidative metal chelator or free radical scavenger was an effective method to control lutein degradation.

The impact of microcrystalline cellulose (MCC) on the physical stability, microrheological property and freeze-thaw stability of papain hydrolysate of soybean isolate protein (SPIH) stabilized curcumin emulsion was studied. Curcumin emulsions were prepared by Microfluidizer containing SPIH and various concentrations of MCC. The curcumin emulsions were assessed by zeta potential, average particle size through dynamic light scattering technique (DLS), stability index by Turbiscan and microrheological behavior through diffusive wave spectroscopy (DWS) technique. With addition of MCC, the negative charge of the droplets was increased, which indicated that the negatively charged fraction from MCC interacted with the protein at the interface. An increase in droplet size and decrease in TSI were noted with increasing MCC concentration. It demonstrated that enough MCC changed microrheological property of curcumin emulsions from purely viscous to viscoelastic over the range of decorrelation times, indicating that the droplets were not free to move due to the droplets network interaction. Freeze-thaw stability analysis demonstrated that MCC brought about a remarkable improvement, which can be attributed to the enhancement of repulsive steric forces between the curcumin droplets. It demonstrated that combined enzymatic hydrolysate of protein and addition of polysaccharide MCC could be an effective method for protecting bioactive compound in emulsions.