Development of plant-based whole egg analogs using emulsion technology.

RuBisCO is a plant protein that can be derived from abundant and sustainable natural resources (such as duckweed), which can be used as both an emulsifying and gelling agent. Consequently, it has the potential to formulate emulsion gels that can be used for the development of plant-based replacements of whole eggs. In this study, we investigated the ability of RuBisCO-based emulsion gels to mimic the desirable properties of whole eggs. The emulsion gels contained 12.5 wt% RuBisCO and 10 wt% corn oil to mimic the macronutrient composition of real whole eggs. Initially, an oil-in-water emulsion was formed, which was then heated to convert it into an emulsion gel. The impact of oil droplet diameter (∼15, 1, and 0.2 µm) on the physicochemical properties of the emulsion gels was investigated. The lightness and hardness of the emulsion gels increased as the droplet size decreased, which meant that their appearance and texture could be modified by controlling droplet size. Different concentrations of curcumin (3, 6, and 9 mg/g oil) were incorporated into the emulsions using a pH-driven approach. The curcumin was used as a natural dual functional ingredient (colorant and nutraceutical). The yellow-orange color of curcumin allowed us to match the appearance of raw and cooked whole eggs. This study shows that whole egg analogs can be formulated using plant-based emulsion gels containing natural pigments.

Effect of ultrasound-assisted Maillard reaction on glycosylation of goat whey protein: Structure and functional properties.

Goat whey protein (GWP) has a rich amino acid profile and good techno-functional attributes but still has limited functional performance for certain applications. This study introduces an innovative ultrasound-assisted Maillard reaction to enhance GWP's functional properties by conjugating it with either gum Arabic (GA) or citrus pectin (CP). Sonication accelerated the Maillard reaction, and the glycosylation of GWP was significantly enhanced after optimization of the conjugation conditions. Gel electrophoresis examination verified the creation of GWP-polysaccharide conjugates, while scanning electron microscopy analysis revealed structural modifications caused by polysaccharide grafting and sonication. The use of ultrasound in the Maillard reaction notably enhanced the solubility, foaming capacity, and emulsifying attributes of the GWPs. Among the conjugates, the GWP-GA ones exhibited the best functional properties. Our findings suggest that this approach can notably improve the functional attributes of GWPs, thus broadening their potential uses in the food sector and beyond.

Amaranth proteins: From extraction to application as nanoparticle-based delivery systems for bioactive compounds.

Amaranth proteins can be produced more sustainably than animal proteins, and they have amino acid compositions that are nutritionally balanced, which makes them attractive candidates for various applications in the food and pharmaceutical industries. This article provides an overview of the composition and techno-functional properties of amaranth protein, including its solubility, emulsification, gelation, foaming, and binding properties. These properties play an important role in the use of amaranth proteins for formulating nanoparticle-based delivery systems with good functional attributes. Amaranth proteins have structural and physicochemical properties suitable for fabricating protein-based nanoparticles. These nanoparticles can be used to encapsulate and control the release of bioactive compounds. However, challenges associated with the presence of anti-nutritional factors in amaranth proteins need to be addressed. These antinutrients negatively affect the bioavailability and digestibility of proteins and bioactive compounds. Hence, strategies to mitigate these challenges are discussed, including processing technologies and genetic engineering methods.

Design, characterization and digestibility of ß-carotene-loaded emulsion system stabilized by whey protein with chitosan and potato starch addition.

The physicochemical properties and gastrointestinal fate of ß-carotene-loaded emulsions and emulsion gels were examined. The emulsion was emulsified by whey protein isolate and incorporated with chitosan, then the emulsion gels were produced by gelatinizing potato starch in the aqueous phase. The rheology properties, water distribution, and microstructure of emulsions and emulsion gels were modulated by chitosan combination. A standardized INFOGEST method was employed to track the gastrointestinal fate of emulsion systems. Significant changes in droplet size, zeta-potential, and aggregation state were detected during in vitro digestion, including simulated oral, stomach, and small intestine phases. The presence of chitosan led to a significantly reduced free fatty acids release in emulsion, whereas a slightly increasing released amount in the emulsion gel. ß-carotene bioaccessibility was significantly improved by hydrogel formation and chitosan addition. These results could be used to formulate advanced emulsion systems to improve the gastrointestinal fate of hydrophobic nutraceuticals.

Progress on molecular modification and functional applications of anthocyanins.

Anthocyanins have attracted a lot of attention in the fields of natural pigments, food packaging, and functional foods due to their color, antioxidant, and nutraceutical properties. However, the poor chemical stability and low bioavailability of anthocyanins currently limit their application in the food industry. Various methods can be used to modify the structure of anthocyanins and thus improve their stability and bioavailability characteristics under food processing, storage, and gastrointestinal conditions. This paper aims to review in vitro modification methods for altering the molecular structure of anthocyanins, as well as their resulting improved properties such as color, stability, solubility, and antioxidant properties, and functional applications as pigments, sensors and functional foods. In industrial production, by mixing co-pigments with anthocyanins in food systems, the color and stability of anthocyanins can be improved by using non-covalent co-pigmentation. By acylation of fatty acids and aromatic acids with anthocyanins before incorporation into food systems, the surface activity of anthocyanins can be activated and their antioxidant and bioactivity can be improved. Various other chemical modification methods, such as methylation, glycosylation, and the formation of pyranoanthocyanins, can also be utilized to tailor the molecular properties of anthocyanins expanding their range of applications in the food industry.

Effects of annealing temperature and time on the structural and physicochemical properties of sweet potato flour hydrogels.

The physicochemical properties of sweet potato flour (SPF) can be modified by annealing. Native SPF was annealed in deionized water at a flour-to-water ratio of 1:3 (w/v) and temperatures of 50, 55, 60, or 65 °C for either 12 or 24 h. Annealed SPF maintained the A-type crystalline region and displayed increased relative crystallinity, increased pasting temperature, and decreased breakdown. SPF gels showed enhanced hardness together with better springiness when SPF was annealed at low temperature/long time or high temperature/short time. Annealed SPF hydrogel sheets contained larger, more uniform, and smoother pores than native ones. Noticeably, hydrogel sheets made of SPF annealed at 50 °C for 24 h exhibited advanced fracture strain from 93% to 176%. Overall, this work showed that annealing could modulate the characteristics of SPR hydrogels, which may widen the extent of applications in food industries. However, the annealing conditions need to be optimized.

Preparation of robust, water-resistant, antibacterial, and antioxidant chitosan-based films by incorporation of cinnamaldehyde-tannin acid-zinc acetate nanoparticles.

Chitosan (CS) films have poor mechanical property, low water-resistance and limited antimicrobial activity, which hinder their application in food preservation industry. Cinnamaldehyde-tannic acid-zinc acetate nanoparticles (CTZA NPs) assembled from edible medicinal plant extracts were successfully incorporated into CS films to solve these issues. The tensile strength and water contact angle of the composite films increased about 5.25-fold and 17.55°. The addition of CTZA NPs reduced the water sensitivity of CS films, which could undergo appreciable stretching in water without breaking. Furthermore, CTZA NPs significantly enhanced the UV adsorption, antibacterial, and antioxidant properties of the films, while reduced their water vapor permeability. Moreover, it was possible to print inks onto the films because the presence of the hydrophobic CTZA NPs facilitated the deposition of carbon powder onto their surfaces. The films with great antibacterial and antioxidant activities can be applied for food packaging application.

Physicochemical stability, antioxidant activity, and antimicrobial activity of quercetin-loaded zein nanoparticles coated with dextrin-modified anionic polysaccharides.

Core-shell biopolymer nanoparticles are assembled from a hydrophobic protein (zein) core and a hydrophilic polysaccharide (carboxymethyl dextrin) shell. The nanoparticles were shown to have good stability and the ability to protect quercetin from chemical degradation under long-term storage, pasteurization, and UV irradiation. Spectroscopy analysis shows that electrostatic, hydrogen bonding, and hydrophobic interactions are the main driving forces for the formation of composite nanoparticles. Quercetin coated with nanoparticles significantly enhanced its antioxidant and antibacterial activities and showed good stability and slow release in vitro during simulated gastrointestinal digestion. Furthermore, the encapsulation efficiency of carboxymethyl dextrin-coated zein nanoparticles (81.2%) for quercetin was significantly improved compared with that of zein nanoparticles alone (58.4%). These results indicate that carboxymethyl dextrin-coated zein nanoparticles can significantly improve the bioavailability of hydrophobic nutrient molecules such as quercetin and provide a valuable reference for their application in the field of biological delivery of energy drinks and food.

Effects of pile fermentation on the physicochemical, functional, and biological properties of tea polysaccharides.

This study investigated the influence of pile fermentation on the physicochemical, functional, and biological properties of tea polysaccharides (TPS). Results indicated that the extraction yield, uronic acid content, and polyphenol content of TPS greatly increased from 1.8, 13.1 and 6.3 % to 4.1, 27.9, and 7.8 %, respectively, but the molecular weight markedly decreased from 153.7 to 76.0 kDa after pile fermentation. Additionally, the interfacial, emulsion formation, and emulsion stabilization properties of TPS were significantly improved after pile fermentation. For instance, 1.0 wt% TPS isolated from dark tea (D-TPS) can fabricate 8.0 wt% MCT oil-in-water nanoemulsion (d32 ≈ 159 nm) with potent storage stability. Moreover, the antioxidant and α-glucosidase inhibitory activities of D-TPS was higher than that of TPS isolated from sun-dried raw tea (R-TPS). Overall, this study indicated that pile fermentation markedly affected the physicochemical and structural characteristics of TPS, thereby improving their functional and biological properties.

Enhancement of lycopene bioaccessibility in tomatoes using excipient emulsions: Effect of dark tea polysaccharides.

This study fabricated a novel excipient emulsion by adding dark tea polysaccharides to improve the bioaccessibility of lycopene from tomatoes. Results indicated that addition of tea polysaccharides greatly increased the antioxidant activity of excipient emulsions. Additionally, tea polysaccharides markedly improved the physical stability of excipient emulsion when being mixed with tomato puree and passing through a simulated gastrointestinal tract, contributing to an increase in electrostatic and steric repulsion between the droplets. Besides, certain amount of tea polysaccharides (0.05 - 0.2 wt%) could increase the rate and extent of lipid digestion in tomato-emulsion mixtures. Finally, lycopene bioaccessibility was significantly increased (from 16.95 % to 26.21 %) when 0.1 wt% tea polysaccharides were included, which was mainly ascribed to the ability of tea polysaccharides to increase lipid digestion and reduce carotenoid oxidation within the gastrointestinal tract. These results suggest that well-designed excipient emulsions may increase carotenoids bioavailability in the complex food matrices.

Extraction and characterization of pectic polysaccharides from Choerospondias axillaris peels: Comparison of hot water and ultrasound-assisted extraction methods.

Influences of conventional thermal and innovative non-thermal extraction methods on the physicochemical characteristics and properties of pectic polysaccharides from Choerospondias axillaris peels were investigated. Results showed that ultrasound-assisted extracted polysaccharides (UP) had a heterogeneous nature with lower molecular weight (127.7 kDa) and lower neutral sugar content (35.1%) but higher contents of protein (4.8%) and phenolic compounds (5.1%) than those of polysaccharides extracted by hot water (HP). Additionally, the monosaccharide composition results showed that glucose (77.8%) was the most abundant monosaccharide in HP, while arabinose (67.1%) was the most abundant monosaccharide in UP. The ultrasound significantly induced the degradation of polysaccharide chains but reduced the thermal degradation of phenolics. Finally, we found that UP had higher apparent viscosity, interfacial, emulsifying and antioxidant activity but lower α-glucosidase inhibition activity than those of HP. The results indicated that we could obtain polysaccharides with different functional and biological properties by using different extraction methods.

Preparation, properties and interaction of curcumin loaded zein/HP-ß-CD nanoparticles based on electrostatic interactions by antisolvent co-precipitation.

In this study, zein/hydroxypropyl-beta-cyclodextrin nanoparticles (ZHNPs) were synthesized using a combination of antisolvent co-precipitation and electrostatic attraction. The structural and physicochemical properties of the NPs were characterized using a variety of analytical methods. NPs with small mean diameters (143.6 nm) and strong cationic surface potentials (+62.1 mV) could be obtained at a mass ratio of zein-to-HP-ß-CD of 1:1. These NPs were then used to encapsulate a model hydrophobic nutraceutical, curcumin. The results of zeta-potential, Fourier-transform infrared spectroscopy, X-ray diffractometry, and fluorescence spectroscopy measurements suggested that electrostatic, hydrogen bonding, and hydrophobic interactions were the main driving forces for NPs formation and curcumin encapsulation. The NPs had a relatively high encapsulation efficiency (89.41 %) for curcumin and improved its antioxidant activity (3.6-fold that of free curcumin) and photostability. Consequently, they could be used as effective food-grade delivery systems for low water-soluble bioactive substances.

Construction of functional soybean peptide-cyclodextrin carboxylate nanoparticles and their interaction with porcine pancreatic α-amylase.

In this study, soybean peptide-succinic acid-modified cyclodextrin (SPT-SACD) nanoparticles (NPs) were successfully fabricated by combining SPT and SACD using an antisolvent precipitation approach. The effects of the average molecular weight of SPT and the SPT/SACD mass ratio on the structure and properties of the SACD-SPT NPs were investigated. Under optimal conditions, the SPT/SACD mass ratio was 2:1, and the SPT average molecular weight was 300 Da. SPT-SACD NPs were prepared under these conditions were spherical and had good uniformity. The particle sizes by DLS of SPT1 (300 Da) /SACD and SPT2 (500 Da) /SACD were in the range of 250-400 nm. The interaction between α-amylase and SPT-SACD NPs was investigated using ultraviolet visible (UV-Vis) absorption, fluorescence, and circular dichroism (CD) spectroscopy. The results of the fluorescence spectra and CD spectroscopy suggested that the presence of SPT-SACD NPs changed the microenvironment of the aromatic amino acid residues, which leads to the change of enzyme protein structure. The SPT-SACD NPs statically quenched the intrinsic fluorescence of the α-amylase by forming a complex with the enzyme. Moreover, the SPT-SACD NPs significantly improved the inhibitory effect of EGCG on α-amylase. The semi-inhibitory concentration (IC50) decreased from 0.324 to 0.248 mg/mL. This study provides an improved understanding of the interaction mechanism between polypeptide-cyclodextrin complexes and digestive enzymes, which may facilitate the design of functional foods.

Encapsulation of bitter peptides in diphasic gel double emulsions: Bitterness masking, sustained release and digestion stability.

Bitter peptides (BP) have been reported to exhibit beneficial physiological activities, but their bitter taste and digestive sensitivity currently limits their application in foods. In this study, W1/O/W2 double emulsions were prepared with bitter peptides in the inner water phase. The effects of gelling the inner and/or outer water phases, as well as crystallizing the oil phase, were then investigated. Aqueous phase gelation reduced the particle size of the double emulsions, improved their physical stability, increased their encapsulation efficiency for the bitter peptides, and reduced the bitterness of the peptides. After simulated oral and gastric digestion, the bitter peptide-loaded W1/O droplets in the double emulsions retained their structure, thereby preventing release of the peptides in the mouth and stomach. Our results suggest that gelled double emulsions may have great potential to create more palatable functional foods containing bitter peptides.

Development of pH-responsive active film materials based on purple corncob and its application in meat freshness monitoring.

The use of petroleum-based food packaging materials is causing environmental damage and increasing greenhouse gas production. Consequently, there is a great interest in developing smart and sustainable alternative materials. In this study, an agricultural waste product (purple corncob extract, PCCE) was used as a raw material to prepare environmentally friendly pH-sensitive packaging materials. Natural pH-sensitive pigments (anthocyanins) and lignin-containing cellulose nanocrystals (LCNC) were extracted from the purple corncobs. A cationic biopolymer (chitosan) was used as a scaffolding material to assemble the film matrix. Composite film (LCNC-PCCE-chitosan) was produced using a simple solvent casting method. Fourier transform infrared spectroscopy and scanning electron microscopy analyses showed that the PCCE and LCNC were well dispersed within the chitosan matrix and they interacted with the matrix through hydrogen bonding and electrostatic interactions. The addition of LCNC improved the hydrophobicity and mechanical properties of the film and imparted antioxidant activity and UV-blocking properties. The presence of anthocyanins in the PCCE endowed the film with a sensitive and reversible pH response, which could be well used to monitor changes in the freshness of pork and shrimp products.

Dietary proteins as excipient ingredients for improving the solubility, stability, and bioaccessibility of quercetin: Role of intermolecular interactions.

Soy protein isolate (SPI), whey protein isolate (WPI) and sodium caseinate (CS) were used as excipient ingredients to improve the water-solubility, chemical stability, and in vitro bioaccessibility of quercetin. Quercetin powder was dispersed in the protein solutions (pH 7.0) and then the mixtures were held at 30 °C for 24 h or 100 °C for 60 min. The mean particle diameter of the colloidal dispersions formed ranged from around 53 to 208 nm, whereas the zeta-potential values ranged from around -23 to -27 mV. The high-temperature treatment (100 °C) of the quercetin-protein mixtures led to a higher quercetin solubility than the low-temperature treatment (30 °C). When held at 100 °C, the solubility of quercetin increased first but then decreased over time when quercetin mixed with WPI, CS and SPI respectively. A simulated gastrointestinal tract study showed that the in vitro bioaccessibility of quercetin increased after being mixed with the protein solutions: from 13.5 % for free quercetin to 20.3 %, 26.5 %, and 36.3 % for SPI, WPI, and CS respectively. Fluorescent spectroscopy analysis indicated that there was about one quercetin molecule bound per protein molecule, with the dominant force being hydrophobic attraction. Per unit mass of protein, the total number of quercetin binding sites available was greater for CS and WPI than for SPI. This phenomenon may account for the greater enhancement in quercetin solubility, stability, and bioaccessibility for CS and WPI than SPI.

Preparation, characterization and in vitro digestive behaviors of emulsions synergistically stabilized by γ-cyclodextrin/sodium caseinate/alginate.

Developing natural, safe, and biocompatible emulsion stabilizers for highly stable emulsions remains a difficult challenge. In this study, stable nano-scale emulsions were prepared using γ-cyclodextrin (γ-CD), sodium caseinate (SC), and alginate (Alg) as emulsifiers. The synergistic stabilization of γ-CD/SC/Alg enabled the emulsions to remain stable even under high-acidic (pH 3.0), high-alkaline (pH 11.0) and high temperature (90 °C) conditions. The improved stability at acidic conditions was attributed to the positive impact of Alg. Additionally, the rheological measurements showed that the emulsions exhibited elastic gel networks and a more stable emulsion structure was formed with the increasing addition of γ-CD. Finally, the gastrointestinal behavior of the emulsions was studied using a standardized INFOGEST method. Results showed that most of the oil were digested and absorbed in the small intestine, and the bioaccessibility of curcumin was high. This work provided a new solution to prepare stable emulsions which could be used as dairy products or desirable food delivery systems for hydrophobic bioactive agents.

Ultrasound-assisted preparation of lactoferrin-EGCG conjugates and their application in forming and stabilizing algae oil emulsions.

The aim of this study was to prepare lactoferrin-epigallocatechin-3-gallate (LF-EGCG) conjugates and to determine their ability to protect emulsified algal oil against aggregation and oxidation. LF-EGCG conjugates were formed using an ultrasound-assisted alkaline treatment. The ultrasonic treatment significantly improved the grafting efficiency of LF and EGCG and shortened the reaction time from 24 h to 40 min. Fourier transform infrared spectroscopy and circular dichroism spectroscopy analyses showed that the covalent/non-covalent complexes could be formed between LF and EGCG, with the CO and CN groups playing an important role. The formation of the conjugates reduced the α-helix content and increased the random coil content of the LF. Moreover, the antioxidant activity of LF was significantly enhanced after conjugation with EGCG. LF-EGCG conjugates as emulsifiers were better at inhibiting oil droplet aggregation and oxidation than LF alone. This study demonstrates that ultrasound-assisted formation of protein-polyphenol conjugates can enhance the functional properties of the proteins, thereby extending their application as functional ingredients in nutritionally fortified foods.

Investigation of the interactions between food plant carbohydrates and titanium dioxide nanoparticles.

Titanium dioxide (TiO2) is commonly used as food whitening in candies, chocolates, and cakes with high carbohydrate contents. The potential interaction between the food carbohydrate and food grade TiO2 nanoparticle was little known. Therefore, we explored the interaction between TiO2 nanoparticles and seven common carbohydrates, including monosaccharides, disaccharides, and polysaccharides. The result showed that all the carbohydrates tested interacted with the surfaces of the TiO2 nanoparticles and formed biocoronas. TEM and SEM images provided information about the morphology formation of biocoronas. The surface potential and size of the TiO2 nanoparticles altered after interacting with the carbohydrates. FTIR spectroscopy and QCM-D findings showed insights into the molecular origin and nature interaction between TiO2 and carbohydrates. The results illustrated that TiO2 nanoparticles can interact with carbohydrates, enter the body as a food additive, and interact with food matrix for a series of reactions. Compared with monosaccharides or disaccharides, food polysaccharides have stronger adsorption on the surface of nanoparticles. This is a preliminary judgment for the subsequent in vitro simulated digestion. Our result could be useful for understanding and controlling the behavior of nanoparticles in food and the human gut.

Impact of pea protein-inulin conjugates prepared via the Maillard reaction using a combination of ultrasound and pH-shift treatments on physical and oxidative stability of algae oil emulsions.

Algal oil is an aquatic plant source of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), which may exhibit health benefits when consumed in sufficiently high quantities. But its application as a healthy lipid in functional foods is often limited by its tendency to rapidly oxidize and produce rancid off-flavors. In this study, algal oil-in-water emulsions were prepared using pea protein isolate (PPI)-inulin conjugates as emulsifiers. These conjugates were prepared via the Maillard reaction using a combination of ultrasound and pH-shift treatments. The algal oil phase was mixed with lemon oil (0 to 1.2 wt%) prior to homogenization to improve its sensory characteristics. The addition of 0.6 wt% of lemon oil did not significantly affect the formation and physical stability of the emulsions but it did mask the unpleasant odor of algae oil. The conjugate-stabilized emulsions exhibited shear thinning behavior and had a higher viscosity than PPI-stabilized emulsions. They also had a higher surface load and formed thicker interfacial layers. The conjugates, especially the conjugates prepared by the combined treatments, also significantly improved the physical and oxidative stability of the emulsions. These effects were attributed to an increase in the steric repulsion between the oil droplets due to the hydrophilic inulin chains, as well as to an increase in the antioxidant activity of the interfacial layers due to the presence of more antioxidant proteins. Overall, our results show that the quality attributes and shelf life of DHA-fortified algae oil emulsions can be significantly improved using a plant-based protein-inulin conjugate.