Application of protein-polysaccharide Maillard conjugates as emulsifiers: Source, preparation and functional properties

Preparation and characterization of microcapsules for tuna oil by maillard reaction products of whey protein isolate and Arabic gum via complex coacervation

This study aimed to prepare Maillard reaction products (MRPs) from whey protein isolate (WPI) and different reducing sugars (glucose, fructose, maltose, lactose), and utilize the optimal MRPs to fabricate tuna oil (TO) microcapsules for enhancing TO's storage stability. The results showed that the optimal wet heat reaction duration of WPI and reducing sugar was 8 h at 75 °C. Glycosylation improves the functional properties of WPI. WPI-maltose coupling (WPI-M) and Arabic gum were selected as the wall material to prepare TO microcapsules by complex coacervation, and the encapsulation efficiency of microcapsules reached 87.41 %. Compared to WPI, WPI-M microcapsules have a more homogeneous emulsion morphology. The peroxide value of microencapsulated protected TO was 35.78 % lower than that of free TO after accelerated oxidation at 55 °C for 16 days. Microcapsules prepared with MRPs wall materials by complex coacervation offer a promising approach for the preservation of compounds.

Maillard reaction conjugates of millet bran globulin and Arabic gum for curcumin encapsulation: Physicochemical characterization, storage stability, and in vitro digestion

In this study, millet bran globulin (MBG) and Arabic gum (AG) conjugates were prepared through the Maillard reaction (MR) and applied to curcumin-loaded Pickering emulsions. The effect of MR on MBG-AG conjugates (MBG-AG con) was evaluated by the degree of grafting (DG), the absorbance of intermediate reactants, and the browning index. The emulsifying properties of MBG-AG con with different DGs were assessed using the emulsifying activity index (EAI) and emulsifying stability index (ESI). Curcumin-loaded Pickering emulsions were prepared using optimized conjugates. Results indicated that MR enhanced the conjugates emulsifying properties, leading to improved emulsion performance. Compared to MBG, the optimized conjugates exhibited approximately 252.3 % and 167.1 % increases in EAI and ESI, respectively. The formation of MBG-AG con was confirmed through polyacrylamide gel electrophoresis, Fourier transform infrared, and fluorescence spectroscopy. Morphological changes before and after MR were observed through scanning electron microscopy. In comparison to MBG-stabilized emulsions, conjugate-stabilized emulsions exhibited smaller droplets, higher curcumin encapsulation efficiency (over 80 %), and better apparent viscosity. During simulated digestion, the bioavailability of curcumin reached 88.67 % in Pickering emulsions stabilized by 5 % conjugates. This study demonstrated the potential application of MBG-AG con prepared via MR in stabilizing Pickering emulsions, providing new theoretical insights into curcumin encapsulation.

Enhancing curcumin stability and bioavailability through chickpea protein isolate-citrus pectin conjugate emulsions: Targeted delivery and gut microecology modulation

The limited solubility, rapid metabolism, and poor bioavailability of curcumin restrict its application. In this study, we synthesized chickpea protein isolate (CPI)-citrus pectin (CP) conjugates to prepare an emulsion delivery system that enhances the stability and bioavailability of curcumin. The CPI-CP emulsion achieved a curcumin encapsulation efficiency of 86.15 %. Additionally, the stability of curcumin within CPI-CP emulsion was enhanced under conditions of thermal, UV irradiation, and oxidation. In vitro digestion demonstrated that the CPI-CP conjugates effectively preserved the interfacial film integrity during gastric digestion, facilitating targeted delivery of curcumin to the small intestine. This resulted in a substantial increase in curcumin bioavailability, from 50.60 % to 85.60 %. In vivo, the emulsion alleviated liver oxidative stress by improving antioxidant enzyme activity and promoted gut health through increased short-chain fatty acid production and modulation of gut microbiota. This research presents an effective strategy for enhancing the stability and bioavailability of curcumin and demonstrates the potential application of CPI-CP conjugates in delivery systems for bioactive substances.

Structural and functional changes induced by different ultrasound-frequency-assisted xylose-glycation inhibits lysinoalanine formation in Tenebrio molitor protein

We explored the effects of sonication-assisted xylose (Xyl) grafting on the structure and functionality of Tenebrio molitor protein (MP). Different ultrasound frequencies (20, 25, 28, 20/25, 20/28, 25/28, 20/25/28 kHz) were used, and the inhibition mechanism of ultrasound-assisted Xyl grafting on the formation of lysinoalanine (LAL) was explored. The results suggested that the turbidity and browning products of MP significantly increase, with MP-Xyl-20 kHz exhibiting the highest grafting degree (43.78 %). Compared with MP, the total sulfhydryl content of MP-Xyl and MP-Xyl-20 kHz was significantly improved by 21.90 % and 98.80 % (P < 0.05). Circular Dichroism, Fourier Transform Infrared Spectroscopy, SEM, and AFM analysis showed changes in MP conformation following various frequencies ultrasound-assisted glycosylation. Notably, emulsifying capacity, stability, and foaming ability of MP-Xyl-20 kHz were significantly enhanced by 97.08 %, 48.03 %, and 55.01 %, respectively, compared with MP. The glycol-conjugated MP treated with ultrasound-assisted glycosylation (MP-Xyl-25/28 kHz) had the lowest LAL content (7.19 μg/mg), representing a 56.56 % and 46.70 % decrease compared to the control MP and MP-Xyl, respectively. The content of LAL exhibited a positive correlation with surface hydrophobicity, whereas it demonstrated a negative correlation with sulfhydryl and carbonyl groups. These findings indicated that sonication-assisted xylose improved the functional characteristics of MP, and the inhibition effect on LAL formation. The outcome of the study could be very beneficial in the modification of MP for food industrial applications.

Fucoidan-Mediated Covalent Modification Induces Oral Tolerance to Shrimp by Generating Tolerogenic Peptides and Reducing Antigen Responsiveness

Food allergy has become a global food safety issue, and inducing tolerance of the immune system to allergens is seen as an effective way to address this problem. In this study, shrimp (Penaeus vannamei) was covalently modified with fucoidan to explore its potential as an oral tolerance inducer. The results showed that this strategy not only had no adverse effect on the growth of mice but also achieved significant immune tolerance induction effects. Specifically, it significantly reduced specific antibody levels, improved vascular permeability and intestinal barrier function, and inhibited mast cell degranulation. Further studies showed that these positive results were related to tolerogenic peptides (SLLKANIQL, GLTEFQAV, GDFPGAFKVF, ALNLNPTLALI, and AALDIDSKPF) produced in shrimp allergens. Moreover, this strategy mainly down-regulated gene expression in exogenous substance metabolic and immune-related signaling pathways, thereby reducing immune response to antigens. Overall, fucoidan-mediated covalent modification promises to be an efficient method for producing oral tolerance inducers.

Novel technologies, effects and applications of modified plant proteins by Maillard reaction and strategies for regulation: A review

With an increase in awareness of health, environmental conservation and animal welfare, the market for plant proteins is expanding. However, the low solubility and poor functional properties of plant proteins near the isoelectric point limit their application in food processing. Glycosylation refers to the structural modification of proteins by introduction of polysaccharides to form protein-polysaccharide conjugates in the early stages of Maillard reaction. Glycosylation is a green and efficient method that has been proved to produce modified proteins with superior solubility, emulsifying and forming properties. Glycosylation and the application of protein-carbohydrate conjugates have become research hotspots in recent years. This paper presented a comprehensive review of the effects of glycosylation on the functional properties of plant proteins and the mechanisms of non-thermal physical treatments assisted glycosylation. It was demonstrated that glycosylation modified the structure of plant proteins and improved their functional properties. Non-thermal physical treatments assisted glycosylation increased the reactive sites of plant proteins and further improved their functional properties. Protein-carbohydrate conjugates could be applied in delivery systems, films, emulsifiers and other applications, which have significant research prospects in food applications.

Radio frequency heating assisted Maillard reaction of whey protein - gum Arabic: Improving structural and unlocking functional properties

Whey protein (WP) is a highly nutritious animal protein, but its functional properties are sensitive to environmental factors, such as temperature, pH, and ionic strength, which prevent its applications in various food systems. The conjugation of proteins with polysaccharides via the Maillard reaction is an efficient method to improve their functionalities. The purpose of this study was to use radio frequency (RF) heating technology to assist the covalent coupling of WP and gum Arabic (GA) for improving their grafting efficiency and functional properties. Results showed that under the optimal condition of RF heating, the degree of glycosylation (DG) of the conjugate could reach 19.19%, while the maximum DG value of the conjugate obtained by water bath (WB) heating was only 10.60%. There was a good correlation between the DG and dielectric properties of WP-GA conjugates. Structural analysis revealed that compared with their mixtures, the network structure of WP-GA conjugates was clear, the content of β-turn and random coil increased, and the fluorescence intensity and surface hydrophobicity decreased. In addition, glycosylation enhanced the emulsifying, foaming, and antioxidant properties of WP-GA conjugates. This study indicates that the RF heating technology has potential application values in the glycosylation modification of proteins.

Insight into the structural, interfacial and functional properties of soybean 11S globulin-debranched starch conjugates through alkaline Maillard reaction

This study examined the effects of the alkaline Maillard reaction on the structural, interfacial, and functional properties of soybean 11S globulin-debranched starch (DBS) conjugates. The results showed that the degree of DBS binding to 11S globulin was influenced by the polymer ratios, which in turn affected the structural, interfacial, and functional characteristics. The 11S-DBS conjugates with a 2:1 biopolymer ratio exhibited the highest grafting degree, largest zeta potential absolute value, smallest particle size, and greatest thermal stability. Conjugates with higher globulin content demonstrated superior interfacial and functional properties, including improved solubility, increased surface hydrophobicity, and reduced interfacial tension. 3D fluorescence scanning revealed a decrease in the signal of aromatic amino acid residues, while microstructural observation provided insights into the binding behavior of different 11S-DBS conjugates. Molecular docking simulations highlighted the key role of hydrogen bonding in the formation of these conjugates. This study enhances understanding of soybean globulin-polysaccharide interaction mechanisms, expanding their potential applications in the food, medical, and bioengineering industries.

Maillard-derived mung bean protein-peach gum conjugates: A novel emulsifier to improve stability, antioxidants, and physicochemical properties of chia seed oil nanoemulsion

This research is designed to enhance the physio-chemical properties, constancy, and antioxidant activities of water-in-oil (W/O) emulsions containing chia seed oil (CSO) by utilizing mung bean protein isolate (MBPI)-peach gum (PG) conjugates, which were created through the Maillard reaction (MR), as the emulsifying agents. The emulsions were prepared using MBPI-PG produced through the Maillard reaction (EMRP) at concentrations of 0.5 %, 1 %, and 1.5 %. Another set of emulsions, serving as control samples, was prepared using MBPI-PG without the MR (EC) at the same concentrations. The EMRP samples demonstrated optimum characteristics during storage over 30 days at 25 °C, particularly at 1 % concentration, including the droplet size (176.37 nm), PDI (0.3), zeta potential (-47.52 Mv), quantity of absorbed protein (63.48 %), creaming index (22.99 %), and viscosity compared to EC. The emulsions prepared with MRP exhibited significantly lower POV (1.45 mM/kg oil) and TBARS (59.17 mM/kg oil) formation rates than EC. The EMRP1% formulation displayed the lowest release of antioxidant compounds among all formulations, suggesting low release control during storage. Molecular docking results confirmed that adding EMRP1% to the CSO emulsion significantly improved its quality and stability. This emulsifier could hold significant promise for future advancements in the food industry.

Covalent interaction of ovalbumin with proanthocyanidins improves its thermal stability and antioxidant and emulsifying activity

BACKGROUND

The structure of proanthocyanidins (PC) contains a large number of active phenolic hydroxyl groups, which makes it have strong antioxidant capacity. This study investigated the structural and functional properties of ovalbumin (OVA) modified by its interaction with PC.

RESULTS

It was found that on increasing the concentration ratio of PC to OVA from 10:1 to 40:1, the free amino and total sulfhydryl contents of OVA decreased from 470.59 ± 38.77 and 29.81 ± 0.31 nmol mg-1 to 96.61 ± 4.55 and 21.22 ± 0.78 nmol mg-1, respectively, and the free sulfhydryl content increased from 7.65 ± 0.41 to 9.48 ± 0.58 nmol mg-1. These results indicated that CN and CS bonds were formed and PC was covalently linked with OVA. The PC content in the OVA-PC conjugates increased from 281.93 ± 12.92 to 828.81 ± 46.09 nmol mg-1 on increasing the concentration ratio of PC to OVA from 10:1 to 40:1. The contents of α-helix and β-turn of OVA decreased, and the contents of β-sheet and random coil increased, confirmed by circular dichroism. The tertiary structure of OVA was also altered according to the results of fluorescence and ultraviolet absorption spectra. The surface hydrophobicity of OVA-PC conjugates decreased with increasing bound polyphenol content. The conjugation of OVA to PC significantly improved its emulsification and antioxidant activity and denaturation temperature.

CONCLUSION

This study may provide valuable information for improving OVA's functional properties and its PC conjugates for applications in the food industry. © 2024 Society of Chemical Industry.

Effects of Conjugation with Basil Seed Gum on Physicochemical, Functional, Foaming, and Emulsifying Properties of Albumin, Whey Protein Isolate and Soy Protein Isolate

Protein conjugation with the Maillard reaction has received considerable attention in the past decades in terms of improving functional properties. This study evaluated the changes in the techno-functional properties of whey protein isolate (WPI), soy protein isolate (SPI), and albumin (Alb) after conjugation with basil seed gum (BSG). The conjugates were developed via the Maillard reaction. Various analyses including FT-IR, XRD, SEM, SDS-PAGE, DSC, RVA, rheology, zeta potential, emulsion, and foaming ability were used for evaluating conjugation products. Conjugation between proteins (WPI, SPI, Alb) and BSG was validated by FT-IR spectroscopy. XRD results revealed a decrease in the peak of BSG after conjugation with proteins. SDS-PAGE demonstrated the conjugation of WPI, SPI, and Alb with BSG. DSC results showed that conjugation with BSG reduced the Tg of WPI, SPI, and Alb from 210.21, 207.21, and 210.90 °C to 190.30, 192.91, and 196.66 °C, respectively. The emulsion activity and emulsion stability of protein/BSG conjugates were increased significantly. The droplet size of emulsion samples ranged from 112.1 to 239.3 nm on day 3. Nanoemulsions stabilized by Alb/BSG conjugate had the smallest droplet sizes (112.1 and 143.3 nm after 3 and 17 days, respectively). The foaming capacity of WPI (78.57%), SPI (61.91%), and Alb (71.43%) in their mixtures with BSG increased to 107.14%, 85.71%, and 85.71%, respectively, after making conjugates with BSG. The foam stability of WPI (39.34%), SPI (61.57%), and Alb (53.37%) in their mixtures with BSG (non-conjugated condition) increased to 77.86%, 77.91%, and 72.32%, respectively, after formation of conjugates with BSG. Conjugation of BSG to proteins can improve the BSG applications as a multifunctional stabilizer in pharmaceutical and food industries.

Effects of Maillard Reaction Durations on the Physicochemical and Emulsifying Properties of Chickpea Protein Isolate

This study investigated the physicochemical and emulsifying properties of chickpea protein isolate (CPI)-citrus pectin (CP) conjugates formed via the Maillard reaction across varying reaction durations. CPI and CP were conjugated under controlled dry-heating conditions, and the resulting conjugates were characterized by measuring their particle size, zeta potential, solubility, thermal stability, surface hydrophobicity, and emulsifying properties. The results showed that as reaction duration increased, the particle size and zeta potential of the CPI-CP conjugates increased significantly, reaching a maximum particle size of 1311.33 nm and a zeta potential of -35.67 mV at 12 h. Moreover, the Maillard reaction improved the solubility, thermal stability, and hydrophobicity of the CPI. Glycosylation increased the emulsifying activity index (EAI) and emulsifying stability index (ESI) of the CPI to 145.33 m2/g and 174.51 min, respectively. Optimal emulsions were achieved at a protein concentration of 1.5 wt% and a 10% volume fraction of the oil phase. The Maillard reaction promoted the interfacial protein content and the thickness of the interfacial layer while decreasing the droplet size and zeta potential of the emulsion. Additionally, the emulsion prepared with CPI-CP-12 h showed outstanding long-term stability. These results demonstrate that a moderate Maillard reaction with CP effectively enhances the physicochemical and emulsifying characteristics of CPI.

Recent advances in nutraceutical delivery systems constructed by protein-polysaccharide complexes: A systematic review

Most nutraceuticals have low stability and solubility, making it difficult to achieve ideal bioavailability by directly incorporating into food. Therefore, constructing delivery systems to protect nutraceuticals is an essential strategy. Proteins and polysaccharides have become ideal materials for encapsulating nutraceuticals due to their superior nutritional value, edible safety, and physicochemical properties. This review first introduces the binding methods of protein-polysaccharide complexes and analyzes their respective merits, defects, and applications. Then, various protein-polysaccharide complex-based nutraceutical delivery systems are systematically summarized, including emulsions, gels, nanoparticles, microcapsules, complexes, and films, which can improve the stability, encapsulation efficiency, and bioaccessibility of nutraceuticals. In addition to traditional globular proteins mentioned in previous reviews, this review also introduces the advantages of another morphology of proteins (protein fibrils with linear structure) in the formation of protein-polysaccharide complexes and the construction of nutraceutical delivery systems. Next, the affecting factors are analyzed to achieve the precise control of protein-polysaccharide complex-based nutraceutical delivery systems. To improve public acceptability of protein-polysaccharide complex-based nutraceutical delivery systems, the safety and regulatory aspects are also discussed in detail. Moreover, the applications of such delivery systems are presented, including dietary supplements, food ingredients, food packaging, and food detection. Finally, several promising research directions that had not been provided before are innovatively proposed, including cell-cultured meat scaffolds, plant-based meat analogs, three-dimensional printing inks, and "three reductions" foods. Overall, this review provides guidance for designing protein-polysaccharide complex-based nutraceutical delivery systems with customized nutrition and superior bioavailability.

Effect of ultrasound-assisted Maillard reaction on functional properties and flavor characteristics of Oyster protein enzymatic hydrolysates

To address the delamination phenomenon during storage and flavor characteristics of Oyster protein hydrolysates (OPH). In this study, xylo-oligosaccharides (XOS) were selected to covalently graft with OPH through ultrasound-assisted Maillard reaction, and the effect of ultrasound-assisted Maillard reaction on the structure, functional properties, and flavor characteristics of OPH were investigated. The results revealed that the ultrasound treatment led to a 1.46-fold increase in the degree of grafting compared with the conventional wet-heat Maillard reaction methods. Structural analyses at various levels indicated substantial alterations in the OPH structure following the ultrasound-assisted Maillard reaction. More ordered α-helical secondary structures were shifting to random coiling, the tertiary structure showed more stretching changes, and the surface structure was characterized by loose and porous features. Compared with OPH, the solubility of the ultrasound-assisted Maillard reaction products (OPH-U-M) increased from 54.67% to 70.14%, leading to a notable enhancement in storage stability. Flavor profile analysis demonstrated a decrease in unsaturated aldehydes and ketones presenting fishy and bitter aromas, while an increase in presenting meat aroma compounds was observed in OPH-U-M. Furthermore, OPH-U-M exhibited superior antioxidant properties with DPPH and ABTS radical scavenging abilities enhancing 46.05% and 42.09% in comparison with OPH, respectively. The results demonstrated that covalently binding with XOS under ultrasonication pretreatment endowed OPH with superior functional properties (including solubility, storage stability, and antioxidant activity), and the improvement of flavor profile. This study can provide theoretical guidance and practical implications for promoting the processing applications of oyster protein.

Glycation of sunnhemp protein with dextran via dry heating: Thermal, micro-structural characterization, and amino acid profiling

This study aims to obtain sunnhemp protein isolate (SHPI) and dextran conjugates by dry heating method of Maillard conjugation. The effects of different incubation time (0, 1, 3, 5, 7, and 9 days) on the molecular flexibility, available lysine content, antioxidant properties, molecular structure, and thermal and micro-structural properties of conjugates were compared with SHPI (no conjugation) at 60°C and 79% relative humidity. The results indicated the formation of SHPI-dextran conjugates as confirmed by the change in molecular flexibility, lysine content, antioxidant activities, color, and water activity values. The molecular structure revealed the confirmation of covalent bonding between SHPI and dextran. Differential scanning calorimetry and thermo-gravimetric analysis results exhibited improvement in the thermal stability of SHPI when conjugated with dextran. The microstructural characterization showed that Maillard conjugation changed the surface structure of SHPI. The analysis of amino acid composition displayed that lysine, arginine, and phenylalanine were the dominant Maillard reaction sites of SHPI and dextran. Among all the conjugated samples, 5 days of incubation time was selected as an optimum condition for the development of SHPI-dextran conjugates on the basis of the aforementioned characterization. Overall, it was concluded that Maillard conjugation of sunnhemp protein with dextran via dry-heating technique could modify and improve its various attributes. PRACTICAL APPLICATION: The conjugation of plant proteins with polysaccharide through the Maillard reaction under dry heating conditions represents a natural and green technique for improving the techno-functional properties of proteins. The study has the potential to establish framework for the utilization of Sunnhemp protein isolate-dextran conjugates. This approach offers the potential for cost-effective production of emulsifiers and development of effective encapsulating matrices. The investigation expands on an underutilized plant protein source facilitating an alternative to animal-based proteins and contributing to the development of a sustainable circular bioeconomy.

Physical modification of vegetable protein by extrusion and regulation mechanism of polysaccharide on the unique functional properties of extruded vegetable protein: a review

Development and utilization of high quality vegetable protein resources has become a hotspot. Food extrusion as a key technology can efficiently utilize vegetable protein. By changing the extrusion conditions, vegetable protein can obtain unique functional properties, which can meet the different needs of food processing. However, extrusion of single vegetable protein also exposes many disadvantages, such as low degree functional properties, poor quality stability and lower tissue fibrosis. Therefore, addition of polysaccharide has become a new development trend to compensate for the shortcomings of extruded vegetable protein. The unique functional properties of vegetable protein-polysaccharide conjugates (Maillard reaction products) can be achieved after extrusion due to regulation of polysaccharides and adjustment of extrusion parameters. However, the physicochemical changes caused by the intermolecular interactions between protein and polysaccharide during extrusion are complex, so control of these changes is still challenging, and further studies are needed. This review summarizes extrusion modification of vegetable proteins or polysaccharides. Next, the effect of different types of polysaccharides on vegetable proteins and its regulation mechanism during extrusion is mainly introduced, including the extrusion of starch polysaccharide-vegetable protein, and non-starch polysaccharide-vegetable protein. Finally, it also outlines the development perspectives of extruded vegetable protein-polysaccharide.

Comparative study of Maillard reaction and blending between soybean protein isolate and soluble soybean polysaccharide: Physicochemical, structure and functional properties

Soybean protein isolate-soluble soybean polysaccharide (SPI-SSPS) complexes and mixtures with varying SPI/SSPS concentration ratios (1: 1, 2:1, 4:1, 8:1) were prepared by Maillard reaction and blending, respectively, and their physicochemical, structure, and functional properties were compared studied. The physical stability of SPI-SSPS complex, which consisted of CN and CS bonds, was better than that of the SPI/SSPS mixture with electrostatic interactions and hydrogen bonds, and both were superior SPI alone. The complex with SPI/SSPS concentration ratio of 8:1 had the highest grafting degree (33.25 %) and a more ordered structure, making its solubility and emulsifying property lower than the SPI/SSPS mixture; however, the physical and thermal stability of the SPI-SSPS complex was higher than that of the SPI and SPI/SSPS mixture. In particular, the SPI-SSPS complex with a high grafting degree showed a higher thermal denaturation temperature (194.06 °C). This study aimed to provide effective modification methods to utilize soybean processing by-products by modifying soybean protein isolate with soluble soybean polysaccharide.

Structural and functional properties of lactoferrin modified with carboxymethyl chitosan: Physical mixing and transglutaminase glycosylation

Protein-polysaccharide combinations frequently demonstrate functional attributes that surpass those of the individual biopolymers. This study aimed to elucidate the physicochemical, structural, and functional properties of two types of lactoferrin (LF)-carboxymethyl chitosan (CMCS) complexes formed by physical mixing and enzymatic glycosylation. LF and CMCS interactions were characterized using phase behavior, particle size, and zeta-potential analysis. The results indicated the formation of an electrostatic complex with a size of <150 nm at pH 8. SDS-PAGE and Fourier transform infrared spectroscopy confirmed that TGase catalyzed the cross-linking and glycosylation of LF, with the extent of glycosylation dependent on the concentration of CMCS. The introduction of CMCS has been observed to result in alterations to the secondary, tertiary, and microstructure of LF, which impact the functional characteristics of LF. The incorporation of CMCS markedly enhances the thermal stability of LF, with a denaturation temperature of 126.66 °C. The addition of CMCS (0.5 wt%) to LF resulted in a significant (P < 0.05) improvement in the emulsifying activity of LF, but it did not improve its foaming properties. This study offers novel ideas and approaches for developing protein and polysaccharide complexes with improved functional properties, thereby expanding the potential applications of edible proteins.

Agar-gelatin Maillard conjugates used for Pickering emulsion stabilization

A few protein- and polysaccharide-based particles have shown promising potential as stabilizers in multi-phase food systems. By incorporating polymer-based particles and modifying the wettability of colloidal systems, it is possible to create particle-stabilized emulsions with excellent stability. A Pickering emulsifier (AGMs) with better emulsifying properties was obtained by the Maillard reaction between acid-hydrolysed agar and gelatin. Laser confocal microscopy imaging revealed that AGMs particles can be used as solid emulsifiers to produce a typical O/W Pickering emulsion, with AGMs adsorbing onto the droplet surface to form a dense interfacial layer. Cryo-scanning electron microscopy analysis showed that AGMs self-assembled into a three-dimensional network structure, which prevented droplets aggregation through strong spatial site resistance, contributing to emulsion stabilization. These emulsions exhibited stability within a pH range of 1 to 11, NaCl concentrations not exceeding 300 mM, and at temperatures below 80 °C. The most stable emulsion oil-water ratio was 6:4 at a particle concentration of 0.75 % (w/v). AGMs-stabilized Pickering emulsion was utilized to create a semi-solid mayonnaise as a replacement for hydrogenated oil. Rheological analysis demonstrated that low-fat mayonnaise stabilized with AGMs exhibited similar rheological behavior to traditional mayonnaise, offering new avenues for the application of Pickering emulsions in the food industry.

Effects of enzymatic hydrolysis combined with glycation on the emulsification characteristics and emulsion stability of peanut protein isolate

Peanut protein isolate (PPI) has high nutritional value, but its poor function limits its application in the food industry. In this study, peanut protein isolate was modified by enzymatic hydrolysis combined with glycation. The structure, emulsification and interface properties of peanut protein isolate hydrolysate (HPPI) and dextran (Dex) conjugate (HPPI-Dex) were studied. In addition, the physicochemical properties, rheological properties, and stability of the emulsion were also investigated. The results showed that the graft degree increased with the increase of Dex ratio. Fourier transform infrared spectroscopy (FTIR) confirmed that the glycation of HPPI and Dex occurred. The microstructure showed that the structure of HPPI-Dex was expanded, and the molecular flexibility was enhanced. When the ratio of HPPI to Dex was 1:3, the emulsifying activity and the interface pressure of glycated HPPI reached the highest value, and the emulsifying activity (61.08 m2/g) of HPPI-Dex was 5.28 times that of PPI. The HPPI-Dex stabilized emulsions had good physicochemical properties and rheological properties. In addition, HPPI-Dex stabilized emulsions had high stability under heat treatment, salt ion treatment and freeze-thaw cycle. According to confocal laser scanning microscopy (CLSM), the dispersion of HPPI-Dex stabilized emulsions was better after 28 days of storage. This study provides a theoretical basis for developing peanut protein emulsifier and further expanding the application of peanut protein in food industry.

Tri-component hydrocolloid as egg white replacement in meringues: gellan gum with soy protein isolate and maltodextrin

BACKGROUND

In the quest for sustainable food ingredients, the present study delves into the potential of a tri-component hydrocolloid blend, comprising gellan gum (GG), soy protein isolate (SPI) and maltodextrin (MD), as a replacement for egg white in meringue production. The research aims to elucidate the intricate physical properties of meringue containing this tri-component structure, focusing on foaming dynamics, rheological behavior and the textural properties of the resulting meringue cookies.

RESULTS

Experiments were conducted with various hydrocolloids (k-carrageenan, GG, and locust bean gum) and GG was identified as optimal for improving foaming capacity and foaming stability. Rheological evaluations showed a positive correlation between increased GG concentration within the tri-component matrix and an increase in both storage modulus (G') and loss modulus (G"), indicating improved structural integrity. Furthermore, a comparative analysis of the texture profiles of cookies prepared with this blend highlighted the ability of higher GG concentrations to satisfactorily replicate the tactile and visual qualities of traditional egg white-based meringues. This result was particularly evident compared to formulations utilizing solely SPI or the combined SPI-MD configuration.

CONCLUSION

Conclusively, the results of the present study highlight the significant potential of the GG-SPI-MD tri-component structure to closely mimic the critical properties of egg white, thus offering a promising plant-based alternative for meringue production. © 2024 Society of Chemical Industry.

Effects of thermal treatment on the formation and properties of whey protein isolate/whey protein hydrolysate-sodium hyaluronate complexes

In dairy products, the added sodium hyaluronate may form complexes with proteins, thereby affecting product properties. In the present study, the interaction between whey protein isolate (WPI)/ whey protein hydrolysate (WPH) and sodium hyaluronate (SH) was characterized under thermal treatment at different temperatures (25 ℃, 65 ℃, 90 ℃ and 121 ℃) after studying effects of protein/SH ratio and pH on complex formation. The addition of SH reduced the particle size of WPI/WPH and increased potential value in the system, with greater variation with increasing treatment temperature. The structural properties of complexes were studied. The binding with SH decreased the contents of free amino group and free thiol group, as well as the fluorescence intensity and surface hydrophobicity. FTIR results and browning intensity measurement demonstrated the formation of Maillard reaction products. Moreover, the attachment of SH improved the thermal stability of WPI/WPH and decreased their antigenicity.

The non-covalent and covalent interactions of whey proteins and saccharides: influencing factor and utilization in food

During the application of Whey proteins (WPs), they often have complex interactions with saccharides (Ss), another important biopolymer in food substrate. The texture and sensory qualities of foods containing WPs and Ss are largely influenced by the interactions of WPs-Ss. Moreover, the combination of WPs and Ss is possible to produce many excellent functional properties including emulsifying properties and thermal stability. However, the interactions between WPs-Ss are complex and susceptible to some processing conditions. In addition, with different interaction ways, they can be applied in different fields. Therefore, the non-covalent interaction mechanisms between WPs-Ss are firstly summarized in detail, including electrostatic interaction, hydrogen bond, hydrophobic interaction, van der Waals force. Furthermore, the existence modes of WPs-Ss are introduced, including complex coacervates, soluble complexes, segregation, and co-solubility. The covalent interactions of WPs-Ss in food applications are often formed by Maillard reaction (dry or wet heat reaction) and occasionally through enzyme induction. Then, two common influencing factors, pH and temperature, on non-covalent/covalent bonds are introduced. Finally, the applications of WPs-Ss complexes and conjugations in improving WP stability, delivery system, and emulsification are described. This review can improve our understanding of the interactions between WPs-Ss and further promote their wider application.

Evaluation of digestibility, solubility, and surface properties of trehalose-conjugated quinoa proteins prepared via pH shifting technique

Soluble trehalose-conjugated quinoa proteins (T-QPs) were effectively prepared using the pH-shifting mechanism. The structural properties of the T-QPs were evaluated using a comparative evaluation, which included analyzing the amide I, surface charge and hydrophobicity, protein conformation, thermal stability, and protein structures. The results suggested that the development of the T-QPs was influenced mainly by no-covalent bonds. These interactions significantly influenced (P < 0.05) the quinoa proteins' conformation and higher-protein structure. T-QP had significant (P < 0.05) surface properties. Furthermore, the T-QPs exhibited improved solubility (79.7 to 88.4%) and digestibility (79.8 to 85.1%). Therefore, quinoa protein proved an excellent plant-based protein for conjugation with disaccharides. These findings provide significant insight into the potential development of modified proteins with enhanced solubility and digestibility by creating trehalose-conjugated plant-based proteins.

The Potency of Maillard Conjugates Containing Whey Protein as Natural Emulsifier

There is a continued need for the advancement of natural emulsifiers to replace synthetic emulsifiers, driven by human health concerns. This study is aimed at producing protein-polysaccharide conjugates through the Maillard reaction and at evaluating its ability as an emulsifier based on its emulsifying properties. The proteins used in this study were bovine milk whey protein and soy protein isolates, while the polysaccharides were maltodextrin and pectin. The protein-polysaccharide conjugation used a Maillard reaction under dry heating conditions. The protein and polysaccharide mass ratios were 1 : 2 and 1 : 3. The results showed that the types of proteins and polysaccharides and their mass affect the surface tension of the conjugate products. Whey protein-pectin conjugates with a mass ratio of 1 : 2 and a concentration of 1% had the lowest surface tension at 43.77 dyne/cm2. This conjugate sample also showed the highest emulsifying index at 27.20 m2/g. The conjugate powder containing pectin as a polysaccharide showed better emulsifying activity than that of those containing maltodextrin. However, the smallest droplet size of the emulsion (256.5 nm) resulted from the emulsification process using whey protein-maltodextrin conjugates as an emulsifier. The FTIR and gel electrophoresis (SDS-PAGE) analysis confirmed the conjugation formation. In general, protein-polysaccharide conjugates containing whey protein could potentially act as a natural emulsifier for food.

Comprehensive Assessment of Polysaccharides Extracted from Squash by Subcritical Water under Different Conditions

The effects of subcritical water microenvironment on the physiochemical properties, antioxidant activity and in vitro digestion of polysaccharides (SWESPs) from squash were investigated. After single-factor experiments, twenty samples were successfully prepared at different extraction temperatures (110, 130, 150, 170 and 190 °C) and extraction times (4, 8, 12 and 16 min). Under a low temperature environment, the whole process was mainly based on the extraction of SWESP. At this time, the color of SWESP was white or light gray and the molecular mass was high. When the temperature was 150 °C, since the extraction and degradation of SWESP reached equilibrium, the maximum extraction rate (18.67%) was reached at 150 °C (12 min). Compared with traditional methods, the yield of squash SWESP extracted by subcritical water was 3-4 times higher and less time consuming. Under high temperature conditions, SWESPs were degraded and their antioxidant capacity and viscosity were reduced. Meanwhile, Maillard and caramelization reactions turned the SWESPs yellow-brown and produced harmful substances. In addition, different SWESPs had different effects on in vitro digestion. In brief, SWESPs prepared under different conditions have different structures and physicochemical properties, allowing the obtainment of the required polysaccharide. Our results show that squash polysaccharides prepared in different subcritical water states had good development potential and application in the food industry.

Design of colloid structure to realize gel salt reduction: a review

Excessive consumption of salt is associated with increased incidence of cardiovascular diseases, hypertension, diabetes, and other health issues. However, it is challenging to find appropriate strategies that balance sensory qualities while achieving sodium reduction as salt plays a crucial role in providing desired appearance, texture, and taste. The impact of hydrocolloid properties (addition and type) on saltiness perception were reviewed. Additionally, considering the interactions between food components, both covalent and noncovalent, we propose designing specialized colloidal structures capable of binding sodium ions to enhance salt-taste perception. The effects of hydrocolloids on the physicochemical, structural, and sensory qualities of gel foods are then discussed. Finally, by addressing current issues with low-salt foods and consumer demands, we provide a future outlook for low-salt food development. The selection of suitable hydrocolloids and precise control of the addition are crucial considerations for achieving salt reduction. The interaction between hydrocolloids and other food components can be utilized to design specialized colloidal structures, thereby accomplishing gel-based salt reduction and enhancing properties. This review serves as a theoretical reference for developing healthy, nutritious, and flavorful low-salt foods that can aid in the prevention and mitigation of diseases associated with excessive salt consumption.

Conjugation of gum Arabic and lentil protein hydrolysates through Maillard reaction: Antioxidant activity, volatile compounds, functional and sensory properties

Lentil protein hydrolysates (LPH) and lentil protein hydrolysates cross-linked (LPHC) were grafted with gum Arabic (GA) through a wet Maillard reaction at 100°C for 2 h and called MLPH and MLPHC. The samples were assessed for absorption, degree of grafting (DG), surface hydrophobicity, antioxidant activity, molecular weight (MW) profile, chemical alteration, volatile compounds, functional and sensory properties. Results showed that Maillard grafting led to increase in absorption and DG (maximum value: MLPHC), and led to the reduction of the surface hydrophobicity and antioxidant activity (minimum value: MLPHC). MW profiles indicated that MLPH and MLPHC formed new bands at MW >250 kDa. Regarding the Fourier transform infrared spectroscopy (FTIR), Maillard conjugation led to the occurrence of peaks at 1759 and 1765 cm-1, while the intensities of amide I bands at 1637 and 1659 cm-1 and amide II bands at 1498 and 1495 cm-1 were decreased. Hydrolysis, cross-linking, and especially Maillard grafting provided well-balanced content of volatile components. Indeed, the proportions of alcohols, ketones, aldehydes, and acids were changed, thereby, the inherent grassy and planty tastes were diminished while new umami taste was developed. Maillard grafting led to significant improvement of functional properties, while MLPH and MLPHC indicated the highest emulsifying activity at pH 10.0 (73.76 and 70.12 m2/g, respectively) and stability (369.64 and 288.22 min), foaming capacity (88.57% and 142.86%) and stability (60.57% and 72%). Sensory analysis has demonstrated that umami taste was highly developed in MLPH and MLPHC, which can be well considered as meat proteins and flavor enhancers such as monosodium glutamate (MSG).

Delivery systems designed to enhance stability and suitability of lipophilic bioactive compounds in food processing: A review

Lipophilic compounds, such as flavors, fat-soluble vitamins, and hydrophobic nutrients possess vital properties including antioxidant effects, functional attributes, and nutritional value that can improve human health. However, their susceptibility to environmental factors including heat, pH changes, and ionic strength encountered during food processing poses significant challenges. To address these issues, diverse bioactive delivery systems have been developed. This review explores delivery systems designed to optimize the stability and suitability of lipophilic bioactive compounds in food processing. Extensive literature analysis reveals that tailoring delivery systems with various biopolymers can protect bioactives through steric hindrance and formation of thick interfacial layers on the emulsion surfaces. Thus, the access of oxygen, prooxidants, and free radicals at the emulsion interface could be inhibited, resulting in enhanced processing suitability of bioactives as well as chemical stability under diverse environmental conditions. The insights presented in this review hold immense value for the food and beverage industries.

Current situation, trend, and prospects of research on functional components from by-products of baijiu production: A review

In the present scenario marked by energy source shortages and escalating concerns regarding carbon dioxide emissions, there is a growing emphasis on the optimal utilization of biomass resources. Baijiu, as the Chinese national spirit, boasts remarkably high sales volumes annually. However, the production of baijiu yields various by-products, including solid residues (Jiuzao), liquid wastewater (Huangshui and waste alcohol), and gaseous waste. Recent years have witnessed dedicated research aimed at exploring the composition and potential applications of these by-products, seeking sustainable development and comprehensive resource utilization. This review systematically summarizes recent research, shedding light on both the baijiu brewing process and the bioactive compounds present baijiu production by-products (BPBPs). The primary focus lies in elucidating the potential extraction methods and applications of BPBPs, offering a practical approach to comprehensive utilization of by-products in functional food, medicine, cosmetic, and packaging fields. These applications not only contribute to enhancing production efficiency and mitigating environmental pollution, but also introduce innovative concepts for the sustainable advancement of associated industries. Future research avenues may include more in-depth compositional analysis, the development of utilization technologies, and the promotion of potential industrialization.

Glycation-induced enhancement of yeast cell protein for improved stability and curcumin delivery in Pickering high internal phase emulsions

Pickering high internal phase emulsions (HIPEs) have gained significant attention for various applications within the food industry. Yeast cell protein (YCP), derived from spent brewer's yeast, stands out as a preferred stabilizing agent due to its cost-effectiveness, abundance, and safety profile. However, challenges persist in utilizing YCP, notably its instability under high salt concentration, thermal processing, and proximity to its isoelectric point. This study aimed to enhance YCP's emulsifying properties through glycation with glucose and evaluate its efficacy as a stabilizer for curcumin (CUR)-loaded HIPEs. The results revealed that glycation increased YCP's surface hydrophobicity, exposing hydrophobic groups. This augmentation, along with steric hindrance from grafted glucose molecules, improved emulsifying properties, resulting in a thicker interfacial layer around oil droplets. This fortified interfacial layer, in synergy with steric hindrance, bolstered resistance to pH changes, salt ions, and thermal degradation. Moreover, HIPEs stabilized with glycated YCP exhibited reduced oxidation rates and improved CUR protection. In vitro digestion studies demonstrated enhanced CUR bioaccessibility, attributed to a faster release of fatty acids. This study underscores the efficacy of glycation as a strategic approach to augment the applicability of biomass proteins, exemplified by glycated YCP, in formulating stable and functional HIPEs for diverse food applications.

Effect of polysaccharide addition on food physical properties: A review

The texture, flavor, performance and nutrition of foods are affected by their physical properties during processing, cooking, storage, and shelf life. In addition to chemical, physical, and enzymatic modification methods, polysaccharide addition is also considered a safe, effective, and convenient food modification strategy. However, thus far, literature review on the effects of polysaccharides on the physical properties of foods is few. Therefore, the present work reviews the effects of polysaccharides on water retention capacity, rheological property, suspension ability, viscoelasticity, emulsifying property, gelling property, stability, and starch regeneration and digestion. Furthermore, the existing problems and future recommendations during food physical property modification by polysaccharides are presented. This work aims to provide some theoretical references for future research, development, and application of polysaccharides on food physical property modification.

Emulsion for stabilizing β-carotene and curcumin prepared directly using a continuous phase of polysaccharide-rich Schizophyllum commune fermentation broth

In this study, we examined the effect of Schizophyllum commune fermentation broth (SCFB) rich in polysaccharides (SCFP) on the stability and bioaccessibility of β-carotene and curcumin. An SCFB-stabilized oil-in-water (o/w) emulsion (SCFBe) was prepared using SCFB as the continuous phase, and then evaluated for storage stability using an SCFP-based emulsion (SCFPe) as the control. The findings revealed that SCFBe is more stable at 60 °C than SCFPe, and stratification or droplet size varied at differing pH levels (3-9) and concentrations of Na+ (0.1-0.5 M) and Ca2+ (0.01-0.05 M). Since the absolute value of the zeta potential of SCFBe is much lower at 60 °C than that at 4 °C and 25 °C, a higher temperature (60 °C) may enhance the reactivity of polysaccharides and proteins in SCFB to improve the stability of SCFBe. Both the protective impact of SCFB on functional food molecules and their capacity to block lipid oxidation increased as polysaccharide content improved. The bioaccessibility of β-carotene after in vitro simulated gastrointestinal digestion is 11.18 %-12.28 %, whereas that of curcumin is 31.64 %-33.00 %. By fermenting edible and medicinal fungi in liquid, we created a unique and environmentally friendly approach for getting food-grade emulsifiers without extraction.

Microwave radiation induces modifications in the protein fractions of tef flours and modulates their derived techno-functional properties

The impact of microwave (MW) treatments on the structure, solubility, and techno-functional properties of the proteins in starchy matrices is still poorly understood. This study aimed to investigate the effects of MW intensity by applying 1, 2, and 6 min of radiation on two tef flour varieties moistened at 15 % and 25 %. The fractionation method recovered ∼83 % of the total protein content in untreated flours. The interaction between treatment time and moisture content (MC) significantly influenced the extraction of protein fractions. Samples treated at 25 %MC showed significant reductions in albumins (up to -74 %), globulins (up to -79 %), and prolamins (up to -32 %). The SDS-extractable proteins of both tef flours presented similar molecular weights (12-100 kDa). SDS-PAGE analysis revealed decreased band intensity in MW-treated samples compared to untreated flours, and confocal analysis showed changes in the native state of proteins in treated samples. Shorter treatments at low MC significantly improved the emulsifying stability of tef flours, particularly in brown tef flour, with an enhancement of up to 203 %. The hydration properties significantly increased in flours treated at 25 %MC for 6 min. Pearson correlation analysis demonstrated the influence of treatment time and MC on protein recovery and functional properties of tef flours.

Effect of extrusion temperature on the structure and emulsifying properties of soy protein isolate-oat β-glucan conjugates formed during high moisture extrusion

In this study, extrusion was used to induce Maillard reaction between soy protein isolate (SPI) and oat β-glucan (OG) and effect of extrusion temperature (70, 90, 110 and 130 °C) on the structure and emulsifying properties of extruded SPI-OG was investigated. SDS-PAGE and fluorescence spectroscopy provided evidence for the formation of SPI-OG conjugates during extrusion. The results showed that 90 °C and 110 °C extruded SPI-OG had the highest level of degree of glycosylation (were 14.34% and 13.70%, respectively, p > 0.05). Structural analysis found that α-helix content of extruded SPI-OG decreased by 8.93-13.14% compared to mixture of SPI and OG. Meanwhile, extruded SPI-OG had lower protein solubility (29.83-34.38%) and surface hydrophobicity (1549-2027), larger average particle size (2363-4807 nm) and higher emulsion stability (74.33-90.15%). Therefore, these findings may provide a theoretical basis for the development of novel food emulsion stabilizers.

Active polysaccharides: a new roadmap for the prevention and treatment of food allergy

Active polysaccharides are extensively utilized in the fields of food and medicine because of their rich functional properties and structural plasticity. However, there are still few systematic studies and reviews on active polysaccharides for allergy. Allergy, especially food allergy, occurs frequently around the world and is related to a variety of factors such as age, genetics and dietary habits. Currently in medicine, avoiding allergens and desensitizing can effectively relieve allergy symptoms, but these are difficult to maintain over the long term and come with risks. Based on the supplementation of dietary nutrition to these two treatments, it has been discovered in recent years that the use of active ingredients from natural substances can effectively intervene in allergies. Considering the potential of active polysaccharides in this regard, we systematically characterize the latent patterns of polysaccharides in allergic symptoms and pathogenesis, including the aspects of gut, immunomodulatory, oxidative stress and signaling pathways, as well as the application prospect of them in allergy. It can be found that active polysaccharides have excellent anti-allergic potential, especially from the ocean. We believe that the active polysaccharides are associated with the treatment of allergic diseases, which may provide the benefits to allergy sufferers in the future.

Black garlic particles as a natural pigment and emulsifier in a Pickering emulsion based low fat innovative mayonnaise: Improved rheology and bioactivity

Black garlic is rich in brown pigments and Maillard reaction products are known for antioxidant activity and health promoting effects. In the present investigation, we report a facile strategy for fabricating low-fat innovative mayonnaise (IM) using black garlic particles (BGP) as a natural pigment, and a functional ingredient. Whey protein concentrate and high methoxyl pectin at optimized concentrations were utilized for fabricating an IM which served as a control. IM5 and IM10 were ternary composites constituting whey protein, high methoxyl pectin along with BGP (@5 and 10% respectively). The formulation IM10 (BGP @10%) showed high firmness and low spreadability quotient, hence IM5 was taken forward for fabrication for two more variants namely IM-J (using low methoxyl pectin (LMP) from jackfruit peels) and IM-C (LMP from citrus). The effect of BGP and LMP on the functional quality of IM was confirmed through zeta potential, antioxidant activity, textural, rheological, and microscopic evaluation. Fluorescence microscopy confirmed the presence of solid particles over the fat phase of IM, while interaction of pectin and whey proteins was demonstrated through fluorescence emission spectroscopy which clearly displayed stabilization of IM through the formation of Pickering emulsion. Pronounced difference in color and flavor score with BGP established high sensory scores in IM5, IM-J, and IM-C. Rheology supported the stabilizing effects of LMP in IM-J and IM-C in terms of speedy recovery of thixotropy, with recovering storage modulus (G'). Enhanced viscosity of IM-C and IM-J further corroborated the dual effect of LMP and BGP in improving emulsifying and functional quality of IM. Enhanced oxidative stability of IM was established by reduced peroxide and Totox values. Overall our results suggest the promising applications of black garlic as functional ingredient in protein and pectin based Pickering emulsions.

Enhancement of gum Arabic/casein microencapsulation on the survival of Lactiplantibacillus plantarum in the stimulated gastrointestinal conditions

Probiotic products that contain lactobacilli have long histories of safe use as Lactobacillus strains have many physiological functions in the gastrointestinal tract (GIT). However, the viability of probiotics can be affected by food processing and the adverse environment. This study investigated the O/W (Oil-in-water emulsions) emulsions formed by coagulation of casein/GA (Gum Arabic) complexes for Lactiplantibacillus plantarum microencapsulation, and the stability of the strains during gastrointestinal environment were also determined. The results showed that the particle size of the emulsion decreased from 9.72 μm to 5.48 μm when the GA concentration increased from 0 to 2 (w/v), and the emulsion particles were found to be more uniform as observed by CLSM (Confocal Laser Scanning Microscope). The surface of this microencapsulated casein/GA composite forms smooth, dense agglomerates and has high viscoelasticity, which effectively improved casein's emulsifying activity (8.66 ± 0.17 m2/g). After the casein/GA complexes microencapsulation, a higher viable count was detected after gastrointestinal digestion in vitro, and the activity of L. plantarum is more stable (about 7.51 log CFU/mL) during 35 days of storage at 4 °C. The results of study will help to design lactic acid bacteria encapsulation systems based on the GIT environment for the oral delivery strategy.

A novel polysaccharide/zein conjugate as an alternative green plastic

The flax seed cake is a waste product from flax oil extraction. Adding value to this wasted material aligns with the concept of circularity. In this study, we explored zein protein conjugation with flax mucilage for packaging material development. Although both flax mucilage and zein have excellent film-forming properties, they lack the required mechanical properties for industrial processing and are sensitive to high humidity. We present a simple and non-toxic one-pot method for developing the novel flax mucilage/zein conjugate. Where the flax mucilage undergoes oxidation to form aldehyde groups, which then react with zein's amino groups in a glycation process. The conjugates were analyzed using different techniques. The flax mucilage conjugate had a water-holding capacity of 87-62%. Increasing the zein content improved the surface smoothness of the films. On the other hand, higher levels of zein led to a significant decrease in film solubility (p < 0.05). The flax mucilage conjugate exhibited thermoplastic and elastic properties; revealing Young's modulus of 1-3 GPa, glass transition temperature between 49 °C and 103 °C and excellent processability with various industrial techniques. Showing its potential as a sustainable alternative to traditional plastics.

Effects of quinoa flour (Chenopodium Quinoa Willd) substitution on wheat flour characteristics

Quinoa is a pseudo-cereal with great nutritional and functional qualities, serving as an excellent substitution to develop quinoa-containing foods. This study aimed to explore the influence of quinoa flour substitution on quality characteristics of wheat flour (WF). WF was substituted with different level of quinoa core flour, ground quinoa whole flour and recombined quinoa whole flour. Increasing levels of quinoa flour in WF declined dough swelling index, while increased falling number of composite flours. Besides, quinoa flour substitution considerably decreased the chemical forces of gluten in composite flours. The proportions α-helix and β-sheets reduced, while the random coil proportion increased in gluten secondary structure. SEM images revealed that the gluten network structure was severely damaged. Our findings indicated that substitution of WF with quinoa flours was promising to be developed as an ingredient for food products.

Behavior of protein-polysaccharide conjugate-stabilized food emulsions under various destabilization conditions

The sensitivity of protein-stabilized emulsions to flocculation, coalescence, and phase separation under destabilization conditions (i.e., heating, aging, pH, ionic strength, and freeze-thawing) may limit the widespread use of proteins as effective emulsifiers. Therefore, there is a great interest in modulating and improving the technological functionality of food proteins by conjugating them with polysaccharides, through the Maillard reaction. The present review article highlights the current approaches of protein-polysaccharide conjugate formation, their interfacial properties, and the behavior of protein-polysaccharide conjugate stabilized emulsions under various destabilization conditions, including long-term storage, heating and freeze-thawing treatments, acidic conditions, high ionic strength, and oxidation. Protein-polysaccharide conjugates are capable of forming a thick and cohesive macromolecular layer around oil droplets in food emulsions and stabilizing them against flocculation and coalescence under unfavorable conditions, through steric and electrostatic repulsion. The protein-polysaccharide conjugates could be therefore industrially used to design emulsion-based functional foods with high physicochemical stability.

Advances in preparation and application of food-grade emulsion gels

Emulsion gel is a semi-solid or solid material with a three-dimensional net structure produced from emulsion through physical, enzymatic, chemical methods or their combination. Emulsion gels are widely used in food, pharmaceutical and cosmetic industries as carriers of bioactive substances and fat substitutes due to their unique properties. The modification of raw materials, and the application of different processing methods and associated process parameters profoundly affect the ease or difficult of gel formation, microstructure, hardness of the resulting emulsion gels. This paper reviews the important research undertaken in the last decade focusing on classification of emulsion gels, their preparation methods, the influence of processing method and associated process parameters on structure-function of emulsion gels. It also highlights current status of emulsion gels in food, pharmaceutical and medical industries and provides future outlook on research directions requiring to provide theoretical support for innovative applications of emulsion gels, particularly in food industry.

Modification and Solubility Enhancement of Rice Protein and Its Application in Food Processing: A Review

Rice protein is a high-quality plant-based protein source that is gluten-free, with high biological value and low allergenicity. However, the low solubility of rice protein not only affects its functional properties such as emulsification, gelling, and water-holding capacity but also greatly limits its applications in the food industry. Therefore, it is crucial to modify and improve the solubility of rice protein. In summary, this article discusses the underlying causes of the low solubility of rice protein, including the presence of high contents of hydrophobic amino acid residues, disulfide bonds, and intermolecular hydrogen bonds. Additionally, it covers the shortcomings of traditional modification methods and the latest compound improvement methods, compares various modification methods, and puts forward the best sustainable, economical, and environmentally friendly method. Finally, this article lists the uses of modified rice protein in dairy, meat, and baked goods, providing a reference for the extensive application of rice protein in the food industry.

Fabrication of a Polysaccharide-Protein/Protein Complex Stabilized Oral Nanoemulsion to Facilitate the Therapeutic Effects of 1,8-Cineole on Atherosclerosis

Atherosclerosis (AS) is a systemic disease characterized by lipid deposition in the blood vessel wall that urgently requires effective and safe therapeutic drugs for long-term treatment. An essential oil monomer-1,8-cineole (CIN) with ameliorative effects on vascular injuries has considerable potential for preventing the progression of AS because of its antioxidant, anti-inflammation, and cholesterol regulatory effects. However, the high volatility and instability of CIN result in low oral bioavailability and a short half-life, thereby limiting its clinical application. We formulated a nanoemulsion using a polysaccharide-protein/protein complex (dextran-bovine serum albumin/protamine, DEX_5k-BSA/PTM) as an emulsifier, with vitamin B12 (VB₁₂) as the ligand to facilitate the transportation across the small intestine. An emulsion preparation method using a microjet followed by ultraviolet irradiation was developed to obtain the CIN-loaded oral nanoemulsion CIN@DEX_5k-BSA/PTM/VB₁₂. The nanoemulsion improved the stability of CIN both in vitro and in vivo, prolonged the retention time in the gastrointestinal tract (GIT), and enhanced the permeability across the mucus layer and intestinal epithelial cells to increase oral bioavailability and plaque accumulation of CIN. Validated in an AS mouse model, CIN@DEX_5k-BSA/PTM/VB₁₂ achieved prominent therapeutic efficacy combating AS. This study highlights the advantages of DEX_5k-BSA/PTM and VB₁₂ in the development of nanoemulsions for CIN and provides a promising oral nanoplatform for the delivery of essential oils.

Preparation, Properties and Application in Electrospinning of Tremella Polysaccharide-Protein Complex

In this paper, the effects of different proteins (soybean protein isolate, wheat protein hydrolysate, tremella protein) on the activity of tremella polysaccharide under different conditions were studied. The optimal protein-polysaccharide complex was determined by grafting degree and activity screening, and the microstructure and rheological properties were studied. The results showed that when the ratio of soybean protein isolate to tremella polysaccharide was 2:1 and the solution pH was 7, the optimal complex was obtained by heating at 90 °C for 4 h, and its grafting degree and antioxidant activity were the best. Studies have shown that tremella polysaccharide and soybean protein isolate complex (TFP-SPI) solution is pseudoplastic fluids. At the same time, tremella polysaccharide (TFP) and TFP-SPI were used for electrospinning to observe its spinnability. When the ratio of PVA/TFP-SPI/PL was 8:1:1, nanofibers with uniform diameter and good morphology were obtained. This paper provides a theoretical basis for the comprehensive utilization of tremella polysaccharide and its electrospun fiber can be used as active film for food packaging.

High-temperature glycosylation modifies the molecular structure of ovalbumin to improve the freeze-thaw stability of its high internal phase emulsion

In this study, ovalbumins (OVAs) were glycosylated with fructo-oligosaccharide (FO) at different temperatures (80 °C, 100 °C, 120 °C, and 140 °C) and durations (1 h and 2 h) via wet-heating. The glycosylated OVAs (GOVAs) were characterized by the degree of glycosylation (DG), particle size, zeta potentials, and structural changes. GOVAs-stabilized high-internal-phase emulsions (HIPEs) were then prepared to compare their macro- and microstructure and freeze-thaw stability. The results showed that the DG of GOVAs increased with the increase in glycosylation temperature and the protein structure unfolded with it. Glycosylation decreased the particle size, zeta potential, and α-helical structures and increased the β-sheets and surface hydrophobicity (H₀) of GOVAs compared with unmodified OVAs. Moreover, GOVAs-stabilized HIPEs exhibited smaller particle sizes, zeta potentials, agglomeration indexes, oil loss rates, and freezing points and higher viscoelasticity, centrifugal stabilities, flocculation indexes, and freeze-thaw stabilities. Notably, HIPEs prepared by GOVAs (glycosylated higher than 120 °C) showed the least changes in macro- and microscopic appearances after freeze-thawing. These findings will provide a novel method for improving and broadening the functionalities of OVAs and potentially develop HIPEs with enhanced freeze-thaw stabilities.

Characteristics and antioxidant properties of Harpadon nehereus protein hydrolysate-xylose conjugates obtained from the Maillard reaction by ultrasound-assisted wet heating in a natural deep eutectic solvents system

BACKGROUND

Harpadon nehereus is a high-protein marine fish. A valuable way to add value to H. nehereus is to convert it into protein hydrolysate. The Maillard reaction is an effective way to improve the functional properties of peptides and proteins, which are affected by many factors such as reactant concentration, water activity, pH, temperature, and heating time. However, the traditional Maillard reaction method is inefficient. The purpose of this study was therefore to explore the effect of the ultrasound-assisted wet heating method on the Maillard reaction of H. nehereus protein hydrolysate (HNPH) in a new-type green solvent - a natural hypereutectic solvent (NADES).

RESULTS

Harpadon nehereus protein hydrolysate-xylose (Xy) conjugates were prepared via a Maillard reaction in a NADES system using an ultrasound-assisted wet heating method. The effects of different treatment conditions on the Maillard reaction were studied. The optimized glycation degree (DG) of HNPH-Xy conjugates was obtained with a water content of 10%, a reaction temperature of 80 °C, a reaction time of 35 min, and an ultrasonic power level of 300 W. Compared with HNPH, the structure of HNPH-Xy conjugates were significantly changed. Moreover, the functional properties and antioxidant activity of HNPH-Xy were all superior to the HNPH.

CONCLUSIONS

An ultrasound-assisted wet-heating Maillard reaction between HNPH and Xy in the NADES system could be a promising way to improve the functional properties of HNPH. © 2023 Society of Chemical Industry.

Novel Colloidal Food Ingredients: Protein Complexes and Conjugates

Food proteins, polysaccharides, and polyphenols are natural ingredients with different functional attributes. For instance, many proteins are good emulsifiers and gelling agents, many polysaccharides are good thickening and stabilizing agents, and many polyphenols are good antioxidants and antimicrobials. These three kinds of ingredients can be combined into protein, polysaccharide, and/or polyphenol conjugates or complexes using covalent or noncovalent interactions to create novel multifunctional colloidal ingredients with new or improved properties. In this review, the formation, functionality, and potential applications of protein conjugates and complexes are discussed. In particular, the utilization of these colloidal ingredients to stabilize emulsions, control lipid digestion, encapsulate bioactive ingredients, modify textures, and form films is highlighted. Finally, future research needs in this area are briefly proposed. The rational design of protein complexes and conjugates may lead to the development of new functional ingredients that can be used to create more nutritious, sustainable, and healthy foods.