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Over the years, there has been an increase in demand for plant-based foods as alternatives. In line with this, this work explores the production and in vitro digestion of a fermented plant-based beverage (FPBB) produced with pea and rice proteins and 0% (FPBB-C), 5% (FPBB-5), and 10% (FPBB-10) uvaia pulp through lactic fermentation with Lacticaseibacillus rhamnosus GG. The in vitro gastrointestinal digestion process was conducted to assess the bioaccessibility of L. rhamnosus GG, total phenolic content (TPC), and antioxidant activity before and after simulating the gastrointestinal conditions. After 48 h of digestion, highly viable L. rhamnosus GG cells remained throughout the gastrointestinal system. FPBB-C (106.89%) and FPBB-5 (109.38%) exhibited higher survival rates than FPBB-10 (102.20%), indicating that these beverages have a higher prebiotic action potential. Compared with the non-digested samples, after 48 h of digestion, all samples exhibited a significant increase in TPC. The same behavior occurs for the antioxidant activity of FPBB-C, FPBB-5, and FPBB-10 by DPPH (4.06, 3.96, and 8.44 mg TEAC mL-1), ABTS (10.28, 11.06, 11.97 mg TEAC mL-1), and FRAP method (917.02, 863.87, and 1983.23 mg TEAC mL-1). Thirteen compounds were identified and quantified in uvaia pulp by HPLC-DAD-ESI-MS, particularly epigallocatechin gallate, quercetin-3-rhamnose, and quercetin-3-glucoside. Isorhamnetin was the main phenolic compound detected in the colon, assumably due to the conversion of quercetin-3-glucoside by the probiotic cells. In conclusion, as all counts were above 9 log CFU g-1, the FPBB formulations containing pea, rice protein, and uvaia pulp become a promising vehicle for carrying L. rhamnosus GG. [ABSTRACT FROM AUTHOR]

Summary: In response to the growing interest in plant‐based alternatives and vegan diets, this study aimed to develop novel sweet potato‐based vegan protein bars enriched with rice protein (RP) as an alternative protein source. The vegan protein bars (VPBs) formulated with varying RP content (0–32 g) were evaluated for nutritional, textural, microstructural and sensory properties. Nutritional analysis revealed a proportional increase in protein content (8.94%–21.77%) and energy value (310.29–353.32 kcal/100 g) with increasing RP content. The progressive inclusion of RP significantly (P < 0.05) improved the textural properties of VPBs, notably increasing cohesiveness (0.07%–0.60%), chewiness (8.71–105.02 g) and firmness (1453.80–3444.03 kg cm−2), with all VPBs receiving favourable sensory evaluation scores. Importantly, all VPBs received favourable sensory scores. Microstructural analysis revealed the mechanism for textural enhancement in enriched VPBs, indicating a positive correlation between higher RP content and the number and size of surface clumps. Amino acid profiling indicated over 50% increases in valine content and essential amino acid scores in enriched VPBs compared to those without RP. Moreover, protein‐enriched VPBs exhibited superior antioxidant activity. In conclusion, these findings suggest the potential of sweet potato and RP in developing VPBs, highlighting the value of plant‐based ingredients in vegan food products. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over the years, there has been an increase in demand for plant-based foods as alternatives. In line with this, this work explores the production and in vitro digestion of a fermented plant-based beverage (FPBB) produced with pea and rice proteins and 0% (FPBB-C), 5% (FPBB-5), and 10% (FPBB-10) uvaia pulp through lactic fermentation with Lacticaseibacillus rhamnosus GG. The in vitro gastrointestinal digestion process was conducted to assess the bioaccessibility of L. rhamnosus GG, total phenolic content (TPC), and antioxidant activity before and after simulating the gastrointestinal conditions. After 48 h of digestion, highly viable L. rhamnosus GG cells remained throughout the gastrointestinal system. FPBB-C (106.89%) and FPBB-5 (109.38%) exhibited higher survival rates than FPBB-10 (102.20%), indicating that these beverages have a higher prebiotic action potential. Compared with the non-digested samples, after 48 h of digestion, all samples exhibited a significant increase in TPC. The same behavior occurs for the antioxidant activity of FPBB-C, FPBB-5, and FPBB-10 by DPPH (4.06, 3.96, and 8.44 mg TEAC mL−1), ABTS (10.28, 11.06, 11.97 mg TEAC mL−1), and FRAP method (917.02, 863.87, and 1983.23 mg TEAC mL−1). Thirteen compounds were identified and quantified in uvaia pulp by HPLC-DAD-ESI-MS, particularly epigallocatechin gallate, quercetin-3-rhamnose, and quercetin-3-glucoside. Isorhamnetin was the main phenolic compound detected in the colon, assumably due to the conversion of quercetin-3-glucoside by the probiotic cells. In conclusion, as all counts were above 9 log CFU g−1, the FPBB formulations containing pea, rice protein, and uvaia pulp become a promising vehicle for carrying L. rhamnosus GG.

In order to improve the solubility of rice protein in aqueous solutions by using oat protein-coupled co-assemble hybridization technology, in this study, different ratios of rice protein and oat protein were used as raw materials, and the two proteins were mixed at pH12, and then restored to neutrality for the co-assemble hybridization. The solubility of the protein was determined and the mechanism of action was explored by analyzing sodium dodecyl sulfate-polyacrylamide gel electrophoresis, particle size, microscopic morphology, emulsification characteristics, foaming characteristics, and Fourier transform infrared spectrometer. The results indicated that the solubility of rice protein-oat protein was higher than that of rice protein (8.49%±1.53%), and the highest solubility 93.07%±2.15% was achieved at the ratio of 1:0.6 (rice protein/oat protein). The particle size of the rice protein-oat protein after co-assemble hybridization was about 0.1 μm, while the structure became looser and hydrophobic interaction and hydrogen bond between rice protein and oat protein were changed, which increased the solubility of rice protein and further improved the emulsification and foaming characteristics. In conclusion, the oat protein-coupled co-assemble hybridization technology is a robust method that can solve the poor water solubility of rice protein.

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reducing meat consumption reduces carbon emissions and other environmental harms. Unfortunately, commercial plant-based meat substitutes have not seen widespread adoption. In order to enable more flexible processing methods, this paper analyzes the characteristics of commercially available spirulina, soy, pea, and brown rice protein isolates to provide data for nonmeat protein processing that can lead to cost reductions. The thermal and rheological properties, as well as viscosity, density, and particle size distribution, were analyzed for further study into alternative protein-based food processing. The differential scanning calorimetry analysis produced dry amorphous-shaped curves and paste curves with a more distinct endothermic peak. The extracted linear temperature ranges for processing within food production were 70–90 °C for spirulina, 87–116 °C for soy protein, 67–77 °C for pea protein, and 87–97 °C for brown rice protein. The viscosity analysis determined that each protein material was shear-thinning and that viscosity increased with decreased water concentration, with rice being an exception to the latter trend. The obtained viscosity range for spirulina was 15,100–78,000 cP, 3200–80,000 cP for soy protein, 1400–32,700 cP for pea protein, and 600–3500 cP for brown rice protein. The results indicate that extrusion is a viable method for the further processing of protein isolates, as this technique has a large temperature operating range and variable screw speed. The data provided here can be used to make single or multi-component protein substitutes. [ABSTRACT FROM AUTHOR]

Objective: To enhance the water solubility and stability of hydrophobic active substances. Methods: A nano-delivery system of rice protein hydrolysate （RPH）-xanthan gum （XG）-curcumin （Cur） was developed, wherein curcumin served as the delivery object, and the encapsulation efficiency, stability, antioxidant activity, and formation mechanism of the nanoparticles were determined and analyzed. Results: The encapsulation efficiency of RPH-XG-Cur nanoparticles reached 78.40%, with a particle size of 74.78 nm, PDI of 0.36, and Zeta potential of -27.93 mV. Remarkably, the incorporation of xanthan gum significantly improved the encapsulation performance as well as pH and ionic strength stability of the nanoparticles. Fourier infrared and fluorescence spectra analysis revealed that hydrogen bonding, electrostatic interaction, and hydrophobic interaction played crucial roles in nanoparticle formation. Conclusion: RPH-XG nanoparticles exhibit great potential as nanocarriers for delivering hydrophobic bioactive substances.

Rice protein (RP) and polyphenols are often used in functional foods. This study investigated the non-covalent interactions between RP and three polyphenols (curcumin, CUR; quercetin, QUE; resveratrol, RES) and used the complexes as emulsifiers to create emulsions. Three polyphenols interacted with RP to varying extents, with QUE showing the greatest binding affinity and inducing the greatest alterations in its secondary structure. Molecular docking analysis elucidated the driving forces between them including hydrophobic interactions, hydrogen bonding, and van der Waals forces. Combination with QUE or RES induced structural changes of RP, increasing particle size of complexes. The synergistic effect of polyphenols and protein also enhanced radical scavenging capacity of complexes. Compared to pure protein, all complexes successfully created emulsions with smaller particle size (378–395 nm vs. 470 nm), higher absolute potential (37.43–38.26 mV vs. 35.62 mV), and greater lipid oxidation stability by altering protein conformation.

The objective of this study was to improve water solubility of the rice protein (RP) by forming complexes with anionic polysaccharides, such as sodium alginate (SA) and xanthan gum (XG). In addition, utilization of the RP complexes as an emulsifier was evaluated. The prepared RP-SA or RP-XG complexes were analyzed by measuring their particle size, ζ-potential, and water solubility as well as by confocal laser scanning microscopy. The formation of a complex between RP-SA and RP-XG improved the water solubility and dispersibility of RP over a wide range of pH values (3, 5, 7, and 9). Confocal fluorescence images showed that the aggregation of RP molecules was prevented by the formation of complexes between RP and polysaccharides. When soybean oil-in-water emulsions were prepared with complexes, RP-SA (ratio 4:1) and RP-XG(ratio 4:1) complex-stabilized emulsions were stable for 4 weeks of storage. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the interactions between metal ions of different valences (Na+, Ca2+, Al3+) and rice protein (RP) and their effects on rice protein fibrillation were investigated. The results showed that adding metal ions could shorten the time of protein fibrillation and increase fibril yield. The fluorescence results showed that high-valent metal ions were more likely to destroy the hydration layer on the surface of the protein, showing higher fluorescence intensity. The dynamic binding of metal ions to proteins promoted fibrils elongation. Moreover, The high-valent metal ions have more binding sites and larger binding constants with proteins. As the morphological studies showed that the length of fibrils increased to more than 1 μm after the addition of metal ions. The rheological results revealed that the viscosity of fibrils formed under the mediation of high-valent metal ions was enhanced and the storage modulus was higher than the loss modulus, indicating stronger molecular forces between fibrils and better elastic properties. This study provided a method for regulating RP fibrillation and meanwhile provided new insights for the application of RP. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fermentation is known to enhance the nutritional profile and confer unique flavors to products. However, the resultant effects on stability and physicochemical properties remain unexplored. RESULTS: This study aims to elucidate the influence of fermentation on the stability and organoleptic characteristics of a rice protein beverage stabilized by carboxymethyl cellulose (CMC). The findings revealed that the average aggregate size escalated from 507 to 870 nm, concurrently exhibiting a significant increase in surface potential. The aggregation enhancement was substantiated by evident morphological changes and confocal laser scanning microscopical (CLSM) observations. A negative correlation was discerned between the physical stability of the beverage and fermentation duration. Moreover, flavor analysis of the beverage post a 3 h fermentation period highlighted an increase in aromatic ester compounds, thereby intensifying the aroma. CONCLUSION: The study corroborates that fermentation can detrimentally influence product stability while concurrently improving its flavor profile. By establishing a mix ratio of 10:1 for rice protein and CMC and forming a relatively stable system through electrostatic interaction at a pH of 5.4, a flavorful rice protein beverage can be derived post 3 h‐fermentation process. These findings offer insights into the impact of varying fermentation durations on the stability and flavor of polysaccharide‐based rice protein beverages. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Techniques capable of producing small-sized probiotic microcapsules with high encapsulation yields are of industrial and scientific interest. In this study, an innovative membrane emulsification system was investigated in the production of microcapsules containing Lacticaseibacillus rhamnosus GG® (Lr), sodium alginate (ALG), and whey protein (WPI), rice protein (RPC), or pea protein (PPC) as encapsulating agents. The microcapsules were characterized by particle size distribution, optical microscopy, encapsulation yield, morphology, water activity, hygroscopicity, thermal properties, Fourier-transform infrared spectroscopy (FTIR), and probiotic survival during in vitro simulation of gastrointestinal conditions. The innovative encapsulation technique resulted in microcapsules with diameters varying between 18 and 29 μm, and encapsulation yields > 93%. Combining alginate and whey, rice, or pea protein improved encapsulation efficiency and thermal properties. The encapsulation provided resistance to gastrointestinal fluids, resulting in high probiotic viability at the end of the intestinal phase (> 7.18 log CFU g−1). The proposed encapsulation technology represents an attractive alternative to developing probiotic microcapsules for future food applications. [ABSTRACT FROM AUTHOR]

It has been reported that fresh edible rice has more bioactive compounds and its protein is easier to digest and has lower hypoallergenic than mature rice. In this paper, the changes in structure and functional properties of proteins at five different stages, including early milky stage (EMS), middle milky stage (MMS), late milky stage (LMS), waxy ripe stage (WS) and ripening stage (RS), during the seed development were investigated. It was found that with the seed developing, the molecular weight of fresh rice protein gradually become larger while the secondary structure changed from the highest content of disordered structure at MMS to the highest content of ordered structure at RS, which affect the surface hydrophobicity and then the functional properties of proteins, including foaming properties, emulsifying properties and oil holding capacity. Fresh rice protein at MMS has the strongest surface hydrophobicity while fresh edible rice protein at RS has the strongest oil holding capability. The results of our study can provide a theoretical basis for the application of fresh rice protein in the food industry and help to develop new fresh edible rice food.

By devising a novel near-infrared (NIR) in-situ online monitoring system, this study proposed a new process control method for rice protein (RP) enzymatic hydrolysis in order to address the challenge of monitoring certain chemical indices in real-time. The endpoint of the enzymatic hydrolysis reaction and the flexible switching point of dual-enzyme hydrolysis were determined through real-time spectrum collection. Correction and prediction models were constructed to predict the angiotensin I-converting enzyme (ACE) inhibitory activity of RP hydrolysis as well as the endpoint and the dual-enzyme flexible switching point at different substrate concentrations in an attempt to establish the new control system. At the RP substrate concentrations of 35, 40, and 45 g/L, the R2 of predicted and measured ACE inhibitory activity values under hydrolysis with a single alcalase were 0.8852, 0.8360, and 0.8613, respectively. In addition, the ACE inhibitory activity of dual-enzyme hydrolysis showed a high growth trend before and after the flexible switching point, and the hydrolysis time was significantly shortened at the same endpoint threshold as that of single alcalase hydrolysis. The results indicated that this method is capable of accurately determining and regulating the endpoint and adaptable transition point of RP hydrolysis. Consequently, this approach holds promise for the regulation of food basic materials during large-scale processing operations.

Rice protein peptides were prepared by using alkaline protease and neutral protease complex en‐ zymatic solutions, combined with ultrasonic treatment technology, and the properties of the products were analyzed by Fourier infrared spectrometer and amino acid analyzer. The experimental results show that af‐ ter the rice protein is compounded, the solubility and the content of short peptides in the solution are sig‐ nificantly improved, the infrared peak position of the product is basically consistent with the protein pep‐ tide, has the basic structure of the polypeptide, and the product has eight kinds of amino acids neces‐ sary for the human body, and the amino acid com‐ position is abundant and has high nutritional value. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the extraction of hydrolysate protein from waste materials (rice grain and rice beverages) in order to increase the value of domestic raw materials. The goal was to create protein beverage products containing rice protein hydrolysates that are customized to the needs of athletes for post-workout muscle restoration. Carbohydrates were extracted from rice paste using an amylase enzyme, followed by protein extraction using the Protease G6 enzyme. The E/S SL ratio, temperature, and time were investigated, with the extraction taking place at a pH of 7.0. The Central Composite Design approach was used in the experimental design to change the extraction conditions. The protein concentration and the concentration levels were determined. The concentration data were then submitted to 95 percent confidence level Analysis of Variance (ANOVA) to find significant differences. To visualize the relationship between protein concentration and the interaction between the E/S SL ratio, temperature, and extraction duration, a contour plot was generated. The results showed that increasing enzyme proportions and temperatures between 50 and 60 degrees Celsius boosted protein concentration. Lower E/S SL ratios and longer extraction times enhanced protein concentration. An E/S, SL ratio of 5%, a temperature of 52 degrees Celsius, and an extraction time of 180 min were shown to be ideal conditions for extracting protein from rice grains utilizing the Protease G6 enzyme. The final protein content was 3.14 g/100 mL. These findings suggested that Protease G6 can be a viable alternative for developing rice protein beverages for athletes and health-conscious individuals. [ABSTRACT FROM AUTHOR]

Edible films provide environmentally friendly alternatives to plastic packages and can be produced by various biopolymers. Biopolymers from food waste are a promising source for packaging applications. In this study, rice protein (RP: 10–20% w/w) was used to reinforce maize starch edible films. Also, Laurus nobilis L. leaf essential oil (EO) was added to the film composition. Thickness, density, solubility and swelling in water, water vapor permeability, mechanical, color, opacity, and FTIR analyzes of films were performed. Antimicrobial and total phenolics and antioxidant activities of films containing EO as active content were also determined. RP and EO provided a reduction in solubility by strengthening the films against water. The percentage solubility value was found as 21.840 in the control film sample and 9.690 for the 20RP + EO sample. RP did not affect water vapor permeability significantly, while EO caused an increase. The maize starch-based control film had the lowest yellowness index (− 0.656) and opacity (4.169), while these values increased with the additives and maximum values were obtained in the film containing 20% RP and EO (26.097 and 12.498, respectively). The antimicrobial effect of EO-containing edible films against B. cereus has been observed. In addition, these films were also tested on strawberries, and it was concluded that the visual quality and shelf life of fruit were positively affected during 5-day storage in ambient conditions. Films containing bay leaf EO and RP have proven to be suitable for active packaging applications. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) accumulation in rice protein has long been considered a significant threat to human health. In the present study, a costless and effective method based on gluconic acid (GA) rinsing of rice protein was developed to reduce Cd contamination in rice protein. Moreover, the effect of GA on the structural and functional properties of rice protein was evaluated. With liquid–solid ratio of 30 mL/g and oscillation time of 120 min, 96.0% and 93.6% of Cd were eliminated from rice protein‐H and rice protein‐L, respectively. In addition, the results of scanning electron microscopy, Fourier transform infrared, and sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses showed that GA treatment did not significantly change the structural properties of rice protein. However, GA treatment increased foaming properties, water holding capacity, and oil holding capacity of the rice protein, without affecting its further applicability. Thus, the proposed GA rinsing method can be considered a green and efficient strategy to solve the issue brought by Cd residual contamination in rice protein. Practical Application: Given the advantages of green and efficient agriculture, gluconic acid (GA) has emerged as a powerful strategy for removing the Cd from rice protein. The method developed herein showed great potentials for applications in the manufacture of rice‐based products. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Flaxseed oil is rich in polyunsaturated fatty acids, and its incorporation into food formulations is limited due to its hydrophobic nature and susceptibility to oxidation. The aim of this work was to analyze the effect of wall material mixtures (modified starch Capsul® and rice and pea protein concentrate) on the efficiency of flaxseed oil encapsulation by freeze-drying, physical characterization, and determining oxidative stability. For the preparation of powders, four emulsions with an oil–wall material ratio of 1:3 were produced and characterized. The mass ratio between rice and pea proteins was fixed at 50–50%. The mass ratio of the protein-Capsul® mixtures was varied by 0–100%, 10–90%, 20–80%, and 30–70%. Based on the creaming index results, all emulsions showed good stability after 24 h of analysis. The powders showed low moisture content (® ratio of 0–100%) to 18.26% (protein-Capsul® ratio of 30–70%). However, the best oxidative stability results (smaller increases in the peroxide index values at the end of the stability experiments) were obtained for the powders containing the highest levels of vegetable proteins (protein-Capsul® ratio of 20–80% and 30–70%, respectively).

Honey is an excellent alternative to be used in different applications by the food, pharmaceutical, and cosmetics industries. However, the use of honey in its liquid form can present several disadvantages due to its high viscosity and density. In addition, honey can naturally crystallize during storage time, limiting its application in new products by industries. Thus, an alternative to using liquid honey in industry is the powder form. The objective of this study was to obtain honey powder by spray drying using a plant-based protein as a carrier. The honey used as raw material showed acceptable physicochemical parameters by the legislation of honey quality control, such as pH of (4.0 ± 0.1), the water content of (20.70 ± 0.3) g/100 g, ash of (0.48 ± 0.02) g/100 g, the fructose content of (35.42 ± 0.14) g/100 g, (43.05 ± 0.46) g/100 g for glucose, (0.56 ± 0.02) g/100 g for sucrose, and 5-hydroxymethylfurfural (HMF) value of (37.47 ± 1.04) mg/kg of honey, leading to the production of the honey powder. The mixture of fresh honey and plant-based protein was made with dispersions of 15, 16 and 18 g/100 g of honey using isolated rice protein as a carrier (total solid at 30 g/100 g d.b.). Finally, the honey powder produced was physicochemically characterized. The dispersion with 16 g/100 g of honey achieved an intermediary sugar/honey recovery of 35.93 ± 0.82% and 68.54 ± 2.16% of total protein recovery, and the spray drying yield was satisfactory > 50%. The overall results suggested that this dispersion is the ideal formulation when commercialization of the honey powder as an ingredient is intended. [ABSTRACT FROM AUTHOR]

Flaxseed oil is rich in polyunsaturated fatty acids, and its incorporation into food formulations is limited due to its hydrophobic nature and susceptibility to oxidation. The aim of this work was to analyze the effect of wall material mixtures (modified starch Capsul® and rice and pea protein concentrate) on the efficiency of flaxseed oil encapsulation by freeze-drying, physical characterization, and determining oxidative stability. For the preparation of powders, four emulsions with an oil–wall material ratio of 1:3 were produced and characterized. The mass ratio between rice and pea proteins was fixed at 50–50%. The mass ratio of the protein-Capsul® mixtures was varied by 0–100%, 10–90%, 20–80%, and 30–70%. Based on the creaming index results, all emulsions showed good stability after 24 h of analysis. The powders showed low moisture content (<3.23%), bulk density (<0.2659 kg/kg), and packed bulk density (<0.4389 kg/kg). Encapsulation efficiency decreased with increasing protein content, ranging from 93.40% (protein-Capsul® ratio of 0–100%) to 18.26% (protein-Capsul® ratio of 30–70%). However, the best oxidative stability results (smaller increases in the peroxide index values at the end of the stability experiments) were obtained for the powders containing the highest levels of vegetable proteins (protein-Capsul® ratio of 20–80% and 30–70%, respectively). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Though rice proteins have been applied to improve the stability of phenolic compounds, it is unclear how rice proteins affect phenolic acid's digestion and bioavailability. This study investigated the consequences of protein-ferulic acid interactions in the gastrointestinal environment. Ferulic acid and rice proteins formed complexes at room temperature, both with and without laccase. Rice protein was reported to be able to prevent ferulic acid from degrading in simulated oral fluid and remain stable in gastrointestinal fluids. With the hydrolysis of pepsin and pancreatin, rice protein-ferulic acid complexes degraded and released ferulic acid. While digested ferulic acid's DPPH scavenging activity was dramatically reduced, it was retained for the rice protein-ferulic acid complex. Moreover, the permeability coefficient of ferulic acid was not affected. Thus, rice protein is a promising food matrix to protect ferulic acid in the digestive tract and maintain the antioxidant functions of ferulic acid. [ABSTRACT FROM AUTHOR]

Objective: This study was to explore the improvement of structural and emulsifying properties of rice protein by interacted with the dark blue pigment of Vaccinium bracteatum Thunb leaves. Methods: The dark blue pigment was prepared from VBTL, and the changes of structural and emulsifying properties of rice protein before and after dyeing were analyzed. Results: The formation of binary complexes between the dark blue pigment and the rice protein decreased the color values of L* and b*, and the hue of the pigment-protein complex changed to dark blue color with the increase of the pigment concentration. The water solubility of the pigment-protein complex increased, and the oil-holding capacity decreased significantly. The analysis circular dichroism spectroscopy showed the changes in the secondary structure of pigment-protein complex with a decreasing in the relative content of α-helices and β-folds and an increasing in the relative content of β-turns and random coil. At the concentration of pigment below 1.5%, foam stability increased, while foaming capacity, emulsifying capacity and emulsion stability decreased. When the concentration of pigment was higher than 1.5%, foam stability decreased, while foaming capacity, emulsifying capacity and emulsion stability increased. Conclusion: The dark blue pigment can improve the emulsifying properties of rice protein by changing its secondary structure.

In order to explore the key components affecting the emulsification characteristics in hydrolyzed rice protein. rice protein was hydrolyzed by acidprotease, papain and trypsin, respectively. The relationships between the structural and functional properties of different hydrolyzed rice proteins were studied by surface hydrophobicity, Fourier transform infrared spectroscopy (FTIR), emulsifying activity index and emulsifying stability index. 10 kDa were separated from the rice protein with degree of 2% treated with trypsin (trypsin 2%) by ultrafiltration. The interfacial tension, quartz crystal microbalance with dissipation (QCM-D), mean diameter particle, confocal laser scanning microscope (CLSM) and storage stability were measured to explore the influence of molecular weight on the interfacial characterization and emulsion stability. The results demonstrated that hydrolysates treated with trypsin exhibited the highest yield. Compared with the rice protein, the surface hydrophobicity of the enzymatic hydrolysis products declined significantly except for the rice protein with degree of 6% treated with trypsin (trypsin 6%). The secondary structure content revealed that the β-sheet contents of hydrolyzed rice protein significantly decreased, showing that the structure of hydrolyzed rice protein was more unfolded. The trypsin 2% exhibited the better emulsifying capacity. The mean diameter particle of 10 kDa had lower interfacial tension and thicker interfacial film than the others. The emulsion prepared by >10 kDa exhibited better emulsion stability. The results indicated that the emulsion stabilized by high molecular peptides was more stable than the smaller ones.

Rice flour (RF) has become a promising food material. In the present study, RF with higher protein content was prepared using a granular starch hydrolyzing enzyme (GSHE). Particle size, morphology, crystallinity, and molecular structures of RF and rice starch (RS) were characterized to establish a hydrolytic mechanism; thermal, pasting, and rheological properties were determined to evaluate processability using differential scanning calorimetry (DSC), rapid viscosity analysis (RVA), and rheometer, respectively. The GSHE treatment resulted in pinholes, pits, and surface erosion through sequential hydrolysis of crystalline and amorphous areas on the starch granule surface. The amylose content decreased with hydrolysis time, while the very short chains (DP < 6) increased rapidly at 3 h but decreased slightly later. After hydrolysis for 24 h, the protein content in RF increased from 8.52% to 13.17%. However, the processability of RF was properly maintained. Specifically, the data from DSC showed that the conclusion temperature and endothermic enthalpy of RS barely changed. The result of rapid RVA and rheological measurement indicated that RF paste viscosity and viscoelastic properties dropped rapidly after 1 h hydrolysis and thereafter recovered slightly. This study provided a new RF raw material useful for improving and developing RF-based foods. [ABSTRACT FROM AUTHOR]

In this study, soy isoflavones-loaded nanoparticles were prepared using rice proteins (RPs) hydrolyzed by four types of enzyme (alcalase, neutrase, trypsin, and flavorzyme). After optimizing the preparation conditions, the encapsulation efficiency (EE) of the nanoparticles ranged from 61.16% ± 0.92% to 90.65% ± 0.19%. The RPs that were hydrolyzed by flavorzyme with a molecular weight of <5 KDa showed better characters on the formation of nanoparticles, and the formed nanoparticles had the highest EE and loading capacity (9.06%), the smallest particle size (64.77 nm), the lowest polymer dispersity index (0.19), and the lowest zeta potential (−25.64 mV).The results of Fourier transform ion cyclotron resonance, X-ray diffraction, and fluorescence spectroscopy showed that the nanoparticles were successfully encapsulated. The study of interaction showed that the formation of nanoparticles may depend mainly on hydrogen bonds, but other interactions, such as hydrophobic interactions and electrostatic interactions, cannot be ignored. After encapsulation, the pH stability, temperature stability, ionic stability, and oxidation resistance of the nanoparticles were enhanced. Moreover, the in vitro release experiment showed that the encapsulated nanoparticles had a certain protective effect on soybean isoflavones. In summary, rice protein hydrolysates are promising carriers for soybean isoflavones. [ABSTRACT FROM AUTHOR]

At least half the population in industrialized countries suffers from obesity due to excessive accumulation of adipose tissue. Recently, rice (Oryza sativa) proteins have been considered valuable sources of bioactive peptides with antiadipogenic potential. In this study, the digestibility and bioaccessibility in vitro of a novel protein concentrate (NPC) from rice were determined through INFOGEST protocols. Furthermore, the presence of prolamin and glutelin was evaluated via SDS-PAGE, and their potential digestibility and the bioactivity of ligands against peroxisome proliferator-activated receptor gamma (PPARγ) were explored by BIOPEP UWM and HPEPDOCK. For the top candidates, molecular simulations were conducted using Autodock Vina to evaluate their binding affinity against the antiadipogenic region of PPARγ and their pharmacokinetics and drug-likeness using SwissADME. Simulating gastrointestinal digestion showed a recovery of 43.07% and 35.92% bioaccessibility. The protein banding patterns showed the presence of prolamin (57 kDa) and glutelin (12 kDa) as the predominant proteins in the NPC. The in silico hydrolysis predicts the presence of three and two peptide ligands in glutelin and prolamin fraction, respectively, with high affinity for PPARγ (≤160). Finally, the docking studies suggest that the prolamin-derived peptides QSPVF and QPY (−6.38 & −5.61 kcal/mol, respectively) have expected affinity and pharmacokinetic properties to act as potential PPARγ antagonists. Hence, according to our results, bioactive peptides resulting from NPC rice consumption might have an antiadipogenic effect via PPARγ interactions, but further experimentation and validation in suitable biological model systems are necessary to gain more insight and to provide evidence to support our in silico findings. [ABSTRACT FROM AUTHOR]

The pulsed electric field (PEF) was applied to improve the extraction yield and properties of rice bran proteins from two rice varieties ("Kum Chao Mor Chor 107" and "Kum Doi Saket"). As compared to the conventional alkaline extraction, PEF treatment at 2.3 kV for 25 min increased the protein extraction efficiency by 20.71–22.8% (p < 0.05). The molecular weight distribution detected by SDS-PAGE and amino acid profiles of extracted rice bran proteins was likely unchanged. The PEF treatment influenced changes in the secondary structures of rice bran proteins, especially from the β-turn to the β-sheet structure. Functional properties of rice bran protein including oil holding capacity and emulsifying properties were significantly improved by PEF treatments by about 20.29–22.64% and 3.3–12.0% (p < 0.05), respectively. Foaming ability and foam stability increased by 1.8- to 2.9-fold. Moreover, the in vitro digestibility of protein was also enhanced, which was consistent with the increment of DPPH and ABTS radical-scavenging activities of peptides generated under in vitro gastrointestinal digestion (37.84–40.45% and 28.46–37.86%, respectively). In conclusion, the PEF process could be a novel technique for assisting the extraction and modification of the protein's digestibility and functional properties. [ABSTRACT FROM AUTHOR]

Reducing meat consumption reduces carbon emissions and other environmental harms. Unfortunately, commercial plant-based meat substitutes have not seen widespread adoption. In order to enable more flexible processing methods, this paper analyzes the characteristics of commercially available spirulina, soy, pea, and brown rice protein isolates to provide data for nonmeat protein processing that can lead to cost reductions. The thermal and rheological properties, as well as viscosity, density, and particle size distribution, were analyzed for further study into alternative protein-based food processing. The differential scanning calorimetry analysis produced dry amorphous-shaped curves and paste curves with a more distinct endothermic peak. The extracted linear temperature ranges for processing within food production were 70–90 °C for spirulina, 87–116 °C for soy protein, 67–77 °C for pea protein, and 87–97 °C for brown rice protein. The viscosity analysis determined that each protein material was shear-thinning and that viscosity increased with decreased water concentration, with rice being an exception to the latter trend. The obtained viscosity range for spirulina was 15,100–78,000 cP, 3200–80,000 cP for soy protein, 1400–32,700 cP for pea protein, and 600–3500 cP for brown rice protein. The results indicate that extrusion is a viable method for the further processing of protein isolates, as this technique has a large temperature operating range and variable screw speed. The data provided here can be used to make single or multi-component protein substitutes.

In order to meet the demand of high mechanical strength hydrogels in the food field, broken rice protein and sodium alginate were used as the main raw materials to prepare a food-grade broken rice protein (RP)-sodium alginate (SA) interpenetrating polymer network (IPN) hydrogels with high mechanical properties through heat treatment and ion cross-linking in this study. The mechanical properties of IPN hydrogels were adjusted by changing the concentration of rice protein (80, 100, 120, 140, 160 mg/mL) in the gel system of rice protein and sodium alginate, and the properties of the hydrogels, such as texture, rheological properties, whiteness, swelling and water content, were measured after the mixture was heated and Ca2+ cross linked. The results showed that: With the increase of the concentration of broken rice protein in the gel system, the storage modulus G', loss modulus G" and gel hardness of RP-SA IPN hydrogels increased. When the broken rice protein concentration was 140 mg/mL, the increase of gel hardness became smaller. The swelling property of hydrogels first decreased and then tended to be flat, but the water distribution was more uniform. Therefore, proper amount of broken rice protein could fill the RP-SA IPN hydrogels network very well, and the morphology of the hydrogel was not changed greatly. At the same time, the mechanical properties of hydrogels could be regulated by regulating the amount of protein added. This study provides a theoretical basis for the application of rice protein in the field of food.

Abstract A secreted 50‐kDa metalloprotease from Serratia marcescens D15 was identified as rice protein hydrolase (SeMPase), which reached the highest proteolytic activity (477.3 U/ml) in basal medium with 1.5% rice protein (RP) at 35°C and 150 rpm for 48 h. SeMPase exhibited a highest catalytic number for RP (275.8 min−1, Kcat), which contained a highly conserved Zn2+‐binding (HEIGH) domain, Met‐turn (SLMSY), and Ca2+ binding domain (GGAGND). RP hydrolysates that prepared by SeMPase showed the highest content of oligopeptides at 72.3%, compared to 64.1% from neutrase, 63.0% from alcalase, 50.2% from trypsin, 47.1% from flavourzyme, and 2.41% from pepsin. Our results showed that cleavage sites of SeMPase exposed in RP are more than those of other proteases because both SeMPase cleavage sites and the amino acid composition of RP are rich in Leu, Val, Phe, Glu, and Ala. SeMPase has significant specificity for the preparation of oligopeptide‐enriched RP hydrolysates, which provides a new and highly valued option for industrial preparation of oligopeptide‐enriched protein hydrolysates.

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Rice protein is a suitable alternative protein source for dairy protein in infant formulas on account of its unique nutrition and hypoallergenicity. Rice protein was isolated through enzymatic hydrolysis (Alcalase, papain, bromelain, Flavourzyme®) in combination with high-pressure processing (HPP) (400 MPa for 15 min at 25 °C) to enhance its functional properties and broaden its food processing applications. The effect of the HPP-treated rice protein hydrolysate on dexamethasone (DEX)-induced atrophy in C2C12 myotubes was also studied. The length of myotubes was observed under a light microscope, and periodic acid Schiff staining. The results showed that even though enzymatic hydrolysis and HPP treatment affected the color of the resulting rice protein, the protein content (3120.31 ± 42.15), branched chain amino acid (BCAA) content (15.12 ± 1.03), peptide content (31.25 ± 0.55), and amino acid composition of the rice protein were significantly increased. Moreover, the combined enzymatic and HPP treatment effectively overcame the problem of limited solubility and water-holding capacity. Rice protein produced through enzymatic and HPP treatment exhibited a higher free radical scavenging activity and oxygen radical absorbance capacity. It also alleviated DEX-induced muscle atrophy in C2C12 myotubes as indicated by the increase in myotube length. In short, the enzymatic and HPP treatment of rice protein not only overcame limitations, but also produced rice protein with high functionality in terms of antioxidant and therapeutic effects on muscle atrophy. The rice protein hydrolysate produced through enzymatic hydrolysis and HPP treatment showed the potential for use as an ingredient for functional foods in the nutraceutical industry. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hybrid meat products are an excellent strategy to incorporate plant proteins into traditional meat formulations considering recent market trends focusing on the partial reduction in red meat content. In this work, we evaluated the effects of different concentrated plant proteins (soy, pea, fava bean, rice, and sunflower) in partially replacing meat in meat emulsion model systems. Soy, pea, and sunflower proteins showed great compatibility with the meat matrix, giving excellent emulsion stability and a cohesive protein network with good fat distribution. Otherwise, adding rice and fava bean proteins resulted in poor emulsion stability. Color parameters were affected by the intrinsic color of plant proteins and due to the reduction in myoglobin content. Both viscoelastic moduli, G′ and G″ decreased with the incorporation of plant proteins, especially for rice and fava bean. The temperature sweep showed that myosin denaturation was the dominant effect on the G′ increase. The water mobility was affected by plant proteins and the proportion between immobilized and intermyofibrillar water was quite different among treatments, especially those with fava bean and rice proteins. In vitro protein digestibility was lower for hybrid meat emulsion elaborated with rice protein. It is concluded that soy, pea, and mainly sunflower proteins have suitable compatibility with the meat matrix in emulsified products. [ABSTRACT FROM AUTHOR]

We investigated whether the production of the free fatty acids (FFAs) by the addition of lipase during rice cooking inhibits starch retrogradation, and to examine whether proteins are involved in this process. Rice milled with milling ratios of 90%, 80%, 70%, and 60% and alkaline-soaked raw rice (AS) were prepared to obtain samples with different protein content. The protein content decreased from 8.24% to 5.83% as the milling ratio decreased from 90% to 60%, and AS contains 4.58% of protein. The prepared rice was cooked with and without lipase, and then treated with two freeze-thaw cycles to accelerate starch retrogradation. The addition of lipase increased the FFAs content and the peroxide value form 1.65 meq/kg to 4.75 meq/kg and decreased the free thiol (SH) content in cooked rice. The degree of swelling was reduced by 0.14 during cooking with the addition of lipase in cooked rice with a milling ratio of 90%. The degree of starch retrogradation (D r) tended to increase as the milling ratios decreased from 90% to 60% and AS showed D r similar to milling ratio of 60%. The degree of amylose-lipid complexes formation, which is involved in the inhibition of starch retrogradation, did not change with or without lipase, suggesting that the inhibitory effect of lipase became smaller as protein decreased. These results suggest that the FFAs produced by lipase converted the free SH of the protein into disulfide bonds, which altered the swelling characteristics of the starch and eventually inhibited the starch retrogradation. [Display omitted] • Addition of lipase to cooked rice showed a tendency to inhibit starch retrogradation. • Proteins were involved in the inhibition of starch retrogradation by lipase. • Lipids were not directly involved in the inhibition of starch retrogradation. • Free thiol content of rice protein decreased by lipase. • Proteins affected the swelling characteristics of rice starch. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the extraction of hydrolysate protein from waste materials (rice grain and rice beverages) in order to increase the value of domestic raw materials. The goal was to create protein beverage products containing rice protein hydrolysates that are customized to the needs of athletes for post-workout muscle restoration. Carbohydrates were extracted from rice paste using an amylase enzyme, followed by protein extraction using the Protease G6 enzyme. The E/S SL ratio, temperature, and time were investigated, with the extraction taking place at a pH of 7.0. The Central Composite Design approach was used in the experimental design to change the extraction conditions. The protein concentration and the concentration levels were determined. The concentration data were then submitted to 95 percent confidence level Analysis of Variance (ANOVA) to find significant differences. To visualize the relationship between protein concentration and the interaction between the E/S SL ratio, temperature, and extraction duration, a contour plot was generated. The results showed that increasing enzyme proportions and temperatures between 50 and 60 degrees Celsius boosted protein concentration. Lower E/S SL ratios and longer extraction times enhanced protein concentration. An E/S, SL ratio of 5%, a temperature of 52 degrees Celsius, and an extraction time of 180 min were shown to be ideal conditions for extracting protein from rice grains utilizing the Protease G6 enzyme. The final protein content was 3.14 g/100 mL. These findings suggested that Protease G6 can be a viable alternative for developing rice protein beverages for athletes and health-conscious individuals.

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Modification of rice protein by extrusion technology can broaden the range of processing and applications for food and feed raw materials. In this study, rice protein was extruded at different screw speeds (100–250 rpm), extrusion temperatures (90–150 °C), and moisture contents (25–40%). Compared with an unextruded protein, the functional properties and structural properties of textured rice protein were evaluated. The results showed that, after extrusion, the solubility of protein was improved, by up to 19.76%, which was 45.23% higher than pre-extrusion; the water holding capacity of extruded rice protein was highest at 200 rpm, 130 °C, and 25%, which could be enhanced by 37.74%; the emulsion stability was enhanced by 152.82% at 200 rpm, 130 °C, and 35%. Under extrusion, the content of sulfhydryl and disulfide bonds of rice protein decreased significantly; the hydrogen bond content increased, and the ionic bond content decreased; the hydrophobic effect decrease, except at 200 rpm, 130 °C, and 40%. The microstructure changed significantly after extrusion, producing protein aggregates with a tight structure. No new characteristic peaks appeared after extrusion, but transformation occurred between the components of the secondary structure: β-sheet and β-turn angles to an α-helix structure toward the transformation, but β-sheet was still the main component. As a safe and efficient modification method, extrusion cooking can effectively improve the functional properties of rice protein to enrich the application of rice protein resources. [ABSTRACT FROM AUTHOR]

The reduction of fishmeal in aquafeeds has been the concern of researchers. Replacing fishmeal with plant proteins affects intestinal function and inflammation, but the interaction between the intestinal responses and gut microbiota remains unclear. In this study, juvenile channel catfish (Ictalurus punctatus) was fed with four diets in which enzymatic rice protein (RP) replaced fishmeal at levels of 0 (FM), 2.5% (RP2.5), 5.0% (RP5.0), and 7.5% (RP7.5) for 8 weeks to solve the problem mentioned above. Quantification of intestinal morphology showed that 2.5% or 5.0% RP significantly increased villus length and goblet cell number, accompanied by higher activities of intestinal trypsin, alkaline phosphatase (AKP), and Na+/K+-ATPase (NKA) in RP2.5 group (P < 0.05). In contrast, 7.5% RP slightly damaged the intestinal mucosa and significantly reduced the activities of amylase, AKP, and NKA, as well as decreased serum complement 4 (C4) and immunoglobulin M (IgM). Noteworthy, RT-qPCR showed that 2.5% RP significantly down-regulated intestinal mRNA expression level of il8 , while up-regulated mif , tlr4 , tlr7 , tgfβ3 , and cldn2. In contrast, 7.5% RP up-regulated the mRNA expression levels of il1β , il8 , and mif , while down-regulated cldn3d. Analysis of gut microbiota showed that 2.5% RP increased the relative abundance of Bacteroidetes and significantly activated potential functions of gut microbiota involved in carbohydrate metabolism. The 7.5% RP increased the diversity of the gut microbiota, accompanied by a significant increase in the relative abundance of conditionally pathogenic bacteria such as Vibrio , Serratia , and Aeromonas (classified as Proteobacteria). Notably, Vibrio was the biomarker species with the greatest difference between the FM and RP7.5 groups (genus level). Correlation analysis indicated that Vibrio may affect immunity through the C4 pathway and further lead to gut inflammation and digestive impairment. Taken above, these results indicated that RP could affect intestinal morphology, digestion, and inflammation, and interact with the composition and potential function of gut microbiota. The low RP supplement (2.5%) improved intestinal morphology and digestion, while high supplement (7.5%) disrupted gut microbiota homeostasis, resulting in damage to intestinal mucosa and inflammatory response. • Replacing 2.5% of fishmeal with RP improved gut morphology and digestion. • The 7.5% RP supplement resulted in damaged intestinal mucosa, decreased digestion, and inflammatory responses. • The 7.5% RP induced gut inflammation by affecting the abundance and predicted function ofpathogenic bacteria. [ABSTRACT FROM AUTHOR]

Rice, Oryza sativa, is the major staple food that provides a larger share of dietary energy for more of the population than other cereal crops. Moreover, rice has a significant amount of protein including four different fractions such as prolamin, glutelin, globulin, and albumin with different solubility characteristics. However, these proteins exhibit a higher amino acid profile, so they are nutritionally important and possess several functional properties. Compared with many other cereal grains, rice protein is hypoallergic due to the absence of gluten, and therefore it is used to formulate food for infants and gluten-allergic people. Furthermore, the availability makes rice an easily accessible protein source and it exhibits several activities in the human body which discernibly affect total health. Because of these advantages, food industries are currently focusing on the effective application of rice protein as an alternative to animal-based and gluten-containing protein by overcoming limiting factors, such as poor solubility. Hence, it is important to gain an in-depth understanding of the rice protein to expand its application so, the underlined concept of this review is to give a current summary of rice protein, a detailed discussion of the chemistry of rice protein, and extraction techniques, and its functional properties. Furthermore, the impact of rice protein on human health and the current application of rice protein is also mentioned. [ABSTRACT FROM AUTHOR]

In this study, rice husk biochar was engineered with abundant iron ion sites to enhance the enrichment of antioxidant peptides from rice protein hydrolysates through metal-chelating interactions. The π-π interactions and metal ion chelation were identified as the primary mechanisms for the enrichment process. Through peptide sequencing, four peptides were identified: LKFL (P1: Leu-Lys-Phe-Leu), QLLF (P2: Gln-Leu-Leu-Phe), WLAYG (P3: Trp-Leu-Ala-Tyr-Gly), and HFCGG (P4: His-Phe-Cys-Gly-Gly). The vitro analysis and molecular docking revealed that peptides P1-P4 possessed remarkable scavenging ability against radicals and Fe 2+ chelating ability. Notably, peptide P4 showed radical scavenging activity comparable to glutathione (GSH) against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS) radicals. Cellular experiments further confirmed that peptide P4 effectively protected HepG2 cells from oxidative stress-induced damage. The modified rice husk biochar proved to be an effective means for enriching rice antioxidant peptides from protein hydrolysates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

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.