A Narrative Review on Rice Proteins: Current Scenario and Food Industrial Application

Self-assembled nanostructures from rice protein and its fractions: Molecular approaches, physicochemical principles, and functional applications

This review investigates the structural composition and physicochemical properties of rice protein (RP) and their functional applications, unraveling the molecular self-assembly approaches of rice protein isolates (RPI), rice protein hydrolysates (RPH), and their different fractions. RPI complexes with polysaccharides through both non-covalent (electrostatic, hydrogen bonding, hydrophobic and π-interactions) and covalent interactions (Schiff base and enzymatic reactions), whereas with polyphenols, it forms colloidal structures mainly through non-covalent forces. After enzymatic hydrolysis and chain segment reorganization, RPH exhibits enhanced interfacial activity and self-assembles into stable nanostructures, with applications in encapsulation and delivery of bioactive compounds. Owing to variations in conformation and amino acid composition, different fractions of RP can assemble into multilevel structures, including nanofibrils, branching clusters, and spherical nanoparticles, under specific environmental conditions. An in-depth exploration of these self-assembly principles can greatly enhance the physicochemical and structural properties of RP, thereby paving the way for a wide range of functional applications.

A metabolic profiling approach to characterize and discriminate plant-based beverages and milk

The rising demand for nondairy and nonanimal protein sources has increased plant-based beverages (PBB) consumption. However, research on their functional properties, metabolic profile, and discrimination potential is limited. This study evaluated the potential of proton nuclear magnetic resonance (1H NMR) spectroscopy as an authentication method to discriminate milk (cow and goat) and PBB macro-groups, including soy-based, fruit-based (almond and coconut), and cereal-based (rice and oat) beverages, based on their metabolic profile. A total of 22 PBB (soy-, almond-, coconut-, rice-, and oat-based beverages), 4 cow milk, and 4 goat milk cartons were analyzed with 1H NMR spectroscopy to obtain their metabolic profile. Relevant metabolites to discriminate PBB macro-groups and cow and goat milk were identified through the Mann-Whitney U test and partial least squares-discriminant analysis. Results revealed that uridine diphosphate glucose and adenosine were key metabolites for the identification of goat and cow milk. At the same time, choline and guanosine emerged as important markers for different PBB macro-group detection. In addition, lactose played a significant role in differentiating milk from PBB. In conclusion, these findings represent an initial step toward applying 1H NMR spectroscopy for authentication and nutritional analysis of PBB, opening the door for further research into their authenticity and metabolic profiling.

Enhancing quality traits in staple crops: current advances and future perspectives

Staple crops such as rice, wheat and maize are crucial for global food security; however, improving their quality remains a significant challenge. This review summarizes recent advances in enhancing crop quality, focusing on key areas such as the molecular mechanisms underlying endosperm filling initiation, starch granule synthesis, protein body formation, and the interactions between carbon and nitrogen metabolism. It also highlights ten unresolved questions related to starch-protein spatial distribution, epigenetic regulation, and the environmental impacts on quality traits. The integration of multi-omics approaches, and rational design strategies presents opportunities to develop high-yield "super-crop" varieties with enhanced nutritional value, better processing characteristics, and attributes preferred by consumers. Addressing these challenges is crucial to promote sustainable agriculture and achieve the dual objectives of food security and environmental conservation.

Enhancement on the solubility of polyploid and diploid rice proteins by enzymatic hydrolysis: From structural and functional characteristics of rice protein hydrolysates

Polyploid rice protein (PRP) has the advantage of high nutritional value, but its functional properties are minimal due to its poor solubility. This work aims to improve the solubility of PRP through enzymatic hydrolysis and assess the effect of hydrolysis time (5-330 min) and protease type (Alcalase, Neutrase, and Trypsin) on the structural, functional, and antioxidant properties of PRP hydrolysates (PRPHs). Compared to PRP, PRPHs exhibited significantly decreased free sulfhydryl content and surface hydrophobicity and improved structural flexibility, regardless of the protease used. With increasing time, the nitrogen solubility index of the hydrolysates increased by 25.01 %, which was attributed to the reduction in molecular weight (< 15 kDa). The highest emulsifying activity (48.81 m2/g) and hydroxyl radical scavenging activity (IC50 of 5.49 mg/mL) were observed from Neutrase hydrolysates at 210 min and 330 min, respectively. Trypsin hydrolysate at 210 min demonstrated the lowest IC50 (0.17 mg/mL) in ABTS+. Moreover, compared to diploid rice protein hydrolysates (DRPHs) obtained under the same conditions, PRPHs by all proteases exhibited superior functional and antioxidant properties and richer amino acid content. This study showed the potential of PRPHs applied to functional foods with favorable functional and antioxidant properties.

Insight into the binding mechanism between rice characteristic odor compounds and glutelin using multi-spectral and molecular dynamics simulation: Comparison of different functional groups

Aroma quality is an important parameter for evaluating the eating quality of rice. However, the interactions between rice proteins and odor compounds are not well understood. In this study, the combination of computer simulation and instrumental analysis was used to investigate the binding mechanism of odor compounds with rice glutenin for the first time. Hexanal, 1-octen-3-ol, methyl heptenone, and 2-pentylfuran, which have different functional groups and aroma characteristics, were selected as target odor compounds. The results showed that glutelin had the strongest binding affinity for 2-pentylfuran, whereas it was less likely to adsorb 1-octen-3-ol. Static quenching was the main interaction between glutelin and odor compounds. After the interaction, the ordered structure of glutelin changed to a random coil structure. Hydrogen bonds and hydrophobic interactions were the main driving forces for the binding of hexanal, 1-octen-3-ol, and methyl heptenone to glutelin, whereas hydrophobic interactions were the main driving forces for 2-pentylfuran binding. The amino acids TRY, LYS, GLN, and ARG played key roles in the binding. An improved understanding of the binding effect of glutelin on the characteristic odor compounds of rice could help flavor scientists or product designers to optimize the rice flavor.

Comparative studies on physicochemical and structural properties of rice proteins

BACKGROUND

Rice (Oryza sativa L.) is a global staple, increasingly recognized for the nutritional and functional properties of its proteins (P). Protein characteristics change significant during rice grain development, encompassing flowering, milky, dough, and mature stages, each potentially suitable for distinct food applications. This study evaluated the impact of grain maturity on the physicochemical and structural properties of proteins in young (Y) and mature (M) grains from four rice varieties; Jasmine Rice 105 (JRP105), Hom Warin (IRP57514), RD6 (RDP6), and Hom Naka (HNKP); Parameters investigated included protein content, solubility, molecular weight distribution, amino acid composition, and secondary structures.

RESULTS

Young rice proteins, particularly from Y-HNKP and Y-IRP57514 varieties, demonstrated significantly higher protein content (633.3 g kg-1) and solubility (19.20%) compared to mature grains. Mature rice proteins, especially from M-HNKP, exhibited higher proportion of β-sheet structures (100%) and lower solubility (11.41%), mainly attributed to increased protein aggregation and enhanced hydrophobic interactions. Additionally, young rice grains, notably Y-RDP6, presented a superior profile of essential amino acids, while mature grains displayed a complex molecular weight distribution due to accumulated storage protein.

CONCLUSION

This study highlights significant differences in protein characteristics between young and mature rice grains. Young rice proteins, notably from Y-JRP105 and Y-IRP57514, are characterized by higher protein content, greater solubility, and enhanced bioavailability, making them ideal for applications in high-protein foods and dietary supplements. Conversely, mature rice proteins, particularly from M-HNKP, exhibit increased structural stability due to higher β-sheet content and protein aggregation, making them suitable for demanding applications and storage stability. © 2025 Society of Chemical Industry.

From Gene to Plate: Molecular Insights into and Health Implications of Rice (Oryza sativa L.) Grain Protein

Rice is a staple food crop widely consumed across the world. It is rich in carbohydrates, quality protein, and micronutrients. The grain protein content (GPC) in rice varies considerably. Although it is generally lower than that of other major cereals, the quality of protein is superior. GPC and its components are complex quantitative traits influenced by both genetics and environmental factors. Glutelin is the major protein fraction (70-80%) in rice. Rice protein is rich in lysine, methionine, and cysteine along with other amino acids. Globally, Protein-Energy Malnutrition (PEM) is a major concern, particularly in Asia and Africa. Additionally, non-communicable diseases (NCDs) including diabetes, cancer, cardiovascular diseases, hypertension, and obesity are on the rise due to various reasons including changes in lifestyle and consumption patterns. Rice plays a very important part in the daily human diet, and therefore, substantial research efforts focus on the genetic characterization of GPC and understanding its role in the prevention of NCDs. The contribution of both rice grain and bran protein in improving human health is an established fact. The present study summarizes the different aspects of rice grain protein including its variability, composition, factors affecting it, and its industrial uses and more importantly its role in human health.

Biological Activities and Phytochemical Profile of Hawm Gra Dang Ngah Rice: Water and Ethanolic Extracts

Hawm Gra Dang Ngah rice (HDNR) is a red rice variety cultivated in Thailand's southern border region, yet its biological properties have not been extensively studied. This study investigates the effects of HDNR extracts on bioactive constituents, spectral fingerprints, and antioxidant capacities. We evaluated the inhibitory effects of aqueous (HDNR-W) and ethanolic (HDNR-E) extracts on monoamine oxidase (MAO), α-glucosidase, and HMG-CoA reductase activities, as well as their cytotoxicity in normal and cancer cells. The results demonstrated that HDNR-E contained significantly higher concentrations of phenolic compounds, flavonoids, and anthocyanins compared to HDNR-W. In contrast, HDNR-W exhibited greater amino acid content than HDNR-E. FT-IR analysis revealed solvent-specific interactions that influenced compound solubility, highlighting distinct extraction efficiencies. Antioxidant assays showed HDNR-E to be markedly more potent, with superior performance in DPPH, ABTS, metal chelation, and FRAP assays, as evidenced by its lower IC50 values relative to HDNR-W. Furthermore, HDNR-E displayed significantly stronger inhibitory activity against both MAO and α-glucosidase compared to HDNR-W. Conversely, HDNR-W demonstrated greater inhibitory efficacy toward HMG-CoA reductase than HDNR-E. Furthermore, HDNR-E exhibited significant antiproliferative effects against A549 lung cancer and MCF-7 breast cancer cells without affecting normal cells. These results highlight the potential of HDNR-E as a valuable source of bioactive compounds and underscore the importance of solvent selection in enhancing the health benefits of rice extracts.

Antiproliferative and antioxidant properties of protein-free and protein-bound phenolics isolated from purple rice (Oryza sativa L.)

Purple rice (Oryza sativa L.) is a rich in endogenous phenolics and proteins. The naturally occurring interactions between phenolic compounds and proteins have been shown to have beneficial effects on human health. In this study, four protein fractions of purple rice (albumin, prolamin, globulin, and glutelin) were extracted, and both protein-free and protein-bound phenolics (PFP and PBP) were isolated from each protein fraction. The major phenolics compounds identified in different protein fraction included protocatechuic acid, vanillic acid, and ferulic acid. Additionally, the PFP in the albumin fraction exhibited the highest number of anthocyanin glycosides (7 types) among all phenolic compounds, while the remaining compounds were identified only as cornflower-3-glucoside and paeoniflorin-3-glucoside. Moreover, the in vitro antioxidant activity and cancer cell inhibitory effects of PFP and PBP in various protein fraction were investigated using chemiluminescence and cellular assays. The results demonstrated that the inhibitory effect of H₂O₂ was more pronounced than that of other free radicals (O₂- and OH-), with albumin and prolamin exhibiting heightened antioxidant activities. Notably, the PBP in various protein fractions showed a higher antiproliferative capacity than their corresponding PFP, indicating a potential synergistic effect of protein-phenolic interactions that differed between the two cell lines, MKN-28 and HT-29.

Protein structural properties, proteomics and flavor characterization analysis of rice during cooking

This study analyzed the changes in rice protein structure, protein profiling, and flavor profiles at different cooking stages, as well as their interrelationships. In the continuous cooking process, changes in protein structure characteristics were mainly reflected in the boiling and stewing stages. Protein unfolding and aggregation were important reasons for significant changes in protein structural characteristics. Protein disulfide isomerases and glycine-rich RNA-binding proteins can be used as marker factors to characterize the changes during rice cooking. The concentrations of aldehydes, esters, and alcohols gradually decreased during cooking. Heterocycles were primarily present in boiled and stewed rice. Fatty acid degradation, starch/sucrose metabolism, glycolysis/gluconeogenesis, and other reaction pathways were closely associated with rice aroma quality. Aldehydes, ketones, and heterocycles were correlated with changes in surface hydrophobicity, secondary structure composition, and other structural properties of the protein. This study preliminarily established the relationship between aroma characteristics and rice protein.

The Influence of the Nutritional and Mineral Composition of Vegetable Protein Concentrates on Their Functional Properties

Vegetable proteins derived from legumes, cereals or pseudocereals have increased in popularity in recent years, becoming very interesting for the food industry. In addition to their nutritional interest, these products have techno-functional properties that allow them to be used in the production of a wide variety of foods. This research has studied the nutritional and mineral composition of 12 samples of rice, pea and soy concentrates. The objective was to investigate the influence of this nutritional composition, mainly mineral components, on the techno-functional properties (water- and oil-binding capacity, swelling, emulsifying, gelling and foaming capacities) of these concentrates. For this purpose, a Pearson correlation matrix and a GH biplot method were applied. The results showed that there is a correlation between mineral content and functional properties. Mg, K and Ca were positively correlated with protein solubility index, oil absorption capacity and swelling capacity. Na and P contents were positively related to water absorption capacity and emulsifying capacity. Gelling capacity was positively correlated with Mg contents and negatively correlated with Cu and Fe contents. The preliminary results reported in this study highlight the necessity to further assess the influence of non-protein components on the techno-functionality of protein concentrates.

Improving solubility of rice protein powder by modifying its physicochemical properties by ultrasound-assisted protein-glutaminase

The effect of ultrasound-assisted protein-glutaminase (PG) deamidation on the physicochemical properties of rice protein (RP) was investigated. After ultrasound pretreatment, the degree of deamidation of RP reached the highest of 60.4 % at deamidating for 16 h. With the deamidating time increasing, the particle size of RP became smaller and the absolute value of ζ-potential gradually increased. For functional properties of RP, ultrasound-assisted PG deamidation improved the foaming capacity, emulsifying capacity and oil-holding capacity of RP. Based on the ameliorative physicochemical properties of RP, the properties of rice protein powder (RPP) were further determined. The solubility of RPP was significantly improved, increased by 102.6 % at 90 °C compared with the non-treated. Meanwhile, the antioxidant activity and flavor of RPP under PG deamidation were remarkably improved. In vitro digestibility of RPP also increased significantly. These results illustrated that PG deamidation could be an efficient method for improving the properties of proteins.

Enrichment of antioxidant peptide from rice protein hydrolysates via rice husk derived biochar

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 Fe2+ 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.

Optimizing Printability of Rice Protein-Based Formulations Using Extrusion-Based 3D Food Printing

The purpose of this study was to investigate the application of an innovative extrusion-based 3D food printing (3DFOODP) technique in developing rice protein-starch (RP-S) gel-based products. The effects of 3DFOODP conditions were examined, which included variations in the concentrations of rice protein (RP) and corn starch (S) (15, 17.5, and 20 wt.%), nozzle size (0.8, 1.5, and 2.5 mm), printing temperature (40°C, 60°C, and 80°C), and ingredient flow speed (5.7, 6.3, and 6.9 mL/min). A hollow cylindrical model was chosen as a test object to determine the printability of RP-S gels. The best 3D printability was achieved using an RP concentration of 17.5% and an S concentration of 15% at 60°C printing temperature with a nozzle size of 1.5 mm, and ingredient flow speed of 6.3 mL/min. With increasing the RP concentration, a rise in apparent viscosity, loss, and storage moduli was observed. The recovery test showed the gels' rapid and reversible response. The freeze-dried 3D-printed RP-S gels showed a porous granular structure, depending on the printing temperature. No chemical interactions between the RP and S were observed as analyzed by FTIR. Overall, RP, in combination with S, provides a new opportunity for the 3DFOODP and their utilization by the alternative protein industry.

Improved qualities of cod-rice dual-protein gel as affected by rice protein: Insight into molecular flexibility, protein interaction and gel properties

Blending plant-based proteins with animal-based proteins to achieve adequate dietary protein intake is a strategy to address dietary deficiencies in the elderly. This research systematically investigated the effect of the ratio of cod protein/rice protein (21:0, 21:1.5, 21:3, 21:4.5, 21:6, 21:7.5, and 21:9) on the gelation properties of dual-protein gels and the underlying dual-protein interaction mechanisms. The results indicated that the myosin heavy chain (MHC) of cod and the glutelin in rice protein are primarily linked by hydrogen bonds, particularly involving Tyr residues, as evidenced by molecular docking and fluorescence quenching results. The addition of rice protein in cod protein promoted α-helix transforming into β-sheet, β-turn and random coil of the original protein solution, which was significantly correlated with molecule flexibility increasing. The decrease in the dual-protein particle size, and rice protein uniformly distributed in a cod protein-based gel network, which promoted the compactness and density of the gel structure. It was found that the hardness and springiness of 21:6 cod-rice protein gel increased by 73.96% and 17.28% compared to single cod gel, respectively. This study provides theoretical basis to the mechanism of dual-protein interaction affecting gel properties from the molecular level.

The OsGAPC3 mutation significantly affects grain quality traits and improves the nutritional quality of rice

The glycolytic enzyme cytoplasmic glyceraldehyde-3-phosphate dehydrogenase (GAPC3) is involved in multiple biological processes in plants, including transcriptional regulation, and material metabolism. However, the relationship between OsGAPC3 and the quality traits of rice is poorly understood. Here we identify OsGAPC3 mutations that enhance the protein content and grain nutritional quality of rice by regulating the OsAAP6 gene expression. The number and volume of type-II protein bodies in the endosperm of the OsGAPC3 mutants, and GPC increase significantly. We report significant increases in chalkiness area and degree, and decreases for starch content, gel consistency, and taste value. Results of proteomic detection and analysis reveal that OsGAPC3 affects the major storage substances (proteins and starch) metabolism in rice, and the accumulation of proteins and starch in the endosperm. Additionally, the OsGAPC3 mutation significantly decreases the rice-seedling salt tolerance. Therefore, OsGAPC3 affects multiple quality traits of rice, participates in regulating rice-seedling salt-stress response. These data can be used to design better-quality and stronger salt-resistant rice varieties.

Nutritional and sensory parameters of amazake from the recycling of stale bread

Stale bread is a waste product with a potential to be recycled. One way to manage this waste material is to process it by fermentation for the purpose of food production. This paper proposes the use of stale wheat and rye bread as ingredients in amazake, a liquid dessert traditionally obtained from rice by fermentation with the koji mould Aspergillus oryzae, followed by liquefaction by the action of fungal enzymes. The stale bread was introduced instead of rice at both the koji stage (wheat bread) and the liquefaction stage (wheat and rye bread). The resulting products had an extended volatile compound profile, from 5 to 15 compounds identified, and modified sensory parameters, compared to the traditional version. Amazake containing bread had an increased protein content, from 1.10 to 6.4 g/100 g, and were more abundant in dietary fibre (up to a maximum of 1.8 g/100 g), additionally enriched with a soluble fraction. The proposed procedure of obtaining of new formula amazake can be directly applied in households to reduce the amount of discarded bread. Due to its simplicity, it also has the potential for further modification in terms of production scale and product parameters.

Selenium mitigates the loss of nutritional quality in rice grown at an elevated concentration of carbon dioxide

Atmospheric CO2 enrichment has the potential to improve rice (Oryza sativa L.) yield, but it may also reduce grain nutritional quality, by reducing mineral and protein concentrations. Selenium (Se) fertilization may improve rice grain nutritional composition, but it is not known if this response extends to plants grown in elevated carbon dioxide concentration (eCO2). We conducted experiments to identify the impacts of Se fertilization on yield and quality of rice grains in response to eCO2. The effect of the Se treatment was not significant for the grain yield within each CO2 condition. However, the reduction in macronutrients and micronutrients under eCO2 was mitigated in grains of plants fertilized with Se. Fertilization with Se increased the concentration of Se in roots, flag leaves, and grains independently of atmospheric CO2 concentrations. Elevation of the transcripts of ion transport-related genes could, at least partially, explain the positive relationship between mineral concentrations and grain mass resulting from Se fertilization under eCO2. Treatment with Se also increased the accumulation of total protein in grains under eCO2. Overall, our results revealed that Se fertilization represents a potential asset to maintain rice grain nutritional quality in a future with rising atmospheric CO2 concentration.

A comprehensive review on the recent trends in extractions, pretreatments and modifications of plant-based proteins

Plant-based proteins offer sustainable and nutritious alternatives to animal proteins with their techno-functional attributes influencing product quality and designer food development. Due to the inherent complexities of plant proteins, proper extraction and modifications are vital for their effective utilization. This review highlights the emerging sources of plant-based proteins, and the recent statistics of the techniques employed for pretreatment, extraction, and modifications. The pretreatment, extraction and modification approach to modify plant proteins have been classified, addressed, and the recent applications of such methodologies are duly indicated. Furthermore, this study furnishes novel perspectives regarding the potential impacts of emerging technologies on the intricate dynamics of plant proteins. A thorough review of 100 articles (2018-2024) shows the researchers' keen interest in investigating novel plant proteins and how they can be used; seeds being the main source for protein extraction, followed by legumes. Use of by-products as a protein source is increasing rapidly, which is noteworthy. Protein studies still lack knowledge on protein fraction, antinutrients, and pretreatments. The use of physical methods and their combination with other techniques are increasing for effective and environmentally friendly extraction and modification of plant proteins. Several studies explore the effect of protein changes on their function and nutrition, especially with a goal of replacing ingredients with plant proteins that have improved or enhanced qualities. However, the next step is to investigate the sophisticated modification methods for deeper insights into food safety and toxicity.

OsG6PGH1 affects various grain quality traits and participates in the salt stress response of rice

Cytoplasmic 6-phosphogluconate dehydrogenase (G6PGH) is a key enzyme in the pentose phosphate pathway that is involved in regulating various biological processes such as material metabolism, and growth and development in plants. However, it was unclear if OsG6PGH1 affected rice grain quality traits. We perform yeast one-hybrid experiments and reveal that OsG6PGH1 may interact with OsAAP6. Subsequently, yeast in vivo point-to-point experiments and local surface plasmon resonance experiments verified that OsG6PGH1 can bind to OsAAP6. OsG6PGH1 in rice is a constitutive expressed gene that may be localized in the cytoplasm. OsAAP6 and protein-synthesis metabolism-related genes are significantly upregulated in OsG6PGH1 overexpressing transgenic positive endosperm, corresponding to a significant increase in the number of protein bodies II, promoting accumulation of related storage proteins, a significant increase in grain protein content (GPC), and improved rice nutritional quality. OsG6PGH1 positively regulates amylose content, negatively regulates chalkiness rate and taste value, significantly affects grain quality traits such as appearance, cooking, and eating qualities of rice, and is involved in regulating the expression of salt stress related genes, thereby enhancing the salt-stress tolerance of rice. Therefore, OsG6PGH1 represents an important genetic resource to assist in the design of high-quality and multi-resistant rice varieties.

Research Progress on the Extraction and Purification of Anthocyanins and Their Interactions with Proteins

Anthocyanins, as the most critical water-soluble pigments in nature, are widely present in roots, stems, leaves, flowers, fruits, and fruit peels. Many studies have indicated that anthocyanins exhibit various biological activities including antioxidant, anti-inflammatory, anti-tumor, hypoglycemic, vision protection, and anti-aging. Hence, anthocyanins are widely used in food, medicine, and cosmetics. The green and efficient extraction and purification of anthocyanins are an important prerequisite for their further development and utilization. However, the poor stability and low bioavailability of anthocyanins limit their application. Protein, one of the three essential nutrients for the human body, has good biocompatibility and biodegradability. Proteins are commonly used in food processing, but their functional properties need to be improved. Notably, anthocyanins can interact with proteins through covalent and non-covalent means during food processing, which can effectively improve the stability of anthocyanins and enhance their bioavailability. Moreover, the interactions between proteins and anthocyanins can also improve the functional characteristics and enhance the nutritional quality of proteins. Hence, this article systematically reviews the extraction and purification methods for anthocyanins. Moreover, this review also systematically summarizes the effect of the interactions between anthocyanins and proteins on the bioavailability of anthocyanins and their impact on protein properties. Furthermore, we also introduce the application of the interaction between anthocyanins and proteins. The findings can provide a theoretical reference for the application of anthocyanins and proteins in food deep processing.

Advancements in Sustainable Plant-Based Alternatives: Exploring Proteins, Fats, and Manufacturing Challenges in Alternative Meat Production

The rise in plant-based food consumption is propelled by concerns for sustainability, personal beliefs, and a focus on healthy dietary habits. This trend, particularly in alternative meat, has attracted attention from specialized brands and eco-friendly food companies, leading to increased interest in plant-based alternatives. The dominant plant-based proteins, derived mainly from legumes, include soy protein isolates, which significantly impact sensory factors. In the realm of plant-based fats, substitutes are categorized into fat substitutes based on fats and fat mimetics based on proteins and carbohydrates. The production of these fats, utilizing gums, emulsions, gels, and additives, explores characteristics influencing the appearance, texture, flavor, and storage stability of final plant-based products. Analysis of plant-based proteins and fats in hamburger patties provides insights into manufacturing methods and raw materials used by leading alternative meat companies. However, challenges persist, such as replicating meat's marbling characteristic and addressing safety considerations in terms of potential allergy induction and nutritional supplementation. To enhance functionality and develop customized plant-based foods, it is essential to explore optimal combinations of various raw materials and develop new plant-based proteins and fat separation.

Selenium and other heavy metal levels in different rice brands commonly consumed in Pretoria, South Africa

For centuries, rice has been a dietary staple food partially due to its accessibility, affordability, and nutritional content. However, it has been documented that plants can bioaccumulate trace elements from soil and store them in their tissues therefore necessitating monitoring of its nutritional quality. The current study investigated the Selenium and heavy metal contents of various brands of rice obtained from different retail stores in Pretoria, South Africa. The analysis was carried out using different rice samples and different methods/stages of cooking rice including the analysis of rinsed rice water (RW), raw rice (RR), cooked rice (CR), and cooked rice water (CW), for trace elements content using the Inductive Couple Plasma Mass Spectrometry. The results revealed that the Se content ranged from 0.013 ± 0.01 mg/kg - 0.089 ± 0.06 mg/kg in RR, 0.013 ± 0.01 mg/kg - 0.046 ± 0.01 mg/kg in CR, 0.01 ± 0.01mg/kg- 0.028 ± 0.00 mg/kg in RW and 0.01 ± 0.01 mg/kg - 0.048 ± 0.01 mg/kg in CW. The calculated estimated dietary intake (EDI) of Se was recorded as follows; raw rice (7.06 × 10-5 mg/day), cooked rice (5.01 × 10-5 mg/day), water from cooked rice (4.54 × 10-5 mg/day) and rinsed water of raw rice (3.97 × 10-5 mg/day). The concentrations of all other heavy metals measured were within the WHO-recommended limits. The HQ for all the trace metals in all the samples did not exceed one, implying that there is no health risk from trace metals analysed in this study from the consumption of the rice brands used in this study. The results of this study demonstrated that reliance on rice alone for the supply of Se may be inadequate owing to the values obtained in our study. Constant monitoring of the nutritional contents of food products may be required to improve the overall nutritional well-being of the consumers.

Rice proteins: A review of their extraction, modification techniques and applications

Rice protein is highly nutritious and easy to digest and absorb. Its hydrolyzed peptides have significant effects on lowering blood pressure and cholesterol. First, a detailed and comprehensive explanation of rice protein extraction methods was given, and it was found that the combination of enzymatic and physical methods could improve the extraction rate of rice protein, but it was only suitable for laboratory studies. Second, the methods for improving the functional properties of rice protein were introduced, including physical modification, chemical modification, and enzymatic modification. Enzymatic modification of the solubility of rice protein to improve its functional properties has certain limitations due to the low degree of hydrolysis, the long time required, the low utilization of the enzyme, and the possible undesirable taste of the product. Finally, the development and utilization of rice protein was summarized and the future research direction was suggested. This paper lists the advantages and disadvantages of various extraction techniques, points out the shortcomings of existing extraction techniques, aims to fill the gap in the field of rice protein extraction, and then provides a possible improvement method for the extraction and development of rice protein in the future.

Recent Trends in Cereal- and Legume-Based Protein-Mineral Complexes: Formulation Methods, Toxicity, and Food Applications

Minerals play an important role in maintaining human health as the deficiency of these minerals can lead to serious health issues. To address these deficiencies, current research efforts are actively investigating the utilization of protein-mineral complexes as eco-friendly, non-hazardous, suitable mineral fortifiers, characterized by minimal toxicity, for incorporation into food products. Thus, we reviewed the current challenges in incorporating the cereal-legume protein-inorganic minerals complexes' structure, binding properties, and toxicity during fortification on human health. Moreover, we further reviewed the development of protein-mineral complexes, characterization, and their food applications. The use of inorganic minerals has been associated with several toxic effects, leading to tissue-level toxicity. Cereal- and legume-based protein-mineral complexes effectively reduced the toxicity, improved bone mineral density, and has antioxidant properties. The characterization techniques provided a better understanding of the binding efficiency of cereal- and legume-based protein-mineral complexes. Overall, understanding the mechanism and binding efficiency underlying protein-mineral complex formation provided a novel insight into the design of therapeutic strategies for mineral-related diseases with minimal toxicity.

Antibacterial and antivirulence factor activities of protein hydrolysates from Phatthalung Sangyod rice (Oryza sativa L.) seeds against zoonotic and foodborne pathogens

Background and Aim

Antimicrobial resistance is an emerging public health threat. Foodborne illnesses are typically caused by bacteria, such as Escherichia coli, Pseudomonas aeruginosa, Bacillus cereus, and Staphylococcus aureus, which are frequently resistant to common antimicrobial agents. Rice is a staple grain in most parts of the world. Our previous work showed that Phatthalung Sangyod rice seed protein hydrolysates (SYPs), especially SYP4, exhibit antifungal activity against several fungal species that are pathogenic for both humans and animals and are non-cytotoxic to animal red blood cells. In this study, we aimed to determine the effects of the bioactive peptides in SYPs against several pathogenic bacteria in humans and animals.

Materials and Methods

After isolating SYP1, it was treated as follows: heated (SYP2), and hydrolyzed using pepsin (SYP3), and proteinase K (SYP4). Then, we used 500 μg of protein to evaluate the antibacterial effects on four pathogenic bacteria, including E. coli, P. aeruginosa, B. cereus, and S. aureus, using agar well diffusion. Using a broth microdilution assay, we determined the minimum inhibitory and bactericidal concentration (MIC and MBC, respectively) values of active SYPs. Using the agar well diffusion and microtube incubation methods, we also assessed the inhibitory effects of SYPs on the bacterial quorum sensing (QS) activity of Chromobacterium violaceum. Sangyod rice seed protein hydrolysates were evaluated for their ability to inhibit the biofilm formation of bacterial cells by a crytal violet assay. Furthermore, using the dropping method, we tested the inhibitory effects of SYPs on the bacterial pigments pyocyanin in P. aeruginosa and staphyloxanthin in S. aureus.

Results

Our results showed that the crude protein lysate (SYP1) did not exhibit antibacterial activity against any of the test bacteria. Intriguingly, after boiling (SYP2) and enzymatic hydrolysis (SYP3 and SYP4), the protein hydrolysates were transformed into bioactive peptides and displayed antibacterial properties against all of the test bacteria at a concentration of 500 μg as determined by agar well diffusion. SYP4 demonstrated the highest antibacterial activity as it completely inhibited all test strains, with inhibition zones ranging from 16.88 ± 0.25 to 21.25 ± 0.5 mm, and also yielded the highest MIC/MBC values against P. aeruginosa, B. cereus, and E. coli, at 256 and >256 μg/mL, respectively. We observed that at least 256 μg/mL of SYP4 is required to exhibit optimal antibacterial activity. At 16-128 μg/mL, it exhibited antibiofilm activity against S. aureus. Furthermore, at 256 μg/mL, SYP4 inhibited pyocyanin in P. aeruginosa and staphyloxanthin in S. aureus. Although SYP2 and SYP3 displayed weak antibacterial activity and their MIC values could not be obtained for all bacteria, they showed strong QS inhibition in C. violaceum at 256 μg protein. Moreover, SYP2 and SYP3, at a minimum concentration of 32 μg/mL, significantly reduced violacein production. SYP3 also showed biofilm reduction activity on S. aureus at least 16-512 μg/mL.

Conclusion

Sangyod Phatthalung protein hydrolysates exerted excellent inhibitory effects against the growth of bacteria and their virulence factors, such as QS, biofilm formation, and/or pigment production. These factors include zoonotic and foodborne pathogens. Therefore, daily consumption of Sangyod Phatthalung rice might reduce the risk of bacterial pathogenesis and foodborne diseases. In conclusion, functional foods or alternate methods of treating bacterial illnesses may be developed in humans and animals.

Nutritional Compositions, Phenolic Contents and Antioxidant Activities of Rainfed Rice Grown in Different Degrees of Soil Salinity

Rice (Oryza sativa) is a staple food crop for over half of the world's population. However, drought as a result of climate change has led to increased soil salinity, thereby reducing agricultural potential, especially rice nutritional compositions and biochemical properties. Nevertheless, soil management by using suitable fertilizers might be able to improve rice quality even though these rice samples were grown in soil with a high degree of salinity. This study investigated nutritional compositions, phenolic contents, and antioxidant activities of twenty-five rainfed rice samples in Khao Dawk Mali 105 (KDML105) and Rice Department 15 (RD15) varieties grown in soil with different degrees of salinity. The soil, however, had been improved by the usage of fertilizer at the tillering and booting stages. Results indicated that all rice samples exhibited similar nutrients, total phenolic contents (TPCs), and antioxidant potentials, suggesting that appropriate fertilizer could improve rice qualities. Principle Component Analysis (PCA) and Pearson correlation results suggested that regardless of rice varieties, organic matter (OM) and soil potassium (Ks) showed a very strong positive correlation with protein and minerals (Ca, Na, K, and Fe), while opposite results were observed with soil pH. Moderate to very weak correlations were also observed between soil parameters and TPCs, as well as between soil parameters and antioxidant activities. The received information will be useful for the future development of appropriate fertilizer usage in salt-tolerant rice with particular nutritional quality.

Cereal bran proteins: recent advances in extraction, properties, and applications

The projected global population is expected to reach around 9.7 billion by 2050, indicating a greater demand for proteins in the human diet. Cereal bran proteins (CBPs) have been identified as high-quality proteins, with potential applications in both the food and pharmaceutical industries. In 2020, global cereal grain production was 2.1 billion metric tonnes, including wheat, rice, corn, millet, barley, and oats. Cereal bran, obtained through milling, made up 10-20% of total cereal grain production, varying by grain type and milling degree. In this article, the molecular composition and nutritional value of CBPs are summarized, and recent advances in their extraction and purification are discussed. The functional properties of CBPs are then reviewed, including their solubility, binding, emulsifying, foaming, gelling, and thermal properties. Finally, current challenges to the application of CBPs in foods are highlighted, such as the presence of antinutritional factors, low digestibility, and allergenicity, as well as potential strategies to improve the nutritional and functional properties by overcoming these challenges. CBPs exhibit nutritional and functional attributes that are similar to those of other widely used plant-based protein sources. Thus, CBPs have considerable potential for use as ingredients in food, pharmaceutical, and other products.

A wild rice-derived peptide R14 ameliorates monosodium urate crystals-induced IL-1β secretion through inhibition of NF-κB signaling and NLRP3 inflammasome activation

Gout is an inflammatory arthritis initiated by the deposition of monosodium urate crystals (MSU) around the joints and surrounding tissues. MSU crystals activate the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome to the release of interleukin-1β (IL-1β). Gout can have a substantial impact on patient's quality of life, and currently available medicines are unable to meet all the clinical needs. This study explored anti-gout potentials of the Rice14 (R14) peptide, a peptide derived from leaves of wild rice Oryza minuta. The effects of R14 peptide on IL-1β secretion in THP-1 macrophages with MSU crystals-induced inflammation were examined. Our results clearly showed that the R14 peptide significantly inhibited the secretion of IL-1β in MSU crystals-induced macrophages, and the effects were dose-related. For safety testing, the R14 peptide did not show both cytotoxicity and hemolytic activity. In addition, the R14 peptide strongly suppressed the phospho-IκB-α and nuclear factor kappa-B (NF-κB) p65 proteins in NF-κB signaling pathway, reduced the NLRP3 expression and inhibited the MSU crystals-mediated cleavage of caspase-1 as well as mature IL-1β. The R14 peptide also reduced MSU-triggered intracellular ROS levels in macrophages. Taken together, these results indicated that R14 peptide inhibited MSU crystals-induced IL-1β production through NF-κB and NLRP3 inflammasome activation. Our findings demonstrated that R14 peptide, the newly recognized peptide from wild rice, possessed potent regulatory activity against IL-1β production in MSU crystals-induced inflammation, and we therefore propose that the R14 peptide is a promising molecule with potential clinical application in the treatment of MSU crystals-induced inflammation.

Rice bran protein-based delivery systems as green carriers for bioactive compounds

Natural protein-based delivery systems have received special interest over the last few years. Different carriers are already developed in the food industry to protect, encapsulate and deliver bioactive compounds. Rice bran protein (RBP) is currently used as a carrier in encapsulating bioactives due to its excellent functional properties, great natural value, low price, good biodegradability, and biocompatibility. Recently, RBP-based carriers including emulsions, microparticles, nanoparticles, nanoemulsions, liposomes, and core-shell structures have been studied extensively in the literature. This study reviews the important characteristics of RBP in developing bioactive delivery systems. The recent progress in various modification approaches for improving RBP properties as carriers along with different types of RBP-based bioactive delivery systems is discussed. In the final part, the bioavailability and release profiles of bioactives from RBP-based carriers and the recent developments are described.