Mechanistic study on the nanocomplexation between curcumin and protein hydrolysates from Great Northern bean (Phaseolus vulgaris L.) for delivery applications in functional foods

CRISPR/Cas12a trans-cleavage cascading dual-template exponential amplification reaction for electrochemiluminescent detection of 17β-estradiol in milk

17β-Estradiol (E2) is a common environmental estrogen that can interfere with the endocrine systems of humans and animals, and poses a carcinogenic risk even at picomolar concentrations. In this study, a functionalized Ru(bpy)32+-embedded metal-organic framework (ZnRuMOF) is synthesized, in which Ru(bpy)32+ served as an electrochemiluminescence (ECL) indicator and the porous structure of ZnRuMOF acts as a nanoreactor to enhance the ECL signal. Based on this, we developed an E2 detection method combining a highly specific CRISPR-Cas12a system and dual-template exponential amplification. This method utilizes the trans-cleavage activity of CRISPR-Cas12a to control a light switch, achieving precise and ultra-sensitive detection of E2. The sensing platform demonstrates excellent performance in detecting E2 concentrations ranging from 1 fg mL-1 to 150 ng mL-1, with a detection limit of 0.27 fg mL-1 (S/N = 3). This study provides a reliable approach for diagnosing and treating diseases related to E2, aiming to protect environmental quality and human health.

The Effect of Lipids on the Structure and Function of Egg Proteins in Response to Pasteurization

In recent years, the consumption of liquid eggs has failed to meet the expectations of the public due to growing concerns regarding food safety and health. It is well known that there are interactions between the components in liquid eggs, and the interaction effect on the structure and functional properties of the proteins and antigenicity remains unclear. To investigate egg component interactions, we focused on four major egg lipids, namely phosphatidylcholine, palmitic acid, oleic acid, and linoleic acid, as well as four major egg proteins, including ovalbumin, ovotransferrin, ovomucoid, and lysozyme. The protein structural changes were analyzed using polypropylene gel electrophoresis, circular dichroism, ultraviolet absorption spectra, and exogenous fluorescence spectra, and the functional properties were assessed through solubility measurements and particle size analysis, while protein antigenicity was evaluated using an enzyme-linked immunosorbent assay. All the results revealed that oleic acid had the most significant effect on proteins' secondary and tertiary structures, particularly affecting ovalbumin and ovotransferrin. Linoleic acid substantially increased the solubility of ovalbumin and ovomucoid, while palmitic acid significantly influenced the particle size of ovalbumin and lysozyme. Thus, we found that different lipids exhibit distinct effects on egg protein properties during pasteurization conditions, with oleic acid showing the most substantial impact on protein structure and antigenicity.

Combining heat treatment and conjugation between guarana extract and pea protein isolate to produce O/W emulsions loaded with vitamin D3

Growing interest in plant-based materials for stabilizing food emulsions is driven by the clean-label trend. Conjugating plant proteins with phenolic compounds from plant extracts enhances their techno-functionality and allows their use as stabilizers of emulsion-based systems. This study aimed to (i) combine heat treatment (HT) and conjugation with guarana extract (GE) to improve the emulsifying ability of pea protein isolate (PPI); (ii) encapsulate vitamin D3 (VD) in PPI/GE-stabilized emulsions; (iii) evaluate the potential of these formulations in improving VD retention during storage and in vitro bioaccessibility. The particles showed a size distribution ranging from 0.5 to 10 µm, depending on the processing sequence. Furthermore, HT on PPI dispersions followed by conjugation with GE led to microgels that stabilized emulsions during 30 days of storage at 25 °C. Also, the conjugates significantly improved VD retention, ranging from 74 to 100 %, after 30 days of storage at 25 °C, even in the presence of UV light. VD-loaded emulsions produced by PPI-GE conjugates showed higher bioaccessibility values (>65 %) compared to emulsions produced by PPI alone (∼58 %) and VD-incorporated sunflower oil (37 %). Given the above, the technological modification of PPI through conjugation with GE phenolic compounds and HT efficiently produced O/W emulsions loaded with VD, improving its bioaccessibility and tailoring a system with potential application in plant-based beverage and dessert formulations.

Impact of pH on the fabrication of egg white reinforced soy protein composite microgels for gastrointestinal delivery purposes

Protein molecules such as soy protein isolate (SPI) and egg white (EW) are highly promising materials for developing hydrogels (especially micro/nanogels) for the encapsulation, protection and controlled release of bioactive substances. However, there are limited numbers of studies on the formulation and behavior of these two gelling materials as microgels. In our study, composite microgels of SPI and EW at various component ratios and pH conditions have been successfully prepared; the rheological behavior and structural properties of these composite microgels before, during and after in vitro digestion have been analyzed; and their performance in curcumin encapsulation and gastrointestinal delivery has also been investigated. It was concluded that the SPI-EW composites at a mass ratio of 50 : 50 showed the best gelling properties in terms of storage modulus. Composite microgels prepared at pH 4 had larger particle sizes with more compact structures than those prepared at pH 7, due to their acidic complex coacervation, and therefore were more resistant to gastrointestinal digestion. The results suggest that the SPI-EW composite microgel particles prepared at pH 4 could achieve better sustained-release of curcumin in the in vitro gastrointestinal tract, with preserved antioxidant activity. Our study shows promise for the utilization of protein-based composite micro/nanogels for oral delivery applications.

Fabrication and characterization of curcumin-encapsulated composite nanoparticles based on soybean protein isolate hydrolysate/soybean polysaccharides: Interaction mechanism, stability and controlled release properties

This study developed a stable nanoparticle (CUR-SPIH/SSPS) using soybean protein isolate hydrolysate (SPIH) and soybean polysaccharides (SPSS) to protect curcumin (CUR) from degradation during storage and exposure to light and heat conditions, achieving controlled release. The SPIH to SPSS mass ratio of 5:1 gave the CUR-SPIH/SPSS nanoparticles with the highest CUR encapsulation efficiency (95.60 ± 3.00 %) and the strongest antioxidant capacity (90.26 ± 2.42 % and 66.78 ± 1.89 % for ABTS•+ and DPPH radical scavenging ability, respectively), and CUR was successfully encapsulated within the CUR-SPIH/SPSS as evidenced by X-ray diffraction. FTIR and fluorescence spectroscopy analysis confirmed that the interactions in CUR-SPIH/SPSS are primarily driven by electrostatic, hydrogen bonding, and hydrophobic interactions. Moreover, the CUR-SPIH/SPSS nanoparticles significantly enhanced CUR's thermal and UV light stability. The UV degradation kinetics showed that the half-life of CUR-SPIH/SPSS (247.55 min) was 1.61 times longer than that of free CUR (154.03 min). The release rate of CUR incorporated into CUR-SPIH/SPSS was significantly delayed during in vitro gastrointestinal digestion. This study introduces an innovative nanoparticle strategy for the stable delivery of lipophilic compounds.

Utilization of soybean protein isolate hydrolysates as carriers: Improved encapsulation efficiency and stability of curcumin

This study aimed to explore the potential of soybean protein isolate hydrolysates (SPIH) prepared via Alcalase as delivery carriers and develop novel SPIH-Cur nanoparticles. Hydrolysis caused the varying degrees degradation in the 7S and 11S subunits, significantly enhancing SPI's antioxidant activity. The reduction in particle size and the exposure of hydrophobic groups in SPIH contributed to the formation of stable SPIH-Cur nanoparticles, due to their well binding capacity to curcumin (Cur). The 30 min SPIH-Cur sample exhibited the highest encapsulation efficiency (83.09 %), owing to its high binding affinity (Ka = 9.56 × 103 M-1). Encapsulation by SPIH also significantly improved Cur's thermal and light stability. Moreover, FTIR, fluorescence spectra, and molecular docking analyses revealed that the formation of SPIH-Cur were primarily driven by hydrophobic forces and hydrogen bonds. Above results provide a foundation for fabricating nanoparticles that deliver lipophilic bioactive compounds with high encapsulation efficiency and stability derived from SPIH.

Extraction methods and nutritional characterization of protein concentrates obtained from bean, chickpea, and corn discard grains

Protein concentrates obtained from discarded grain flours of white chickpea Sinaloa (Cicer arietinum) (CC), "Azufrazin" bean (Phaseolus vulgaris) (BC), and white corn (Zea mays) (MC), were characterized biochemically through bromatological analyses (protein, lipid, fiber, moisture, ashes, and nitrogen free extract), HPLC techniques (amino acids content), and spectrophotometry (anti-nutrients: phytic acid, trypsin inhibitors, and saponins). The percentage of protein obtained from CC, BC, and MC was 71.23, 81.10, and 55.69%, respectively. Most peptides in the BC and CC flours had a molecular weight of <1.35 kDa, meanwhile, MC peptides were heavier (1.35 to 17 kDa). The amino acids (AA) profile of flours and protein concentrates were similar; however, all the protein concentrates showed an increased AA accumulation (300 to -400%) compared with their flours. The protein concentrates from BC registered the highest AA accumulation (77.4 g of AA/100 g of protein concentrates). Except for the phytic acid in CC and trypsin inhibitor in CC and MC, respectively, the rest of the protein concentrates exhibited higher amounts of the anti-nutrients compared with their flours; however, these levels do not exceed the reported toxicity for some animals, mainly when used in combination with other ingredients for feed formulations. It is concluded that CC and BC protein concentrates showed better nutritional characteristics than MC (level of protein, size of peptides, and AA profile). After biochemical characterization, protein concentrates derived from by-products have nutritional potential for the animal feed industry.

Fabrication, in-vitro digestion and pH-responsive release behavior of soy protein isolate glycation conjugates-based hydrogels

Hydrogel made by glycated soy protein isolate (SPI) conjugates is a promising gastrointestinal targeted delivery system for bioactives. In this study, SPI conjugates were prepared with dextran molecules at various molecular weights by Maillard reaction -based heating, and then used to fabricate hydrogel aided by transglutaminase. The modification on the structure, interfacial and rheological properties of SPI by dextran was studied. The physicochemical properties, digestion behavior and curcumin-encapsulation capacity of resultant SPI-dextran hydrogels were comprehensively studied. As compared to SPI and SPI-glucose conjugates-based hydrogels, SPI-dextran hydrogels showed lower mechanical properties but more homogeneous gel network. Dextran with higher molecular weight showed lower grafting degree on SPI, but was more effective on improving the thermos-set gel performance, and resistance to in vitro gastrointestinal digestion. The contribution of glycinin and β-conglycinin, two major individual proteins of SPI, in the dextran conjugates formation were predicated by molecular docking for the first time. The impact of molecular weight of dextran on glycated SPI hydrogel-based delivery systems was comprehensively investigated, which is promising for development of functional food applications.

Formation and Characterization of Self-Assembled Rice Protein Hydrolysate Nanoparticles as Soy Isoflavone Delivery Systems

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.

Effects of glycation methods on the interfacial behavior and emulsifying performance of soy protein isolate-gum Arabic conjugates

Glycated conjugation of plant protein such as soy protein isolate (SPI) with saccharides is one popular strategy to modify the physicochemical characteristics of these plant protein resources, which may be affected by the glycation methods including dry-heating and wet-heating. In this study, the impact of these two glycation methods on the rheological and emulsifying properties of a binary system made by SPI-gum Arabic (GA) was studied. The results indicated that dry-heating conjugates had higher viscosity and more elastic characteristics than those wet-heating conjugates. The emulsifying properties of SPI-GA conjugates by different preparation routes were evaluated by various oil phases including eugenol, cinnamaldehyde and soybean oil. Overall, emulsions stabilized by dry-heating conjugates showed lower zeta-potential value than those with wet heating conjugates. The interfacial properties of these conjugates were compared using soybean oil emulsion as a model. Higher emulsifying ability and stability were obtained by emulsions with dry-heating conjugates, which was attributed to their more compact structures, higher protein adsorption capacity and thicker viscoelastic films formed at the interface, and therefore enhanced electrostatic repulsion between droplets. The findings in this study are useful for fabrication and utilization of protein-polysaccharide glycation conjugates as emulsifiers in functional foods.

Preparation, Characteristics, and Advantages of Plant Protein-Based Bioactive Molecule Delivery Systems

As a renewable resource, the market trend of plant protein has increased significantly in recent years. Compared with animal protein, plant protein production has strong sustainability factors and a lower environmental impact. Many bioactive substances have poor stability, and poor absorption effects limit their application in food. Plant protein-based carriers could improve the water solubility, stability, and bioavailability of bioactive substances by different types of delivery systems. In this review, we present a detailed and concise summary of the effects and advantages of various plant protein-based carriers in the encapsulation, protection, and delivery of bioactive substances. Furthermore, the research progress of food-grade bioactive ingredient delivery systems based on plant protein preparation in recent years is summarized, and some current challenges and future research priorities are highlighted. There are some key findings and conclusions: (i) plant proteins have numerous functions: as carriers for transportation systems, a shell or core of a system, or food ingredients; (ii) plant protein-based carriers could improve the water solubility, stability, and bioavailability of bioactive substances by different types of delivery systems; and (iii) plant protein-based carriers stabilize bioactive substances with potential applications in the food and nutrition fields.