Tb3+ assisted dithioerythritol stabilized copper nanocluster with AIE behavior for ratiometric fluorescent determination of fluoroquinolones.

BACKGROUND: Fluoroquinolones (FQs) are widely used in livestock and poultry industry because of their satisfactory effects in preventing and treating bacterial infection. However, due to irrational use and poor biodegradability, FQs can easily remain in food animals and further enter the human body through the food chain. Therefore, accurate and sensitive detection of FQs residues in animal-origin food is significant. The traditional methods commonly used for FQs detection have some limitations. Ratiometric fluorescence detection technology has the advantages of fast, sensitive, self-correcting, and easy visualization. However, the reports on the use of ratiometric fluorescence probes for FQs detection are limited. RESULTS: In this work, a novel probe was proposed for ratiometric fluorescent analysis of FQs. In this probe, the fluorescence of dithioerythritol stabilized copper nanoclusters (DTE-Cu NCs) was significantly enhanced due to the Tb3+ triggered aggregation-induced emission effect. FQs bound Tb3+ in Tb3+/DTE-Cu NCs through carboxyl and carbonyl groups, so that Tb3+ was effectively sensitized to emit green fluorescence. However, the red fluorescence of DTE-Cu NCs was not interfered. The fluorescence of the probe transformed from red to green with the increase of FQs concentration. Using norfloxacin (NOR), difloxacin (DIF), and enrofloxacin (ENR) as FQs simulants, this probe showed a sensitive linear response ranged from 0.025 to 22.5 µM, with the limits of detection of 9.6 nM, 9.3 nM, and 7.7 nM. The application potential for FQs detection was verified via a standard addition assay of egg samples with the recovery rate of 90.4 %-114.7 %. SIGNIFICANT: The fluorescence probe based on Tb3+/DTE-Cu NCs is expected to realize the ratiometric fluorescence sensitive detection of FQs. The establishment of this simple, effective, and rapid detection platform opens up a new way for the detection of FQs residues in animal-origin foods, and also provides a new idea for the design of rapid detection platforms for other hazard factors.

Effect of camellia oil body-based oleogels on the film-forming properties of soy protein isolate.

Soybean protein isolate (SPI) was frequently used to make edible films due to its highly degradability and excellent film forming ability. However, the limited barrier properties and low tensile strength of SPI films prevent their application in food packaging. In this study, the SPI film was modified by blending camellia oil body-based oleogel (COBO). COBO improved the mechanical properties of SPI film and increased its light-blocking, water insolubility and barrier properties. Micrograph, particle size distribution, protein conformation and crystalline structure analysis illustrated that camellia saponin in COBO formed hydrogen bonds with SPI, significantly reduced the particle size of the film-forming emulsion, and enhanced the order and uniformity of composite films structure, thus improved the overall performance of the SPI films. The SPI-COBO film packing delayed the weight loss, total soluble solids content increase, and the decrease in hardness of stored strawberries. This study puts forwards a new approach for SPI film modification by blending natural emulsified lipids, contributing to the development of sustainable packaging alternatives.

Sialyltransferase ST3GAL6 silencing reduces α2,3-sialylated glycans to regulate autophagy by decreasing HSPB8-BAG3 in the brain with hepatic encephalopathy. / å”¾æ¶²é ¸ç³–åŸºè½¬ç§»é ¶ST3GAL6的沉默可通过减少α2,3-å”¾æ¶²é ¸åŒ–èšç³–é™ä½ŽHSPB8-BAG3è¡¨è¾¾ä»Žè€Œè°ƒæŽ§è‚æ€§è„‘ç— å°é¼ å¤§è„‘ä¸­çš„è‡ªå™¬.

End-stage liver diseases, such as cirrhosis and liver cancer caused by hepatitis B, are often combined with hepatic encephalopathy (HE); ammonia poisoning is posited as one of its main pathogenesis mechanisms. Ammonia is closely related to autophagy, but the molecular mechanism of ammonia's regulatory effect on autophagy in HE remains unclear. Sialylation is an essential form of glycosylation. In the nervous system, abnormal sialylation affects various physiological processes, such as neural development and synapse formation. ST3 ß|-galactoside α2,|3-sialyltransferase 6 (ST3GAL6) is one of the significant glycosyltransferases responsible for adding α2,3-linked sialic acid to substrates and generating glycan structures. We found that the expression of ST3GAL6 was upregulated in the brains of mice with HE and in astrocytes after ammonia induction, and the expression levels of α2,3-sialylated glycans and autophagy-related proteins microtubule-associated protein light chain 3 (LC3) and Beclin-1 were upregulated in ammonia-induced astrocytes. These findings suggest that ST3GAL6 is related to autophagy in HE. Therefore, we aimed to determine the regulatory relationship between ST3GAL6 and autophagy. We found that silencing ST3GAL6 and blocking or degrading α2,3-sialylated glycans by way of Maackia amurensis lectin-II (MAL-II) and neuraminidase can inhibit autophagy. In addition, silencing the expression of ST3GAL6 can downregulate the expression of heat shock protein ß8 (HSPB8) and Bcl2-associated athanogene 3 (BAG3). Notably, the overexpression of HSPB8 partially restored the reduced autophagy levels caused by silencing ST3GAL6 expression. Our results indicate that ST3GAL6 regulates autophagy through the HSPB8-BAG3 complex.

Machine Learning Reveals Serum Glycopatterns as Potential Biomarkers for the Diagnosis of Nonalcoholic Fatty Liver Disease (NAFLD).

Nonalcoholic fatty liver disease (NAFLD) has emerged as the predominant chronic liver condition globally, and underdiagnosis is common, particularly in mild cases, attributed to the asymptomatic nature and traditional ultrasonography's limited sensitivity to detect early-stage steatosis. Consequently, patients may experience progressive liver pathology. The objective of this research is to ascertain the efficacy of serum glycan glycopatterns as a potential diagnostic biomarker, with a particular focus on the disease's early stages. We collected a total of 170 serum samples from volunteers with mild-NAFLD (Mild), severe-NAFLD (Severe), and non-NAFLD (None). Examination via lectin microarrays has uncovered pronounced disparities in serum glycopatterns identified by 19 distinct lectins. Following this, we employed four distinct machine learning algorithms to categorize the None, Mild, and Severe groups, drawing on the alterations observed in serum glycopatterns. The gradient boosting decision tree (GBDT) algorithm outperformed other models in diagnostic accuracy within the validation set, achieving an accuracy rate of 95% in differentiating the None group from the Mild group. Our research indicates that employing lectin microarrays to identify alterations in serum glycopatterns, when integrated with advanced machine learning algorithms, could constitute a promising approach for the diagnosis of NAFLD, with a special emphasis on its early detection.

Development of dual-channel starch-based film incorporated with betanin@ß-cyclodextrin inclusion complex and berberine for indicating shrimp freshness.

In this study, the ß-cyclodextrin encapsulated betanin (BET@ß-CD) with improved thermal stability and retention as well as the berberine (BBR) with aggregate induced luminescence effect were incorporated into corn amylose (CA) biomatrix to develop colorimetric/fluorescent dual-channel smart film. Results shown that the added functional components were uniformly distributed in the film matrix. The high tensile strength (78.87%), low water solubility (31.15%) and water vapor permeability (1.24 × 10-10 g Pa-1 s-1 m-1) of the film predicted its acceptable stability. It was worth mentioning that the film displayed excellent responsiveness to volatile ammonia (0.025-25 mg/mL) with at least 4 times recyclability. Application experiment demonstrated that the film can achieve macroscopic dynamic monitoring of the freshness of shrimps stored at 25 °C, 4 °C, -20 °C under daylight (red to yellow) and UV light (yellow-green to blue-green). Thus, the study suggests an attractive and effective strategy for constructing dual-mode smart packaging materials for food freshness detection.

Sialyltransferase ST3GAL6 silencing reduces α2,3-sialylated glycans to regulate autophagy by decreasing HSPB8-BAG3 in the brain with hepatic encephalopathy. / å”¾æ¶²é ¸ç³–åŸºè½¬ç§»é ¶ST3GAL6的沉默可通过减少α2,3-å”¾æ¶²é ¸åŒ–èšç³–é™ä½ŽHSPB8-BAG3è¡¨è¾¾ä»Žè€Œè°ƒæŽ§è‚æ€§è„‘ç— å°é¼ å¤§è„‘ä¸­çš„è‡ªå™¬.

End-stage liver diseases, such as cirrhosis and liver cancer caused by hepatitis B, are often combined with hepatic encephalopathy (HE); ammonia poisoning is posited as one of its main pathogenesis mechanisms. Ammonia is closely related to autophagy, but the molecular mechanism of ammonia's regulatory effect on autophagy in HE remains unclear. Sialylation is an essential form of glycosylation. In the nervous system, abnormal sialylation affects various physiological processes, such as neural development and synapse formation. ST3 ß|-galactoside α2,|3-sialyltransferase 6 (ST3GAL6) is one of the significant glycosyltransferases responsible for adding α2,3-linked sialic acid to substrates and generating glycan structures. We found that the expression of ST3GAL6 was upregulated in the brains of mice with HE and in astrocytes after ammonia induction, and the expression levels of α2,3-sialylated glycans and autophagy-related proteins microtubule-associated protein light chain 3 (LC3) and Beclin-1 were upregulated in ammonia-induced astrocytes. These findings suggest that ST3GAL6 is related to autophagy in HE. Therefore, we aimed to determine the regulatory relationship between ST3GAL6 and autophagy. We found that silencing ST3GAL6 and blocking or degrading α2,3-sialylated glycans by way of Maackia amurensis lectin-II (MAL-II) and neuraminidase can inhibit autophagy. In addition, silencing the expression of ST3GAL6 can downregulate the expression of heat shock protein ß8 (HSPB8) and Bcl2-associated athanogene 3 (BAG3). Notably, the overexpression of HSPB8 partially restored the reduced autophagy levels caused by silencing ST3GAL6 expression. Our results indicate that ST3GAL6 regulates autophagy through the HSPB8-BAG3 complex.

A novel dual-channel cassava starch/polyvinyl alcohol-based film for visual monitoring of shrimp freshness.

In this study, the polyvinylpyrrolidone-alizarin nanoparticles (PVP-AZ NPs) with favorable water dispersion and the carbon quantum dots (RQDs) with aggregate induced emission effect were synthesized to construct an eco-friendly film for food freshness monitoring. The introduction of PVP-AZ NPs and RQDs enhanced the network structure and thermal stability of the cassava starch/polyvinyl alcohol film, and reduced its crystallinity and light transmittance via non-covalent binding with the film-forming matrix. The developed film exhibited visually recognizable colorimetric and fluorescent responses to ammonia at 0.025-25 mg/mL, and it can be reused at least 6 times. Practical application experiment proved that the film, as an indicator label, can achieve accurate, real-time, and visual dynamic monitoring of the freshness of shrimp stored at 25 °C, 4 °C, and - 20 °C under daylight (orange yellow to purple) and UV light (red to blue). The integration of multivariate detection technology can eliminate the interference of external factors by self-correction to improve sensitivity and reliability, which provides a reference for the development of other food quality and safety monitoring platforms.

Remodeling mechanism of gel network structure of soy protein isolate amyloid fibrils mediated by cellulose nanocrystals.

The differences in the gelling properties of soy protein isolate (SPI) and soy protein isolate amyloid fibrils (SAFs) as well as the role of cellulose nanocrystals (CNC) in regulating their gel behaviors were investigated in this study. The binding of CNC to ß-conglycinin (7S), glycinin (11S), and SAFs was predominantly driven by non-covalent interactions. CNC addition reduced the particle size, turbidity, subunit segments, and crystallinity of SPI and SAFs, promoted the conversion of α-helix to ß-sheet, improved the thermal stability, exposed more tyrosine and tryptophan residues, and enhanced the intermolecular interactions. A more regular and ordered lamellar network structure was formed in the SAFs-CNC composite gel, which could be conducive to the improvement of gel quality. This study would provide theoretical reference for the understanding of the regulatory mechanism of protein amyloid fibrils gelation as well as the high-value utilization of SAFs-CNC complex as a functional protein-based material or food ingredient in food field.

Insight into the improvement mechanism of gel properties of pea protein isolate based on the synergistic effect of cellulose nanocrystals and calcium ions.

Here, the influence and potential mechanism by which cellulose nanocrystals (CNC) collaborated with Ca2+ enhancing the heat-induced gelation of pea protein isolate (PPI) were investigated. It was found that the combination of 0.45% CNC and 15 mM Ca2+ synergistically increased the gel strength (from 14.18 to 65.42 g) and viscoelasticity of PPI while decreased the water holding capacity. The improved particle size, turbidity, and thermostability as well as the reduced solubility, crystallinity, and gel porosity were observed in CNC/CaCl2 composite system. CNC fragments bind to specific amino acids in 11S legumin and 7S vicilin mainly through hydrogen bonding and van der Waals forces. Moreover, changes in the protein secondary structure and enhancement of the molecular interaction induced by CNC and Ca2+ could favor the robust gel network. The results will provide a new perspective on the functional regulation of pea protein and the creation of pea protein gel-based food.

Insight into the solubilization mechanism of wheat gluten by protease modification from conformational change and molecular interaction perspective.

The low solubility limits the utilization of other functional characteristics of wheat gluten (WG). This study effectively improved the solubility of WG through protease modification and explored the potential mechanism of protease modification to enhance the solubility of WG, further stimulating the potential application of WG in the food industry. Solubility of WG modified with alkaline protease, complex protease, and neutral protease was enhanced by 98.99%, 54.59%, and 51.68%, respectively. Notably, the content of ß-sheet was reduced while the combined effect of hydrogen bond and ionic bond were increased after protease modification. Meanwhile, the reduced molecular size and viscoelasticity as well as the elevated surface hydrophobicity, thermostability, water absorption capacity, and crystallinity were observed in modified WG. Moreover, molecular docking indicated that protease was specifically bound to the amino acid residues of WG through hydrogen bonding, hydrophobic interaction, and salt bridge.

Fluorescent responsive membrane based on terbium coordination polymer and carbon dots with AIE effect for rapid and visual detection of fluoroquinolone.

In this study, based on aggregation-induced emission (AIE) effect and antenna effect, a novel portable fluorescent responsive membrane was constructed with red carbon dots (R-CDs) as reference signal and terbium coordination polymer (Tb-AMP CPs) as response signal for visual, instrument-free, and sensitive detection of fluoroquinolones (FQs). Specifically, the fluorescent responsive membrane (R-T membrane) was prepared by physically depositing R-CDs with AIE property and Tb-AMP CPs on the surface of polyvinylidene fluoride filter membranes at ambient temperature. In the presence of FQs, Tb3+ in the Tb-AMP CPs of the prepared membrane coordinated with the ß-diketone structure of FQs, which turned on the yellow-green fluorescence through the "antenna effect". As the concentration of FQs increased, the R-T membrane achieved a fluorescent color transition from bright pink to yellow-green. Its visual detection sensitivity for three FQs, including ciprofloxacin, difloxacin, and enrofloxacin, was 0.01 µM, and the detection limits were 7.4 nM, 7.8 nM, and 9.2 nM, respectively, by analyzing the color parameter green. In the residue analysis of FQs in real samples, the constructed membrane also exhibited remarkable anti-interference and reliability, which is of great significance for ensuring the safety of animal-derived food.

Preparation of the black rice starch-gallic acid complexes by ultrasound treatment: Physicochemical properties, multiscale structure, and in vitro digestibility.

This study aimed to investigate the multiscale structure, physicochemical properties, and in vitro digestibility of black rice starch (BRS) and gallic acid (GA) complexes prepared using varying ultrasound powers. The findings revealed that ultrasonic treatment disrupted BRS granules while enhancing the composite degree with GA. The starch granules enlarged and aggregated into complexes with uneven surfaces. Moreover, the crystallinity of the BRS-GA complexes increased to 22.73 % and formed V6-I-type complexes through non-covalent bonds. The increased short-range ordering of the complexes and nuclear magnetic resonance hydrogen (1H NMR) further indicated that the BRS and GA molecules interacted mainly through non-covalent bonds such as hydrogen bonds. Additionally, ultrasound reduced the viscoelasticity of the complexes while minimizing the mass loss of the complexes at the same temperature. In vitro digestion results demonstrated an increase in resistant starch content up to 37.60 % for the BRS-GA complexes. Therefore, ultrasound contributes to the formation of V-typed complexes of BRS and GA, which proves the feasibility of using ultrasound alone for the preparation of starch and polyphenol complexes while providing a basis for the multiscale structure and digestibility of polyphenol and starch complexes.

Mn-modified porphyrin metal-organic framework mediated colorimetric and photothermal dual-channel probe for sensitive detection of organophosphorus pesticides.

Herein, a novel dual-mode probe for organophosphorus pesticides (OPs) colorimetric and photothermal detection was developed based on manganese modified porphyrin metal-organic framework (PCN-224-Mn). PCN-224-Mn had excellent oxidase-like activity and oxidized colorless 3,3,5,5-tetramethylbenzidine (TMB) to blue-green oxidation state TMB (oxTMB), which exhibited high temperature under near-infrared irradiation. l-ascorbate-2-phosphate was hydrolyzed by acid phosphatase to produce ascorbic acid, which weakened colorimetric and photothermal signals by impacting oxTMB generation. The presence of OPs blocked the production of ascorbic acid by irreversibly inhibiting the activity of acid phosphatase, causing the restoration of chromogenic reaction and the increase of temperature. Under the optimal conditions, the probe showed a good linear response to OPs in the concentration range of 5 âˆ¼ 10000 ng/mL, using glyphosate as the analog. The detection limits of glyphosate in colorimetric mode and photothermal mode were 1.47 ng/mL and 2.00 ng/mL, respectively. The probe was successfully used for sensitive identification of OPs residues in tea, brown rice, and wheat flour. This work proposes a simple and reliable colorimetric/photothermal platform for OPs identification, which overcomes the problem that single-mode detection probes are susceptible to external factors, and has broad application potential in the field of food safety.

Influence of the structure and physicochemical properties of OSA modified highland barley starch based on ball milling assisted treatment.

This study aimed to investigate the influence of ball milling assisted treatment on the degree of substitution of octenyl succinic anhydride (OSA) modified highland barley starch (HBS) and on the physicochemical properties and structure of HBS. Scanning electron microscopy (SEM) findings showed that with the increasing of ball milling time, the surface morphology of OSA modified HBS became rougher and rougher and the particle morphology and crystal structure were damaged. When the pretreatment time of ball milling was 40 min, the degree of substitution of OSA modified HBS was 1.32 times higher than that of the conventional modification method. In addition, the longer the ball milling assistant, the longer the short-range ordering of the OSA modified HBS significantly decreased, and the relative crystallinity decreased (from 16.68 % to 7.93 %), leading to a decrease in thermal stability too. However, it greatly enhanced the aging resistance and flowability. In terms of emulsification properties, the emulsification properties of OSA modified HBS increased from 60.67 % to 75.67 %. Therefore, the HBS with better freeze-thaw stability and higher degree of substitution can be prepared by ball milling pretreatment and OSA modification, which provides technical support for further development of starch resources.

Exploring the formation mechanism of resistant starch (RS3) prepared from high amylose maize starch by hydrothermal-alkali combined with ultrasonic treatment.

In this study, type III resistant starch (RS3) was prepared from high amylose maize starch (HAMS) using hydrothermal (RS-H), hydrothermal combined ultrasonication (RS-HU), hydrothermal-alkali (RS-HA), and hydrothermal-alkali combined ultrasonication (RS-HAU). The role of the preparation methods and the mechanism of RS3 formation were analyzed by studying the multiscale structure and digestibility of the starch. The SEM, NMR, and GPC results showed that hydrothermal-alkali combined with ultrasonication could destroy the granule structure and α-1,6 glycosidic bond of HAMS and reduce the molecular weight of HAMS from 195.306 kDa to 157.115 kDa. The other methods had a weaker degree of effect on the structure of HAMS, especially hydrothermal and hydrothermal combined ultrasonication. The multiscale structural results showed that the relative crystallinity, short-range orderliness, and thermal stability of RS-HAU were significantly higher compared with native HAMS. In terms of digestion, RS-HAU had the highest RS content of 69.40 %. In summary, HAMS can generate many short-chain amylose due to structural damage, which rearrange to form digestion-resistant crystals. With correlation analysis, we revealed the relationship between the multiscale structure and the RS content, which can be used to guide the preparation of RS3.

Synergistic effect and mechanism of cellulose nanocrystals and calcium ion on the film-forming properties of pea protein isolate.

The current serious environmental problems have greatly encouraged the design and development of food packaging materials with environmental protection, green, and safety. This study aims to explore the synergistic effect and corresponding mechanism of cellulose nanocrystals (CNC) and CaCl2 to enhance the film-forming properties of pea protein isolate (PPI). The combination of 0.5 % CNC and 4.5 mM CaCl2 resulted in a 76.6 % increase in tensile strength when compared with pure PPI-based film. Meanwhile, this combination effectively improved the barrier performance, surface hydrophobicity, water resistance, and biodegradability of PPI-based film. The greater crystallinity, viscoelasticity, lower water mobility, and improved protein spatial conformation were also observed in CNC/CaCl2 composite film. Compared with the control, the main degradation temperature of composite film was increased from 326.23 °C to 335.43 °C. The CNC chains bonded with amino acid residue of pea protein at specific sites via non-covalent forces (e.g., hydrogen bonds, Van der Waals forces). Meanwhile, Ca2+ promoted the ordered protein aggregation at suitable rate and degree, accompanied by the formation of more disulfide bonds. Furthermore, proper Ca2+ could strengthen the cross-linking and interaction between CNC and protein, thereby establishing a stable network structure. The prepared composite films are expected to be used for strawberry preservation.

Development of antioxidant and smart NH3 -sensing packaging film by incorporating bilirubin into κ-carrageenan matrix.

BACKGROUND: Active and smart food packaging based on natural polymers and pH-sensitive dyes as indicators has attracted widespread attention. In the present study, an antioxidant and amine-response color indicator film was developed by incorporating bilirubin (BIL) into the κ-carrageenan (Carr) matrix. RESULTS: It was found that the introduction of BIL had no effect on the crystal/chemical structure, water sensitivity and mechanical performance of the Carr-based films. However, the barrier properties to light and the thermal stability were significantly improved after the addition BIL. The Carr/BIL composite films exhibited excellent 1,1-diphenyl-2-picryl-hydrazyl (i.e. DPPH)/2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (i.e. ABTS) free radical scavenging abilities and color responsiveness to different concentrations of ammonia. The application assay reflected that the Carr/BIL0.0075 film was effective in delaying the oxidative deterioration of shrimp during storage and realizing the color response of its freshness through the change of b* value. CONCLUSION: Active and smart packaging films were successfully prepared by incorporating different contents of BIL into the Carr matrix. The present study helps to further encourage the design and development of a multi-functional packaging material. © 2023 Society of Chemical Industry.

Changes in morphological and structural characteristics of high amylose maize starch in alkaline solution at different temperatures.

In this study, high amylose maize starch(HAMS)was treated by Hydrothermal-alkali. SEM, SAXS, XRD, FTIR, LC-Raman, 13C CP/MAS NMR, GPC and TGA were used to study the changes in the granules and structure of HAMS. The results show that the granule morphology, lamellar structure, and birefringence of HAMS remained intact at 30 °C and 45 °C. With increasing temperature, the starch granules are fragmented, and the crystallinity, DD, FWHM values, molecular weight, and thermal stability of HAMS decrease. The double helical structure dissociated, and the content of amorphous regions increased, indicating the from order to the disorder of the HAMS structure. A similar annealing behavior occurred in HAMS at 45 °C, with the rearrangement of amylose and amylopectin occurring. At 75 °C and 90 °C, the short-chain starch produced by chain breakage regroups to form an ordered double helix structure. In general, the granule structure level of HAMS was damaged to different degrees at varying temperatures. HAMS showed gelatinization behavior in alkaline solutions when the temperature is 60 °C. This study expects to provide a model for the gelatinization theory of HAMS systems.

Self-assembly and interaction mechanisms of edible dock protein and flavonoids regulated by the phenolic hydroxyl position.

In this study, chrysin (Chr), baicalein (Bai), apigenin (Api) and galangin (Gal) were selected as the representative flavonoids with different position of phenolic hydroxyl groups, and edible dock protein (EDP) was used as a material to construct delivery system. Subsequently, the molecular interactions and functional properties of flavonoids-loaded EDP nanomicelles were investigated. Results exhibited that hydrogen bond, hydrophobic interaction and van der Waals force were the main driving forces for self-assembly of flavonoids and EDP molecules. Meanwhile, this self-assembly remarkably enhance the storage and digestion stability of flavonoid compounds. Among four flavonoids, the order of loading ability was: Api > Gal > Bai > Chr. Herein, Api had a largest loading capacity (6.74%) because of its active phenolic hydroxyl group in ring B. These results suggested that the position of phenolic hydroxyl groups in flavonoids is a key factor to regulate its self-assembly with protein molecules.

Influence pathways of nanocrystalline cellulose on the digestibility of corn starch: Gelatinization, structural properties, and α-amylase activity perspective.

This work focused on the pathways by which NCC regulated the digestibility of corn starch. The addition of NCC changed the viscosity of the starch during pasting, improved the rheological properties and short-range order of the starch gel, and finally formed a compact, ordered, and stable gel structure. In this respect, NCC affected the digestion process by changing the properties of the substrate, which reduced the degree and rate of starch digestion. Moreover, NCC induced changes in the intrinsic fluorescence, secondary conformation, and hydrophobicity of α-amylase, which lowered its activity. Molecular simulation analyses suggested that NCC bonded with amino acid residues (Trp 58, Trp 59, and Tyr 62) at the active site entrance via hydrogen bonding and van der Waals forces. In conclusion, NCC decreased CS digestibility by modifying the gelatinization and structural properties of starch and inhibiting α-amylase activity. This study provides new insights into the mechanisms by which NCC regulates starch digestibility, which could be beneficial for the development of functional foods to tackle type 2 diabetes.