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Food Biophysics
Journal Prestige (SJR): 0.74  Citation Impact (citeScore): 2 Number of Followers: 2  Hybrid journal (It can contain Open Access articles)ISSN (Print) 1557-1866 - ISSN (Online) 1557-1858 Published by Springer-Verlag  [2468 journals]
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- Optimizing the Appearance of Plant-based Foods Using Natural Pigments and
Color Matching Theory-
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Abstract: Abstract The appearance of a food significantly affects consumer’s liking and buying decisions. For next-generation plant-based foods, consumers expect them to have the same appearance (color and opacity) as the animal-based products they replace. Therefore, matching the color of plant-based foods to their conventional animal-based counterparts could increase their liking and acceptance by consumers. In this study, three plant-derived food colorants, red beet (red), turmeric (yellow), and butterfly pea flower (blue), were blended to match the color of raw meat, cooked meat, cooked whole egg, and cheddar cheese. Initially, the pigments were incorporated into three separate emulsions representing the three primary colors (red, yellow, and blue). The Kubelka-Munk and color matching theories were then used to determine the amount of each emulsion required to match the spectral reflectance of the animal-based products. Our results show that color matching theory could be used to formulate plant-based emulsions with similar optical properties to animal-based products, including chroma and lightness. However, some discrepancies were observed, which may have been due to differences in the scattering of light by the complex food matrices in animal-based products. The color matching approach developed in this study could be useful for the development of plant-based food products with improved appearances, thereby expanding their consumer appeal.
PubDate: 2023-09-09
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- In vitro Digestibility and Gastrointestinal Fate of Plant-based Chicken
Analogs Prepared Using a Soft Matter Physics Approach-
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Abstract: Abstract In this study, the potential gastrointestinal fate of a plant-based chicken analog prepared using a soft matter physics approach was compared to that of real chicken breast. The chicken analog was created from potato protein and gellan gum using a complex coacervation-shearing-gelling approach. The INFOGEST static in vitro gastrointestinal model was then used to compare the digestion of the chicken analog to real chicken breast. Changes in the appearance, physiochemical properties, microstructure, protein digestion, and lipid digestion of the chicken samples were recorded after being subjected to simulated oral, gastric, and small intestine conditions. The protein digestibility of the plant-based chicken was higher than the real chicken after exposure to simulated stomach conditions, but it was lower after exposure to simulated small intestine conditions. The digestibility of the fat in the plant-based chicken was lower in the intestinal phase than that for the real chicken. This reduced digestibility of the fat and protein in the small intestine for the chicken analogs may have been because of the gellan gum they contained. This hydrocolloid increased the viscosity of the intestinal fluids and may have inhibited interactions between digestive enzymes and macronutrients. Our results have important implications for assessing the potential impacts of adopting a more plant-based diet on human health and wellbeing.
PubDate: 2023-09-08
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- Effect of High-pressure Homogenization on Structure and Properties of Soy
Protein Isolate/polyphenol Complexes-
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Abstract: Abstract Understanding the effects of typical unit operations on the structure and properties of protein/polyphenol complexes has important guiding value for the design and development of two-component functional foods. Therefore, the effects of high-pressure homogenization (HPH) on the structure, physicochemical properties, and in vitro digestive characteristics of soy protein isolate (SPI)-black soybean coat extract (BE) complexes were investigated. UV-Vis and intrinsic fluorescence spectra manifested that the tertiary conformation of protein was partially unfolded after HPH treatment. In addition, with the enhancement of HPH pressure, the zeta-potential magnitude and average particle size of SPI-BE complexes increased and decreased, respectively. On the other hand, HPH had no significant effect on in vitro digestion, anthocyanin content, and free radical scavenging ability of SPI-BE complexes. These findings can provide new insights and guidance for the optimization and regulation of protein-polyphenol co-existing food systems, and provide reference for their application in food industry.
PubDate: 2023-09-01
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- Microstructure, Rheology and Stability of Vegetable Cream-Like Emulsions
Prepared with Natural Oils: Effects of Homogenization Speed and
Polyglycerol Polyricinoleate Concentration-
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Abstract: Abstract The aim of this work is to analyze the microstructure, rheology and stability of vegetable cream-like emulsions prepared with polysorbate 80 (Tween 80) as hydrophilic emulsifier and coconut oil (CO), palm oil (PO) or sunflower oil (SO) in dispersed lipid phase. The effects of homogenization speed and polyglycerol polyricinoleate (PGPR) concentration in lipid phase were studied. Aggregation of oil globules by partial coalescence was observed in emulsions prepared with CO and PO due to the partial crystallization of the lipid phase, showing higher viscoelastic parameters and higher creaming stability in comparison to the systems with SO. The increase of homogenization speed led to the formation of smaller globules, reducing the partial coalescence degree in emulsions with CO due to the decrease of capture efficiency, but favoring the same process in systems with PO, presumably because of the increase of collision frequency. The addition of PGPR increased the partial coalescence degree in emulsions with CO and PO, which would be attributed to the modification of the crystallization behavior of the lipid phase. However, smaller aggregates were observed in the presence of PGPR, probably because of the formation of a more packed, less hydrated structure. In the long term, the inclusion of PGPR in systems with CO and PO was more effective to increase creaming stability than the increase of homogenization speed. The findings of this work could be relevant for the formulation and stabilization of whipped dairy cream simulators prepared with vegetable components.
PubDate: 2023-09-01
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- Association between Lysozyme and Carboxymethyl Konjac Glucomannan to
Produce Dispersible Coacervates-
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Abstract: Lysozyme was subjected to coacervate with carboxymethyl konjac glucomannan (CMKGM) to check if dispersible coacervates could be formed to extend its application in edible antibacterial coating. The results indicated that complex coacervation could occur between the two polyelectrolytes within a narrow pH range from pH 2.5 to 6.0 and the greatest interaction was recorded at 35 °C in the absence of NaCl. The dispersion status of the lysozyme – CMKGM coacervates was closely related to the phase separation pH as well as lysozyme to CMKGM mixing ratio and conditions that led to the presence of free CMKGM in the aqueous phase favored the formation of dispersible coacervates. Rheological measurements revealed that the high viscosity of CMKGM solution contributed greatly to the dispersion status of the lysozyme – CMKGM coacervates. Association with CMKGM caused structural changes to lysozyme, but only slightly affected its lytic activity. Contact angle measurement revealed that the lysozyme – CMKGM coacervates were more hydrophobic than the two single polyelectrolytes. Hence, the dispersible lysozyme – CMKGM coacervates were potential in the fabrication of composite antibacterial edible coatings. Graphical
PubDate: 2023-09-01
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- Development and Characterization of Fully Hydrogenated Soybean Oil and
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Abstract: Abstract Nanostructured lipid carriers (NLC) have shown great potential as a delivery system for lipophilic bioactive compounds as they provide protection, high water dispersibility, chemical stability, and oral bioavailability. The less compact crystal structure created by high- and low-melting-point lipids has more space for the entrapment of bioactive compounds, such as β-carotene, the carotenoid with the highest provitamin A activity. The objective of this study was to produce and characterise β-carotene-loaded NLC. The study assessed the physical and crystallization properties, entrapment efficiency (EE), and loading capacity (LC) of NLC produced with fully hydrogenated soybean oil and high oleic sunflower oil as high- and low-melting-point lipid matrices, respectively, and soy lecithin, Tween 80, and whey protein isolate (WPI) as emulsifiers. WPI promoted the production of NLC with larger particle size, lower physical stability, and lower IE and LC, compared with other emulsifiers. The melting range of the resulting NLC was within a suitable range for incorporation in foods, with a peak melting temperature above body temperature.
PubDate: 2023-09-01
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- Effect of Transglutaminase on Structure and Gelation Properties of Mung
Bean Protein Gel-
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Abstract: The aim of this study was to investigate the effect of transglutaminase (TGase) treatment on structure and gelation properties of mung bean protein gel (MBPG). Structure properties for MBPG were determined by surface hydrophobicity, free sulfhydryl groups, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Fourier transform infrared spectra (FTIR), intermolecular forces and scanning electron microscopy (SEM). And the gelation properties of MBPG were characterized by rheological properties, textural properties, and water holding capacity (WHC). TGase treatment reduced surface hydrophobicity and free sulfhydryl group content of MBPG. SDS-PAGE showed that TGase cross-linking caused the protein band of TGase-induced MBPG to become shallow or disappear, especially 50.1 kDa band. In addition, TGase treatment changed the secondary structure of MBPG, with a reduction in β-sheet and an increase in β-turn and random coil. Intermolecular forces analysis manifested that covalent cross-linking and disulfide bonds were the primary forces involved in TGase-induced MBPG, and TGase treatment limited non-covalent interactions. SEM images indicated that the network structure of TGase-induced MBPG was more compact with smaller and more uniform pores than that of the control, especially at 30 U/g. Compared with the control, storage modulus (G′), hardness, chewiness, springiness, cohesiveness and WHC of 30 U/g TGase-induced MBPG reached the maximum of 45537 Pa, 1337.59 g, 1111.43, 0.99, 0.93, 87.0%, respectively. The results of this study showed that TGase treatment was a reliable method to improve the gelation properties of MBPG, especially at 30 U/g. Graphical
PubDate: 2023-09-01
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- Modulating the Assembly of Egg Yolk Granule-Based Delivery Systems using
NaCl: Physicochemical Properties and Curcumin Bioactivity-
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Abstract: Abstract Our previous study demonstrated the potential of yolk granules for the encapsulation and delivery of lipophilic bioactive compounds. In this work, by modulating reassembly of granules using NaCl, curcumin was successfully encapsulated in reassembled granules, resulting in formation of nanoparticles (Gra-Cur NPs). It has been found that curcumin was mainly bound to the granules through hydrophobic interactions. The encapsulated curcumin was in an amorphous state. The Gra-Cur NPs exhibited good dilution, storage, and thermal stabilities. The UV-light stability of curcumin was significantly improved after encapsulation. The encapsulated curcumin had similar or better free radical scavenging activity than curcumin dissolved in organic solvent. The anti-proliferation activity against HT-29 cells of encapsulated curcumin was higher than that of curcumin dissolved in DMSO. The encapsulated curcumin also had better bioavailability, as shown by an Caco-2 cell model. The findings of this study may facilitate the design, fabrication, and application of granule-based delivery systems.
PubDate: 2023-09-01
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- V-amylose Nanocarriers Complexed with Debranched Sweet Potato Starch:
Structural Characteristics and Digestibility-
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Abstract: Abstract V-amylose, consisting of crystal aggregates of nanometric size, is attracting great attention due to its encapsulating capacity utilized as a superior delivery system of bioactive compounds. Debranched starches (DSs) possess remarkable self-assembling properties to enhance the formation of V-amylose, but the effect of debranching degree on the conformational properties of the DSs has yet systematically investigated. In this study, the molecular structural characteristics of the DSs with different debranching degrees and their complexing ability with lauric acid (LA) and in vitro digestibility were investigated. The DSs displayed a broad/trimodal molecular weight (MW) distribution and comprised three types of glucan molecules with different degrees of polymerization (DP). The proportions of chains with DP 19–22 and 49–67 in the DSs increased with increasing debranching degree, while the proportion of chains with DP 1554–4252 decreased. The complexing indices were positively associated with the debranching degree. A combination of V- and B-type polymorphs with increased crystallinity were detected in the DSs-LA mixtures compared to their native counterpart, reflecting the formation of crystalline structures of single-helical V-amylose and amylose double helices. The crystallinities were facilitated by the effect of the DSs and were strongly related to the increased resistance to digestion. These results can help to elucidate the effect of partially debranched starches on V-amylose formation as a delivery system of bioactive compounds.
PubDate: 2023-09-01
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- Effect of 10 MeV Electron Beam Irradiation on the Structure and
Functional Properties of Wheat Starch-
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Abstract: Abstract Electron beam irradiation (EBI) is now an effective and eco-friendly method to modify the properties of starch. In this study, wheat flour was irradiated at 10 MeV/up to 25 kGy of the electron beam, to analyze the effects of EBI on functional properties and the structure of wheat starch. The functional properties of wheat flour treated by EBI showed an increase in solubility from 15.19% to 50.48%, an increase in water/oil adsorption from 77.67% and 75% to 88.33% and 89.9%, and a decrease in swelling from 12.73 g/g to 5.98 g/g compared to the unirradiated wheat flour. EBI also decreased the rapidly digestible starch and therefore, increase the slowly digestible starch and resistant starch content. The structure of starch was characterized by scanning electron microscopy (SEM), polarized light microscopy (PLM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR), indicating that the long-range crystal structure and short-range ordered structure of wheat starch by EBI decreased. Our results, therefore, may provide some detailed understanding of functional property changes of high starch-based foods by electron beam irradiation treatment technology.
PubDate: 2023-09-01
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- Switchable pH-responsive Biopolymeric Stabilizers Made by Sonothermal
Glycation of Sodium Caseinate with κappa-carrageenan-
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Abstract: Abstract Food-approved biopolymeric stabilizers that can construct stable emulsions, but destabilize on purpose using a specific stimulus like pH change would be of great importance to food and pharmaceutical industries (bioactive delivery). However, such edible stabilizers are reasonably rare, since they must possess superb interfacial activity (rapid, robust, and reversible adsorption at the oil/water interface) to be efficient in the stabilization of such unique systems. Herein, we report the formation of sodium caseinate (SC)-κappa-carrageenan (kC) conjugates that can offer such stabilizing ability. SC-kC conjugates were prepared by wet-heating Maillard reaction after sonication pre-treatments (400 W, 20 kHz) for 10, 20, and 30 min. The SC-kC conjugation was confirmed by Fourier transform infrared spectroscopy, CD spectra, and glycation degree (GD). With increased sonication duration, a higher GD (59.75 ± 0.69% in 30 min) was observed, which led to an improved interfacial activity (higher adsorption quantity and rate at interface), lower particle size (< 500 nm) as well as higher emulsifying activity and stability indices. It was observed that the emulsion prepared with the 30 min ultrasonic conjugate had the lowest mean droplet size (1.65 ± 0.10 μm) and polydispersity index (0.46 ± 0.00) along with the highest absolute zeta potential value (-35.76 ± 0.54 mV). Furthermore, it was found that sonothermal glycation with kC empowered the SC to fabricate emulsions with excellent pH-responsive behaviors where it can be easily switched on (pH = 7) and off (pH = 4.5) over four cycles and remain stable with further emulsification. Therefore, unique emulsion systems with attributes desired for many applications can be fabricated by SC-kC conjugates.
PubDate: 2023-09-01
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- Phytoglycogen to Enhance the Solubility and in-vitro Permeation of
Resveratrol-
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Abstract: Abstract This study investigated the capability of phytoglycogen (PG) to improve the water-soluble amount and bioavailability of resveratrol (RES). RES and PG were incorporated through co-solvent mixing and spray-drying to form PG-RES solid dispersions. The soluble amount of RES of PG-RES solid dispersions reached 289.6 μg/mL at PG:RES ratio of 50:1, compared with 45.6 μg/mL for RES alone. X-ray powder diffraction and Fourier-transform infrared spectroscopy tests suggested a significant reduction of RES crystallinity in PG-RES solid dispersions and the formation of hydrogen bonds between RES and PG. Caco-2 monolayer permeation tests showed that, at low RES loading concentrations (15 and 30 μg/mL), PG-RES solid dispersions achieved greater permeation of RES (0.60 and 1.32 μg/well, respectively) than RES alone (0.32 and 0.90 μg/well, respectively). At an RES loading of 150 μg/mL, PG-RES solid dispersion realized RES permeation of 5.89 μg/well, suggesting the potential of PG in enhancing the bioavailability of RES.
PubDate: 2023-09-01
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- Effects of Rehydration Time, Temperature and Ultrasound Treatment on
Rehydration, Quality and Structure Properties of Low Moisture Texturized
Soybean Protein-
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Abstract: Abstract This study investigated effects of rehydration time, temperature, and ultrasound treatment on rehydration rate (RR), water holding capacity (WHC), color, composition (protein content and soluble sugar content), molecular weight distribution (MWD), thermal properties and microstructure of TSP (texturized soybean protein made under low moisture condition). The increase in rehydration time and temperature increased RR, WHC, leading to loss of color, protein and soluble sugars of rehydrated TSP. The enhancement of temperature augmented the porosity of the microstructure, decreased the thermal stability, but did not change the molecular weight distribution of proteins of rehydrated TSP. After TSP was rehydrated for 20 min without ultrasound treatment, The RR and WHC curves were basically stable, and the loss of protein content reached a constant. And the rehydrated TSP at 40℃ for 20 min had a higher sensory score than other groups without ultrasound. Ultrasound further enhanced RR and WHC and shortened the time for TSP to reach water absorption saturation (15 min). Ultrasound had no significant effect on the protein content of rehydrated TSP, but reduced the soluble sugar content. There was the maximum sensory score of rehydrated TSP with ultrasound treatment at 40℃ for 15 min. These results provide theoretical support for the rehydration of TSP in food industry processes.
PubDate: 2023-09-01
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- Effect of Fatty Acids with Different Chain Lengths and Degrees of
Unsaturation on Film Properties of Potato Starch-Fatty Acids Films for
Chicken Packaging-
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Abstract: Abstract The effects of fatty acids with different chain lengths (10–18 carbons) and degrees of unsaturation (0–2) on the moisture content, water solubility, water vapor permeability (WVP), light transmission, thickness, in vitro digestion and release properties of potato starch-fatty acid films (PS-FA films) were studied, and the PS-FA films were used for packing chicken meat. Results showed that PS-FA films had lower moisture content, water solubility, WVP, light transmission, and vitamin C release values and higher IR spectra ratio R1047/1022, slowly digestible starch and resistant starch contents than potato starch film (PS film), except for PS-oleic acid and PS-linoleic acid films. Compared with other PS-FA films, the PS-lauric acid film (PS-LA film) with 12-carbon FAs showed better film properties. Moreover, the chicken meat quality assessment showed that the weight loss, pH, total bacterial count and total volatile base nitrogen of PS-FA films were lower than PS film, especially for PS-LA film. Findings indicated that the appropriate FA structures could be used to produce PS-FA films with enhanced performance for food packaging.
PubDate: 2023-09-01
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- Effect of Commercially Utilized Thermal Treatments on Interactions Between
Casein and β-lactoglobulin and Their Digestion in Simulated
Gastrointestinal Environment-
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Abstract: The objective of present study is to investigate and compare the effects of different commercially utilized thermal treatments of 65 ℃ for 30 min, 80 ℃ for 15 s, 95 ℃ for 5 min and 137 ℃ for 5 s on the interactions between casein and β-lactoglobulin (β-LG) and the consequent digestion profile in simulating gastrointestinal (GI) environments. It was demonstrated, by the measurements of turbidity, polyacrylamide gel electrophoresis, and molecular affinity between β-LG and casein, that high temperature (95 ℃ and 137 ℃) or long heating time (30 min) significantly increased the turbidity of β-LG and casein mixture, promoted the self-aggregates of β-LG, and enhanced the complexation of β-LG and κ-casein, as a result of the intermolecular thiol and disulfide interchange, as well as the strong affinity between β-LG and casein. Comparatively, the pasteurization of about 80 ℃ for 15 s decreased the turbidity of the model mixture of β-LG and casein, and did not lead to β-LG and κ-casein aggregates cross-linked with disulfide. In addition, the affinity of the heated casein and β-LG with the thermal treatment of 80 ℃ for 15 s was the lowest compared with the ones shown in the other three treatments. In the simulated gastric condition, the model mixture of β-LG and casein heated at 80 ℃ for 15 s appeared to be digested faster compared with the one treated at 137 ℃ for 5 s. However, this phenomenon could not be observed obviously in the simulated intestinal condition. Therefore, the formation of disulfide between the reactive thiols in denatured β-LG and κ-casein accounts mainly for the β-LG self-aggregates and the β-LG-casein complexes in the commercially utilized thermal treatments. In terms of interactions between β-LG and casein, pasteurization may be considered as an ideal thermal treatment of milk for heating processing, without significant impact on product properties. Graphical
PubDate: 2023-09-01
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- Effects of Microwave Treatment on the Physicochemical Properties and
Edible Qualities of Germ-Remaining Rice-
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Abstract: Abstract In this study, germ-remaining rice (GRr) was treated with microwave irradiation for 1, 2, or 3 min to extend its shelf-life. The application of microwave irradiation significantly decreased the activity of lipase in GRr, due to the thermal effects and the removal of the metallic prosthetic group in lipase. Microwave irradiation did not change the germ-remaining ratio but decreased the crack ratio and broken rice ratio. Besides, the decreasing in moisture content and water mobility, as well as the denaturation of rice protein, enhanced the interactions between swollen starch granules and hydrated proteins, resulting in increased viscosity of rice flour. The inactivation of lipase delayed the oxidation of lipids in GRr during 120-day of storage, and the extensive treatment for 3 min facilitated the deterioration of GRr while proper treatment for 1 min preserved the edible qualities and sensory properties. The results of this study provide insights into successful utilization of microwave treatment to extend the shelf-life of GRr.
PubDate: 2023-09-01
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- Inhibitory Mechanisms of Plant Volatile 1-Octanol on the Germination of
Aspergillus Flavus Spores-
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Abstract: Abstract Biogenic volatile organic compounds have promising applications in controlling fungal spoilage of postharvest agro-products and perishable foods. In a previous study, we discovered that the plant volatile 1-octanol showed considerable potential for controlling Aspergillus flavus growth. In this study, the inhibitory effects of 1-octanol on the germination of A. flavus spores were investigated. A. flavus spores did not germinate when exposed to 1.5 µL/mL 1-octanol, and 3.5 µL/mL 1-octanol caused spore death. Biochemical analysis showed that 1-octanol caused a decrease in ergosterol and ATP content, and an increase in hydrogen peroxide and superoxide anion content in a dose-dependent manner. Transcriptomic analysis demonstrated that there were 4117 differentially-expressed genes in A. flavus spores exposed to 1.5 µL/mL 1-octanol, mainly enriched in metabolic pathways, steroid biosynthesis, secondary metabolite biosynthesis, ribosomes, glutathione metabolism, the mitogen-activated protein kinases signaling pathway, and pyruvate metabolism. Flow cytometry results showed that 1-octanol treatment resulted in hyperpolarization of the mitochondrial membrane potential, accumulation of reactive oxygen species, and apoptosis. TdT-mediated dUTP nick end labeling/4′,6-diamidino-2-phenylindole double staining and monodansylcadaverine staining results indicated that 1-octanol treatment resulted in DNA fragmentation and induced autophagy, respectively. These results provide new insights into the inhibitory mechanism of 1-octanol on A. flavus spore gemination and would facilitate the application of 1-octanol for the protection of postharvest agricultural products.
PubDate: 2023-08-11
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- Effect of Trehalose on the Properties of Potato Starch - Lycium barbarum
Polysaccharide Composite Gel-
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Abstract: In this study, the effect of trehalose on the structural and gelation properties of fresh and stored potato starch/Lycium barbarum polysaccharide (POS/LBP) composite gels was investigated. The pasting properties of the LBP/POS composite were modified by trehalose, where the pasting temperature, peak viscosity, trough viscosity, and final viscosity of the composite are all increased significantly with the addition of the trehalose in a concentration-dependent manner. The rheology properties of the POS/LBP gel were also significantly affected by trehalose but in a different way before and after storage. The addition of trehalose increased both the storage and loss modulus of the fresh gel but decreased those dynamic moduli after storage for 21 days at 4 °C. Moreover, trehalose had minimal effect on the hardness of the fresh gel but significantly weakened it after storage. SEM analysis further confirmed that the stored composite with 10% trehalose had a porous and thin network compared to the control. On the other hand, the composite gel had a lower syneresis value when trehalose was added. This effect was greatly enhanced during repeated freezing and thawing cycles, suggesting the ability of trehalose to improve the gel stability during storage. As revealed by FTIR and XRD analysis, the relative crystallinity and short-range order of the POS during storage were decreased by trehalose, suggesting that trehalose could potentially inhibit the amylose retrogradation. Overall, this study showed that trehalose is a promising functional ingredient for modifying the structural and gel properties of POS-based gel. Graphical
PubDate: 2023-08-04
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- Physics of Starch System: Rheological and Mechanical Properties of
Hydrothermally Modified Elephant Foot Yam Starch-
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Abstract: Abstract Heat moisture treatment (HMT) was used to improve the functionalities of elephant foot yam starch (EFYS) by using selected heating techniques such as hot air oven (HAO), autoclave (AL), and microwave (MW). The swelling power and solubility were reduced significantly after HMT modification, whereas an increase in amylose content was detectable after HMT modification, and the maximum changes were identified in HAO-modified EFYS (28.48%) as compared to its native counterpart (18.01%). The study demonstrates that the maximum drop in peak viscosity (1045 cP) was perceived in HAO-modified EFYS, which confirms its thermostability as compared to native (1114 cP) and other treated starches (1059 to 1098 cP). All the starch pastes exhibited shear-thinning behavior, however, isothermal heating of starch paste at 95 °C revealed a rise in apparent viscosity with increasing shear rate in all HMT-modified EFYS. Large amplitude oscillatory shear (LAOS) measurements of modified starch samples showed the predominating solid-like behavior in modified EFYS. The HAO-treated EFYS had the highest elasticity of the others, which represents the enhanced structural rigidity due to the formation of transient network structures. Furthermore, Lissajous-Bowditch plots confirmed the early deviation of the structural integrity from elastic to viscous behavior in HAO-treated EFYS. Overall, the HAO-modified EFYS showed significant improvement in functionalities and structural integrities under high shear and high oscillation strain, which infers its potential industrial applications. Based on our results, we propose specific physical models suggesting the effect of molecular structural arrangements of amylose and amylopectin expressing the essential rheological differences between native and HMT EFYS.
PubDate: 2023-08-01
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- Non-covalent Complexes Between β-lactoglobulin and Baicalein:
Characteristics and Binding Properties-
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Abstract: Abstract To better obtain protein–flavonoid complexes owned more powerful functions, non-covalent complexes between β-lactoglobulin (β-LG) and baicalein/p-coumaric acid/polydatin (Bai/p-CA/PD) were investigated. The properties of these complexes were investigated using ultraviolet (UV)-visible spectra, circular dichroism (CD) spectra, Fourier-transform infrared (FTIR), etc.; the non-covalent complexes' parameters were evaluated using fluorescence spectra and molecular docking. The peaks shifted in UV, and α-helix decreased in CD, confirming the formation of the complexes. The blue shift of amide bands and -OH peaks in FTIR indicated that the hydrophobic interactions and hydrogen bonds were strengthened. Differential scanning calorimetry (DSC) indicates that β-LG-Bai had heat resistance (improved melting peak: 188.8 °C to 195.8 °C). ABTS assay showed synergistic effects of β-LG-Bai (76.7% [β-LG-Bai] > 70.6% [β-LG + Bai], 50 μmol/L). Bai had a higher quenching ability (70.81%) than p-CA (38.69%) and PD (40.95%). The affinity order was Bai > PD > p-CA, and molecular docking binding energy (-6.02 [Bai], -5.39 [p-CA], and -5.4 kcal/mol [PD]) verified the affinity relationship. The binding constants increased with increasing temperature (2.166, 4.581, and 5.741, × 105 L/mol, for 298, 308, and 318 K, respectively), indicating that a higher temperature promoted stabilization of β-LG-Bai, which is consistent with hydrophobic interactions in molecular docking being the driving force of the β-LG-Bai complexes. The β-LG-Bai non-covalent complexes own synergistic antioxidant effects and improved high-temperature stability characteristics, which may have promising applications in functional foods.
PubDate: 2023-07-27
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