The influence of a hydroxypropyl-beta-cyclodextrin composite on the gelation of kappa-carrageenan

Enhancement of gel characteristics of curdlan thermo-irreversible gels by β-cyclodextrin and its possible mechanisms

In this study, the influences of various concentrations of β-cyclodextrin (β-CD) on the gelation properties of curdlan thermo-irreversible gels were evaluated. The results revealed that water-holding capacity and freeze-thaw stability of the curdlan/β-CD complex gels initially increased but then decreased with increasing β-CD concentration, with the curdlan gel containing 1 % (w/v) β-CD demonstrating the best performance. Moreover, textural characteristics including hardness, gumminess, cohesiveness, and chewiness exhibited similar trends, but springiness showed minor effect. Compared with the pure curdlan gel, the curdlan/β-CD mixed gels exhibited better elastic behavior and greater thermal stability but lower crystallinity. Additionally, scanning electron microscopy (SEM) images of the curdlan/β-CD composite gels revealed fine network structures with relatively continuous pores. The intermolecular hydrogen bonds between curdlan and β-CD were responsible for the enhanced gel properties. Thus, these data suggest that the inclusion of β-CD ameliorates the texture and stability of the curdlan gel by forming hydrogen bonds.

Advances in the preparation and application of cyclodextrin derivatives in food and the related fields

Cyclodextrin (CD) derivatives have recently gained worldwide attention, which have versatile advantages and restrained the defects of parent CDs. The superior properties of CD derivatives in encapsulation, stabilization, and solubilization facilitate their application in food, biomedicine, daily chemicals, and textiles. In this review, the preparation, classification, and main benefits of CD derivatives are systematically introduced. By introducing targeted groups into the parent CD molecule, they exhibit significant improvement in their required characteristic. Besides, the important point closely related to application, the safety assessment, has also been highlighted. Most tested CD derivatives have been verified to be relatively safe in a limited dosage. Then, the applications of CD derivatives have been described in detail from the food to its related field. In food field, CD derivatives play an important role in the stability and bioavailability of bioactive compounds, control flavor release, and improve the antimicrobial and antioxidant properties of packaging materials. These advantages can also be expanded to the related field, offering innovative solutions that enhance product quality, human health, and environmental sustainability. This review highlights the broad applications and potential of CD derivatives, underscoring their role in driving advancements across multiple industries.

Food nanotechnology: opportunities and challenges

Food nanotechnology, which applies nanotechnology to food systems ranging from food production to food processing, packaging, and transportation, provides tremendous opportunities for conventional food science and industry innovation and improvement. Although great progress and rapid growth have been achieved in food nanotechnology research owing to the unique food features rendered by nanotechnology, at a fundamental level, food nanotechnology is still in its initial stages and the potential adverse effects of nanomaterials are still a controversial problem that attract public attention. Food-derived nanomaterials, compared to some inorganic nanoparticles and synthetic organic macromolecules, can be digested rapidly and produce similar digestion products to those produced normally, which become the mainstream and trend for food nanotechnology in practical applications, and are expected to be a vital tool for addressing the security problem and easing public concerns. These food-derived materials enable the favourable characteristics of nanostructures to be combined with the safety, biocompatibility, and bioactivity of natural food. Very recently, diverse food-derived nanomaterials have been explored and widely applied in multiple fields. Herein, we thoroughly summarize the fabrication and development of nanomaterials for use in food technology, as well as the recent advances in the improvement of food quality, revolutionizing food supply, and boosting food industries based on foodborne nanomaterials. The current challenges in food nanotechnology are also discussed. We hope this review can provide a detailed reference for experts and food manufacturers and inspire researchers to participate in the development of food nanotechnology for highly efficient food industry growth.

Investigating Texture and Freeze-Thaw Stability of Cold-Set Gel Prepared by Soy Protein Isolate and Carrageenan Compounding

In this study, the purpose was to investigate the effects with different concentrations of carrageenan (CG, 0-0.30%) on the gel properties and freeze-thaw stability of soy protein isolate (SPI, 8%) cold-set gels. LF-NMR, MRI, and rheology revealed that CG promoted the formation of SPI-CG cold-set gel dense three-dimensional network structures and increased gel network cross-linking sites. As visually demonstrated by microstructure observations, CG contributed to the formation of stable SPI-CG cold-set gels with uniform and compact network structures. The dense gel network formation was caused when the proportion of disulfide bonds in the intermolecular interaction of SPI-CG cold-set gels increased, and the particle size and zeta potential of SPI-CG aggregates increased. SG20 (0.20% CG) had the densest gel network in all samples. It effectively hindered the migration and flow of water, which decreased the damage of freezing to the gel network. Therefore, SG20 exhibited excellent gel strength, water holding capacity, freeze-thaw stability, and steaming stability. This was beneficial for the gel having a good quality after freeze-thaw, which provided a valuable reference for the development of freeze-thaw-resistant SPI cold-set gel products.

Comprehensive investigation into the effects of yeast dietary fiber and temperature on konjac glucomannan/kappa-carrageenan for the development of fat analogs

In this study, yeast dietary fiber (YDF) was incorporated into konjac glucomannan/kappa-carrageenan (KGM/κ-KC) for the development of fat analogs, and the impact of YDF on the gelation properties and behavior of KGM/κ-KC composite gels was assessed. YDF improved the composite gel whiteness value, and affected the mechanical properties of the composite gel, especially enhancing its hardness, and decreasing its chewiness, elasticity, and gel strength, making it more similar to porcine back fat. When the yeast dietary fiber content was 0.033 g/mL and the heating temperature was 80 °C (T80-2), the textural properties of the composite gel were closest to porcine back fat. The frequency sweep results suggested that YDF incorporation led to enhancement of the intermolecular interaction and intermixing and interaction among more easily at higher processing temperatures (80 °C and 90 °C). By scanning electron microscopy, the fatty surface of porcine back fat was flat and covered with a large amount of oil, while KGM/κ-KC/YDF composite gels developed a dense, stacked network structure. YDF caused more fragmented, folded, and uneven structures to emerge. Overall, YDF could influence the gel behavior of KGM/κ-KC composite gels, and change their colors and mechanical properties. This work could serve as a guide for preparing fat analogs with KGM/κ-KC composite gels.

β-Cyclodextrin Modified Hydrogels of Kappa-Carrageenan for Methotrexate Delivery

This work is aimed at developing a kappa-carrageenan (kCR) gel with increased methotrexate (MTX) content. β-Cyclodextrin (βCD), which is able to inclusion complex formation with MTX, has been used to increase the drug concentration in the hydrogel. The rheological behavior of the designed gels was investigated and the influence of MTX and βCD on the viscoelastic properties of kCR gel was studied in detail. The effect of βCD and its concentration on the MTX-releasing rate from the kCR gels was examined. The properties of kappa- and iota-carrageenans loaded with MTX were compared and the differences observed were explained in terms of different binding affinities of MTX to these polymers. The obtained gels provided desirable viscoelastic properties useful for topical application.

Pickering Emulsion Stabilized by β-Cyclodextrin and Cinnamaldehyde/β-Cyclodextrin Composite

A Pickering emulsion was prepared using β-cyclodextrin (β-CD) and a cinnamaldehyde (CA)/β-CD composite as emulsifiers and corn oil, camellia oil, lard oil, and fish oil as oil phases. It was confirmed that Pickering emulsions prepared with β-CD and CA/β-CD had good storage stability. The rheological experiments showed that all emulsions had G' values higher than G″, thus confirming their gel properties. The results of temperature scanning rheology experiments revealed that the Pickering emulsion prepared with β-CD and CA/β-CD composites had high stability, in the range of 20-65 °C. The chewing properties of Pickering emulsions prepared by β-CD and corn oil, camellia oil, lard, and herring oil were 8.02 ± 0.24 N, 7.94 ± 0.16 N, 36.41 ± 1.25 N, and 5.17 ± 0.13 N, respectively. The chewing properties of Pickering emulsions made with the CA/β-CD composite and corn oil, camellia oil, lard, and herring oil were 2.51 ± 0.05 N, 2.56 ± 0.05 N, 22.67 ± 1.70 N, 3.83 ± 0.29 N, respectively. The texture properties confirmed that the CA/β-CD-composite-stabilized-emulsion had superior palatability. After 28 days at 50 °C, malondialdehyde (MDA) was detected in the emulsion. Compared with the β-CD and CA + β-CD emulsion, the CA/β-CD composite emulsion had the lowest content of MDA (182.23 ± 8.93 nmol/kg). The in vitro digestion results showed that the free fatty acid (FFA) release rates of the CA/β-CD composite emulsion (87.49 ± 3.40%) were higher than those of the β-CD emulsion (74.32 ± 2.11%). This strategy provides ideas for expanding the application range of emulsifier particles and developing food-grade Pickering emulsions with antioxidant capacity.

Comparative study on the effect of inhibitory methods on the color and gelation properties of alkali induced heat-set konjac gel from Amorphophallus bulbifer

As a newly superior konjac variety, the Amorphophallus bulbifer (A. bulbifer) was easily browning during the alkali-induced process. In this study, five different inhibitory methods, such as citric-acid heat pretreatment (CAT), mixed with citric acid (CA), mixed with ascorbic acid (AA), mixed with L-cysteine (CYS), and mixed with potato starch (PS, containing TiO2), were separately used to inhibit the browning of alkali-induced heat-set A. bulbifer gel (ABG). The color and gelation properties were then investigated and compared. Results showed that the inhibitory methods had significant influences on the appearance, color, physicochemical properties, rheological properties, and microstructures of ABG. Among them, the CAT method not only significantly inhibited the browning of ABG (ΔE value dropped from 25.74 to 14.68) but also improved the water-holding capacity, moisture distribution, and thermal stability without damaging the textural properties of ABG. Moreover, SEM revealed that both CAT and adding PS methods could exhibit the more dense gel network structures of ABG than other methods. It was reasonable to conclude that ABG-CAT offered a superior method to prevent browning compared to the other methods based on the texture, microstructure, color, appearance, and thermal stability of the product.

Chemical modification of κ-carrageenan with poly(2-hydroxypropylmethacrylamide) through microwave induced graft copolymerization: Characterization and swelling features

In the last decade, interest in the development of new graft copolymers based on natural polysaccharides has grown remarkably due to their potential applications in the wastewater treatment, biomedical, nanomedicine, and pharmaceutical fields. Herein, a novel graft copolymer of κ-carrageenan with poly(2-hydroxypropylmethacrylamide) (κ-Crg-g-PHPMA) was synthesized using a 'microwave induced' technique. The synthesized novel graft copolymer has been well characterized in terms of FTIR, ¹³C NMR, molecular weight determination, TG, DSC, XRD, SEM, and elemental analyses, taking κ-carrageenan as a reference. The graft copolymers' swelling characteristics were investigated at pH 1.2 and 7.4. The results of swelling studies displayed that the incorporation of PHPMA groups on κ-Crg provides increasing hydrophilicity. The effect of PHPMA percentage in the graft copolymers and pH of the medium on the swelling percentage was studied and the findings exhibited that swelling ability increased with the increment in PHPMA percentage and pH of the medium. The best swelling percentage was attained at pH = 7.4 and a grafting percentage of 81 % reaching 1007 % at the end of 240 min. Moreover, cytotoxicity of the synthesized κ-Crg-g-PHPMA copolymer was assessed on the L929 fibroblast cell line and obtained to be non-toxic.

GelMA/κ-carrageenan double-network hydrogels with superior mechanics and biocompatibility

Hydrogels are crosslinked hydrophilic polymer networks of high-water content. Although they have been widely investigated, preparing hydrogels with excellent mechanical properties and biocompatibility remains a challenge. In the present work, we developed a novel GelMA/κ-carrageenan (GelMA/KC) double network (DN) hydrogel through a dual crosslinking strategy. The three-dimensional (3D) microstructure of KC is the first network, and covalently crosslinked on the κ-carrageenan backbone is the second network. The GelMA/KC hydrogel shows advantages in physical properties, including higher compression strength (10% GelMA/1% KC group, 130 kPa) and Young's modulus (10% GelMA/1% KC group, 300), suggesting its excellent elasticity and compressive capability. When using a higher concentration of GelMA, the hybrid hydrogel has even higher mechanical properties. In addition, the GelMA/KC hydrogel is favorable for cell spreading and proliferation, demonstrating its excellent biocompatibility. This study provides a new possibility for a biodegradable and high-strength hydrogel as a new generation material of orthopedic implants.

Pickering emulsions stabilized by β-cyclodextrin and cinnamaldehyde essential oil/β-cyclodextrin composite: A comparison study

Here, a cinnamaldehyde essential oil (CEO)/β-Cyclodextrin (β-CD) composite with a high embedding rate (91.74 ± 0.82%) was prepared. Its structure was characterized by Fourier transform infrared spectrometer (FT-IR) and X-ray diffractometer (XRD). Pickering emulsions prepared by β-CD and CEO/β-CD at different concentrations (1-5%) were comparatively investigated. The CEO/β-CD emulsions had better storage stability. Rheological results confirmed the emulsions were all gel-like elastic emulsions and had shear thinning phenomenon. Fluorescence microscopy and scanning electron microscopy (SEM) results confirmed that the most of excessive β-CD was adsorbed on the surface of emulsion droplets as crystals, formed thick protective shell in β-CD emulsions, while the most of excessive composites were distributed in the aqueous phase forming a stable network structure in CEO/β-CD emulsions. It caused these two emulsions had different rheological properties, and different changing trends in droplet size.

Catechin/β-cyclodextrin complex modulates physicochemical properties of pre-gelatinized starch-based orally disintegrating films

The study aimed to develop pre-gelatinized starch-based orally disintegrating films (ODFs) containing catechin/β-cyclodextrin (CAT/β-CD) complex and to evaluate the influence of the complex on the physicochemical properties of the ODFs. SEM images showed that a compacter and more homogeneous ODFs were formed due to interactions between starch matrix and CAT/β-CD. FTIR spectra demonstrated that the interactions between starches or starch and CAT/β-CD were enhanced by hydrogen bonds. Thermal stability of ODFs was improved by incorporating CAT/β-CD, its peak decomposition temperature was enhanced from 310.74 to 321.83 °C. Tensile strength was increased from 11.597 ± 0.153 to 22.172 ± 0.752 MPa, while elongation at break decreased by from 11.233% ± 1.079% to 3.633% ± 0.058%. The prepared ODFs have an acceptable in vitro disintegration time, which were between 9.03 ± 0.79 s and 42.23 ± 1.76 s. Antimicrobial test showed that ODFs incorporating CAT/β-CD inhibited the growth of S. aureus and S. mutans successfully. The limited release of CAT molecules from the ODFs was also found. In addition, the ODFs have excellent antioxidant capacity. Its antioxidant activity remained at around 70% after 28 days of storage. The study indicated that the combination of ODFs and β-CD complex have a high potential for the delivery of natural active ingredients.

Xylitol and Maltitol Improve the Rheological Property of Kappa-Carrageenan

To further extend the use of κ-carrageenan (κ-C) in real food systems (such as beverages), the understanding of gelation properties of κ-C with the presence of food ingredients is critical. The effects of xylitol and maltitol (up to 30 wt %) on the rheological and structural properties of κ-C were inspected by means of rheometer and Fourier transform infrared (FTIR). With the addition of xylitol, the gelation temperature increased from 44.1 to 57.3 °C, while the gelation temperature increased from 44.1 to 61.4 °C in maltitol systems. With the increasing concentration of both xylitol and maltitol, the values of fractal dimension d_f and complex modulus G* of κ-C increased, while the relaxation exponent n decreased from 0.87 to 0.39 of xylitol and 0.87 to 0.78 of maltitol, respectively. These indicated that the gel networks of aqueous κ-C were improved by the addition of xylitol and maltitol. The FTIR results showed that the interaction between κ-C and these polyols contributed to the increase of hydrogen bonds. The effects of maltitol on κ-C were stronger than those of xylitol because of more equatorial-OH bonds in maltitol. These findings contribute to a better understanding of the gelation processes of κ-C/polyols systems.

High-Amylose Corn Starch/Konjac Glucomannan Composite Film: Reinforced by Incorporating β-Cyclodextrin

Glycerol-plasticized high-amylose corn starch/konjac glucomannan (HCS/KGM) composite films incorporated with various concentrations of β-cyclodextrin (β-CD) were prepared and investigated for structural, mechanical, and physical properties. The results of X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analyses, and scanning electron microscopy indicated that β-CD excluded from the polymer chains and aggregated to form crystals during film formation, which drove HCS to interact with KGM more compactly. The thickness and transparency of the films increased after β-CD was incorporated. More associations of HCS/KGM enhanced the mechanical properties and reduced the moisture content of the films. The water vapor permeability of the HCS/KGM composite film was also improved significantly with the incorporation of β-CD. The enhanced association between biopolymers in the presence of β-CD will advance the development of a degradable active composite packaging film.

Fabrication of kappa-carrageenan hydrogels with cinnamon essential oil/hydroxypropyl-β-cyclodextrin composite: Evaluation of physicochemical properties, release kinetics and antimicrobial activity

A novel antimicrobial gel composed of κ-carrageenan (KC) and a cinnamon essential oil (CEO)/hydroxypropyl-β-cyclodextrin (HPCD) composite was developed. The CEO/HPCD composite was characterized by UV-visible spectrophotometry and Fourier-transform infrared spectroscopy (FT-IR), and the changes in the principal components of CEO upon encapsulation by HPCD were analyzed by gas chromatography-mass spectrometry (GC-MS). The physicochemical properties, release kinetics and antimicrobial activity of the fabricated gels were investigated. The hardness of the KC gels increased with composite concentration in the range of 1.0-3.0% (w/v) and thereafter decreased. A similar trend was observed for the gumminess and chewiness, whereas the gel springiness remained essentially constant. The CEO/HPCD composite also enhanced the fluidity of the system, and the syneresis was positively correlated with the composite concentration. The controlled release of CEO from the gels was affected by the relative humidity (RH) and CEO content. The Ritger-Peppas model indicated that the CEO release kinetics from the gels proceeded through a combination of diffusion and framework erosion. The KC gel containing 5% CEO/HPCD composite displayed effective antimicrobial activity, prolonging the shelf life of sliced bread by at least two days. The reported gels may have potential applications as a promising material for food preservation.

Influence of two functional dextrins on the gel properties of kappa-carrageenan

The physicochemical properties of κ-carrageenan (KC) can be improved by incorporation with small-molecule cosolvents. The texture and rheological properties, micromorphology, and crystallinity of KC incorporating indigestible dextrin (IDD) and beta-limit dextrin (BLD) were investigated. The rheological properties and sol-gel transition temperatures of the gels were slightly improved and the hardness of KC gels was significantly increased after the two dextrins were mixed in. Fourier transform infrared spectroscopy results indicated hydrogen-bonding interactions were strengthened in the presence of the dextrins. Confocal laser scanning microscope images revealed that a more homogenous structure was formed of the KC gel after the addition of dextrins. Moreover, X-ray diffraction patterns indicated the crystallinity of KC gel decreased upon dextrin addition. At the same dextrin content, IDD exerted a greater influence than BLD. IDD contents exceeding 3% (w/w) led to undesirable effects, whereas up to 5% (w/w) of BLD could be added. The two dextrins affected the rearrangement of the KC random coils in the sol state, and facilitated aggregation of the KC chains during cooling to form gel network structures after gelation. Therefore, the appropriate addition of these two dextrins can improve the texture and stability of KC gels and expand their application in functional foods.