Evaluating the addition of xylooligosaccharides into alginate-gelatin hydrogels

Structural characterization of pure xylan from corncob and its effect on xylooligosaccharides yield after enzymatic hydrolysis

The structure of xylan plays a significant role in the degradation rate by xylanase to product xylooligosaccharides (XOS). In this study, xylan was extracted and purified from corncob, yielding two xylan fractions (WUAX-2, WUAX-3) with purities exceeding 90 %. The structures of WUAX-2 and WUAX-3 were characterized and hydrolysis efficiency was studied in relation to their structures. FT-IR results indicated that although xylan fractions had the same types of functional groups, WUAX-3 exhibited a higher level of -OH, CH, and CO groups compared to WUAX-2. NMR, the vibration signal of WUAX-2 and WUAX-3 was β-(1 → 4) -linked D-lignin unit β-D-xylopyran. X-ray diffraction results confirmed that WUAX-2 was a stable single-crystal structure. Meanwhile, the number of side-chains of WUAX-2 in the liquid was smaller than that of WUAX-3. WUAX-2 and WUAX-3 were hydrolyzed by a high-temperature-resistant xylanase (XynA) and yielded primarily xylohexaose (X6), xylotriose (X3), and xylobiose (X2). The XOS yield of WUAX-2 was 4.25 times higher than that of WUAX-3. These results indicate that the fewer xylan side-chains and substituent groups of xylan, the higher the enzymatic hydrolysis efficiency. The findings provide a deep understanding of the effect of xylan structure on the enzymatic behavior.

Mechanisms of gel formation in collagen/hydroxypropyl methylcellulose aqueous mixtures below the threshold for macroscopic phase separation

The gelation mechanisms of aqueous collagen/hydroxypropyl methylcellulose (HPMC) mixtures were investigated below the macroscopic phase separation threshold. This study examines the interactions between collagen and HPMC, the phase behavior, and the resulting gel and structural properties. The results indicate that at low mixing concentrations, hydrogen bonding between collagen and HPMC, along with excluded volume effects, induces microscopic phase separation under partially phase-compatible conditions. As the HPMC concentration increases, the phase morphology transitions from a collagen-dominant phase to an HPMC-dominant phase, accompanied by enhanced hydrogen bonding between the two components. Gel formation in these mixtures follows a two-step gelation process, with HPMC influencing gelation kinetics. The excluded volume effect results in collagen concentration, while an optimal HPMC concentrations facilitates the entanglement of collagen chains, promoting the formation of α-helix, β-turn, and antiparallel β-sheet conformations, and ordered triple-helix structures, thereby enhancing gel properties. However, at excessively high HPMC concentrations, excessive hydrogen bonding and excluded volume effects hinder the formation of triple-helix structures, leading to a gel network with reduced mechanical properties. This study highlights the critical role of HPMC concentration in modulating collagen gel formation and provides insights into the complex interactions governing gelation in protein-polysaccharide systems.

Preservation of freshly-cut lemon slices using alginate-based coating functionalized with antioxidant enzymatically hydrolyzed rice straw-hemicellulose

Food coatings are efficient preservative measures, a crucially needed approach to meet hunger growth as well as food management. In the current study, the construction of an efficient coating using alginate polymer fortified with antioxidant rice straw-hemicellulose hydrolysate was examined. Rice straw hemicellulose fraction was extracted under thermal alkaline conditions with a recovery percentage of 15.8%. The extracted hemicellulose fraction was enzymatically hydrolyzed with microbial xylanase with hydrolysis percentage of 53.8%. Characterization of the produced hydrolysate was performed with the aid of thin layer chromatographic analysis (TLC), high-performance liquid chromatographic analysis (HPLC), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) analysis. The reported data showed that xylobiose (240.68 mg/g) in addition to coumaric (383.33 µg/g) and ferulic acid (298.77 µg/g) as the main constituents of the carbohydrate and the polyphenolic contents, respectively. The hydrolysate possessed antioxidant capacity that significantly increased in a direct correlation with the concentration of the hydrolysate. Finally, the prepared coating solution effectiveness in the preservation of lemon slices against fungal growth was monitored up to 20 days with a significant concentration dependent decrease in weight loss and an increase in its antioxidant activity. The combination of xylooligosaccharide-rich rice straw hydrolysate with alginate-based coating not only improved the storage shelf-life of fresh fruits and vegetables but also provided microbial safety and potential benefits for human health.

Nanostarch-Stimulated Cell Adhesion in 3D Bioprinted Hydrogel Scaffolds for Cell Cultured Meat

Three-dimensional (3D) bioprinting has great potential in the applications of tissue engineering, including cell culturing meat, because of its versatility and bioimitability. However, existing bio-inks used as edible scaffold materials lack high biocompatibility and mechanical strength to enable cell growth inside. Here, we added starch nanoparticles (SNPs) in a gelatin/sodium alginate (Gel/SA) hydrogel to enhance printing and supporting properties and created a microenvironment for adherent proliferation of piscine satellite cells (PSCs). We demonstrated the biocompatibility of SNPs for cells, with increasing 20.8% cell viability and 36.1% adhesion rate after 5 days of incubation. Transcriptomics analysis showed the mechanisms underlying the effects of SNPs on the adherent behavior of myoblasts. The 1% SNP group had a low gel point and viscosity for shaping with PSCs infusion and had a high cell number and myotube fusion index after cultivation. Furthermore, the formation of 3D muscle tissue with thicker myofibers was shown in the SNP-Gel/SA hydrogel by immunological staining.

Ultrasonic-assisted glycosylation with κ-carrageenan on the functional and structural properties of fish gelatin

BACKGROUND

Fish gelatin (FG) has multifunctional properties similar to mammalian gelatin (MG), and it has been recognized as the optimal alternative to MG. While its poor surface-active and gelling properties significantly limit its application values, glycosylation has been successfully used to increase surface-active properties of FG, but the influence of ultrasonic-associated glycosylation (UAG) on the gelling and structural characteristics of FG is still rarely reported. This article explores UAG (100-200 W, 0.5-1 h) with κ-carrageenan (κC) on the functional properties (emulsifying, gelling and rheological properties) and structural characteristics of FG.

RESULTS

The longer time and higher power of ultrasonics accelerated the glycosylation reaction with an increase in glycosylation degree and browning index values. Compared with original FG, FG-κC mixture and bovine gelatin, UAG-modified FG possessed higher emulsification activity index, emulsion stability index, gel strength, hardness and melting temperature values. Among them, gelatin modified by appropriate ultrasonic conditions (200 W, 0.5 h) had the highest emulsifying and gelling properties. Rheological results showed that UAG contributed to the gelation process of gelatin with advanced gelation time and endowed it with high viscosity. Structural analysis indicated that UAG promoted κC to link with FG by the formation of covalent and hydrogen bonds, restricting more bound and immobilized water in the gels, exhibiting higher gelling properties.

CONCLUSION

This work showed that UAG with κC is a promising method to produce high gelling and emulsifying properties of FG that could replace MG. © 2023 Society of Chemical Industry.

The Effect of Packaging Methods, Storage Time and the Fortification of Poultry Sausages with Fish Oil and Microencapsulated Fish Oil on Their Rheological and Water-Binding Properties

The aim of the study was to investigate how liquid fish oil and microencapsulated oil additives influenced the rheological characteristics and the dynamics of water binding in vacuum-packed (VP) and modified-atmosphere-packed (MAP) poultry sausages during 21-day storage. In contrast to the control sample, the sausages enriched with microencapsulated fish oil (MC) were characterised by the greatest ability to accumulate deformation energy. The elastic properties of all sausage variants increased significantly in the subsequent storage periods, whereas the dynamic viscosity of the samples tended to decrease. This phenomenon was confirmed by the gradual reduction of water activity (Aw) in all sausages in the subsequent storage periods. The packaging method influenced the dynamics of water binding in an oil-additive-form-dependent manner. During the storage of the VP and MAP sausages, in samples with the fish oil additive the T1 value tended to increase while the Aw decreased. The T1 value in the MAP MC sample was similar. The FO additive resulted in greater mobility of both proton fractions in the MAP samples than in the VP samples. There were inverse relationships observed in the MC samples. The NMR tests showed that the VP samples with the MC additive were slightly better quality than the other samples.

Cod Liver Oil’s Encapsulation into Sodium Alginate/Lupin Protein Beads and Its Application in Functional Meatballs’ Preparation

Cod liver oil (CLO) is an essential source of healthy ω-3 fatty acids to be employed in functional meals. However, its autoxidation sensitivity, solubility, and odour present it as challenging to handle. Its encapsulation might mitigate these problems. This research studied using alginate/lupine protein as a wall material for CLO encapsulation as well as to characterise CLO microcapsules for their size, sphericity factor, encapsulation efficiency, morphology (scanning electron microscopy), in vitro release, and thermal stability. In this study, the oxidative stability, quality parameters, and sensory attributes of meatballs enriched with free CLOs and encapsulated CLOs throughout storage at 4 ± 1 °C for 16 days were assessed. The CLO microspheres had a homogeneous round shape, a diameter of 0.82 ± 0.06 mm, a sphericity factor of 0.092 ± 0.01, an encapsulation efficiency of 95.62% ± 1.13%, and an accumulative release rate of 87.10% after 270 min in the stimulated gastrointestinal conditions. Additionally, it was discovered that encapsulated oil was more stable than free CLOs to heat treatments (70–100 °C, 24 h). pH, thiobarbituric acid-reactive substances, peroxide value, conjugated dienes value, and carbonyl content of meatballs enriched with microencapsulated CLOs were significantly lower when compared to free CLOs and/or control samples. CLO microcapsules improved the sensory characteristics of meatballs throughout storage; however, meatballs directly containing CLOs were rejected. Thus, the viability of alginate/LPI complex microcapsules containing CLOs to enrich meat products subjected to storage with refrigeration could be indicated without any change in the characteristics.