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BACKGROUND: Hairtail (Trichiurus haumela) surimi exhibits poor gelation properties and a dark gray appearance, which hinder its utilization in high‐quality surimi gel products. The effect of Pickering emulsions stabilized by myofibrillar proteins (MPE) on the gel properties of hairtail surimi has been unclear. In particular, the impact of MPE under NaCl and KCl treatments on the quality of hairtail surimi gels requires further elucidation. RESULTS: Pickering emulsions stabilized by myofibrillar proteins and treated with NaCl or KCl (Na‐MPE, K‐MPE) were added to hairtail surimi in amounts of 10–70 g kg−1. The addition of 50 g kg−1 Na‐MPE and K‐MPE improved the gel strength, textural properties, whiteness, and water‐holding capacity (WHC) of hairtail surimi. The relative content of β‐turn and β‐sheet in the surimi gels increased and the relative content of random coils and α‐helix decreased with the addition of oil. The addition of Na‐MPE and K‐MPE did not affect the secondary structure of surimi gels but stimulated the gelation of hairtail surimi gels. Hairtail surimi containing K‐MPE demonstrated similar performance in terms of hardness, microstructure, and WHC compared with the addition of Na‐MPE. CONCLUSION: The quality of hairtail surimi gels can be improved by the addition of Na‐MPE or K‐MPE. The K‐MPE proved to be an effective option for enhancing the properties of hairtail surimi gels at 50 g kg−1 to replace Na‐MPE. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Summary: After abalone muscle hot water extract (AHE) was digested in‐vitro, three components (F1, F2, and F3) were separated using the Sephadex G‐15 column, and the antioxidant activity and absorption across Caco‐2 cells were analysed. The result showed that the half‐maximal inhibitory concentrations of F2 for scavenging hydroxyl and ABTS radicals were 0.763 and 0.028 mg mL−1, respectively, which were lower than those of F1 and F3. Moreover, the Trolox equivalent antioxidant capacity was increased after the F2 was transported through the Caco‐2 cell‐monolayered Transwell chamber. The mass spectrometry analysis revealed that the transported samples contained oligopeptides (Leu‐Tyr, Gly‐Ala‐Ala, and His‐Gly‐Ser‐Ala), and the Leu‐Tyr displayed the highest antioxidant activity and transport rate. Overall, these results suggest that oligopeptides with high antioxidant capacities can be produced from AHE through a combination of in‐vitro digestion and absorption across Caco‐2 cells. [ABSTRACT FROM AUTHOR]

The effect of hydration degree on the structure of V-type starch and its thymol inclusion complex was investigated by encapsulating the thymol into V-type starch treated at different hydration times. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and differential calorimetry (DSC) were used to characterize V-type starch and its inclusion complexes, and the content of thymol was determined by gas chromatography. The results showed that the successful complexation between V-type starches and thymol was formed, and the inclusion complex exhibited an endotherm with peak temperature at 118 The inclusion complex after hydration for 72 h exhibited the largest endother- mic peak with AH of (7.31 ± 0.29) J/g. The XRD results showed that the crystallinity of V-type starch increased from 35.2% to 41.1% as the hydration time increased from 0 h to 72 h. The water in internal and external of V-type starch granule reached balance after 72 h of hydration, and the water coating on the surface of the granules gradually disap-peared and the particle roughness increased. The gas chromatography showed that the thymol content in the inclusion complex was positively correlated with hydration time. The research results provide a theoretical basis for the development of microcapsule wall materials of natural polymer materials, and are of great significance for the innovation and develop¬ment of high-value applications of flavor compounds. [ABSTRACT FROM AUTHOR]

The physicochemical properties of chitosan obtained from the shells of swimming crab (Portunus trituberculatus) and prepared via subcritical water pretreatment were examined. At the deacetylation temperature of 90 °C, the yield, ash content, and molecular weight of chitosan in the shells prepared via subcritical water pretreatment were 12.2%, 0.6%, and 1187.2 kDa, respectively. These values were lower than those of shells prepared via sodium hydroxide pretreatment. At the deacetylation temperature of 120 °C, a similar trend was observed in chitosan molecular weight, but differences in chitosan yield and ash content were not remarkable. At the same deacetylation temperature, the structures of chitosan prepared via sodium hydroxide and subcritical water pretreatments were not substantially different. However, the compactness and thermal stability of chitosan prepared via sodium hydroxide pretreatment was lower than those of chitosan prepared via subcritical water pretreatment. Compared with the chitosan prepared by sodium hydroxide pretreatment, the chitosan prepared by subcritical water pretreatment was easier to use in preparing oligosaccharides, including (GlcN)2, via enzymatic hydrolysis with chitosanase. Results suggested that subcritical water pretreatment can be potentially used for the pretreatment of crustacean shells. The residues obtained via this method can be utilized to prepare chitosan. [ABSTRACT FROM AUTHOR]

BACKGROUND Application of fish skin collagen has received increasing attention due to mammalian derived diseases and religious limitations. Collagen fibril gel could be formed in vitro through the self‐assembly process. The present study investigated the effect of pH on the self‐assembly in vitro of acid‐solubilized collagen (ASC) from golden pompano skin by determining the turbidity, rheological viscoelasticity, network structure, gel strength, and thermal stability of collagen fibril gel. RESULTS: The isoelectric point of ASC was pH 5.27. The turbidity–time and rheological viscoelasticity results indicate that the collagen self‐assembly rate in vitro at pH 7.0 was the slowest. The rate was accelerated by increasing or decreasing the pH. Scanning electron microscopy images show that the fibril diameters of the collagen fibril gels and the collagenous fibril number in the collagen fiber increased with the pH. The gel strength of the collagen fibril gel prepared at pH 5.0 was 22.06 g and increased up to 220.46 g when pH increased to 8.0. No obvious peaks were observed in the differential scanning calorimetry curves of the collagen fibril gels prepared at pH 5.0, whereas high endothermic peak temperature (Tm) and enthalpy change (ΔH) were found in the collagen fibril gels prepared at pH 6.0–8.0. CONCLUSION: It is concluded that the physical properties of ASC fibril gels can be improved by increasing the fibril diameter controlled by pH. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The histologic structure of eel muscle was observed, and the acid solubilized collagen (ASC) and pepsin solubilized collagen (PSC) from eel muscle were prepared and examined. The collagenous fiber amount in both head and tail seemed to be higher than that in the trunk. The Glu, Asp, Arg, Ala, Leu, and Lys contents accounted for about 54% of total amino acids in the eel muscle. There were no significant differences in the amino acid composition and ultraviolet spectra between ASC and PSC. The molecular weights of α1 subunit in both collagens were 129 and 123 kDa, respectively; but their molecular weights of α2 subunit were 113 kDa. According to peptide mapping analysis, it was found that there were obvious differences in primary structures between ASC and PSC. The amide A band positions of ASC and PSC appeared at 3320 cm−1 and 3312 cm−1 of Fourier transform infrared spectra, respectively. No obvious difference was found in the thermal stability of both collagens, probably due to the synergistic effect of molecular weight and hydrogen bonds. [ABSTRACT FROM AUTHOR]

A novel and simple process for the preparative extraction, separation, and purification of high-purity (–)-borneol and xanthoxylin, synchronously, from the leaves ofBlumea balsamifera(L.) DC was developed. Simultaneous distillation and extraction, silica gel column chromatography, and recrystallization were applied to the preparation. Two objective compounds with the purity of 98% were obtained, and the losses were minimal during the whole procedure. It is the first time that the preparation of high-purity (–)-borneol and xanthoxylin at the same time were achieved. [ABSTRACT FROM AUTHOR]