This study evaluated the effects of different levels of ultrasonic power (200, 400, 600 W) and treatment time (0, 10, 15 and 30 min) on the structure, emulsification characteristics, and in vitro digestibility of chickpea protein isolate (CPI). The changes in surface hydrophobicity of CPI indicated that ultrasound treatment exposed more hydrophobic amino acid residues. The analysis of sulfhydryl content and zeta potential showed that ultrasound caused the disulfide bond of CPI to be opened, releasing more negatively charged groups, and the solution was more stable. In addition, Fourier Transform Infrared Spectroscopy (FT-IR) and intrinsic fluorescence spectroscopy showed that ultrasound changes the secondary and tertiary structure of CPI, which is due to molecular expansion and stretching, exposing internal hydrophobic groups. The emulsification and foaming stability of CPI were significantly improved after ultrasonic treatment. Ultrasonic treatment had a minor effect on the solubility, foaming capacity and in vitro digestibility of CPI. All the results revealed that the ultrasound was a promising way to improve the functional properties of CPI.

• 200 W, and 9 min induced the highest emulsification of MPs from C. peled. • HIU induced structural modification of MPs, which strengthened the emulsification. • HIU improved the oxidative modification of MPs and the degradation of MHC. • Oxidation and MHC degradation partial contribute to the emulsification improvement.

Allicin, as a natural antibacterial active substance from plants, has great medical and health care value. However, due to its poor stability, its application in the field of food and medicine is limited. So, in this paper, allicin–zein–sodium caseinate composite nanoparticles (zein–Ali–SC) were prepared by antisolvent precipitation and electrostatic deposition. Through the analysis of the particle size, ζ-potential, encapsulation efficiency (EE), loading rate (LC) and microstructure, the optimum preparation conditions for composite nanoparticles were obtained. The mechanism of its formation was studied by fluorescence spectrum, Fourier infrared spectrum (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The stability study results showed that the particle size of composite nanoparticles was less than 200 nm and its PDI was less than 0.3 under different NaCl concentrations and heating conditions, showing good stability. When stored at 4 °C for 21 days, the retention rate of allicin reached 61.67%, which was 52.9% higher than that of free allicin. After freeze-drying and reheating, the nanoparticles showed good redispersibility; meanwhile, antioxidant experiments showed that, compared with free allicin, the nanoparticles had stronger scavenging ability of free radicals, which provided a new idea for improving the stability technology and bioavailability of bioactive compounds.

In order to develop low-salt and healthy surimi products, we limited the amount of NaCl to 0.5 g/100 g in this work and studied the effect of CaCl₂ (0, 0.5, 1.0, 1.5, and 2.0 g/100 g) on the 3D printing quality of low-salt surimi gel. The results of rheology and the 3D printing showed that the surimi gel with 1.5 g/100 g of CaCl₂ added could squeeze smoothly from the nozzle and had good self-support and stability. The results of the chemical structure, chemical interaction, water distribution, and microstructure showed that adding 1.5 g/100 g of CaCl₂ could enhance the water-holding capacity and mechanical strength (the gel strength, hardness, springiness, etc.) by forming an orderly and uniform three-dimensional network structure, which limited the mobility of the water and promoted the formation of hydrogen bonds. In this study, we successfully replaced part of the salt in surimi with CaCl₂ and obtained a low-salt 3D product with good printing performance and sensory properties, which could provide theoretical support for the development of healthy and nutritious surimi products.

In this study, the quality (sensory evaluation, microbial enumerate, color, tvb-n (total volatile basic nitrogen), tca-soluble peptide (trichloroacetic acid-soluble peptide), muscle glucose, lactate, total sugar, Bas (Biogenic amines), VOCs (volatile organic compounds) and the microbial dynamic structure in samples stored at 4 °C were evaluated, and the relationship between VOCs and the diversity structure of microorganisms was also discussed. It was determined by sensory evaluation that the shelf life of samples was around 8 days. Protein and sugar were detected in large quantities by microorganisms in the later stage. At the same time, this also caused a large amount of Bas (biogenic amines) (tyramine, cadaverine, and putrescine). According to high-throughput amplicon sequencing, the initial microbiota of samples was mainly composed of Pseudomonas, Acinetobacter, Planifilum, Vagococcus, Hafnia, Mycobacterium, Thauera, and Yersinia. Among them, Pseudomonas was the most advantageous taxon of samples at the end of the shelf life. The minor fraction of the microbial consortium consisting of Vagococcus, Acinetobacter and Myroides was detected. The substances 3-methyl-1-butanol, ethyl acetate, and acetone were the main volatile components. The glucose, lactic acid, and total sugar were negatively correlated with Yersinia, Hafnia-Obesumbacterium, Thauera, Mycobacterium, and Planifilum; the proportion of these microorganisms was relatively high in the early stage. TVB-N and TCA-soluble peptides were positively correlated with Pseudomonas, Shewanella, Brochothrix, Vagococcus, Myroides, and Acinetobacter, and these microorganisms increased greatly in the later stage. The substance 3-methyl-1-butanol was positively correlated with Pseudomonas and negatively correlated with Mycobacterium. Ethyl acetate was associated with Hafnia-Obesumbacterium, Thauera, and Yersinia. Acetone was positively correlated with Acinetobacter.

The effects of changes in the malondialdehyde (MDA) content on the quality of fish during the low-temperature storage period are unclear. Therefore, the effects of the MDA content on Coregonus peled quality and protein changes were investigated following storage under refrigeration (4 °C) and super chilling (−3 °C) for 15 days (d). The results showed that the MDA content continued to increase during storage and that the highest content was produced at 1.42 mg/kg during refrigeration. The fillet pH, drip loss, texture (hardness and elasticity), and myofibril fragmentation index deteriorated significantly during the storage period. Increased oxidation of the myofibrillar protein (MP) was observed in the 15 d storage period, and the MP carbonyl content was 1.19 times higher under refrigeration than in super chilling, while the protein α-helix structure decreased by 12.48% and 12.20% under refrigeration and super chilling, respectively. Electropherograms also showed that myosin degradation was particularly severe in the refrigeration storage period of 15 d. Overall, the MDA formed at the refrigeration and super chilling storage temperatures could promote structural changes in, and the oxidative degradation of, proteins to different degrees, leading to the deterioration of the fillet quality. This study provides a scientific basis for investigating the relationship between fish quality and changes in the MDA content during low-temperature storage.