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Summary: In this study, the effect of different fermenters on the quality and flavour of fermented mandarin fish was investigated via pH, salt content, moisture content, thiobarbituric acid, microbial community, free amino acids and volatile compounds. The results demonstrated that the inoculated fermentation effectively suppressed fish fat oxidation, resulting in significantly higher levels of umami amino acids in mandarin fish compared to the natural fermentation group (P < 0.05). Additionally, certain bitter amino acids were also inhibited. Moreover, the total amino acid content of the mixed inoculated fermentation group was significantly elevated compared to other groups, reaching 300.21 ± 5.37 mg/100 g. The synergistic effect of free amino acids and flavour‐enhancing nucleotides significantly influenced the taste of the fermented fish, with the mixed inoculation fermentation group exhibiting a significantly higher Equivalent umami concentration (EUC) value compared to other groups, reaching 216.06 ± 20.13 mgMSG/100 g on the sixth day of fermentation. A total of 47 volatile compounds were detected by using headspace gas chromatography‐ion mobility spectrometry (HS‐GC‐IMS), and the results demonstrated that inoculated fermentation positively influenced the development of fish flavour, and mixed inoculated fermentation proved to be more effective. This study provides a theoretical foundation for the industrial production of fermented fish products and offers potential avenues for technical enhancement. [ABSTRACT FROM AUTHOR]

The effects of adding cellulose with different particle sizes and proportions on the gel properties of three common surimi products, namely fish balls, fish intestines, and fish cakes, were studied, and the best particle sizes and proportions were selected. This experiment determined the best particle size and proportion by studying the effects of adding different particle sizes and proportions of cellulose on the whiteness, water holding capacity, gel strength, total texture analysis, water distribution, and sensory aspects of fish balls, fish intestines, and fish cakes. The experiment found that the addition of cellulose could effectively improve the whiteness, water retention, gel strength, and texture characteristics of three common surimi products, and reduce the content of free water. The water holding capacity of fish balls, fish intestines, and fish cakes, gel strength, hardness, chewiness, and the proportion of water that was difficult to flow would increase with the increase of cellulose particle size, and first increase and then decrease with the increase of the addition proportion. It was found that the particle size of cellulose was 200 μm. When the addition ratio was 2%, the sensory evaluation would be more popular with consumers. After comprehensive consideration, the particle size of added cellulose was 200 μm. When the addition ratio was 2%, the quality of three common surimi products could be improved to the greatest extent, and the water holding capacity of fish balls, fish intestines and fish cakes can be increased by 14.5%, 22.1%, and 8.9% respectively. Gel strength increased by 121.9%, 108.7%, nd 65.5%. Hardness increased by 97.5%, 107.0%, and 158.8%. The proportion of non-flowing water increased by 0.8%, 1.7%, and 1.7%. [ABSTRACT FROM AUTHOR]

The effects of ultrasonic power (0, 150, 300, 450, and 600 W) on the extraction yield and the structure and rheological properties of pepsin-soluble collagen (PSC) from albacore skin were investigated. Compared with the conventional pepsin extraction method, ultrasonic treatment (UPSC) significantly increased the extraction yield of collagen from albacore skin, with a maximum increase of 8.56%. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that peptides of low molecular weight were produced when the ultrasonic power exceeded 300 W. Meanwhile, secondary structure, tertiary structure, and X-ray diffraction analyses showed that the original triple helix structure of collagen was intact after the ultrasonic treatment. The collagen solutions extracted under different ultrasonic powers had significant effects on the dynamic frequency sweep, but a steady shear test suggested that the collagen extracted at 150 W had the best viscosity. These results indicate that an ultrasonic power between 150 and 300 W can improve not only the extraction yield of natural collagen, but also the rheological properties of the collagen solution without compromising the triple helix structure. [ABSTRACT FROM AUTHOR]

To identify the key amino acids (AAs) affecting the allergenicity of hemocyanin (HC) allergens from Chinese mitten crabs, in this study, two epitopes, P1-SHFTGSKSNPEQR and P2-LSPGANTITR were employed and four potential key AAs (P1: F3 and N9 and P2: N6 and R10) were predicted. Mast cell and mouse models revealed that four mutants induced lower levels of immunoglobulin E (IgE) and Th2 type cytokines (15.47-49.89 %), proving that F3, N9, N6, and R10 were the key AAs of two epitopes. Mutants reduce allergic responses via the Th2 pathway. However, the roles of every key AA affecting allergenicity were different (P1-F3 > N9 and P2-N6 > R10). In addition, lower transport and higher efflux were observed in the mutants during transport absorption by Caco-2 cells. The allergenicity of HC was stronger when the transport absorption efficiency of epitopes and mutants was higher and their efflux was lower. Our study provides a novel method for revealing the allergenic molecular mechanisms of food allergens., Competing Interests: Declaration of competing interest The authors attested that there were no conflicts of interest concerning this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

To analyze the effect of various drying treatments (microwave drying (MD), hot air drying (HAD), vacuum drying (VD), and vacuum freeze drying (VFD)) on taste compounds in Penaeus vannamei, relevant indicators such as free amino acids, 5'-nucleotides, and organic acids were performed. Multidimensional infrared spectroscopy (MM-IR) results found that there were notable variations in taste properties of P. vannamei. There were 18 autocorrelation peaks in 3400-900 cm -1 were screened using second-derivative infrared spectroscopy (SD-IR) and two-dimensional correlation infrared spectroscopy (2DCOS-IR). Variations in functional groups were the major contributors to taste profiles. The TAV of glutamic acid (Glu), guanine (GMP), and inosinemonphosphate (IMP) were greater than one and had notable impacts on taste profiles. VD had the highest equivalent umami value, followed by VFD, HAD, and MD. This study may provide a theoretical guide for the production of dried P. vannamei products on an industrial scale., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)