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Summary: Shrimp undergo rapid deterioration after death, primarily due to enzyme activity and microbial growth, with freezing serving as its primary preservation method. In this study, shrimp underwent both conventional freezing (CF) and magnetic field‐assisted freezing (MF), and the shrimp meat's metabolites were scrutinised via metabonomic analysis techniques. The results demonstrate that MF treatment effectively preserved umami components like glutamic acid (log2(FC) = 0.37) and inosinic acid (1.02) while inhibiting the accumulation of spoilage‐related metabolites such as inosine (HxR) (−2.51), hypoxanthine (Hx) (−1.43) and uric acid (UA) (−1.24). Moreover, specific compounds, including 3‐methylhistidine, 1,6‐bisphosphate, phosphatidylcholine (PC), phosphatidylethanolamine (PE), HxR, Hx and UA were recognised as potential biomarkers throughout the freezing process. This research offers crucial insights into the intricate molecular mechanisms behind magnetic field‐assisted freezing. [ABSTRACT FROM AUTHOR]

Electronic tongue and metabolomic analysis (GC-MS and UPLC-MS techniques) were conducted to investigate the taste characteristics and metabolome of black sea bream before and after temporary rearing in natural seawater and artificial seawater, respectively. The natural seawater group showed reduced bitterness with advanced saltiness and sweetness, while the artificial seawater group had decreased umami. Metabolomic analysis revealed that most flavor-related metabolites and immune function-associated metabolites were downregulated, with a greater impact observed in the artificial seawater group. The artificial seawater group showed reduced immunity and disease resistance compared to the natural seawater group, indicating a greater level of environmental stress. [ABSTRACT FROM AUTHOR]

Postmortem metabolism in shrimp is an important factor affecting muscle quality during its preservation. Electron beam irradiation (EBI) can effectively kill microorganisms and inactivate enzymes. In this study, the tandem mass tag (TMT) method was used to study the changes in the muscle metabolism of Solenocera melantho postmortem before and after EBI (6 kGy). The TMT method identified a total of 656 proteins, including 120 differentially expressed proteins (DEPs) (56 upregulated, 64 downregulated). The analysis of these results showed that EBI can inactivate most enzymes and slow down their corresponding metabolic processes. These results also showed that irradiation can denature some proteins. The study revealed the effects of EBI on the muscle quality of S. melantho at the molecular level. [ABSTRACT FROM AUTHOR]

Summary: Free fatty acids (FFAs) and triacylglycerols (TAGs) are the main components of edible vegetable oils. In this work, electrospray ionisation (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FT‐ICR MS) was employed to characterise the molecular composition of FFAs and TAGs in various vegetable oils, including soybean, rapeseed, corn, sunflower, peanut, linseed and olive oils. Semiquantitative analysis of FFAs and structural analysis of TAGs by MS/MS were further conducted to reveal the differences in the molecular compositions of the various vegetable oils. It was found that each vegetable oil has characteristic fingerprints of FFAs and TAGs. MS/MS measurements showed that the high‐abundance TAGs in each vegetable oil were mainly composed of their abundant FFAs and glycerol. FFA and TAG fingerprints of genetically modified (GM) and nongenetically modified (non‐GM) vegetable oils were similar, exhibiting only subtle differences, as confirmed by principal component analysis (PCA). [ABSTRACT FROM AUTHOR]

The emission of hydrogen sulfide in the waste gas from slaughter plant, fishmeal feed processing and some other food industrial processing could cause serious air pollution to the surrounding environment. The purpose of this study was to screen heterotrophic bacterium strains for the removal of hydrogen sulfide odor. One heterotrophic bacterial mutant ZJNB-B3 was derived from the sulfide degrader Bacillus cereus XJ-2 and its sulfide removal efficiency was 97%. Based on the morphology studies, biochemical tests and 16S rRNA gene analysis, the strain was identified as Bacillus cereus ZJNB-B3. The NCBI GenBank accession number is MF679650. Batch tests showed that the strain tolerated up to 300 mg/L of toxic S²⁻ concentration. Response surface methodology was applied to optimize the conditions of degradation of sulfide. The optimal parameters were as follows: initial sulfide concentration 211.8 mg/L, initial pH 6.72, inoculum volume 5.04%, and incubation temperature 30 ℃. The accumulated sulfate concentration was 63.8 mg/L and the sulfide removal efficiency was 97.3% after 48 h incubation. No sulfuric acid was generated during sulfide oxidation by the strain. Sulfide could be removed effectively by this strain under mild pH conditions. The results suggested that the strain may have great industrial application potential. This study provides the fundamentals for the removal of hydrogen sulfide gas.