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The effects of heat treatment on the proteome of Apostichopus japonicus have been evaluated using label-free quantitative proteomics by ultrahigh performance liquid chromatography-quadrupole/time of flight (UHPLC-Q/TOF) mass spectrometry with sequential window acquisition of all the theoretical fragment ion (SWATH) acquisition mode. Chemometric tools are integrated to reveal proteomic changes by mining the protein quantitation data from fresh and differently heat-treated samples. SWATH allows the quantitation of 548 proteins, of which 24 proteins are significantly sensitive to heat treatment and 13 proteins vary significantly responding to different heat procedures (boiling, steaming, and microwave heating), and 5 of them are sharing proteins. Gene ontology (GO) annotation of the differentiating proteins highlights most of them are relevant to molecular functions. The results can be favorable to evaluate the effects of heat treatment on the nutrition and function of processed sea cucumbers and facilitate the selection of an optimal thermal treatment., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The article reports on discrimination of dried sea cucumber Apostichopus japonicus (A. japonicus) products from different geographical regions in China (Xiapu, Jiaonan, Weihai, Yantai, Dalian). For this purpose, sequential window acquisition of all theoretical fragment ion mass spectra (SWATH-MS)-based proteomic analysis combined with chemometrics was evaluated. Proteome variations of A. japonicus samples determined by SWATH-MS using ultra-high performance liquid chromatography coupled to quadrupole time of flight mass spectrometer were mined by chemometric tools to clarify the correlation between protein quantitation data and geographical origin. A differentiating OPLS-DA model was constructed with 55 SWATH-MS quantified proteins. A. japonicus samples from five locations were clearly classified by the developed OPLS-DA model and 100% prediction accuracy was achieved in validation testing as well as real-life sample analysis. Seventeen proteins were identified as discriminatory biomarkers allowing geographical provenance. The proposed method might be applied in origin authentication of commercially dried A. japonicus products., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Incorrect labeling and adulteration of shrimp occurs due to interspecies similarities and carapace removal during processing. This study attempted to identify three related commercial shrimp species of the order Decapoda: Marsupenaeus japonicus, Fenneropenaeus chinensis, and Litopenaeus vannamei. All measurable trypsin-digested peptides in the individual shrimp were detected using ultrahigh-performance liquid chromatography quadrupole time-of-flight (UPLC-Q-TOF) mass spectrometry with sequential window acquisition of all theoretical fragment ion spectra (SWATH) data-independent acquisition. Further analysis of peptide biomarkers was carried out with an orthogonal partial least-squares discriminant analysis (OPLS-DA) model. BLAST was used for species-specific analysis. Subsequently, multiple reaction monitoring (MRM) methods were developed for sensitivity and selectivity screening of the selected peptides, and 27 were identified as biomarkers allowing rapid and accurate discrimination of shrimp species without high-resolution mass spectrometry or statistical model building. These strategies could be applied in authentication of other products containing highly homologous proteomes.

To understand the nutritional characteristics of new species of Nepture volute (NV), its meat is used for nutritional analysis. NV had about 10% proteins containing essential amino acids except for tryptophan, 0.2% lipids containing 70% unsaturated fatty acids, 0.1% hydroxy acids with the function of fat reduction, 0.07% Ca, 0.002% Fe, 0.001% Zn. NV protein (NVP) with histone 3, perivitelline, cytochrome oxidase subunit played important role of cellular component, molecular functions and biological process in NV cells metabolism. Moreover, salt-soluble and acid-soluble proteins dominated NVP, suggesting high gel forming ability and small molecular weight. NVPs were pseudoplastic fluid (n < 0.2 in Power law), exhibiting shear thinning. Moreover, high rate of α-helix: β-sheet in NVPs led to more than 50% protein digestibility, 70% amino acids digestibility, 80% protein and trace elements absorption rates. NV also had antioxidant function (DPPH scavenging rate 23.289%) after digestion due to the presence of aromatic (phenylalanine) and acidic amino acids (aspartic acid, glutamate). Thereby, NV could complement multiple nutrients and had potential anti-oxidation and weight-losing functions. • Nutrients of Nepture volute (NV) including proteins, lipid, trace elements (Ca, Fe, Zn) were determined. • The NV proteins (NVP) properties (structure, rheology, thermal stability) were determined. • The NVP types and functions were analyzed based on proteomics. • Antioxidation and digestion/absorption rates of NV nutrients were analyzed by in vitro digestion/caco-2 cells model. [ABSTRACT FROM AUTHOR]