Xiaoguo Ying

This study evaluated the effects of different proteases on the extraction, flavor profile, and oxidative stability of blackthroat seaperch (Doederleinia berycoides) liver oil obtained by aqueous enzymatic extraction. Trypsin-assisted extraction yielded oil with the greatest oxidative stability. Combined analysis by gas chromatography-ion mobility spectrometry and gas chromatography-mass spectrometry identified aldehydes as the characteristic volatile compounds in the liver oil. The relative odor activity value analysis identified (E)-2-nonenal, furaneol, benzeneacetaldehyde and 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-3-buten-2-one as the key volatile compounds. Differences in oxidative stability and thermal behavior were observed among the extraction methods, with the antioxidant capacity of blackthroat seaperch liver oil following the order of pepsin (PS) > alkaline protease > trypsin (TS) > neutral protease extraction methods. Differential scanning calorimetry analysis revealed that PS melting and cooling profiles enhanced flavor release and persistence, while TS and PS exhibited ω-3 fatty acid pyrolysis. These findings demonstrate the importance of enzyme selection for liver oil flavor and stability and support the valorization of blackthroat seaperch by-products.

Although aquatic products are abundant in premium proteins and other vital nutrients, their unique fishy smell often restricts public acceptance and the development of related products. Therefore, pre-marinating is usually used to improve sensory quality and mitigate fishy smell. In this study, sea bass filets were marinated for 1 h at a solid–liquid ratio of 3:5 (w/w) using 15% orange juice, 15% grapefruit juice, and 10% lemon juice. Subsequently, their effects on the flavor and sensory quality of sea bass were examined. The results of gas chromatography-ion mobility spectrometry (GC-IMS) showed that marinating the filets in citrus juice led to a notable increase in volatile compounds, including esters with fruity flavor such as ethyl butyrate and terpenes with pleasant citrus aromas such as limonene. The results of texture profile analysis (TPA) showed that pre-marinading with orange juice and grapefruit juice significantly reduced the hardness of fish and resulted in higher sensory evaluation scores (p < 0.05). Lemon juice treatment produced the most noticeable whitening effect (p < 0.05). These findings suggest that citrus juices can be effectively incorporated as marinade ingredients for sea bass, providing both theoretical insight and practical guidance for improving the marinating technology for aquatic products.

The aim of this experiment was to investigate the effect of a natural additive Rosa roxburghii Tratt. extraction (RRTE) on the gel properties and flavour of hairtail (Trichiurus lepturus) surimi gels. The effects of different additive concentrations of RRTE on the flavour improvement of hairtail surimi gels were systematically investigated by combining the electronic nose and sensory evaluation techniques. The results showed that the addition of RRTE, especially 2% (m/m) RRTE, could effectively improve the odour score; enhanced the gel strength, water-holding capacity and rheological properties; improved the elasticity, hardness and viscoelasticity of the hairtail surimi gels. The results of water migration and protein secondary structure analysis showed that RRTE could effectively stabilise the internal water distribution of hairtail surimi gels and inhibit protein denaturation. Microstructural observation showed that the gel structure of hairtail surimi in the RRTE added group was more uniform and dense, and the fractal dimension was reduced. The comprehensive results showed that RRTE, as a natural additive, could significantly improve the gel properties and flavour of hairtail surimi gels, providing a scientific basis for the high value-added processing of hairtail surimi products.

Background/Objectives: Shrimp surimi-based products (SSPs) are composed of minced shrimp meat and are highly susceptible to food fraud as fish surimi. This study employed a double-gene metabarcoding approach to authenticate SSPs sold on Chinese e-commerce platforms. Methods: 16S rRNA and 12S rRNA genes were amplified and sequenced from 24 SSPs. Mislabeling was evaluated based on the correspondence between the ingredients (only those of animal origin) reported on the products’ labels and the molecular results. Results: Overall, 87.50% of SSPs (21/24) were found to be mislabeled. The replacement of Penaeus vannamei with other shrimp species was particularly noteworthy. Interestingly, in some SSPs, the primary species detected in terms of sequence abundance were not shrimp but fish, pork, chicken, and cephalopods, raising concerns regarding both health risks and ethical issues related to SSP consumption. The 12S rRNA sequencing results revealed that fish species like Gadus chalcogrammus, Evynnis tumifrons, and Priacanthus arenatus were added to some SSPs in significant proportions, with certain products relying on fish priced from “Low” to “High” levels to substitute higher-cost shrimp. Notably, many fish species in SSPs were highly vulnerable to fishing, raising sustainability concerns. Overall, the high mislabeling rate in SSPs, as well as the detection of endangered fish species (Pangasianodon hypophthalmus), underscores significant quality control issues. Conclusions: DNA metabarcoding has proven to be an effective tool for ingredient authentication in processed seafood.

To investigate and compare the changes in muscle quality of hooked, trawl-net, and radar-net hairtail (Trichiurus haumela, HH, TH, and RH) during thermal processing, the physicochemical properties of three kinds of hairtail were determined under heating at 30, 50, 70 and 90 °C for 10 min. Additionally, the muscle tissues were observed via Oil Red O (ORO) staining, Masson staining, and scanning electron microscopy (SEM). The results showed that with increased heating temperature, pH, L*, b*, chewiness, and gumminess in hairtail muscle increased, while a* and shearing force decreased. The springiness, relative contents of hydrophobic and disulfide bonds, myosin surface hydrophobicity, and TCA-soluble peptide content increased first and then decreased. However, the relative contents of ionic and hydrogen bonds showed an opposite trend. Histological observations revealed that heating disrupted hairtail muscle tissue, manifested by the blurriness and disorder of myofibrils and breakage of myofibrillar bundle membranes. The RH muscle exhibited the highest chewiness, gumminess, and chemical force levels, accompanied by the lowest content of TCA-soluble peptide. Furthermore, the RH muscle presented the greatest fat droplet content, diffusivity, and integrity of collagen and myofibers. Correlation analysis revealed a close correlation between muscle quality and protein function in HH, TH, and RH. This study provides a theoretical basis for the difference in muscle quality in three different types of hairtail.