Shichen Zhu

Pro-oxidative factors compromise surimi gel quality by inducing protein denaturation and aggregation. This study elucidated the interactions between malondialdehyde (MDA) and hemin with surimi actomyosin through multispectral analysis and molecular dynamics (MD) simulations. The results suggested that MDA and hemin induced actomyosin oxidation by altering protein conformation, surface hydrophobicity, and the microenvironment of aromatic residues, especially under low-pH/high-temperature conditions. The MD results confirmed that MDA weakly interacted with myosin owing to its flexible backbone and limited hydrophobicity (ΔE = +0.24 kcal/mol), whereas hemin forms stable interactions (ΔE = −33.64 kcal/mol), likely due to its central iron atom, rigid porphyrin ring, and polar groups. Under co-exposure, hemin facilitated the relocation of MDA into deeper binding pockets, forming a synergistic network driven by hydrogen bonding, van der Waals forces, and hydrophobic interactions (ΔE = +0.05 kcal/mol for MDA; −28.71 kcal/mol for hemin). These findings provide molecular-level insights into surimi quality deterioration and support strategies to mitigate protein oxidation during processing. The alternative text for this image may have been generated using AI.

Aquatic products are highly susceptible to quality deterioration during short‐term distribution prior to consumption. In practice, expanded polystyrene (EPS) boxes combined with cold‐chain conditions are widely used to maintain product quality; however, the high cost and inherent limitations of conventional cold‐chain systems restrict their application in short‐term distribution. In this study, the preservation performance of large yellow croaker ( Pseudosciaena crocea ) under four short‐term distribution preservation systems was evaluated by integrating muscle quality parameters, freshness indicators, microbial safety, and flavor characteristics. The results clarified the upper limits of preservation time under different preservation systems. Compared with the EPS‐only preservation system, incorporation of the vacuum packaging‐ice pack (VI) strategy significantly extended the preservation time at both 30°C and 4°C, indicating its potential as a cost‐effective alternative to conventional cold‐chain distribution. Flavor analyses further showed that although the VI strategy extended the preservation limit to 72 h at 30°C, its ability to maintain flavor quality was limited, as reflected by the accumulation of bitter amino acids and the presence of off‐flavor volatiles such as E‐2‐hexenal, 2‐nonanone, and trimethylamine. In contrast, the 4°C‐VI system exhibited the best overall performance, achieving both prolonged preservation time and superior flavor quality. Overall, this study provides a practical framework for selecting economical and effective short‐term distribution strategies for high‐value marine fish. Practical Applications: This study offers actionable guidance for optimizing the short‐term distribution of fresh large yellow croaker using standard expanded polystyrene (EPS) boxes. The results demonstrate that integrating vacuum packaging with ice packs effectively extends product usability and maintains acceptable quality during short‐distance transport, providing a reliable solution even where full cold‐chain infrastructure is unavailable. These findings equip seafood producers and distributors with a scientifically grounded framework for selecting cost‐effective preservation strategies tailored to real‐world distribution scenarios.

In this work, the ice-inhibiting effects and their underlying mechanisms of inulin with various chain lengths were elucidated through experimental measurements and molecular dynamics simulations. The results suggested that long-chain inulin (HP group) exhibited strong and stable ice-inhibiting effects, with a minimum %MGS (12.18%) and limited ice growth of 36.61% after 100 min of freezing. The extensive contact area of long-chain inulin with water molecules (higher R_g and solvent-accessible surface area (SASA) values) favored their hydrogen-bond formation, which further disrupted the original hydrogen-bonding network of water by transforming the hydrogen-bonding mode (DDAA-OH mode into the DA mode). The remarkable cryoprotective effects of the HP group on scallops were evidenced by no significant difference in mass loss, water-holding capacity (WHC), and structural stability of the myofibrillar protein with the commercial antifreeze group (p > 0.05). This study provides strong evidence to broaden the cryoprotection applications of inulin to improve the quality of frozen food.

In this work, a natural zwitterionic, betaine with varied dosages (4%, 6%, 8%, 10%, and 12%, w/v) was used to improve the freeze‐thaw stability of frozen surimi gels. Specifically, Group 8B‐S (8% betaine, w/v) increased gel strength and storage modulus of frozen surimi gels by 25.03% and 26.86% compared with the control group, respectively. Besides, the findings indicated that betaine also showed a versatile cryoprotection effect on frozen soy protein gels and agar gels, indicated by the relatively high gel strength. Differential scanning calorimetry (DSC) measurements showed that 8% betaine significantly reduced freezing point and freezable water content by 52.03% and 14.94% compared with the control group, respectively. Furthermore, the results of Raman spectroscopy and molecular dynamics simulations demonstrated that the ionic solvation effects of betaine disrupted the network, number, and lifetime of hydrogen bonds within water molecules, thereby improving ice recrystallization inhibition activity. This work establishes a theoretical framework for the creation of phosphorus‐free antifreeze agents used in high‐quality frozen food gels.

To investigate difference in the quality of the different parts (back, tail muscles, and fish skin) of Opsariichthys bidens from pond and rice field cultures, a comparative study was conducted in terms of nutritional composition, volatile flavor profiles and gut microbiota. In detail, the texture, free amino acids, fatty acids were further assessed. The results suggested that the moisture content, crude protein and crude fat content in the skin of O. bidens are higher than those in the back and tail muscles, regardless of breeding modes. The fish cultured in the rice field had a higher protein content than those from the pond culture, while the fat content of the rice field-cultured fish was significantly low compared to the fish from the pond culture, especially in the back and tail parts. A total of 43 volatile components were detected by Gas Chromatography–Mass Spectrometry (GC-MS), with a maximum of 18 types of aldehydes and the highest concentration being nonanal. Compared to pond cultures, the fish from the rice field cultures showed more abundant flavor composition and odor-active compounds. The total content of DHA (Docosahexaenoic Acid) and EPA (Eicosapentaenoic Acid) in the rice field-cultured fish was higher than that of the pond group, while no significant disparity in amino acid composition was observed (p > 0.05). Comparative and clustering analyses of gut microbiota revealed notable discrepancies in the gut microbiota of O. bidens from two aquaculture systems. However, an inherent correlation between the gut microbiome and meat quality would be further emphasized in further studies. This study can offer a theoretical reference for the development of high-quality aquatic products by selecting the appropriate aquaculture models.