Effect of lipid oxidation on quality attributes and control technologies in dried aquatic animal products: a critical review

Preparation, identification and application of lipid-Maillard reaction products during the drying process of squid fillets

Squid fillets are susceptible to lipid oxidation and Maillard reaction during the drying process. In this study, a novel additive agent lipid-Maillard reaction products (L-MRPs) was optimized by response surface methodology, then the main antioxidant components of L-MRPs were identified. Finally, L-MRPs was applied to the drying process of squid fillets (LMSF) by comparing with the control group. The results showed that the optimal reaction conditions were pH 10.90, lipid content 1.70 %, reaction temperature 104 °C, reaction time 105 min. The DPPH radical scavenging activity of final L-MRPs was 89.78 %. The main antioxidant components of L-MRPs were Fru-Arg (19.31 μg/g), pyrroles (762.04 μg/g) and other HCCs (293.97 μg/kg). Besides, compared to the control group, LMSF group showed lower thiobarbituric acid reactive substances value (4.58 mg/kg) and formaldehyde content (17.00 mg/kg), but more flavor compounds (455.78 μg/kg) and higher sensory scores. Finally, the potential antioxidant and flavor-enhancing mechanism of L-MRPs was proposed.

Effects of Hot-Air Drying Temperatures on Quality and Volatile Flavor Components of Cooked Antarctic krill (Euphausia superba)

Hot-air drying is a key step for Antarctic krill (Euphausia superba) onboard processing; however, few studies have explored the effects of different drying temperatures on the quality and flavor alternations of Antarctic krill. In this study, we investigated the effects of hot-air drying temperatures on the physicochemical properties and flavor of Antarctic krill. Sensory evaluation, as well as physical and chemical property tests, revealed that Antarctic krill treated with hot-air drying exhibited substantial changes in moisture status, lipid oxidation indices, and b* value. The sensory evaluation of Antarctic krill under high temperatures (120 °C and 150 °C) showed higher scores (8.45 ± 0.05 and 8.58 ± 0.22, respectively) on smells, whereas the color changes caused by high temperatures also resulted in lower overall sensory evaluation scores. The POV and TBARS values reached the highest at 26.63 ± 0.28 mg/g and 1.45 ± 0.19 mg/100 g, respectively. The b* value decreased significantly to 22.32 ± 4.56 following 150 °C treatment. Furthermore, a total of 53 volatile compounds were identified by GC-IMS, and the results showed that aldehydes, alcohols, alkanes, ketones, pyrazines, and furans were the main flavor sources of Antarctic krill. At the same time, the GC-MS results showed that the thermal process had no significant effect on the nutrient content of Antarctic krill. The findings obtained in this study provide foundational information for future research on ship-borne processing and high-value utilization of Antarctic krill.

Efficacy of trehalose, tea polyphenol and their combinaton-loaded sodium alginate coating pretreatments on microstructure, flavor and quality of heat pump dried scallop adductors

BACKGROUND

Protein denaturation/oxidation and lipid oxidation critically affect quality of dried aquatic products. Measures to maintain protein structure and reduce oxidation are assumed beneficial to maintain quality of dried products. Herein, scallop adductors without pretreatment (CK) and with different pretreatments including trehalose (TR), tea polyphenol (TP), their combinations (TR-TP), and TR-TP-loaded sodium alginate coating (TR-TP-SA) were performed to reveal their effects on microstructure, flavor, and quality of heat pump dried scallop adductors.

RESULTS

Compared to the CK, pretreatments observably enhanced rehydration ratio, crude protein, total phenolic content, and DPPH (2,2-diphenyl-1-picryhydrazyl) radical scavenging activity by 2.93-429.55%, 8.98-22.46%, 50.54-440.59%, and 1.46- to 2.95-fold, while decreased total color difference, hardness, and chewiness by 5.99-15.48%, 21.06-69.02%, and 21.61-68.08%, respectively. The dominant taste amino acids in dried samples were sweet amino acids, accounting for 92.94-95.87% of total free amino acids which increased with TP pretreatment, while decreased with other pretreatments compared to the CK. Scanning electron microscopy analysis exhibited more uniform, loose and porous structures for pretreated samples compared to the CK sample, and Fourier-transform infrared spectroscopy analysis demonstrated an increase in α-helix while a decrease in random coils (except TR), β-sheet, and β-turns. Flavor analysis revealed a vital contribution of pretreatments to a significant increase (ranging from 1.25- to 6.55-fold) in aldehydes of dried samples.

CONCLUSION

Principal component and hierarchical cluster analyses confirmed that all pretreatments markedly improved flavor profile and overall quality, suggesting potential benefits of these pretreatments in enhancing the quality of dried samples. © 2025 Society of Chemical Industry.

Sterilized Processed Cheese: Principles, Technological Aspects, and Properties: A Review

Sterilized processed cheese is a dairy product with prolonged shelf life compared to regular processed cheese. The extension of durability is made possible by the thermosterilization of processed cheese, while regular processed cheese is submitted to pasteurization process during manufacturing. Sterilized processed cheese can be classified as long-life foods and their shelf life may reach up to 24 months, if stored at ambient temperature (approx. 25 ± 1 °C). This fact is an advantage over regular processed cheese, which has a shelf life of only around 6 months. Sterilized processed cheese finds application in everyday life when refrigeration facilities are not available; i.e., it is intended for regular retail. However, their most important use is for storage in state material reserves and, moreover, for catering for members of the armed forces and/or members of the integrated rescue system. This review aimed to gather general information on sterilized processed cheeses, their characterization, usage and production. Furthermore, the review discusses the principles of sterilization and factors affecting the course of sterilization focusing on the setting the sterilization limits and sterilization parameters in order to maximize end-product quality. Moreover, last part of the review is devoted to the effect of sterilization and long-term storage on the qualitative parameters of sterilized processed cheese.

Insight into the mechanism of Maillard reaction and lipids mutually contribute to the flavor release of squid fillets during the drying process

Dried squid fillet is a popular seafood product with a unique flavor. However, its flavor release mechanism is unclear. In this study, volatile compounds (VOCs) were dynamically monitored in thawed squid (TS), salted squid (SS) and dried squid for 6 h (D6) and 24 h (D24). Subsequently, the Maillard reaction (MR) substrate, lipid oxidation index, free fatty acids and lipid profiles were detected. The results showed that the number of VOCs increased from 11 in TS (114.26 μg/kg) to 19 in D24 (1257.89 μg/kg). Besides, MR between glucose/ribose and amino acids (methionine, arginine, etc.) contributed to 3-methyl-butanal, methional and 2,3-butanedione. Meanwhile, lipid oxidation index, lipidomics and correlation analysis indicated that lipids (phosphatidylcholines and triglycerides) containing polyunsaturated fatty acids (C18:2, C20:4, C20:5 and C22:6) were precursors of 3-methyl-butanal, nonanal, heptanal, dodecane and tetradecane. Briefly, lipid hydrolysis, oxidation and MR mutually contributed to the flavor during the drying process of squid fillets.

How lipids, as important endogenous nutrient components, affect the quality of aquatic products: An overview of lipid peroxidation and the interaction with proteins

As the global population continues to grow and the pressure on livestock and poultry supply increases, the oceans have become an increasingly important source of quality food for future generations. However, nutrient-rich aquatic product is susceptible to lipid oxidation during storage and transport, reducing its nutritional value and increasing safety risks. Therefore, identifying the specific effects of lipid oxidation on aquatic products has become particularly critical. At the same time, some lipid oxidation products have been found to interact with aquatic product proteins in various ways, posing a safety risk. This paper provides an in-depth exploration of the pathways, specific effects, and hazards of lipid oxidation in aquatic products, with a particular focus on the interaction of lipid oxidation products with proteins. Additionally, it discusses the impact of non-thermal treatment techniques on lipids in aquatic products and examines the application of natural antioxidants in aquatic products. Future research endeavors should delve into the interactions between lipids and proteins in these products and their specific effects to mitigate the impact of non-thermal treatment techniques on lipids, thereby enhancing the safety of aquatic products and ensuring food safety for future generations.

Regulating effects of low salt dry-curing pre-treatment on microbiota, biochemical changes and flavour precursors of grass carp (Ctenopharyngodon idella) fillets during storage at 4 °C

Low salt dry-curing (LSD), as a healthier pre-treatment for the preservation of fishery products, is a potential technique substitute for excessively salty curing. The regulatory effects of 2 % and 3 % LSD on the quality evolution through an intrinsic correlation between microbiota succession and flavour precursors of refrigerated grass carp fillets were investigated in this study. The results showed that the LSD pre-treatment was effective in promoting proteolysis, free amino acid and fatty acid metabolism with the microbiota succession and quality evolution. Compared with unpre-treated samples, the 3 % LSD pre-treatment effectively extended the shelf life by 10 days within the acceptable quality attributes. Not only did the LSD pre-treatment lead to catalytic microbiota succession and inhibitive spoilage substance production but it also improved the flavour precursors, which are taste-active amino acids and polyunsaturated fatty acids (PUFAs). Moreover, considerable correlations between quality attributes, taste-active amino acids, PUFAs and microbiota were obtained.

Encapsulation Alleviates the Auto-browning of Epigallocatechin-3-gallate in Aqueous Solutions through Regulating Molecular Self-Aggregation Behavior

Catechins are widely recognized for superb antioxidant capability, but their application as food antioxidants is hindered by susceptibility to auto-browning under high-moisture conditions. Here, we proposed a strategy of ordered encapsulation with cyclodextrin-based metal-organic frameworks (CD-MOFs) to alleviate the auto-browning phenomenon of catechins while preserving their antioxidant capability and demonstrated the feasibility of this strategy via selecting epigallocatechin-3-gallate (EGCG) as a model. Even in aqueous solutions, EGCG@CD-MOFs still possessed delayed browning, in contrast with pristine EGCG, characterized by suppressed efficiencies on the generation of oxidative dimers (theasinensin A) and semiquinone radicals. Mechanism insights revealed that ordered encapsulation brought dual regulations on the self-aggregation behavior of EGCG: EGCG@CD-MOFs exhibited a gradual structural collapse from the framework toward irregular aggregates as O-K bonds broke progressively, which restricted molecular mobility of EGCG, and EGCG molecular conformations became constrained by the structure of EGCG@CD-MOFs as well as rich intermolecular forces, even after structural collapse.