Frying is an old method of processing food, especially fish. Mackerel is one of the most consumed fish worldwide because of its high nutritional value. Previously, only a study on the effects of deep frying of fried mackerel has been performed. However, no study has been conducted on the effects of different frying methods on the physiochemical and nutritional properties of chub mackerel. Therefore, in this study, we evaluated the physiochemical and nutritional characteristics of deep fried, vacuum fried, and air fried chub mackerel. Thawing methods were compared and the best method was selected. High frequency defrosting (HFD) was used to thaw frozen fillet mackerel before frying. Response surface methodology (RSM) was used to optimize the temperature and frying time of the three frying methods. The physiochemical and nutritional characteristics, including volatile basic nitrogen (VBN), thiobarbituric acid-reactive substances (TBARS), pH, overall acceptance, proximate, fatty acid, and amino acids of fried mackerel were investigated. The HFD exhibited the lowest number of drips with a short thawing time. The RSM showed that the optimum temperature and frying time for deep, vacuum, and air frying were 165 °C for 3 min, 95 °C for 7 min, and 160 °C for 15 min, respectively. Vacuum frying showed the lowest increase in VBN, TBARS, and pH, and significantly (p < 0.05) differed from the others. It also resulted in increased amino acid and preserved fatty acid content. These findings suggest that vacuum frying is the best frying method which has little oxidation and can maintain nutrition. The results of this study could be applied in the fisheries industry to produce the best fried mackerel and preserve its high nutritive value.

Chub mackerel (CM) is a commercial fish in Korea, owing to its availability and nutritional values. This study aimed to develop a ready-to-heat (RTH) Korean preparation of CM, known as Godeungo gangjeong. We utilized vacuum frying technology to fry the CM and evaluated its quality. Conventional frying with a deep fryer was performed in parallel to assess the superiority of the vacuum fryer. We optimized the frying conditions of vacuum frying (VBF) and deep frying (DBF) using response surface methodology. At optimum conditions of 95 °C for 7 min 42 s, VBF produced better sensory, chemical, and microbial properties than DBF at 190 °C for 5 min 30 s. The nutritional values, including amino acid and fatty acid contents, were investigated and found to be higher in VBF than in DBF. Sensory properties also showed better scores on VBF than DBF, especially in appearance, aroma, taste, and overall acceptability. The VBF produced lower volatile basic nitrogen (VBN), thiobarbituric acid reactive substances (TBARS), and total bacterial count (TBC) than DBF. The findings confirmed that vacuum frying is a better option to produce RTH Godeungo gangjeong, since it provides less oxidation and maintains the product quality. Using the Arrhenius approach, the product was concluded to preserve both quality and safety for 9 months of storage at −18 °C.

In Korea, the web-foot octopus (Amphioctopus sp.) is commonly consumed as jjukkumi bokkeum, a spicy stir-fried octopus dish. Using steaming and smoking methods, we made jjukkumi bokkeum home meal replacement (HMR) products. The response surface methodology (RSM) was employed to optimize the steam and smoke processes. Quick freezing was applied to freeze the test product at −35 °C. Then, the physicochemical, biological, nutritional characteristics, and shelf-life of the test HMR products were evaluated. The optimal conditions for steaming and smoking were 95 °C for 2 min and 70 °C for 11 min, respectively. The pH, volatile basic nitrogen content, and thiobarbituric acid-reactive substances content decreased after steaming and smoking, indicating that these processes maintained these parameters well. Sensory evaluation revealed that there were no changes in these characteristics after freezing and reheating. Further, the test HMR products contained the daily nutritional requirements of macro and micronutrients, as well as amino acids and fatty acids. The shelf-life of the HMR products was estimated to be 15 months. The findings of this study indicate that the application of steam and smoke processes to produce a jjukkumi bokkeum HMR product results in a high-quality product with a long shelf-life.

Changes in lifestyle and food consumption patterns have contributed to a growing demand for home meal replacements (HMRs), emphasizing the need for high-quality seafood-based products. This study aimed to develop a grilled Pacific cod (Gadus macrocephalus) fillet HMR prototype and to evaluate optimal processing conditions, quality characteristics, and shelf-life stability. High-frequency thawing was selected to improve raw material handling by minimizing drip loss to 11.91% and reducing thawing time to 15 min. A thyme-based marinade at a concentration of 3% for 20 min was applied to reduce odor and enhance sensory quality, and superheated steam grilling was compared with conventional heating methods. Processing parameters were optimized using response surface methodology, and smoking conditions were evaluated using different wood types. Superheated steam grilling produced superior sensory attributes under optimal conditions of 340 °C for 4 min, followed by cherry wood smoking at 60 °C for 5 min. The combined processing approach reduced total bacterial counts while maintaining acceptable physicochemical quality characteristics. Thermal processing increased texture firmness and nutritional density due to moisture loss, reduced lipid oxidation, and modified amino acid and fatty acid profiles. Shelf-life modeling indicated safe storage for up to 18 months under frozen conditions. These findings demonstrate that integrated marination, superheated steam grilling, and controlled smoking can be effectively applied to produce a safe, stable, and high-quality grilled Pacific cod HMR product.