This study aimed to determine the best storage method and storage period of pork-fish composite meatballs, prepared using pork and fish meat as raw materials by a one-step thermal molding process. The changes in the chromaticity, texture properties, pH value, total colony count, thiobarbituric acid reactive substances (TBARs) value, total volatile basic nitrogen (TVB-N) content, and sensory quality of the composite meatballs during refrigerated (4 ℃) and frozen storage (−18 ℃) were investigated. The results showed that the brightness value, whiteness value, hardness and sensory score of the composite meatballs were significantly decreased with storage time (P < 0.05). Meanwhile, the pH value was first increased and then decreased. The TBARs value and TVB-N content were significantly increased (P < 0.05). After storage at 4 ℃ for 15 days, the TBARs value exceeded 2 mg/kg, and the hardness, cohesiveness and sensory score of the product were significantly decreased by 16.29%, 12.20% and 31.11% (P < 0.05), respectively. The total bacterial count in the composite meatballs stored at −18 ℃ for 60 days was lower than the national standard limit, and both TBARs value and TVB-N content were within the national standard range. The quality characteristics remained good for 60 days at −18 ℃. In conclusion, the composite meatballs could be stored at 4 ℃ for 15 days and at −18 ℃ for more than 60 days.

A new fish noodle product was developed from a mixture of frozen fish surimi and chicken breast meat by extrusion molding. The effects of raw material temperature, extrusion height and cooking time on the tensile strength and deformation of fish noodles were studied, and these independent variables were optimized using response surface methodology (RSM). The results of single-factor experiments showed that the tensile strength and deformation reached the maximum values of 4.45 g/mm² and 3.56 at 20 ℃, respectively, and the maximum tensile deformation of 4.07 was obtained when the extrusion height was 10 cm. When the boiling time was 4 min, the maximum tensile strength and deformation of 4.31 g/mm² and 4.18, respectively were obtained. The optimum process parameters were determined as follows: raw material temperature 21 ℃, extrusion height 8 cm, and cooking time 4 min. The tensile strength and deformation of the product prepared under the optimized conditions were 7.27 g/mm² and 4.18, respectively. The relative errors between the actual and theoretical values were 0.41% and 0.48% for tensile strength and deformation, respectively, indicating the model can accurately reflect the relationship between the independent variables and the responses. The protein and NaCl contents of the fish noodles produced using the optimal process parameters were 5.7% and 0.99%, respectively, which are both better than the requirements of relevant standards.

To clarify the most suitable fish paste for preparing lion’s head meatballs, this study investigated the effect of adding 6 different silver carp fish pastes: fresh unwashed (group 1-1), fresh washed (group 1-2), frozen unwashed without antifreeze agent (group 2-1), frozen washed without antifreeze agent (group 2-2), frozen unwashed with antifreeze agent (group 3-1), and frozen washed with antifreeze agent (group 3-2) on the basic nutrients, color, texture properties, water-holding capacity, sensory and flavor properties, thiobarbituric acid reactive substance (TBARs) value, and total volatile basic nitrogen (TVB-N) content of pork/fish composite meatballs. The results showed that the contents of protein and fat in meatballs from groups 2-1 and 2-2 were lower than those in groups 3-1 and 3-2, and the contents of water, protein and fat were 61.68%, 11.32% and 19.41% for group 2-1, and 62.45%, 11.09% and 19.33% for group 2-2, respectively. The gel properties, hardness, elasticity, cohesion, and sensory quality of groups 3-1 and 3-2 were significantly higher than those of groups 2-1 and 2-2 (P < 0.05), but there was no significant difference compared with groups 1-1 and 1-2. The odor response value of groups 3 was lower than that of groups 1, and groups 3 had the highest sweetness value (3039.66) and lowest bitterness value (534.59). The TBARs value and TVB-N content in groups 1-2, 2-2, and 3-2 (with washed fish paste) were significantly lower than those in groups 1-1, 2-1 and 3-1 (with unwashed fish paste) (P < 0.05). Since fresh fish paste is not easy to store and subject to spoilage, frozen washed fish paste with antifreeze agent can be used to produce composite meatballs.

To clarify the taste differences between surimi products from different fish species and establish a taste fingerprint of surimi products, three species of marine fish (hairtail, red sea snapper, and golden thread) and three species of freshwater fish (silver carp, grass carp, and black carp) were used to produce surimi gels. The taste profiles of the gels were analyzed by an electronic tongue, high performance liquid chromatography and gas chromatography, and a taste fingerprint of surimi was established by significance analysis of microarray (SAM), cluster analysis, and heatmap analysis. The results showed that the taste characteristics of the six surimi products were significantly different. Hairtail surimi contained high levels of glutamate (2.37 mg/100 g) and aspartic acid (1.32 mg/100 g). Golden thread surimi showed the lowest contents of glutamate and aspartic acid. In addition, grass carp surimi contained relatively high contents of proline (tasting sweet) and histidine (tasting bitter). The proportion of polyunsaturated fatty acids in marine surimi was about twice as high as that in freshwater surimi. Among the freshwater surimi products, the proportion of polyunsaturated fatty acids was relatively higher in silver carp surimi. Compared with freshwater surimi, marine fish surimi had a higher content of betaine, inosine 5’-monophosphate (IMP) and guanosine 5’-monophosphate (GMP), and a lower content of hyperxanthine (Hx). Through SAM, a total of 46 differential substances were selected between the six surimi products, and the taste fingerprint constructed based on these differential substances by heatmap analysis could directly reflect the taste differences and major differential substances between freshwater and marine fish surimi.