Effects of processing conditions on the protein quality of fried anchovy kamaboko Engraulis japonica

Abstract

The effects of processing and frozen storage conditions on the quality of anchovy Engraulis japonica fried surimi gels were investigated. Protein content decreased after surimi gel processing from 19.6% (raw meat) to 12.1% (kamaboko) due to the added ingredients and change in water content. Lipid content decreased from 2.8% (raw meat) to 1.3% in minced and 0.5% in surimi, but fried kamaboko showed a 6.9% lipid level. Thiobarbituric acid values and thiobarbituric acid reactive substances levels were highest in kamaboko samples, 89.5 and 1.9 mg/g solid, and increased gradually with storage time to 101.8 and 4.6 mg/g solid, respectively. In vitro protein digestibility increased from 79.2% in raw anchovy to 88.5% in kamaboko samples. Levels of trypsin inhibitor decreased gradually with processing and during storage time from 2.43 in raw anchovy to 0.31 mg/g solid in the kamaboko sample after 60 days of frozen storage. No noticeable changes in total essential amino acid was observed during processing conditions. Computed protein efficiency ratio for kamaboko was highest (2.59) compared with whole anchovy (1.96), minced (1.94) and surimi (2.50). Fresh fried anchovy kamaboko showed similar values of hardness, springiness, gumminess and chewiness to commercial surimi gel, but a higher values were seen for fracturability and adhesiveness, and lower values for cohesiveness and resilience. The frozen and thawed anchovy kamaboko showed higher values for all of these rheological parameters compared with fresh and commercial kamaboko. Anchovy kamaboko showed the lowest lightness (62.9) and redness (0.16) and similar yellowness (11.9) compared with commercial kamaboko. Frozen storage and vacuum packaging were effective maintaining the shelf life of anchovy kamaboko within 30 days, but were not effective after 45 days due to fat oxidation. © The Korean Society of Fisheries and Aquatic Science.