Effects of Processing Conditions on Protein Quality of Fried Anchovy Kamaboko

Abstract

The effects of processing conditions and frozen storage on the quality of anchovy (Engraulis japonica) fried kamaboko products (raw anchovy, minced, surimi and kamaboko) were investigated. The results revealed significant variation in moisture content from 73.8 (raw meat) to 83.2% (surimi) and those decreased nearly of 64.8% in kamaboko products. Protein content decreased after kamaboko processing from 19.6 (raw meat) to 12.1% (kamaboko) due to the added ingredients. Lipid content decreased from 2.8 (raw meat) to 1.3 in minced and 0.5 % in surimi, but fried kamaboko showed 6.9 % levels in lipid. TBA values and TBARS levels were highest in kamaboko samples 89.5 and 1.9 mg/g solid and increased gradually with the storage time until 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, while levels of TI were gradually decreased with the processing conditions and during the storage time from 2.43 in raw anchovy to 0.31 mg/g solid in the kamaboko sample for 60 days of frozen storage. Noticeable changes were not observed in total essential amino acid during processing conditions. Computed protein efficiency ratio (C-PER) for kamaboko was highest (2.59) compared with whole anchovy (1.96), minced (1.94) and surimi (2.50). Anchovy kamaboko showed a higher digestibility (88.5%), and C-PER value (2.59), compared with the other surimi products. Fresh anchovy kamaboko showed almost similar values of hardness, springiness, gumminess and chewiness than commercial kamaboko, highest value of fracturability and adhesiveness, lowest value of cohesiveness and resilience, while frozen and thawed anchovy kamaboko showed the highest values for all of these rheological parameters. 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 to maintain the shelf life of anchovy kamaboko within 30 days, but not effective after 45 days due to fat oxidation.