Process and Quality Characteristics of Ocean Pout Surimi

Abstract

Experiments were conducted to utilize ocean pout (Macrozoarces americanus) for the product ion of surimi, a washed fish mince made stable for frozen storage by incorporation of cryoprotectants. Principal factors affecting gel forming properties, freeze-thaw stability and sensory quality of ocean pout surimi were examined alone, as well as, in combination with either red hake or turkey meat under various conditions. Parameters studied were: i) moisture and salt levels, ii) thermal gelation in a single as well as a two-stage heating process, iii) optimization of gel formimg properties and freeze-thaw stability of blended surimi, iv) texture-modifying effect of different nonfish proteins in the ocean pout surimi and its applicability as a binder in formed products, and v) use of ocean pout in the turkey as an extender. Compressive force (cohesiveness) and penetration force (rigidity) were measured for the evaluation of gel forming properties of surimi, and expressible moisture for water binding ability as well as freeze-thaw stability of surimi gel. Sensory quality of ocean pout incorporated turkey roll was also evaluated. The 74% moisture level produced the most cohesive gel while NaCl progressively increased cohesiveness and rigidity, accompanied by a general decrease in expressible moisture. Thermal gelation was best demonstrated on a single-stage heating at 90 C by maintaining the integrity of the gel; regardless of the length of time of heating as compared to a two-stage heating, heat~setting at different temperatures and subsequent cooking at 90 C. Blending ocean pout surimi with red hake surimi resulted in increases in all measured physical characteristics as the red hake surimi level increased. At the 5% level, egg albumin outperformed the rest of nonfish proteins in improving the texture as well as reducing the amount of expressible moisture. The gel strengthening ability of egg albumin reached a maximum at a 2% level above which significant decrease in all parameters were observed. The development of a turkey roll from a blend of ocean pout surimi and turkey at different combinations, showed that the product was acceptable up to a 50% replacement with ocean pout surimi; regardless of whether a nonfish protein was incorporated or not.