Quality Assessment of Lightly Salted Atlantic Salmon Fillets Injected With Brine Solutions Containing Sodium Bicarbonate

Abstract

The objective of this study was to produce lightly salted Atlantic salmon ( Salmo salar L.) fillets with improved technical and sensory attributes. Brine containing 0, 50, 150 or 250 g/L NaCl with or without additional 25 g/L sodium bicarbonate (NaHCO 3) was injected into the fillets. 24 hours after injection, the muscle NaCl concentration ranged from 0.2 to 2.4%, and pH ranged from 6.18 to 6.48. Untreated fillets lost 1% weight, whereas the weight increase was 4% of the fillets injected with NaCl or a combination of NaCl and NaHCO 3. Liquid loss (LL) during storage at 4°C for three days were similar for the untreated fillets and the fillets injected with 50 g/L NaCl (LL 12%), while LL was reduced to 7.5% with the addition of NaHCO 3 to the 50 g/L brine. LL was the lowest for the groups injected with 250 g/L NaCl. Injection of NaCl resulted in higher lipid oxidation compared with untreated fillets, determined as doubled levels of alkanals (4.3 vs. 10.4 ng/g) and pentenols (8.0 vs. 15.1 ng/g), but addition of NaHCO 3 counteracted the action of NaCl as a pro-oxidant. Furthermore, NaHCO 3 addition of the 50 g/L brine significantly improved the color of raw and cooked fillets (higher a*-value, Salmo Fan score, red/orange color tone). Sensory assessment of cooked fillet revealed that brine added NaHCO 3 gave superior odor (less rancid), flavor (less metallic) and higher scores for tenderness. In conclusion, addition of NaHCO 3 to the brine solutions improved liquid retention, storage stability, color, odor and flavor of lightly salted salmon fillets.