Combined Effect of High Hydrostatic Pressure and Lysine or Cystine Addition in Low-Grade Surimi Gelation with Low Salt Content

摘要

The aim of this study was to reduce the sodium chloride (NaCl) level in surimi-based products by adding lysine or cystine in combination with high hydrostatic pressure (HHP). For experiments, Alaska pollock surimi was used to prepare gels in a factorial design (3 × 3 × 2) using three additive levels (no additive, lysine, and cystine), three NaCl levels (0, 0.3, and 3 %), and two HHP levels (0 and 300 MPa/10 min/10 °C). After blending, the pastes, consisting of surimi, additives, and different levels of salt, were stuffed into casings, high pressure treated, and stored at 5 °C for 24 h (suwari gel). Subsequently, samples were heated at 90 °C for 30 min (kamaboko-type gel). To assess the degree of protein denaturation prior to gelation at 90 °C, suwari gels were analyzed by differential scanning calorimetry to determine myosin denaturation enthalpy. Kamaboko-type gels were characterized by lightness properties, water binding capacity, and mechanical properties (by puncture test). Results showed that the pressure treatment at 300 MPa and/or the addition of lysine or cystine (0 and 0.1 %) to low-sodium-chloride samples (0 and 0.3 %) resulted in gels with similar quality characteristics to those with the regular 3 % sodium chloride addition, most likely due to the protein unfolding induced by both HHP treatment and the additives used.