Effects of ultrasound and sodium reduction on restructured cooked ham formulated with PSE pork loin

Abstract

Developing cooked cured meat products with superior technological quality and lower sodium content has become a significant challenge for the food industry, primarily due to limitations associated with the use of PSE meat and NaCl reduction in formulations. In this context, emerging technologies such as high-intensity ultrasound are being investigated as alternatives to improve water retention, texture, and structural stability in processed products. Thus, the objective of this study was to evaluate the effects of ultrasound application on the technological quality of cooked cured products made from PSE and RFN meat. Two experiments were conducted to evaluate the effects of ultrasound on cooked ham products made from RFN and PSE pork. In the first experiment, different ultrasound power levels and durations at 20 kHz were evaluated (255 and 400 W for 5, 10, and 15 min). In the second study, ultrasound at 20 kHz and 450 W for 10 min was applied in conjunction with sodium reduction treatments and partial NaCl replacement with KCl: a control with 1.8% NaCl (CT), partial replacement with 1.08% NaCl + 0.75% KCl (RTK), and NaCl reduction to 0.75% (RT). The results demonstrated a significant effect (P<0.05) of raw material quality on technological parameters. In the first study, cooked hams made from RFN meat exhibited lower cooking loss (4.34%) and greater hardness (83.66 N) compared to PSE products, which showed higher cooking losses (6.28%) and lower hardness (66.99 N). Residual nitrite levels were also higher in RFN products (52.26 mg/kg) compared to PSE products (26.72 mg/kg). In the second experiment, RFN products exhibited lower reheating losses (5.59%) and higher chewiness (20.39 N), whereas PSE products showed higher losses (7.92%) and lower chewiness (17.12 N). Severe NaCl reduction significantly increased cooking loss (11.78%) and reduced hardness (60.94 N), while partial substitution with KCl maintained values similar to the control. Ultrasound treatment had a limited effect, reducing only syneresis (5.69%) and losses during initial freezing cycles, with no significant changes in pH, instrumental color, or lipid oxidation. Thus, raw material quality was the primary factor determining the products' technological performance, with RFN meat yielding better results than PSE meat. Ultrasound showed complementary potential but was insufficient to fully offset the negative effects associated with PSE meat and low-sodium formulations.