Dados do Trabalho

Título

Effect of Ohmic Heating on the rheological parameters of Pork burgers

Introdução

Rheological attributes are crucial for burgers because they affect texture, stability, and sensory experience, influencing both consumer satisfaction and product quality.

Material e Métodos

This study analyzed rheological parameters of pork burgers subjected to ohmic heating (OH) by creep test and uniaxial compression using a TA.XTplusC Texture Analyser (Stable Microsystems, UK) at 4°C. Pork burgers presented the same formulation and different processing methods: unprocessed (RAW), grilled (GRL), and ohmic heating: 10V (OH1), 12.5V (OH2) and 15V (OH3). All the burgers were heated from 4 to 75 °C, and stored in refrigeration (3°C±1) until analysis.

Resultados e Discussão

The modulus of deformability (E_D) reflects stiffness and increased from 24.6kPa (untreated sample-RAW) to 76.4kPa while treated with 10 V (OH1). Higher voltages (OH2: 96.5kPa, OH3: 81.6kPa) further increased firmness. Fracture strain (ε_f) were similar regardless treatment (0.819-0.908). Fracture stress (σ_f) was much higher in OH samples (OH1: 67.61kPa, OH2: 73.75kPa, OH3: 72.16kPa) compared to RAW (7.43kPa). The work of fracture (W_f) was the lowest in RAW (4.82 kJ/m³) and higher in ohmic-heated samples (OH1:34.90 kJ/m³, OH2:36.95 kJ/m³, OH3:38.45 kJ/m³). Instantaneous elastic compliance (J_0) was lowest in RAW (1.33×10⁻⁷ Pa⁻¹) but higher in OH samples, indicating increased initial compliance and flexibility. Viscoelastic compliance (J_1) was higher in RAW (1.10×10⁻⁵ Pa⁻¹) compared to OH1 (0.409×10⁻⁵ Pa⁻¹) and OH3 (0.298×10⁻⁵ Pa⁻¹), showing reduced viscoelasticity. Retardation time (τ) was longest in RAW (19.6 s) and shorter in OH-treated samples, indicating quicker stress relaxation. Newtonian viscosity (η_N) was significantly higher in ohmic-heated samples, especially OH1 (74.286×10⁶ Pa•s) and OH3 (84.7×10⁶ Pa•s), compared to RAW (9.31×10⁶ Pa•s), indicating a more viscous nature post-treatment. The increased firmness and energy to break indicate a stronger and stiffer microstructure in OH samples, which may be a reflection of the protein denaturation caused by electroporation with a subsequent water loss.

Conclusão

In conclusion, ohmic heating proved to be an effective method for improving textural attributes and hamburger products' mechanical stability. The resulting enhancements in firmness, toughness, and elastic properties elevate the overall quality and appeal of the hamburgers, making them more robust. Still, these results must be associated with other sensory analyses such as consumer acceptance.