We compared the freezing rates of PEF-treated chicken samples with non-PEF-treated samples. Influence of the (prior) application of pulsed electric fields (PEF) on the freezing rates of chicken samples.
Main conclusions
- No improvement in freezing rate was observed between PEF-treated samples and non-PEF-treated samples.
- No improvement was observed in the water-holding capacity (WHC) and cook-loss (CL) of thawed samples.
Background
PEF is a technology that produces cellular electroporation that favours mass transfer processes, such as juice extraction, drying and the maceration process, among others. There is no clear conclusion about its effect on the food-freezing process, but there are articles that show its potential to improve the functionality, extractability and recovery of nutritional compounds, as well as to accelerate the freezing process.
Purpose of the study
The objective of this study was to evaluate the potential of PEF to accelerate the freezing process of chicken samples and its subsequent impact on sensory properties.
Methods
- Sample: chicken
- PEF treatment: 1 kV/cm; 28 kJ/kg; 200 µs.
- Freezing conditions: freezing tunnel; air temperature of -20 °C.
- Thawing conditions: cold room at 4 °C.
- Water-holding capacity (WHC): 5–6 g samples were prepared and wrapped in a gauze and placed in a Falcon tube with glass pearls. These tubes were centrifuged at 1300 rpm for 15 minutes. WHC = 100 - weight loss (%)
- Cook-loss (CL): samples of 2 g were weighed and placed in test tubes and immersed in boiling water until a final sample temperature of 75 °C was reached at the thermal centre.
CL = weight loss (%)
What was investigated
Freezing time
The freezing time to reach -15 °C was 65 minutes for both those samples that were pre-treated with PEF and those that were untreated.
Water-holding capacity (WHC)
No improvement was observed between PEF-treated samples and non-PEF-treated samples.
Cook-loss (CL)
No improvement was observed between PEF-treated samples and non-PEF-treated samples.