Characterisation of pore properties of deep-fat-fried chicken nuggets breading coating using mercury intrusion porosimetry technique

The objective of this study was to characterise the pore properties of deep-fat-fried chicken nuggets coating under different processing conditions namely frying temperatures (170, 180 and 190 °C) and time (0-240 s) using porosimetry technique. Porosity range obtained was between 39.93 and 68.99%. Porosity of the freeze-dried samples decreased with frying time. The main effect of temperature on porosity was significant (P < 0.05). Porosity showed a high positive and negative correlation with moisture and fat contents, and the correlation coefficients ranged between 0.88 and 0.96 and 0.78 and 0.8, respectively. Bulk density increased with frying time, while apparent density was relatively the same. Pore distribution showed bimodality. There was no significant effect of temperature on pore size distribution. Over 70% of the pore volume is made up of pores greater than 1 μm. Pore volume ranged between 0.54 and 1.5 cm³ g^-1, and it decreased with frying time. Mean pore diameter was between 0.006 and 389 μm, while with frying time, it ranged between 0.25 and 8.32 μm. Total pore area was between 2.53 and 16.53 m² g^-1. Hysteresis phenomenon showed that some of the pores were not perfectly cylindrical in shape.