EFFECT OF TEMPERATURE ON THE PHYSICAL PROPERTIES OF CHICKEN STRIPS DURING DEEP-FAT FRYING

Figures & data

Figure 1. Typical temperature profile of chicken slabs during deep-fat frying at three temperatures.

Predictive Empirical Equations for the Central Temperature as a Function of Time of Chicken Slabs at Three Frying Temperatures

Oil Temperature (°C)	Equation	Correlation (r)
130^a	T=35.415 log t+77.698	0.872
140^b	T=38.875 log t+80.367	0.886
150^c	T=45.137 log t+83.253	0.886
T=−0.002t ^9+ 0.064t ^8− 0.97t ^7 +8.008t ^6−37.867t ^5+101.111t ^4−130.128t ^3+16.473t ^2+123.506t+15.633	0.951
T=91.420t+12.619 (t from 0 to 1 min)	0.989
T= 3.343t+89.895 (t from 1 to 8 min)	0.947

^aBased on twelve experimental tests.

^bBased on twelve experimental tests.

^cBased on fifteen experimental tests.

Figure 2. Experimental temperature data for frying of chicken strips at 150°C.

Table 2. Thermal Properties Evaluated During the Frying Process of Chicken Slabs at Three Frying Temperatures

Thermal Diffusivity Date
Average Heat Transfer
Oil Temperature (°C)	n	α (m^2/s)×10^7	σ×10^7	Coefficient (h) (W/m^2°C)
130	59	1.458	0.333	207.6
140	64	1.459	0.251	223.3
150	95	1.478	0.365	331.0

n=Number of samples.

σ=Standard deviation.

Figure 3. Moisture content profiles of chicken slabs during deep-fat frying at three temperatures.

Figure 4. Average moisture content of chicken strips during deep-fat frying at three temperatures

Table 3. Predictive Equations for Moisture Content as a Function of Time of Chicken Slabs at Three Frying Temperatures

Oil Temperature (°C)	Equation	Correlation (r)
130	w= 71.535−5.056t	0.975^a
W= 71.750−5.023t	0.991^b
W =80.422−15.380t ^0.5	0.978^b
140	w=71.406−7.039t	0.970^a
W= 71.865−7.142t	0.990^b
W= 82.743−20.795t ^0.5	0.966^a
150	w=69.818−10.744t	0.924^a
w =70.698×10^−0.099t	0.895^a
W =64.631−8.031t	0.943^b
W= 52.743−39.237 log t	0.974^a
W= 75 e^−0.2845t	0.999^b
W =74.328−22.213t ^0.5	0.988^b

^aBased on all moisture content data (w).

^bBased on average moisture content data (W).

Figure 5. Measured and predicted moisture content for frying of chicken slabs at 150°C.

Table 4. Calculated Moisture Diffusion Coefficients and Activation Energy for Frying of Chicken Slabs

Oil Temperature (°C)	Diffusion Coefficient, D (m^2/s)	Activation Energy, E a (kJ/mol)
130	0.886×10^−8
140	1.299×10^−8	34.39
150	1.544×10^−8

Figure 6. Oil content profile of deep-fat fried chicken strips as influenced by frying temperature and time.

Table 5. Predictive Equations for the Oil Content as a Function of Time of Chicken Slabs at Three Frying Temperatures

Oil Temperature (°C)	Equation	Correlation (r)
130	o=1.184+0.438t	0.813^a
O= 1.071+0.460t	0.906^b
O=1.822t ^0.366	0.925^b
O= 0.492+1.266t ^0.5	0.970^b
140	o=1.717t ^0.495	0.872^a
O= 1.091+0.533t	0.843^b
O=1.751t ^0.466	0.845^b
O= 0.408+1.475t ^0.5	0.908^a
150	o=2.497+2.850 log t	0.763^a
O= 2.400+2.574 log t	0.900^b
O =0.894+1.583t ^0.5	0.881^b

^aBased on all oil content data (o).

^bBased on average oil content data (O).

Table 6. Correlation Between Oil Content and Moisture Content for Frying of Chicken Strips at Three Temperatures

Frying Temperature (°C)	Equation	Correlation (r)
130	O=11.978−0.149 W	0.966
140	O=10.889−0.134 W	0.848
150	O=8.157−0.102 W	0.944
Average temperature-independent	O=10.152−0.126 W	0.930

O=Average oil content.

W=Average water content.

Table 7. Predictive Models for Percentages of Length and Width Shrinkage and Thickness Expansion of Fried Chicken Slabs at Three Temperatures

Temperature (°C)	Dimension	Equation	Correlation (r)
130	Length shrinkage	L=24.95+7.589 log t	0.825
Width shrinkage	wi=17.838+2.297 t	0.937
Thickness expansion	th=43.58−4.120 t	0.939
140	Length shrinkage	L=24.895+1.381 t	0.930
Width shrinkage	wi=17.642+2.715 t	0.931
Thickness expansion	th=44.96−5.649 t	0.940
150	Length shrinkage	L=26.161+1.441 t	0.957
Width shrinkage	wi=20.79+13.382 log t	0.946
Thickness expansion	th=52.241 (10^−0.88t)	0.948