Post on 03-Jan-2016
description
Superheated Steam as Pretreatment to Reduce Oil Uptake During Deep-Fat
Frying of Chicken Nuggets
Julieta Rosete Hidalgo, María Elena Sosa Morales, Jorge F. Vélez Ruiz
Universidad de las Américas, Puebla, México
Stefan CenkowskiUniversity of Manitoba, Winnipeg, Canada
CSBE/SCGAB, Vancouver, BC, Jul 13-16, 2008
Why?The current proportion of children in America who are overweight have tripled since 1980.
Approximately 65% of people are overweight. The data also show that 31% of people now suffer from Obesity, compared with only 23% in 1994.
According to American statistics, obesity increases a risk of a number of life threatening conditions, such as diabetes, heart disease, stroke, high blood pressure, and some types of cancer.
Overall objective• To lower the oil uptake in deep-fat frying of chicken
nuggets by pre-treating them with superheated steam prior to frying
• Specific objectives• compare the final moisture content, • oil uptake, and • the quality attributes (color, texture, density, thermal
conductivity)
Materials and Methods
Frying of nuggets at140 and 160°C, 3 min SS temperature: 110 and 140 ºC
Duration of treatment: 3 y 5 min SS flow rate: 11.23 kg/h at 5 kPa
Methods
Temperature: Thermocouples type J
Moisture determination: 110°C, 24 h (AOAC, 1995)
Oil content: petroleum-ether extraction 6 h, 78 min
Thermal conductivity: Thermal properties analyzer (KY-2, Decagon Devices)
Density: mass volume displacement method
Texture: Penetration 15%, 5mm/s with a 2 mm dia. probe (Texture Analyzer TA- TX2)
Color: Hunter Lab values at two locations (Chroma Meter CR-400 (Minolta)
Statistical analysis: analysis of variance (ANOVA) and means separated using Tukey’s method at 0.05 significance level (Minitab)
Methods
Conditions used in combined SHS and deep-fat frying of chicken nuggets
VariableConditions
Control 1 2 3 4
Steam temperature,°C - 110 110 140 140
SS treatment time (min)
- 3 5 3 5
Frying time,160°C (s) 180 100 60 70 50
Moisture loss during deep-fat frying of chicken nuggets at 160C
30
40
50
60
70
80
0 1 2 3
Frying time (min)
Moi
stur
e co
nten
t (%
wb)
Core
Crust
Oil gain during deep-fat frying of chicken nuggets at 160C
0
5
10
15
20
25
30
0 1 2 3
Frying time (min)
Oil
co
nte
nt
(% w
b)
Core
Crust
Temperature changes during deep-fat frying of chicken nuggets for a control sample
0
10
20
30
40
50
60
70
80
0 15 30 45 60 75 90 105 120 135 150 165 180
Frying time (s)T
em
pera
ture
(°C
)
Coretemperature
0
20
40
60
80
100
120
140
160
0 30 60 90 120 150 180 210 240 270 300
SSH treatment time (s)
Tem
pera
ture
(°C
)
SSH chamber - Cond1&2 Core - Cond 1Core - Cond 2SSH chamber - Cond 3&4Core - Cond 3Core - Cond 4
…and for SS treatment with conditions 1- 4
The penetration force measured for chicken nuggets pretreated with SS and fried (conditions 1- 4) vs control
1.58
1.09
1.38
1.13
1.45
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
Force (N)
sistemas
Control
Condition 1
Condition 2
Condition 3
Condition 4
Control 1 2 3 4
Density of fried and SS pre-treated nuggets as compared to control
890.05980.05
892.72944.98 890.56
0
300
600
900
Density
(kg/m3)
sistemas
ControlCondition 1Condition 2Condition 3Condition 4
Control 1 2 3 4
Conclusions
In comparison to 3-min deep-fat frying, a reduced oil uptake was obtained in the core (2.5% wb) and in the crust (16.7% wb) when SS treated at110C for 5 min followed by 1-min frying but resulted in higher moisture content of the core (1.7-3.7% wb) and the crust (13.5-18.8% wb).
No change: in density, thermal conductivity Similar texture and more yellowish color