Embed Size (px)
Citation preview
Crystallization Properties of Crude Palm Oil in Static and
Dynamic Condition
Nur WulandariHanna Mery Aulia
FEN-0.2.4
• Department of Food Science & Technology -Faculty of Agricultural Enginering & Technology
• SEAFAST CenterBOGOR AGRICULTURAL UNIVERSITYINDONESIA
Indonesia is the largest producer of palm oil in the world
Crude palm oil (CPO)
Transportation in relatively high T > 55 oC prevent crystallization
Study of fat crystallization of CPO
2
Introduction
www.surabaya.indonetwork.co.id
3
Research on crystallization properties of palm oil
Crystallization study were conducted in isotermal condition solid sample
•Vuillequez et al. (2010); Tarabukina et al. (2009); Graef et al. (2008, 2009); Chong et al. (2007); Miskandar et al. (2005)
Crystallization properties of CPO in static and dynamic condition
Treatments of cooling rateand shear rate
Objective
The objective of this research was to obtainbasic data about fat crystallization propertiesof CPO under static and dynamic condition
44
5
Materials Crude palm oil (CPO)
sample from private industry in Jakarta
Methods
6
Instruments of Analysis
•DYNAMIC CONDITION•Rheological Properties•T 55 - 25 oC (hold)•Cooling rate (0.2, 0.5, 1 ºC/minute)•Shear rate (40, 100, 400 s-1)
Haake ViscometerRV20 (Karlsruhe, Germany)
•STATIC CONDITION•Solid fat content (SFC)
•T 55 – 25 oC (hold)
•Cooling rate (0.2, 0.5, 1 ºC/minute)
Nuclear Magnetic Resonance (NMR) Analyzer Bruker Minispec PC 100
Methods
Crystallization kinetics were studied by Avrami model with parameters of crystallization rate (k) and Avrami constant (n) (Metin & Hartel 2005)
Value of n and k were calculated from linearization of Avrami equation , as slope and intercept at ln t = 0
F is crystal fraction developed during crystallization time (minutes)
ln (-ln (1-F) = ln (k) + n [ln(t)] (1)
Half time of crystallization (t1/2) calculated from Arrhenius equation
(t1/2)n = 0.693/k (2)
7
Methods
7
Results: Static condition
SFC were increased during isothermal crystallization at cooling rate of 1, 0.5, and 0.2 ºC/minutes
8
1 oC/min 0.5 oC/min
0.2oC/min
Determination of crystalization kinetic of CPO using Avrami model
(cooling rate 0.2 oC/min, Tc 25 oC, hold 40 minutes)
9
ParametersCooling rate (ºC/min)
0.2 0.5 1Avrami exponent(n) 1.614 2.032 2.170Avrami constant (k) 0.013 0.003 0.002Induction time (min) 2 5 7SFC max (%) 12.815 11.245 10.725t ½ (min) 11.953 15.750 14.884
10
CPO crystallized under slow cooling rate had higher solid fatcontent (SFC); higher Avrami constant (k) and lower Avramiexponent (n) than CPO which crystallized under fast cooling.CPO which crystallized under fast cooling had higher inductiontime and crystallization half time.
CPO crystallization kinetic parameters in static condition , studied from the increment of
isotermal SFC at 25 ºC
11
Apparent viscosity of CPO during shear rate and cooling rate treatments, hold at 25 oC for 60 minutes
1 oC/min 0.5 oC/min
0.2oC/min
Results: Dynamic condition
CPO crystallization kinetic parameters in dynamic condition, studied from increment of isotermal
viscosity at 25 ºC
Cooling rate
(ºC/min)
Shear rate (s-1)
Induction time (min)*
0.2
400 2.5a
100 9.5b
40 10b
0.5
400 11.5c
100 20.5d
40 21d
1
400 15e
100 20.5d
40 21d12
*data followed by different alphabets showed significant difference (p<0.05)
CPO which crystallized under higher shear rate:had higher rate of crystallization with lower induction time
Conclusions
13
Cooling rate and shear rate were the important parameters in crystallization properties of CPO. CPO which crystallized under higher shear rate had higher rate of crystallization and lower induction time
Acknowledgement Doctoral Grant from Directorate
General of Higher Education, Ministry of Education & Culture, Republic of Indonesia
SEAFAST Center –LPPM IPB
14
