photocatalytic production and use of cla-rich soy oil proctor...photocatalytic production and use of...
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Photocatalytic production and use of CLA-rich soy oil
A. Proctor & V.P. JainDepartment of Food Science
University of Arkansas
September 8th 2006Renewable Resources & Biorefineries Conference
University of York, UK
Introduction: CLA
• Conjugated linoleic acid
• Positional and geometrical isomers of linoleic acid• 28 different isomers (Adolf, 1999)• Found naturally – Beef
– Dairy products
CLA rumen biosynthetic pathway
α Linoleic acid(cis-9, cis-12 octadecadienoic acid)
cis-9, trans-11 CLA
Vaccenic acid(trans-11 octadecenoic acid)
Rate limiting step (Lawson et al, 2001)
Stearic acid(Octadecanoic acid)
Health Benefits of CLA
• Anticarcinogenic (Ha and others, 1987)
• Antimutagenic (Yeong and others, 1989)
• Antioxidant (Yeong and others, 1989)
• Decreases atherosclerosis (Ha and Pariza, 1987)
• Decreases body fat (Park and others, 1997)
• Enhances immune system (Yeong and others, 1989)
Health Benefits of CLA
• Human CLA needs are 3g/day to produce physiological effects (Ip et al. 1994)
• Actual human CLA intake 0.3g /day (Ip et al, 1989; Beaulieu et al. 2002)
• Increasing dietary animal fat to obtain desirable CLA levels is not recommended
Synthetic CLA
• Methyl esters– methyl ricinoleate (Berdeaux et al, 1997)
– methyl linoleoate photoisomerization (Seki et al., 1998)
• Vegetable oil linoleic acid– alkali isomerization (Iwata et al, 1999)
– base conjugation (Delmonte et al, 2003)
– ‘green’ photoisomerization of soy oil (Gangidi & Proctor, 2004)
Soy Oil for CLA production ?
• Soy oil composition- 50 % linoleic oil, for conversion to CLA
• Availability- 34mMT soy oil world supply (2005-2006)*
- 115mMT world vegetable oil supply (2005-2006)*
- 80% of US total oil intake is soy oil
* Oil Crops Situation and Outlook Report 2006
Outline: CLA-rich soy oil
1. Production and oxidative quality
2. Kinetics study
3. Frying study
1. CLA-Rich Soy Oil Production and Oxidative Quality
J. Ag and Food Chem. 2006 54: 5590-5596
Customized System
UV Lamp
Customized System
Reaction Vessel
Customized System
Immersion Well
Customized System
Customized System
•
Effect of Iodine Concentration – Processing(Jain & Proctor 2006)
700g fully refined commercial soy oil
• iodine concentration 0.1, 0.15, 0.25 %
• irradiation for 0 – 144 hours (duplicate)
• temperature 22-25 °C
• stirred with magnetic stirrer
CLA isomer: FAME analysis (triplicate) (Christie & others 2001; Ma & others 1999)
• total CLA• cis 9, trans 11 CLA• trans 10, cis 12 CLA• trans, trans isomers (8,10; 9,11; 10,12)
Lipid oxidation products • hydroperoxides: ATR FTIR (Ma & others 1999)• aldehyde carbonyls: 1H NMR (Ma & others 1999)• GC – MS: hexanal (Monsoor & Proctor 2004)
Effect of Iodine Concentration – Analysis
Effect of iodine concentration on total CLA Yields
0
5
10
15
20
25
0 50 100 150time (h)
CLA
(% to
tal o
il)
0.25 % Iodine0.15 % Iodine0.1% Iodine
LSD0.05 = 0.67
Effect of iodine concentration on cis 9, trans 11 CLA
0
0.4
0.8
1.2
1.6
2
0 50 100 150time (h)
CLA
(%to
tal o
il)
0.25 % Iodine0.15 % Iodine0.1 % Iodine
LSD0.05 = 0.05
Effect of iodine concentration on trans 10 cis 12 CLA
0
0.4
0.8
1.2
1.6
2
0 50 100 150time (hours)
CLA
(% to
tal o
il)
0.25 % Iodine0.15% Iodine0.1% Iodine
LSD0.05 = 0.05
Effect of Iodine Concentration on t, t (8,10; 9,11; 10,12) CLA
0
20
5CL
10ta
15
A (%
tol o
il)
0.25 % Iodine0.15 % Iodine0.1 % Iodine
LSD0.05 = 0.48
0 50 100 150time (h)
Dairy Beef Soy oil (Proctor & Jain 2006)
CLA fatty acid
c-9, t-11 CLA 0.6 0.1 1.8
t-10, c-12 CLA <0.01 0.02 1.7
Total CLA 0.7 0.6 23.8
CLA (%) content of bovine lipids and soy oil
t, t CLA also has major health benefits (Gavino 2002; Lai et al 2005)
Oxidation Analysis
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
1000 1500 2000 2500 3000 3500
0% I2, 0 hour
0.1% I2, 144 hours
0.15% I2 , 144 hours
0.25% I2, 144 hours
Hydroperoxide peaks absent(3400 to 3600 cm-1)
ester C=O1750 cm-1Hydrocarbons
ATR – FTIR spectra of photoisomerized oil samples for hydroperoxide peaks
Conjugated = bond
1H NMR spectra of 144 hour photoisomerized oil for proton peaks of aldehyde carbonyl
12.0 11.0 10.0 9.0 8.0
ppm
Aldehyde CHO range
144 hours photoisomerized oil sample, 0.15 % Iodine
1H NMR spectra of unirradiated oil of aldehydecarbonyl proton peaks
8.09.010.011.012.0
ppm
Aldehyde CHO range
Unirradiated oil , 0.15 % Iodine
1H NMR spectra of unirradiated oil with 200 ppm hexanal
8.09.012.0 11.0 10.0
ppm
Aldehyde CHO range
Unirradiated oil with 200 ppm hexanal, 0.15 % Iodine
Partial GC - MS chromatograms: hexanal
6.05.04.03.02.0
6.05.04.03.02.0
6.05.04.03.02.0
Unirradiated oil, 0.15 % Iodine
Unirradiated oil with 1 ppm added hexanal, 0.15 % Iodine
144 hours photoisomerized oil sample, 0.15 % Iodine
• trans, trans major isomers produced
• t, t CLA also has health benefits
• c, t & t, c CLA levels greater than in dairy/meat
• long processing time
• ‘apparently’ relatively oxidatively stable:
Significance
*Linoleic acid CLA
2. Kinetics
CLA-isomers Irradiation
cis-9, cis-12 linoleic acid
cis-9, trans-11 CLA, trans-10, cis-12 CLA, trans-9, cis-11 CLA, cis-10, trans-12 CLA
trans- , trans- CLA(8,10 : 9,11 : 10,12)
A
B
C
Soy oil C18:2 fatty acid profile during photo-irradiation
0
10
20
30
40
50
60
0 2
Fatty
aci
d co
nc (%
tota
l oil)
. Linoleic acidcis-, trans- / trans-, cis-trans-, trans- C
4 48 72 96 120 144Time (h)
LA
A
B
C
CLA-isomers: irradiation
cis-9, cis-12 linoleic acid
cis-9, trans-11 CLA, trans-10, cis-12 CLA, trans-9, cis-11 CLA, cis-10, trans-12 CLA
trans- , trans- CLA(8,10 : 9,11 : 10,12)
A
B
C
second order kinetics
zero order kinetics
• A to B reaction dependent on LA conc.
• B to C reaction is fastest as it achieves the most thermodynamically stable CLA form
Kinetics
3. CLA-rich soy oil and frying
C18 fatty acids in photoisomerized soy oil, and oil extracted from potato chips fried in CLA-rich soy oil (n=4)
Photoisomerized oil (%) Oil extracted from chips (%)
Linoleic Acid 31.46a 30.87a
Linolenic Acid 4.73a 4.64a
c 9, t 11 CLA 1.78a 1.79a
t 9, c 11/c 10,t 12 CLA 2.74a 2.81a
t 10, c 12 CLA 1.75a 1.81a
t, t CLAb 14.73a 14.55a
Means with different letters within rows differ significantly, p<0.05Fatty acids expressed on total oil w/w basisbt,t CLA consists of t,8, t,10 CLA, t,9,t,11 CLA & t,10, t,12 CLA
PV of RBD & CLA rich oil &these oils extracted from potato chips after frying
PV (Meq / 1000g sample)
RBD soy oil (control) 1.0b
CLA-rich soy oil (control) 0.9a
Oil extracted from chips made with CLA-rich oil 1.0b
Oil extracted from chips made with RBD oil 0.9a
CLA-rich soy oil after frying 1.0b
Values are means, n=4. Means with different letters within a column differ significantly, p<0.05
• Oil Composition stable at frying temperatures
• FA composition in chip similar to that of oil
• Frying oil and extracted oil was oxidative stabile
Significance
• Pr
RESEARCH ISSUES
ocessing:
inor compounds:and oxidation compounds:
long processing time, processing modifications: USDA NRI grant 2006-2009
• MiodoGC-MS studies
• Shelf Life:oxidation stability studies
• Oxidation chemistry:oxidation/polymerization mechanisms