Download - Chem Changes of Olive Oil v.2
-
7/29/2019 Chem Changes of Olive Oil v.2
1/29
MoFT 2013/14 1
Chemical Changes of Olive Oil
FST 5101 Macro-components of Foods
Law Boon Pin
Suraya HashimDevathaa Nadarajan
Nur Zahidah Syahirah Marzuki
Rumaizah Muhammad
-
7/29/2019 Chem Changes of Olive Oil v.2
2/29
Chemistry of Olive OilFactors that affect the composition of olive oil:
Olive variety
Edaphoclimatic condition (different soil & climatic conditions)
Harvesting period and technique
Fruit ripening degree
Leaf removal, extraction system
Best olive producing area:
cool region - Tuscany
MoFT 2013/14 2
-
7/29/2019 Chem Changes of Olive Oil v.2
3/29
Chemistry of Olive Oil Composition of olive oil
MoFT 2013/14 3
Source: http://www.fao.org/docrep/003/x6545e/X6545E01.htm
-
7/29/2019 Chem Changes of Olive Oil v.2
4/29
Composition of Olive Oil
MoFT 2013/14 4
Major Minor
Triacylglycerols :
Myristic acid (C14:0)Oleic Acid (C18:1)
Linoleic Acid (C18:2)
Palmitic Acid (C16:0)
Stearic Acid (C18:0)
Linolenic Acid (C18:3)Arachidic acid (C20:0)
Glycerol, FFA
Phenolic Compound
Tocopherol (Vitamin E), Vitamin K
Pigments: e.g. chlorophyll , carotenoid
Phospholipids
Sterols
Mono- & Diglycerides
Fatty alcohols, waxes, and diverse
aroma compounds
-
7/29/2019 Chem Changes of Olive Oil v.2
5/29
Fatty Acids in Olive Oil
MoFT 2013/14 5
Fatty acid Type Percentage (%)
Oleic acid (C18:1) Monounsaturated (Omega-9) 55.0 83.0
Linoleic acid (C18:2) Polyunsaturated (Omega-6) 3.5 21.0Palmitic acid (C16:0) Saturated 7.5 20.0
Stearic acid (C18:0) Saturated 0.5 5
Myristic acid (C14:0) Saturated 0.1 1.2
Arachidic acid (C20:0) Saturated 0.1 0.3
Linolenic Acid (C18:3)
(-Linolenic acid)Polyunsaturated (Omega-3) 0.0 1.5
Source: http://www.oliveoilsource.com/page/chemical-characteristics
-
7/29/2019 Chem Changes of Olive Oil v.2
6/29
Chemistry of Olive Oil -cont
Tryglycerides in olive oil: OOO > POO > OOL > POL > SOO
Chemical reactions involving olive oil Interesterification
Hydrogenation
Hydrolysis
Oxidation
MoFT 2013/14 6
-
7/29/2019 Chem Changes of Olive Oil v.2
7/29
Interesterification in Olive Oil Is a process where the fatty acids migrate and
recombine with glycerol in a more randomfashion under certain conditions
The distribution of fatty acids is changed onglycerol backbone, while the nature of the fattyacids remain the same.
Interesterification is often used to increase the
solidity of fat without partial hydrogenation.
This leads to significant changes in physicalproperties of fat such as the melting point.
MoFT 2013/14 7
-
7/29/2019 Chem Changes of Olive Oil v.2
8/29
Interesterification in Olive Oil
MoFT 2013/14 8
rearranges the fatty acids on the glycerol backbone of a triglyceride
-
7/29/2019 Chem Changes of Olive Oil v.2
9/29
Interesterification in Olive OilThe interesterification reaction may be chemical or enzymatic:
CHEMICALLY: spontaneously by heating above the melting
temperature of triglyceride. It is easier and faster in the
presence of metal catalysts.eg: zinc oxide, iron oxide, etc. Or
alkali like NaOH.
*relatively cheap and is used on an industrial scale to produce
plastic saturated fat content in low or no trans fat.
MoFT 2013/14 9
-
7/29/2019 Chem Changes of Olive Oil v.2
10/29
Interesterification in Olive Oil Enzymatically: (Enzymes such as esterase or acylase act as
catalyst) offers better control of products generated duringthe reaction.
Very specific and can be selected to cleave specific bondsesters, ie occupying a particular position on the molecule.
Conducted at lower temperatures than chemical
interesterification, there is less degradation.
Finally, the interesterification process can produce any type offat or oil includes heavy fats suitable for deep-frying, semi-solid fats to make margarine, or liquid oils for bottling.
MoFT 2013/14 10
-
7/29/2019 Chem Changes of Olive Oil v.2
11/29
Hydrogenation in Olive Oil Hydrogenation is a
process of forcing H2
into oil at high
temp/pressure As a result, double
bonds in oil open and
becomes single bonds
Catalyst used: usuallynickel, but sometimes
palladium, rhodium
or platinum
MoFT 2013/14 11
-
7/29/2019 Chem Changes of Olive Oil v.2
12/29
Hydrogenation in Olive Oil Double bonds not only decrease in number but also migrate
during hydrogenation
Oils contain cis- C=Cs and they are not uniform in structure
The purpose of hydrogenation is to increase shelf life and tomake oil more stable
Partial hydrogenation is usually preferred
Isomers of unsaturated fatty acids are formed
Cis- bonds are converted into trans- bonds
MoFT 2013/14 12
-
7/29/2019 Chem Changes of Olive Oil v.2
13/29
Factors affecting hydrogenation
MoFT 2013/14 13
-
7/29/2019 Chem Changes of Olive Oil v.2
14/29
Trans Fatty Acids
Usually found in hydrogenated shortenings and margarines
Trans-fat are labeled as saturated fats Increases LDL and lowers HDL
Trans fat is bad for health as its characteristics resemble to saturated
fat
MoFT 2013/14 14
-
7/29/2019 Chem Changes of Olive Oil v.2
15/29
Hydrolysis in Olive Oil Two types of reaction: chemical hydrolysis
and enzymatic hydrolysis
Enzymatic occurs in olive crop whereaschemical occurs after oil is extracted fromcrop
Enzymatic reaction depends on humidity,temperature, ferment, and various
microorganisms
Hydrolysis is basically a reaction whichsplits the esters using water
MoFT 2013/14 15
-
7/29/2019 Chem Changes of Olive Oil v.2
16/29
Hydrolysis in Olive Oil Reactions could be conducted using diluted acid or diluted
alkali
Both reactions are heated under reflux
MoFT 2013/14 16
Diluted Acid Diluted alkali
Reversible reaction Non-reversible reaction
Produce carboxylic acid and
glycerol
Produce salt of a carboxylate and
glycerol
-
7/29/2019 Chem Changes of Olive Oil v.2
17/29
Hydrolysis in Olive Oil
Hydrolysis using diluted alkali is also
known as saponification because of its
relationship with the soap processing.
Ester linkage is broken to form glycerol
and soap
MoFT 2013/14 17
-
7/29/2019 Chem Changes of Olive Oil v.2
18/29
MoFT 2013/14 18
-
7/29/2019 Chem Changes of Olive Oil v.2
19/29
Oxidation is one
of the major
causes in olive
oil quality
deterioration.
MoFT 2013/14 19
Oxidation in Olive Oil
-
7/29/2019 Chem Changes of Olive Oil v.2
20/29
Initiators of Oxidation
MoFT 2013/14 20
Heat
Light (Photo-oxidation)
Exposure to oxygen
(triggered when the oil enters in
contact with oxygen in the air,first during the milling process,
and later on during storage in
tanks and bottles).
The more the heat, light and O2exposure, the faster is the
oxidation rate
-
7/29/2019 Chem Changes of Olive Oil v.2
21/29
Oxidation in Olive Oil
MoFT 2013/14 21
Figure 1 shows how the oxidation of fatty acids in olive oil
changes with time.
-
7/29/2019 Chem Changes of Olive Oil v.2
22/29
Effects of Oxidation towards Olive Oil
MoFT 2013/14 22
Unpleasant odor and flavor:
The more the peroxides present, the more rancid the oil
-
7/29/2019 Chem Changes of Olive Oil v.2
23/29
Antioxidants in Olive Oils
MoFT 2013/14 23
Vitamin E (alpha-tocopherol)
Carotenoids
Phenolic compounds (simple phenols:
hydroxytosol and tyrosol)
The more
antioxidants andphenolics present,
the lower the
oxidation rate
-
7/29/2019 Chem Changes of Olive Oil v.2
24/29
Antioxidants in Olive Oils
MoFT 2013/14 24
Antioxidant can supply the free radical with a replacement for
its missing electron.
-
7/29/2019 Chem Changes of Olive Oil v.2
25/29
Conclusion Some products resulting from the chemical changes of olive
oil:
MoFT 2013/14 25
Cosmetics
Toiletries
Cooking/Dressing Oils
Spreads
-
7/29/2019 Chem Changes of Olive Oil v.2
26/29
Comparison of Dietary Fats
MoFT 2013/14 26
Source: Vaclavik, V.A. (1998), Essentials of Food Science, An Aspen Publication, page226
7%
10%
12%
13%
15%
15%
19%
27%
43%
48%
51%
68%
91%
21%
76%
71%
57%
9%
54%
33%
54%
9%
2%
10%
3%
2%
11%
0.05%
1%
1%
1%
8%
0.05%
0.05%
1%
1%
0.05%
1%
0%
61%
14%
16%
29%
75%
23%
48%
19%
47%
49%
39%
28%
7%
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
Canola Oil
Safflower Oil
Sunflower Oil
Corn Oil
Olive Oil
Soybean Oil
Peanut Oil
Cottonseed Oil
Lard
Beef Tallow
Palm Oil
Butter Fat
Coconut Oil
Saturated Polyunsaturated Alpha-Linolenic A cid Monounsaturated
-
7/29/2019 Chem Changes of Olive Oil v.2
27/29
References:
1. http://www.fao.org/docrep/003/x6545e/X6545E01.htm
2. http://www.oliveoilsource.com/page/chemical-characteristics
3. Vaclavik, V.A. (1998). Essentials of Food Science. An Aspen Publication.
Page 226
4. Charley, H. & Weaver, C. (1998). Foods A Scientific Approach. A Merrill
Prentice Hall Publication. Page 241-266
5. http://www.soap-making-resource.com/saponification-table.html
6. http://www.cargillfoods.com/na/en/products/oils-shortenings/solutions/interesterification/index.jsp
MoFT 2013/14 27
-
7/29/2019 Chem Changes of Olive Oil v.2
28/29
Random Interesterification
MoFT 2013/14 28
-
7/29/2019 Chem Changes of Olive Oil v.2
29/29
The Characteristics of Oils in Soap
MoFT 2013/14 29
Oil or fat (acid) SAP Hard/Soft Cleansing Fluffy lather Stable lather Skin care
avocado oil 133.7 soft fair yes no amazing!
coconut oil 191.1 hard great yes no fair
castor oil 128.6 soft fair yes yes great
olive oil 135.3 soft good no no great
palm oil 142 hard great no yes fair
peanut oil 137 soft fair no yes great
soybean oil 135.9 soft good no yes fair
sweet almond oil 137.3 soft good no yes amazing!
jojoba oil 69.5 soft fair no yes great
kukui nut oil 135.5 soft good no yes great
lard 138.7 hard good no yes fair
tallow 140.5 hard good no yes fair
Source: http://www.soap-making-resource.com/saponification-table.html