Transcript Lipids - Food Science & Human Nutrition

Lipids
Lipids
(generally soluble in organic solvents)
Plant sources
(olive, palm)
Animal sources
(butter, lard, tallow)
Oils and Fats
Triacylglycerol
Sterols
Waxes
(monoesters)
Food – 98 %
Lipids
Definition of Lipids

Naturally occurring biological substances made primarily of C, H,
and O of pronounced hydrophobicity that are soluble in organic
solvents but have limited solubility in water
◦
◦
◦
◦

Petroleum distillates (e.g. hexane)
Chloroform
Ethers (e.g. diethyl ether)
Alcohols
Term Fat vs. Oil, chemically identical (both lipid) but……
◦ Fat = solid at room temp.
◦ Oil = liquid at RT
 Special case – the term fat can be used to refer to oils from food sources to avoid confusion
with other oils such as petroleum oils

Lipids have more C and H than carbohydrates, which is why they
are said to be energy dense, when utilized  2.25 times more =
9 kcal/g vs. 4 kcal/g.
Lipids
Biological roles
A. Structural
- found in membranes
- protective barriers
B. Regulatory
- steroids/prostaglandins (hormones)
- phospholipids
C. Storage
- triglyceride is an energy
storage molecule
D.Vitamins
- fat-soluble
- precursor molecules
Lipids
Role in foods
A. Calories (kcal)
v.s.
– American Heart Association
recommends energy from fat < 2535 % of all calories ideal
- satiety
B. Essential fatty acids (can’t synth.)
- linoleic acid, linolenic acid
C. Flavor
- lipid soluble compounds or offflavors
D. Texture
– mouth feel & appearance
E. Color
- carotenoids
F. Heat transfer medium (frying)
v.s.
Fat Content of Some Selected Foods
Food
% Fat
Food
% Fat
Brazil nuts
67
Hamburger
20
Walnuts
61
Avocado
16
Almonds
54
Ice Cream
13
Peanuts
50
Tuna, canned
8
Sunflower
seeds
47
Poultry, dark
meat
7
Pork roast
30
Salmon
6
Cheese
30
Whole milk
4
Beef roast
25
Poultry, light
meat
4
Ham, cured
22
Shredded
wheat cereal
2
6
Lipids
Classification of lipids (structure)
1) Simple lipids
◦
Mono, Di, and Triacylglycerols

◦
Account for 98 % lipids in foods
Fatty acids
Waxes
2) Compound lipids
◦
◦
Glycerol
backbone
- some polarity
Phospholipids
Glycolipids
3) Derived lipids – often hydrolyzed 1&2
◦
◦
◦
◦
Free fatty acids
Sterol esters
Tocopherol (Vit-E)
-carotene
Triglyceride
Lipids
Classifications of lipids (polarity)
1) Non-polar lipids
(neutral lipids)
◦
◦
◦
◦
◦
◦
Fatty acids
Mono-, di-, & triacylglycerols
Waxes
Sterols
Carotenoids
Tocopherols
2) Polar lipids
◦
◦
◦
◦
Glycerophospholipid
Glyceroglycolipid
Sphingophospholipid
Sphingoglycolipid – contains
sphingoid base (nitrogen) and
sugar
Lipids
Structure & properties of fatty acids


Fatty acid are composed of a hydrocarbon chain with
methyl group (CH3) on one end and a carboxyl group
(COOH) on the other.
Basic properties common to most fatty acids
1. Most are even carbon #
2. Most are monocarboxylic acids
3. Most are part of triacylglycerides (triglycerides)
Lipids
NOMENCLATURE
3 ways to name
1) Short - # of Carbons, # double bonds
2) Common – reflective of source, little if any structural
info
3) Systematic – follows IUPAC rules
1. Number of carbons
◦
C4-C24 most common
◦
E.g. C8 = octa
C12 = dodec, C18 = ?
2. Saturation
◦
= saturated with H bonds
(no double bonds)
◦
Unsaturated
(double bonds)


Mono (1 = bond)
Poly (>1 = bond)
Lipids
2. Saturation – Systematic Naming
◦ No double bond = Anoic
 E.g. C18:0
◦ One double bond = Enoic
 E.g. C18:1
◦ Two double bonds = Dienoic
 E.g. C18:2
◦ Three double bonds = Trienoic
 E.g. C18:3
3. Geometric configuration
of double bonds
◦ Cis vs. Trans
◦ Has an influence on
the fatty acid backbone
structure
Lipids
4. Position of double bonds
◦ Delta (Δ) system - count # of carbons to the = bond from the COOH
end
 E.g. Δ 9-octadecenoic acid
 Means: a) C18 = octadecenoic
b) 1 double bond = octadecenoic
c) double bond is 9 carbons from the COOH end
◦ Omega (ω) system - count # of carbons to the = bond from the CH3
end – used for abbreviations of fatty acids
 E.g. Δ 9-octadecenoic acid would be C18:1ω9
 What about all-cis-9,12,15-octadecatrienoic?
 Delta = same as systematic = Δ 9,12,15-ocatadecatrienoic acid
 Omega = C18:3ω3 (1st double bond is at C16, 3 carbons from the methyl end)
 ω-3, ω-6 and ω-9 the most common
 Methyl (CH3) end dictates biological activity (more commonly used in
nutrition and food science)
 ω-3 essential b/c our bodies are not able to synthesize fatty acids that have
double bonds between an existing double bond and the methyl end
Lipids
Commonly Encountered Major fatty acids in foods
 Saturated
◦ Palmitic (16:0)
◦ Stearic (18:0)

Monoenoic
◦ Oleic (18:1ω9)

Dienoic
◦ Linoleic (18:2ω6) – Δ9, 12 - common in plants; some in animal

Trienoic
◦ Linolenic (18:3ω3) Δ9, 12, 15

Tetraenoic
◦ Arachidonic (20:4ω6) - Δ 5, 8, 11, 14 - part of membrane phospholipids
Lipids
Structure/function properties of fatty acids
1.Length of fatty acids
◦ Longer chain length leads to increase in melting point and gives more
stable fat crystals
◦ Classes:
 C4 – C8 - liquid @ room temperature (20-25°C)
 These are water soluble  good emulsifiers
 C10 - C14 - viscous @ room temperature
 C16 - C26 - solid @ room temperature
◦ For example:
 C6:0  MP = -2°C
 C10:0  MP = 31.5°C
 C16:0 MP = 63°C
Lipids
Factors affecting the properties of fatty acids
2. Double bonds
◦ An increase in # of double bonds decreases the melting point
Example:
18:0 = 71.2°C
18:1 = 16.3°C
18:2 = -5°C
18:3 = -11°C
Lipids
Factors affecting the properties of fatty acids
3. Cis vs. Trans
◦ Cis has lower melting point than Trans
 Cis produces a kink in the fatty acid chain which creates a more open fatty
acid crystal structure
Melting Point
Kink
18:1c
18:1t
15°C
44 °C
18:2c
18:2t
-5 °C
29 °C
18:3c
18:3t
-11 °C
71 °C
Lipids
The structure and properties of triacylglycerols



>98% of fatty acids in food products are
found as triacylglycerols (also the largest
group of neutral lipids)
Structure: Fatty acid esters of glycerol
(three carbon alcohol)
Most triglycerides are mixed (i.e. contain
different fatty acids)
Glycerol
backbone
Fatty acids
Triacylglycerol
Lipids



We use stereochemical
numbering system (sn) to
indicate the position of the
fatty acids on the glycerol
backbone
If you have 20 fatty acids to
chose from then you have 203
(i.e. 8000) possible numbers
of different triacylglycerols
Complete randomization at
positions seldom observed
Lipids
Arrangement of fatty acids on triacylglycerides
1. Not random (usually)
2. Specificity controlled
3. General pattern

Position Plant
Mammal
Milk
Bird
Fish
1
S
S
S
S
S-LC
2
U
U
S
U
U
3
U
LC
U or SC
S or U
LC
The arrangement can significantly affect physical properties of fat
LC : Long chain; SC: Short chain
Lipids

Solid fat index (SFI)
◦ Reflects percentage of oil
that is solid
◦ Therefore, the rest is
liquid

Curve shows that tallow has
a broader melting point while
cocoa butter has a uniform
sharp melting point
(desirable)
Lipids
One can produce triacylglycerols with specific properties
Examples:
1. Medium chain triglycerides (MCT’s)
◦
C8:0 and C10:0 fatty acids (from palms, coconuts, milk)

◦
◦
Hydrolyze, fractionate, re-esterify with glycerol
Metabolized in the liver (not through the gut) and thus used
more for energy than for deposition as fat and thus have
fewer kcal (8.3 kcal/g)
Used as flavor, color and vitamin carriers in foods and
pharmaceuticals; also in reduced fat applications – MCTs are
bland
Lipids
2. Salatrim (short and long chain triacylglyceride molecule),
Benefat® (Danisco)
◦ Triacylglycerol made to contain a short chain (C2:0, C4:0 or C6:0)
and a long chain (C18:0) fatty acid esterified to glycerol backbone
◦ Get only 5 kcal/g because:
 Get less energy from short chain fatty acids
 Stearic acid (C18:0) is incompletely absorbed
◦ Can be custom made to suit a variety of applications but it is not
suitable for frying
3. Caprenin (Proctor and Gamble Co.)
◦ Has C8:0, C10:0 and C22:0
◦ Only 5 kcal/g due to partial absorbance of behenic acid (C22:0)
◦ Confectionary applications
Lipids
Important Compound Lipids
1. Phospholipids



Make up cellular membranes
Lipid molecules that contain a phosphate group
attached to a functional group
Have both hydrophobic
(fatty acids) and hydrophilic
(phosphate and functional
group) portions
◦ Good emulsifiers

May have a protective effect
against ulcers (milk PL)
Lipids
2. Glycolipids

Contain at a minimum one sugar
◦ Some may also have a phosphate amino group (glycosphingolipids)


Found in all tissues of animals
Have same solubility characteristics as regular lipids
3. Sterols


Made of four fused hydrophobic rings with a hydrophilic OH group
Not so important as a food ingredient but important for dietary reasons
◦ Cholesterol mostly in animal foods
◦ Can contribute to coronary heart
disease (arteriosclerosis)
◦ 300 mg/day the recommended intake limit
Lipids
4. Fat substitutes

Sucrose fatty acid polyesters
◦ Olestra, brand name Olean® (Procter and Gamble Co.)
 FDA approved for use in frying oils (snacks) in 1996
 6-8 fatty acids (>C12) esterified to sucrose
 Caloric free due to its bulky structure and because lipases cannot hydrolyze
it
 May lead to loss of fat soluble vitamins and can give diarrhea – FDA now
requires warning labels

Sucrose and polyol fatty acid esters
◦ 1-3 fatty acids esterified to sucrose or a polyol (e.g. sorbitol)
◦ Have caloric value (polyol fatty acid esters only about 1.5 kcal/g)
◦ Used as emulsifiers and stabilizers
Lipids
Functional Properties
Lipids – Functional Properties
Crystallization



Solid fats are most all in a crystal form
Cooling liquid fat (oil) results in it loosing heat and molecular motion
is decreased  Fat molecules come in close contact and the non-polar
nature of the fatty acids align via strong hydrophobic interactions
(attractive forces) and a crystal is formed
Simple triacylglycerides (identical FA on the glycerol)
◦ strong bond and tightly packed crystals

Mixed triacylglycerides (the FA are different)
◦ Weaker bonds and packing is less = weaker and more numerous crystals
◦ Most fats fall into this category

The actual nature and thus the functionality of the crystals formed is
highly influenced by the type of fatty acids that are on the glycerol
backbone
Lipids – Functional Properties
-crystals
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
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


Formed on rapid cooling
Randomly associated
triglycerides
Size < 1µm
Very delicate, needle like, smooth, shiny and fine-grained
texture
Unstable due to their disorder
Heating transforms this form to the two other higher
stability forms (’ or )
Lipids – Functional Properties
’-crystal
Close packing
 Crystal axes alternate
 Intermediate of  and -crystals
 Many food fats are processed in this manner to produce a
fine-grained texture (more grainy than  but less than )
 The desired form for many processed fats

◦ Shortenings & Margarine
 Ideal texture
 Good at incorporating air
Lipids – Functional Properties
-crystals
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



Have more order and greater
packing than the -crystals
Most stable
Very large coarse crystals with
grainy texture
Size = 25-45 µm
This crystal is the ideal form for some fats
◦ Chocolate fat (cocoa butter β’→β)




Mp = 35-36 °C
Brittle/firm until eaten
Develops a glossy sheen – fat bloom
Improper storage leads to chocolate bloom (change in crystal structure)
Lipids – Functional Properties
Most of the crystal forms are interconvertible
 Polymorphism
LIQ.


'
Determined by:
◦
◦
◦
◦
◦
Fatty acid type (length, unsaturation and cis vs. trans)
Distribution of fatty acid on glycerol backbone
Rate of cooling
Agitation
Storage conditions

Lipids – Functional Properties
Crystal structure and melting point relationship
 With longer fatty acids there is more packing and stronger
crystals result  MP
 Fatty acid heterogeneity (nonuniformity)   = more
packing and MP
  Fatty acid heterogeneity  ’ = less packing and MP
  double bonds (cis)  kink in the fatty acid = less packing
(bulkier crystal) and MP (trans form = MP)
 For the same fatty acid the melting point follows this order:
>’>
Lipid crystal forms summary
H
OH
O
O
H
H
OH
H
CH3
H
O
H
random
=α
CH3
CH3
HO
weakest association
between chains
O
OH
O
CH3
H
= β′
OH
O
CH3
H
OH
some association
between chains
some order
O
CH3
O
CH3
O
OH
OH
OH
most order
CH3
most association
between chains
CH3
=β
33
Lipids – Functional Properties
Hydrogenation




Canola and Soybean oil blend
Very important chemical modification method
The objective is to chemically reduce unsaturated fatty acids into saturated fatty acids
(i.e. remove double bonds)
The result
◦ Functional properties of the oil/fat is modified to ones desired
 Liquid oil  solid (vegetable oil  margarine)
 Higher melting point (due to less double bonds and trans fatty acids)
 By proper control of the reaction one can get a range of textures (SFI
profiles)
◦ Main reasons to perform hydrogenation
1. Impart specific physical or chemical property
2. A cheaper oil/fat source can be converted to mimic a more expensive oil/fat
(e.g. using cottonseed oil and hydrogenate to a product similar to cocoa butter)
3. Give product unique functional characteristics
4. Increased stability of oil/fat =  shelf life
 Fewer double bonds and more trans fatty acids lead to less oxidation
problems
◦ Reduced nutritional value
 More saturation and more trans fatty acids
Most hydrogenated oils/fats are partially hydrogenated (trans, cis, removed double
bonds)
Lipids – Functional Properties

The reaction factors:
◦ Oil source
 type of FA and their position has a dramatic effect on the final oil/fat
properties
◦ High temperature
◦ H2 gas
 bubbled into oil under pressure
◦ Agitation
◦ Catalyst
These will have a great impact on
which of the double bonds in a
fatty acid are hydrogenated and
which will migrate in the fatty acid
 usually Ni on an inert silica support
 removed by centrifugation or filtration

Possible reactions (example with linolenic acid)
18:3  18:2  18:1  18:0
A.
B.
C.
The hydrogenation process:
Oleic acid (18:1) – (letters correspond to
figure)
Nickel catalyst adsorbs onto the double
bond
Hydrogen atom binds to a carbon leaving
one Ni bond
At this point the reaction can go in several
possible directions:
D.
1. Another hydrogen atom can bind to
the second carbon and give a saturated
fatty acid (1 in figure)
2. A H-atom may be lost from the carbon
giving 2 unsaturated trans (or cis) isomers
(2 & 4 in figure)
3. The original H-atom may be lost and a
new H-atom can come in to form a trans
double bond (3 in figure)
4. The fatty acid may detach from the
catalyst and thus lead to no change in its
structure (A in figure)
1
2
3
4
Lipids – Functional Properties
Hydrolytic rancidity


Happens faster with extracted fats/oils
General mechanism involves the cleavage of the fatty acids from the
glycerol backbone (is a hydrolysis = cleavage & addition of water)
◦ Usually only the fatty acids at position 1 and 3 (outside fatty acids)

Indication of quality loss in foods and fats/oils
◦ Free fatty acids are volatile (especially short chain) and can exert an
unfavorable odor and flavor
◦ Free fatty acids are more prone to lipid oxidation reactions (i.e. to become
rancid)
◦ Free fatty acids may react with other food components, e.g. can make proteins
lose their functionality
Lipids – Functional Properties
A. Chemical hydrolysis
◦ Catalyzed primarily by heat (225-280 °C)
◦ Deep fat frying
 Viscosity increases
 Foaming increases
 Fat degradation products polymerize
 Color darkens
 Off odors/flavors form
 Smoke point decreases
EXAMPLE
% FFA
0.01
1
10
100
SMOKE PT
450F
320F
260F
200F
ACID VALUE
0.02
1.9
19
190
Lipids – Functional Properties
B. Enzymatic hydrolysis
◦ Caused by enzymes that are naturally present in the foods  native Lipases
◦ Lipases can also be introduced via contaminating microorganisms (can be
intentional ex. cheese making)
◦ Thermal processing can be used to inactivate Lipases (generally above 60 °C
but time & temp factor in)
Grains, flour
◦ aw  FFA   loaf volume
Fish
◦ frozen storage  FFA (due to phospholipases)  toughening   water
holding ($$)   flavor and color problems (rancidity)
Dairy
◦
◦
◦
◦
Lipases specific for sn-3
Agitation, pumping, etc favors the reaction
Inactivated by high heat
Problems
1. Off-flavors
2. Poor churning (mono and diglycerides - emulsifiers)
3. Poor cheese (FFA inhibit the enzyme Rennin)
Lipids – Functional Properties
Oxidative rancidity



Oxidative rancidity is the result of chemical reactions usually
involving O2 and lipid
Referred to as autoxidation since it is a autocatalytic
process which reaction rate increases as reaction proceeds
Leads to major quality problems in foods
1. Off-flavors
2. Color change (browning, loss of pigments)
3. Degradation of nutrients
 Essential fatty acids
 Essential amino acids
 Vitamins
4. Toxicity?
Lipids – Functional Properties

Rate of oxidation reaction affected by
◦ Fatty acid composition (saturated vs. unsaturated)
◦ Degree of unsaturation
 Rxn rate increases with degree of unsaturation (18:0, 18:1, 18:2, 18:3) – except for
conjugated series
◦ Presence of pro- and antioxidants
 Pro-oxidants catalyze oxidation
 Metals, light
 Antioxidants delay oxidation
 Synthetic – BHA, BHT, polyphenols
◦ Partial pressure O2
 Low pressure minimizes oxidation, less O2! (Vacuum packaging, flushing)
◦ Storage conditions
 Temperature
 Light
◦ Water activity
◦ pH
Lipids – Functional Properties
The three steps of autoxidation
A Hydrogen atom is abstracted from
the fatty acid (R) by an initiator and
a fatty acid free radical (missing an
electron) is formed
O2
A peroxyl free radical (ROO•) is formed
in the presence of O2  Hydroperoxide
(ROOH) is formed in the presence of
another FA. Rxn repeats rapidly!
The propagation step is terminated
by the reaction between two
radicals
Lipids – Functional Properties
Initiation
 Induced by:
◦ Light (Visible, UV-rays, γ-radiation)
 Chlorophyll (sensitizer)
 1O2 = singlet oxygen
◦ Heme compounds (hemoglobin and myoglobin in muscle foods)
◦ Metal compounds
 Only low concentration needed (0.1 ppm)
 From soil (plants), animal (needed nutrient), metallic processing & storage equipment
Direct rxn of a metal with substrate (RH)
M
Cu
Fe
n+
2+
+ RH
M
Cu
3+
Fe
[n-1]+
+
2+
+
R•
+
H+
Molecular mechanism 4 isomers are formed
of initiation
Attack is adjacent
to the double bond
C C C C C C
H2 H2 H H H2 H2
.
C CH C
H
H2
C CH C
H
H2
.
Radical can
potentially form
at either site
.
C CH C C C C
H H H2 H2
H2
.
C C C CH C C
H2 H H
H2 H2
C C C
H2 H2 H
.
C
H
C C CH C
H
H2 H2
.
CH C
H2
C
H
C
H2
Initiation of linoleic acid (18:2)
(1)
(2)
Propagation of linoleic acid (18:2) – peroxyl radical formation
stability ↓
(1)
(2)
stability ↓
Propagation of linoleic acid (18:2) – hydroperoxide
formation (OOH)
ROOH (primary products)
can be very unstable and
decompose to form
secondary oxidation
products:
Acids
Alcohols
Aldehydes (acetaldehyde)
Carbonyls
Ketones
These are responsible for
the rancid odor/flavor of
oxidized fat
You can follow the progress of lipid oxidation
chemically and sensorially
Sensory detection
Hydroperoxides
Aldehydes
Time
Lipids – Functional Properties

For the exam your should be able to predict how many fatty
acid radicals can form for oleic, linoleic and linolenic acid and
know where they would be located
Where would the first
attack be located?
Where else could
attack occur?
15 14 13 12 11 10 9 8 7
C C C C C C C C C
H2 H2 H H H2 H H H2 H2
Which radical would be
the most important?
Stability?
How many radicals
can form per lipid?
Lipids – Functional Properties
Prevention/retardation of autoxidation

Remove oxygen
◦ Vacuum or modified atmosphere
packing

Reduce light
◦ E.g. use opaque packaging, filters, cans

Remove catalysts (e.g. metals)
EDTA
Cu2+
◦ Chelators (EDTA; citric acid; phosphoric acid)


Avoid high temperatures
Use less unsaturated fatty acids or use
saturated fatty acids
◦ No double bonds  far less to none oxidation
◦ Hydrogenation  fewer double bonds

Use antioxidants
EDTA in soda
http://en.wikipedia.org/
wiki/Vault_%28soft_drin
k%29
http://www.squirtsoda.c
om/
Lipids – Functional Properties
Antioxidants



Can be very effective in slowing
down lipid oxidation
They function by inhibiting/delaying
the propagation chain reaction by
scavenging the free radical
intermediates
Some foods have natural
antioxidants but to stabilize them
even further we add both
synthetic and natural antioxidants
to them
Antioxidants
Versus
Propagation
rxn
Propagation rxn
Lipids – Functional Properties
Common synthetic antioxidants
Common antioxidants
Vitamin E (tocopherol)
- A natural antioxidant -
Vitamin C (ascorbic acid)
- A natural antioxidant -
Lipids – Functional Properties
O
OH
O
O
C
+
ROO • +
ROOH
C
OH
OH
OH
OH
CONTROL
PV
ANTIOXIDANT
Induction period
t
"Quench free radicals" - therefore prolong induction period
- will eventually oxidize
Lipids – Functional Properties
Emulsions
 Consist of 2 immiscible phases
◦ Dispersed phase (also called discontinuous
phase)
◦ Continuous phase
 Oil and water
◦ These phases do not like each other and
strive to separate
◦ Oil in water (o/w) - milk, salad dressing
◦ Water in oil (w/o) - butter, margarine
Lipids – Functional Properties
Macro-emulsion
◦ Particle size 0.5 - 100 µm
◦ Milky due to light scattering
 Micro emulsion
◦ Particle size 0.01 - 0.5 µm
◦ Clear
◦ Can have high viscosity - higher than
equivalent volume of o/w or w/o

Lipids – Functional Properties

Emulsion formation
◦ To form an emulsion the dispersed phase needs to be
divided into small particles and then needs to be stabilized
Large droplets
(salad dressing)
High shear
(more work)
◦ You need input of energy to form the
emulsion
◦ Without stabilizers (emulsifiers) the emulsion will
rapidly break down since the small droplets will
coalesce and form larger droplets
Small droplets
(milk)
http://www.youtube.co
m/watch?v=oBbWJX
EZoRQ
- put sound off
Lipids – Functional Properties

Emulsion stabilization
◦ To provide the emulsion
with long term stability one
needs to employ emulsifiers
along with high energy input
◦ Emulsifiers decrease the tension
(surface tension) between the two phases
◦ They can do this by having a hydrophobic and
hydrophilic character at the same time
O/W
W /O
Lipids – Functional Properties

Common emulsifiers
◦
◦
◦
◦
OH
OH
Mono and diacylglycerides
Detergents (Tween)
Phospholipids (lecithin)
Proteins
Monoglyceride
Oil droplet

H2O phase
All have polar (e.g. OH) groups and non polar (e.g. fatty acid
or hydrophobic amino acids) groups
Lipids – Functional Properties

The effectiveness and function of an emulsifier is defined by
its HYDROPHILIC - LIPOPHILIC balance (HLB)
HLB = % weight of hydrophilic portion of emulsifier
5
Scale goes from 1-20
1 = entirely non-polar (hydrophobic)
20 = entirely polar (hydrophilic)
Lipids – Functional Properties

Emulsifier classification
◦ HLB 1 - 8
= hydrophobic
◦ HLB 8 - 11 = intermediate
◦ HLB 11 - 20 = hydrophilic

HLB values for industrial/food
applications
◦ 3 - 6 HLB = w/o emulsifiers
◦ 8 - 18 HLB = o/w emulsifier