Fundamental of AntioxidantsAntioxidant Location •Location, Location, Location????? •Antioxidant...

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Fundamental of Antioxidants

Antioxidants

• Free Radical Scavengers (Chain breaking antioxidants)

• Singlet Oxygen Quenchers • Metal Chelators • Encapsulation

Free Radical Scavengers Mechanisms of Action

Hydrogen dissociation energy

Reduction Potential

ROO•/ROOH 1000

PUFA•/PUFA-H 600

TOCOPHEROXYL•/TOCOPHEROL 500

ASCORBATE•/ASCORBATE 282

Buettner, 1993

Compounds with a high reduction potential can oxidize compounds with lower reduction potentials

• Act by lowering the energy of free radicals so they are less effective

♦ Each free radical

scavenger can inactivate 2 free radicals

Depletion of Rosemary Antioxidant and Formation of Hexanal in Corn Oil

Antioxidant Location

• Location, Location, Location????? • Antioxidant paradox was described by Porter

(1980) • A paradox was suggested because polar

antioxidant are most effective in bulk oils while nonpolar antioxidants are best described in oil-in-water emulsion

• The increase effectiveness of nonpolar antioxidants in oil-in-water emulsions is due to their ability to concentrate in the oil droplet or at the oil-water interface

α-tocopherol

Trolox

H3CCH3CH3CH3

Bulk Corn Oil (Huang et al., 1996)

Trolox

Tocopherol

BULK OILS

Hydrophobic FRS Evenly distributed

Hydrophilic FRS Concentrated at surface

FREE RADICAL SCAVENGER

Air Air

Chen, et al.(2011) Crit Rev Food Sci Nutr 51:901-916

Reverse micelle Lamellar Mixed reverse micelle

Surface Active Components + Water = Association Colloids

Structures are on nano-scale so they do not scatter light

Emulsified Corn Oil (Huang et al., 1996)

Trolox

Tocopherol

Emulsified Oil

Nonpolar antioxidant Polar antioxidant

Commercially Available Free Radical Scavengers

Lipid Soluble BHT, BHA, TBHQ Tocopherols Rosemary Extract Surface Active Ascorbyl Palmitate Water Soluble Propyl Gallate (partial) Ascorbic Acid Grape Seed Extract

Synthetic Antioxidants

Water Solubility BHT = BHA < TBHQ < PG Often used in package liners Most limited to 0.02% of fat content

BHA vs BHT

• BHT less effective than BHA due to steric hinderence

• BHT more volatile than BHA

• BHA is listed on California Proposition 65 (reasonably anticipated to be a human carcinogen)

steric hinderence

• Often most effective synthetic antioxidant

• Works synergistically with citric acid

• Less steam volatile than BHA and BHT

• More regulatory restrictions especially in EU

(1990-2013) Source WoS

Σ = 40 840 publications

Number of publications related to Antioxidants/phenolic compounds…

Courtesy of Pierre Villeneuve

Natural Free Radical Scavengers

One electron reduction potential (E°́) of the radical form of antioxidants.

Compounds E° ́ (mV)

PUFA (bis-allylic-H) o-Coumaric acid Ferulic acid b-coumaric acid p-Coumaric acid Uric acid pyrogallol Catechin EC Gallic acid Methyl gallate Sinapic acid Chlorogenic acid ECG 3,4-dihydroxylcinnamic acid Theaflavin digallate Caffeic acid Catechol 4-Methylcatechin 4-methylcatehol Theaflavin Taxifolin α-tocopherol Trolox EGC EGCG Myricetin Fisetin Quercetagetin Quercetin Ascorbic acid

600 596 595 590 590 590 575 570 570 560 560 556 550 550 540 540 534 530 520 520 510 500 500 480 430 430 360 330 330 330 282

Rosemary Antioxidants

H3C CH3

COOHOH

CarnosolCarnosoic Acid

Rosmarinic Acid

Green Tea Extract

Reduction

Potential ROO•/ROOH 1000 PUFA•/PUFA-H 600 TOCOPHEROXYL•/TOCOPHEROL 500 ASCORBATE•/ASCORBATE 282

Antioxidant Interactions Free Radical Scavengers

AAH TO

TOH LOO

LOOH NADH

Compounds which do not strongly inhibit oxidation by themselves could be important to

oxidative processes if they are involved in recycling.

Propyl gallate in Tween 20 Stripped Corn Oil-in-Water Emulsions Huang and Frankel, 1997

Propyl gallate in Tween 20 Commercial Corn Oil-in-Water

Emulsions

Controlling Metals

♦Low concentrations in raw materials ♦Physical Separation ♦ Chelators

Chelators

♦Can Decrease Prooxidant Activity of Metals by: • Sterically Hinder Metal/Lipid or Hydroperoxide

Interactions • Decreasing Metal Solubility • Maintaining Metals in Their Oxidized Less

Reactive States • Partitioning Metals away from Lipid Surfaces

Commercially Available Chelators

• Organic Acids (citric) • EDTA • Polyphosphates • Proteins/Peptides

– pH must be above pKa of functional group – Activity is often dependent on metal:chelator

ratios

Sodium Tripolyphosphate

Citric Acid

Common Food Chelators

• EDTA – pKa 1.7, 2.6, 6.3, 10.6 – Iron binding constant 1.2 x 1025

– Complex is anionic making it water soluble – Complex is highly bioavailable

♦Citric Acid • pKa 3.1, 4.7 and 5.4 • Iron binding constant 1.5 x 1011

• Effective in bulk oils and high fat meats • Often prooxidative in oil-in-water emulsions

♦Polyphosphates • pKa 0.8 and 2.0 • Iron binding constant 7.2 x 1022

• Effective in cooked meats • Often prooxidative in oil-in-water emulsions

Iron Chelation by Anionic Gums

Antioxidant activity of anionic gums

Challenges Alteration of viscosity Promote emulsion destabilization pKa around 4 Activity low at low pH

Siderophores

Enterobactin, catecholate siderophore

Ferrichrome hydroxamate siderophore

• Kraft has a patent • Might decrease iron bioavailability • Natural source available?

Chelating Active Packaging

Replace EDTA? Enable Additive Free Label Claim

Maintain Product Quality

US Provisional Appl. Ser. No. 61/570,417

Material Synthesis

Polypropylene (PP)

- COO-

Poly(acrylic acid) (PAA)

Chelating monomer:

Acrylic acid oil

Fe2+ Fe2+

- - - - - - -

- - - -

Non-migratory

Wavenumber (cm-1)1000 1200 1400 1600 1800 2000

.20 PPPP-g-PAA

Material Characterization ATR-FTIR Spectroscopy

Storage time (day)

0 2 4 6 8 10 12 14

PPPP-g-PAA

Storage time (day)

0 2 4 6 8 10 12 14

PPPP-g-PAA

Significant Lag Phase Extension

Storage time (days)

0 2 4 6 8 10 12 14

Storage time (days) 0 2 4 6 8 10 12 14

Demonstration Lipid Oxidation

Multifunctional Antioxidants Flavonoids and Polyphenols

Fig. 1 The separation of groups of compunds of PYC by normal phase silica gel HPLC using an acidid polar solvent system and UV detection as described by Cheynier and coworkers <ce:cross-ref refid="BIB17"> [17]</ce:cross-ref> . Chemical structures of catech...

L Packer , G Rimbach , F Virgili

Antioxidant activity and biologic properties of a procyanidin-rich extract from pine ( pinus maritima ) bark, pycnogenol

Free Radical Biology and Medicine, Volume 27, Issues 5–6, 1999, 704 - 724

Metal Chelating by Flavonoids

Polyphenols generally have higher chelating capacity then monomers

Perron et al., 2010

Gallol groups have higher iron binding and iron oxidation rates than catechol analogs (Perron et al., 2010)

Flavonoids can promote iron oxidation and reductions

Fe3+ Reducing Activity (uM/min) of Galloyl Derivatives

pH 3.0 pH 7.0

Control 0 0

Methyl Gallate 9.56±0.31 0.17±0.03

Gallic Acid 11.6±0.89 0.24±0.05

PROOXIDANTS Metals

Fe+2 Fe+3 + LOOH + LO● + OH-

Electron Source e.g. Flavonoids

Iron Redox Cycling

Effect of water soluble antioxidants on oxidation of fish oil emulsion

Control

Grape seed extract

Flavonoids and Polyphenols in Grape Seed Extract

Mellen et al., 2010, Am Coll. Nutr. 29:469-475

Natural Antioxidants

♦Grape seed extract • Up to 95% flavonoids • Scavenge free radicals and chelate metals • Astringent Off-flavors • Trade source Gravinol (Kikkoman)

Multifunctional Antioxidants Proteins and Peptides

Alpha-Lactoalbumin http://www.acsu.buffalo.edu/~andersh/research/HAMLET.asp

Proteins as Antioxidants

♦Mechanisms • Metal Chelation

Chelation of Iron by Proteins

Proteins as Antioxidants

♦Mechanisms • Free radical scavenging

Continuous Phase β-Lg

Residue Ratio(%) Buried? Met7 16.2 Trp19 0.0 Tyr20 27.7 Met24 0.0 Tyr42 8.6 Trp61 41.4 Phe82 0.9 Tyr99 18.3

Tyr102 7.2 Phe105 9.1 Met107 4.6 Phe136 0.1 Met145 9.6 His146 28.2 Phe151 7.0

Solvent Accessibility of amino acids in β-Lg

Altering the Solvent Accessibility of Amino Acids in β-Lg

Hydrolysis

Inhibition of Lipid Oxidation in a Menhaden Oil-in-Water Emulsion by β-Lg or Chymotrypsin Hydrolyzed β-Lg

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34Time (day)

Control0.5 mg β-Lg/g oil2.5 mg β-Lg/g oil0.5 mg CTH/g oil2.5 mg CTH/g oil

Iron Chelating Activity of β-Lg and Chymotrypsin Hydrolyzed β-Lg

Treatment

1 mg/ml β-Lg

1 mg/ml CTH

Peroxyl Radical Scavenging Activity of β-Lg and Chymotrypsin Hydrolyzed β-Lg

0 10 20 30 40Time (min)

Blank 7.5 μg/ml CTH 7.5 μg/ml β-Lg Fluorescein only

Heating

time (h) CP / G 1:0.5 CP / G 1:1 CP/G 1:2 CP

0 70.5±4.6a, A 70.7±4.8a, A 68.8±4.9a, A 72.4±4.8a, A

1 70.3±4.1a, A 62.5±5.2b, B 60.3±3.2b, B 69.8±3.6a, A

3 60.0±4.5b, B 51.7±3.7c, C 50.8±4.8c, C 68.0±5.3a, A

6 54.7±4.3c, B 44.0±3.4d, C 45.8±3.8d, C 69.8±5.2a, A

12 50.0±3.4c, B 40.1±4.0d, C 40.0±3.4e, C 71.0±4.9a, A

Bitterness Scores of Casein Peptides Maillard Products

Multifunctional Antioxidants

• Phospholipids/Lecithin – Inhibit oxidation by:

• Metal Chelation • Free radical scavenging • Formation of Maillard products • Increasing the efficiency of antioxidants (e.g.

tocopherols)

Food Science Department

DOPC/DOPE + α-tocopherol in bulk oil

In the presence of phospholipids reverse micelles - DOPC decreased the antioxidant activity of α-tocopherol

DOPE increased the antioxidant activity of α-tocopherol

α-tocopherol

α-tocopherol quinone

2. DOPE regenerated α-tocopherol ?

1. DOPC/DOPE + α-tocopherol quinone 2. DOPC/DOPE + α-tocopherol

PE/PC on α-tocopherol regeneration

DOPE headgroup, ethanolamine, can regenerate α-tocopherol.

Singlet Oxygen Quenchers • Quench singlet oxygen or interact with excited

photosensitizers • Carotenoids with > 9 double bonds are the

most active • Effective in nature but rarely used as food

antioxidant

β-Carotene

Photosensitizer Generated Singlet Oxygen

Photosensitizer (grd)

Photosensitizer (ext.)

Carotenoid (grd.)

Carotenoid (ext.)

Energy to Environment

How to Control Singlet Oxygen

♦Light blocking bottles

♦Remove photosensitizers • Oil refining

♦Metal Chelators

• Inhibit superoxide pathway

Light-induced generation of hydroperoxides and reducing agents

O2 Riboflavin

Light 1O2 + O2

- + Fe+3 O2 + Fe2+

+ LH LOOH Radicals

Other Methods to Inhibit Lipid Oxidation

Oxygen Concentrations

• Reduction of oxygen with processing equipment and packaging technologies • Vacuum • Modified atmosphere • Oxygen scavengers

• Must remove oxygen quickly in products which are oxidizing rapidly (e.g. cooked products)

Oxidation of fish oil with different dissolved oxygen concentrations

Encapsulation

Oils can be stabilized by embedding the oil in a dry matrix to inhibit oxygen exposure

Each Particle

Encapsulation

♦ Dried oils must have very low amounts of surface/exposed lipid to minimize oxidation

♦ Spray dried oils are very effective in: ♦ Powdered food systems ♦ Low moisture systems

Encapsulation Problem: In liquid-based foods, encapsulation can

dissolve leaving the lipid unprotected

Hydration

Hydrogenation

• Remove double bonds • Used to:

– Solid fat for baking and spreads – Increase oxidative stability of fats – Partial hydrogenation designed to decrease

concentration of most unsaturated fatty acid (e.g. 18:3) to increase oxidative stability and decrease fatty acids that produce volatile breakdown products with low sensory thresholds

Packaging to Inhibit Lipid Oxidation

Causes of Lipid Oxidation Packaging Control Strategies

Oxygen Low Oxygen Transmission Rate (glass, metal, some polymers)

Light Opaque materials (metal, some polymers)

Free Radicals ?? Metal ??

Properties of polymer packaging films

• Barrier Characteristics – Water Vapor Transmission Rate – Oxygen Permeability – Carbon Dioxide Permeability – Light transmission

food package environment

Oxygen Transmission Rates of Common Polymer Packaging Films

Material Oxygen Transmission Rate (cm3.mm/m2.day.atm at 23oC, 0%rh)

EVOH (ethylene vinyl alcohol) 0.02

PVDC (polyvinylidine chloride) 0.03

Cellophane 0.5

Nylon 6 1.02

PET (polyethylene terephthalate) 2.79

HDPE (high density polyethylene) 49.6

PP (polypropylene) 68.5

LDPE (low density polyethylene) 274

Permeability and Other Film Properties (1995)

Multilaminates

• Improve value & function of package material by using multiple materials in concert

PE FOIL PE PAPER PE

METALLIZED NYLON PE

ETHYLENE VINYL

ACETATE

DRY FOOD SEASONING

COFFEE

Migratory vs. Non-Migratory

Blending Coating Surface Grafted Non-migratory

Impregnate with antioxidant and let them volatilize into the foods

Chelating Active Packaging

Replace EDTA? Enable Additive Free Label Claim

Maintain Product Quality

US Provisional Appl. Ser. No. 61/570,417

Material Synthesis

Polypropylene (PP)

- COO-

Poly(acrylic acid) (PAA)

Chelating monomer:

Acrylic acid oil

Fe2+ Fe2+

- - - - - - -

- - - -

Non-migratory

Wavenumber (cm-1)1000 1200 1400 1600 1800 2000

.20 PPPP-g-PAA

Material Characterization ATR-FTIR Spectroscopy

Storage time (day)

0 2 4 6 8 10 12 14

PPPP-g-PAA

Storage time (day)

0 2 4 6 8 10 12 14

PPPP-g-PAA

Significant Lag Phase Extension

Storage time (days)

0 2 4 6 8 10 12 14

Storage time (days) 0 2 4 6 8 10 12 14

Demonstration Lipid Oxidation

Antioxidant Application Strategies

Applying Antioxidant for Maximum Effectiveness

• Critical to optimize – Concentration – Interactions – Location – Stability

• Due to wide spread variations in food composition, it is difficult if not impossible to predict how antioxidants will work in different foods

Antioxidant Concentrations

• All antioxidants have a maximum concentrations of effectiveness – Chelators

• At low concentrations can increase metal solubility without decreasing reactivity = prooxidant

– Free radical scavengers • Activity very dependent on concentration

– Metal redox cycling – High or low antioxidant radical concentrations can promote

fatty acid oxidation

Prooxidant and Antioxidant Activity of Ascorbic Acid

Ascorbic Acid (mM)

Decker and Hultin, 1990

Mechanism of Prooxidant and Antioxidant Activity

Fe+2 Fe+3 + LOOH + LO● + High Ascorbate Conc.

Low Ascorbate Conc. LOH + Dehydroascorbate

Prooxidant > Antioxidant Antioxidant > Prooxidant

Ascorbic Acid

Prooxidant and Antioxidant Activity of α-Tocopherol

Frankel, 1990

Mechanism of Prooxidant and Antioxidant Activity

α-Tocopherol

LOO• + α-Tocopherol LOOH + Fe+2

α-Tocopherol

LO• + Fe+3

α-Tocopherol quione

Antioxidant Stability and Reactivity

• Antioxidants must survive processing operation and interactions with other food components

• Antioxidants can be lost by: – Oxidation – Volatilization – Enzymatic degradation – Thermal Degradation

• Oxidation: – Antioxidants are more prone to oxidation than

fatty acids – If antioxidants are obtained in oil the oil must not

be oxidized – Antioxidants should be stored and treat like other

oxidizable lipids – Purified antioxidants tend to be very stable

• Volatilization – Antioxidants will be lost during

• Normal storage (evaporation) • Extrusion (steam distillation) • Frying (steam distillation)

– Antioxidants can also be introduced into foods by volatilization (packaging)

• Enzymatic Degradation – Phosphatases

• Thermal Degradation – Antioxidant Enzymes – Mallaird reaction

• Ascorbic acid • Amines (proteins and phospholipids) • Sulfhydryls

• Competing Reactions – Antioxidants can loose effectiveness by competing

reactions • Chelators and Calcium

– Dried products

• Singlet oxygen quenchers and singlet oxygen

Other Factors to Consider to Control Lipid Oxidation in Food

Systems

Oil Refining and Lipid Oxidation

♦The process of oil extraction and rendering promotes lipid oxidation • Activates lipase and lipoxygenase • Destroys or removes antioxidants • Increase oxygen exposure • Exposes lipids to high temperatures (rendering) • Releases and activates transition metals

♦Many steps of oil refining are designed to remove oxidation products and prooxidants

Steps of Oil Refining

♦Degumming ♦Neutralization ♦Bleaching ♦Deodorization ♦Winterization

Degumming ♦Removal of phospholipids by acid hydration

• Decrease foaming • Decrease water content • Decrease browning

♦Decrease phospholipids from 1-3% to less than 0.005%

♦Impact on oxidative stability • Aids in removal of prooxidative water • Removes some tocopherols and phenolics • Phospholipids are antioxidative

Neutralization

♦Oil mixed with caustic soda ♦FFA for water-soluble sodium salts that are

removed ♦Decreases FFA from 0.3-5% to less than

Bleaching

♦Remove pigments with bleaching clays ♦Impact on oxidative stability

• Also removes residual FFA, phospholipids and hydroperoxides

• Removes photosensitizers • Performed under vacuum since bleaching clays

can promote oxidation ♦All bleaching clay must be removed or it

will promote oxidation

Deodorization

♦Remove off-flavors with steam distillation under vacuum.

♦Removes tocopherols and sterols which are sold as separate ingredients.

♦High temperatures decompose hydroperoxide thus decreasing peroxide value.

♦Following deodorization, 0.005-0.01% citric acid is added for stabilization.

Winterization

♦Decrease temperature to crystallize most saturated TAG

♦Crystals removed by filtration to produce liquid oil high in unsaturated fatty acids

♦Used to make salad oils that will not solidify in refrigerator

♦Decreases oxidative stability since increases unsaturation

Interesterification (IE)

♦Could be used to increase oxidative stability by increasing the level of saturated fatty acids on TAG

♦Oxidative stability of fatty acids at sn-2 are slightly higher so stereospecific IE could slow or increase oxidation

Chemical Esterification can Decreases Oxidative Stability

Adapted from Neff, Elagaimy and Mounts., 1994

Is Decreased Oxidative Stability due to Removal of Antioxidant or Addition of

Prooxidant? ♦Antioxidants

• Tocopherols – Can be lost during purification

Sample α-tocopherol

β-tocopherol

γ-tocopherol

δ-tocopherol

Soybean Oil1

182 17 641 194 1033

IE Soybean Oil1

161(12%) 13 (24%) 571 (11%) 130 (33%) 875 (15%)

Is Decreased Oxidative Stability due to Removal of Antioxidant or

Addition of Prooxidant? • Antioxidants

– Tocopherols • Can be lost during purification • Can be chemically modified

Chemical Modification of Tocopherols during Interesterification

Reactive Site

Blocked

α-tocopherol

α-tocopherol-palmitate ester Adapted from Hamam and Shahidi, 2006

+ Palmitate

Formation of Minor Components by Interesterification

♦ Randomization increased MAG from 0 to 0.3% and DAG from 1.4 to 5.1%

♦ MAGs and DAG can increase lipid oxidation rates

Adapted from Wang, Jiang and

Hammond, 2005

Raw Material Quality ♦Impact on lipid oxidation (so many factors and

so little resources) • Lipid hydroperoxides • Metals • Free Fatty Acids • Temperature • Antioxidant concentrations

Raw Material Quality ♦Lipid Hydroperoxides are the substrate for

lipid oxidation ♦All lipids have hydroperoxides ♦Push for lower specs of hydroperoxide ♦Look for hydroperoxides in other ingredients

(e.g. emulsifiers)

Typical lipid hydroperoxide concentrations in food oils

Oil Peroxide Value

(Meq/kg) (mmol/kg)

Canola a 5.00 2.50

Coconut a 4.97 2.48

Corn b 3.93 1.96

Olive b 8.50 4.25

Extra virgin olive a 14.92 7.46

Peanut a 6.99 3.50

Palm kernel b 0.75 0.38

Palm olein a 7.99 4.00

Hydroperoxide concentrations in surfactants

Brij 10 4.0 uM/g Brij 35 13.7 uM/g Tween 20 16.8 uM/g Tween 40 11.6 uM/g SDS 0.6 uM/g DTAB 0.4 uM/g Lecithin 13.0 uM/g

Raw Material Quality ♦Transition metals are a major prooxidant for

lipid oxidation • All ingredients and have metals • Concentrations in the low ppb can promote

oxidation • Metals can come from unlikely sources

Sugar Beet Pectin = 1.91 ± 0.02 ppm Fe and 0.08 ± 0.00 ppm Cu Citrus Pectin = 0.13 ± 0.00 ppm iron and 0.04 ± 0.00 ppm copper

Raw Material Quality ♦Free fatty acids are a major prooxidants for

lipid oxidation • Crude Oils = 0.3-0.7% • Refined = < 0.05% • Rendered animal products ???

♦Foods/food ingredients can contain lipases which can further produce FFA

Raw Material Quality

♦Variations in antioxidants (know and unknown) can make it difficult to predict: • Inherent oxidative stability • Effect of added antioxidants

– Antioxidants have maximal levels of activity so adding more may not be effective

• Antioxidant interactions

Raw Material Quality Antioxidants

♦ Endogenous antioxidant concentration can vary widely Fat or oil Tocopherols

(% w/w)

Tocotrienols

(% w/w)

Soybean 0.13 + 0.03 0.009 + 0.01

Canola 0.07 + 0.01 NR

Corn 0.15 + 0.02 0.04 + 0.04

Cottonseed 0.09 + 0.00 0.003 + 0.003

Sunflower 0.07 + 0.01 0.03 + 0.03

Peanut 0.05 + 0.03 0.03 + 0.02

Olive 0.01 + 0.00 0.01 + 0.01

Palm kernel 0.0003 0.003 + 0.003

Raw Material Quality ♦ Endogenous antioxidant type can vary widely

Oil α β γ δ

High-erucic acid rapeseed 268 - 426 -

Canola 272 - 423 -

Soybean 116 34 737 275

Sunflower 613 17 19 -

Corn 134 18 412 39

Flax oil 26 - 213 9

Tocopherol Homolog Concentrations in Refined Oils

Raw Material Quality

♦Temperature ♦Oxidation rates typically follow Q10 kinetics

• For every 10 C increase, rate doubles

♦Will lead to oxidation of antioxidants first so quality parameters are not effected but oxidative stability decreases

♦Could result in variations in antioxidant concentrations of raw materials

♦Maintain lowest storage temperatures possible

Oxidation History ♦ Most lipid containing raw materials have oxidized during

their production ♦ Fish Oil

• Oxidation begins during rendering • Crude oil is steam distilled

– Removes volatile – Breaks down hydroperoxides

• Antioxidant Added ♦ Oil quality may be good but oil contains nonvolatile

oxidation products and has lower concentrations of endogenous antioxidants

Oxidation History

♦Refined oils contain nonvolatile oxidation products that are not removed by steam distillation = Core Aldehydes

♦Core aldehydes are potentially toxic and

prooxidative

Oxidative Stability of ω-3 Fatty Acid Delivery System With Algae Oil

Oxidative Stability of ω-3 Fatty Acid Delivery System With Menhaden Oil

Fundamental of AntioxidantsAntioxidant Location •Location, Location, Location????? •Antioxidant...

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