Sequestrants

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Sequestrants Antioxidants

• Unsaturated fatty acids are subject to oxidation
  with the formation of off flavors
• Lipid oxidation is accelerated by iron and copper
• Seqestrants bind minerals and help prevent
  oxidation
• Antioxidants stop free radical propagation

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Oxidation Reviewhttp//class.fst.ohio-state.edu/F
ST605/lectures/lect3.html
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Oxidation Accelerators

• Oxygen
• Unsaturation
• Heat
• Copper, iron
• Free radicals
• Light

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What can we do to prevent or reduce oxidation?

• Remove oxygen
• How?
• Gas (N2 ,CO2 ) flush
• Vacuum pack
• Exhaust before closing
• Chemically remove it - Iron, glucose oxidase
• Oxygen impermeable packages to keep it out

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What can we do to prevent or reduce oxidation?

• Reduce unsaturation
• Hydrogenation
• Different fat source
• Reduce fat
• Reduce temperature
• Note lipids still oxidize in the freezer
• Reduce light

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What can we do to prevent or reduce oxidation?

• Reduce iron, copper ions
• Sequester iron, copper ions
• EDTA, citrate, phosphates
• Scavenge free radicals

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Initiation

• Light
• Metal ions
• Oxygen
• Solutions
• Packaging
• Sequesterants
• Singlet oxygen quenchers

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Propagation

• Antioxidants (free radical scavengers)
• Donate Hs to quench free radicals
• Sequesterants

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Termination

• No one cares because your product is already past
  the point where it can be sold.

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Sequesterants

• Bind metal ions
• Complex doesnt promote oxidation
• Important also for
• Solubility
• Texture
• Color
• Taste

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Sequesterants

• EDTA
• Citrate
• Other organic acids
• Phosphates

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Stability Constants log K

• Ion Ca2 Fe2 Fe3 Cu2
• EDTA 10.7 14.3 25.7 18.8
• Citric Acid 3.5 3.2 11.8 6.1
• Pyrophosphate 5.0 22 6.7

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Antioxidants Reviewhttp//class.fst.ohio-state.ed
u/FST605/lectures/lect6.html
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Characteristics of Antioxidants

• Donate H
• Typically Phenolic
• SH would work
• Number of H's that can be donated
• Solubility
• Vapor pressure
• Flavor
• Color

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Resonance Stabilization
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GRAS Antioxidants

• Ascorbic acid
• Erythorbic acid
• Ascorbyl palmitate
• Thiodipropionic acid
• Butylated hydroxy anisole (BHA)
• Butylated hydroxy toluene (BHT)
• Calcium ascorbate
• Dilauryl dithiopropionate
• Gum Guaiac (0.1 max)
• Sodium ascorbate
• Tocopherols
• Max 0.02 of the fat

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Antioxidants 21 CFR 172

• BHA
• BHT
• Ethoxyquin
• 4-hydroxymethyl-2,6-di-tert-butyl phenol
• TBHQ
• TBHP
• Anoxomer

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BHA BHT

• BHA
• BHT

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BHA

• Commonly used in animal products
• Good carry through
• Used in packaging materials
• More expensive than BHT

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BHT

• Cheap
• Widely used in industrial applications
• Used in combination with BHA for synergistic
  effect
• More volatile than BHA

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Propyl Gallate

• Decomposes at 148 C
• Poor carry through
• Can form colored complexes
• Has three donateable Hs
• Usually used in combination

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TBHQ

• 2 Hs
• Good carry through for frying
• Can turn pink at high pH
• Often combined with BHA

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Natural Antioxidants

• Tocopherol
• Ascorbic acid
• Sulphydryl containing proteins

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What would be the difference in the oxidation of
these products?

• An uncooked potato
• A potato chip
• Instant potato flakes

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QuizWhere do you find antioxidants and
sequesterants?
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Answer

• Products containing unsaturated fatty acids,
  especially poly unsaturated acids where
• Lipid content is a major ingredient in the food
• a long shelf-life is desired
• Foods have a significant levels of copper or iron
• Package permits exposure to light