Processing Effects on Phytonutrients

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• Processing Effects on Phytonutrients
• Luke R. Howard, Ph.D
• Luke R. HoLukeward, Ph.D.

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Phytonutrient/Phytochemical

• Components in a plant
• based diet other than
• traditional nutrients that
• can reduce the risk of
• degenerative diseases

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Factors Influencing Phytonutrient Content of
Fruits and Vegetables

• Genotype
• Cultural practices
• Environmental growing conditions
• Maturation
• Postharvest handling and storage conditions
• Processing

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Chemical and Physical Factors Influencing the
Stability of Vitamins and Phytonutrients

• Heat
• Light
• Oxygen
• Co-factors
• Metals
• Enzymes
• Chemical structure/solubility
• Tissue localization Free vs bound

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Processing Factors Influencing Phytonutrient
Content

• Unit operations
• Washing/cleaning
• Physical removal of tissues
• Soaking (beans and peas)
• Blanching (steam vs water)
• Particle size reduction
• Enzyme treatments, pressing, clarification

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Processing Factors Influencing Phytonutrient
Content

• Filling and Brining
• Ratio of productbrine
• Dissolved oxygen
• Food additives

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Processing Factors Influencing Phytonutrient
Content

• Preservation method
• Thermal process (time and temperature, still vs
  agitated, aseptic)
• Freezing process (rate and temperature)

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Factors Influencing Phytonutrient Content of
Fresh-cut Products

• Washing/sanitizing
• Peel removal
• Degree of wounding
• Package atmosphere
• Storage temperature

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Processing Effects on Blueberry Polyphenolics
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Fresh Berries (Blueberries, Blackberries, Black
raspberries)
Analysis of Fresh Berries
Frozen Berries
Individually Quick Frozen (IQF)
Baking
Puree
Juice
Canning
Canned (Water)
Canned (Syrup)
Clarified
Non-Clarified
Pie-Frozen Berries
Pie-Canned in Water
Sampling 1 d, 1 mo, 3 mo, 6 mo
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Total Anthocyanin Retention and Polymeric Color
in Blueberry Juices
Retention
Polymeric color
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Total Anthocyanin Retention and Polymeric Color
in Canned Blueberries
Retention
Polymeric color
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Total Anthocyanin Retention in Blueberries Canned
in Syrup
Retention
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Total Anthocyanin Retention and Polymeric Color
in Blueberry Puree
Retention
Polymeric Color
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Total Flavonol Retention in Blueberry Juices
Retention
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Total Flavonol Retention in Blueberries Canned in
Syrup
Retention
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Total Flavonol Retention in Blueberry Puree
Retention
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Total Procyanidin Retention in Blueberry Juices
Retention
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Total Procyanidin Retention in Blueberries Canned
in Syrup
Retention
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Total Procyanidin Retention in Blueberry Puree
Retention
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Chlorogenic Acid Retention in Blueberry Juices
Retention
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Chlorogenic Acid Retention in Blueberries Canned
in Syrup
Retention
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Chlorogenic Acid Retention in Blueberry Puree
Retention
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ORACFL Retention in Blueberry Juices
Retention
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ORACFL Retention in Canned Blueberries
Retention
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ORACFL Retention in Blueberry Puree
Retention
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Phenolic and Antioxidant Changes in Fresh-cut
Carrots
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Processing and Sampling

• Carrot coins (with peel removed) packed in
  ventilated bags
• Stored at 4oC
• Sampled at 0, 3, 7, 14 and 21 days

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Chemical Analyses

• Phenolics HPLC
• HCA quantified as chlorogenic acid equivalents
  at 320 nm
• pHBA quantified as hydroxybenzoic acid
  equivalents at 265 nm
• Carotenoids HPLC C30 column
• Beta, alpha and carotene isomers quantified as
  beta carotene equivalents

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HPLC chromatogram of a canned sample (at 450 nm)
with the peak maxima for all-trans(1) lutein, (6)
?-carotene, and (7) ?-carotene. Other labeled
peaks (2) 13-cis ?, (3) 13-cis ?, (4) 15-cis ?,
(5) 13-cis ?, and (8) 9-cis ?.
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PCL Antioxidant Assay

• Antioxidant capacity
• Measured using a Photochem antioxidant analyzer
• L hv O2 L. O2.-
• Detection of excess superoxide radicals left
  after quenching by antioxidants
• O2.- L. L (luminescence)

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HCA and pHBA Contents of Fresh-cut Carrots as
Affected by Storage
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Antioxidant Capacity of Fresh-cut Carrots as
Affected by Storage
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Relationship Between HCA Content and Antioxidant
Capacity
R20.988
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Alpha, Beta and Total Carotene Contents of
Fresh-cut Carrots as Affected by Storage
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Other Studies
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Effect of Cooking on Total Flavonoid Content of
Spinach
Concentration (mg/kg FW)
Gil et al. (1999) J. Agric. Food Chem., 47,
2213-2217.
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Effect of Peel Removal on Total Phenolic Content
in Ross Clingstone Peaches
c
b
a
Total phenolics (mg/kg FW)
Asami et al. (2003), J. Sci. Food Agric., 83,
56-63
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Effects of Thermal Processing and Canned Storage
on Total Phenolic Content in Peaches
Total phenolics (mg/kg FW)
Storage Time (months)
Asami et al. (2003), J. Sci. Food Agric., 83,
56-63
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Comparison of Individual Procyanidin Oligomers in
Frozen and Canned Clingstone Peaches
Normalized Peak Area
Asami et al. (2003), J. Sci. Food Agric., 83,
56-63
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Total Flavonoid Content of Frozen Vegetables as
Affected by Storage

Total flavonoids (mg/kg DW)
Puupponen-Pimia et al. (2003), J. Sci. Food
Agric., 83, 1839-1402
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Total Carotenoid Content of Frozen Vegetables as
Affected by Storage
Total Carotenoids (mg/100g DW)
Puupponen-Pimia et al. (2003), J. Sci. Food
Agric., 83, 1839-1402
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Retention of Flavonoids in Canned Green Beans
Retention
Price et al. (1998) J. Agric. Food Chem., 46,
4898-4903.
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Retention of Polyphenolics in Pasteurized
Blueberry Juice
Retention
Skrede et al. (2000), J. Food Sci., 65, 357-364
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Effect of Cooking on Procyanidin Content of Pinto
Beans
Concentration (mg/100g FW)
Gu et al. (2004) J. Nutr. 134 613-617
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Total Anthocyanin Content of Canned Cherries
Stored at 22oC
Concentration (mg/100g FW)
Chaovanalikit and Wrolstad (2004) J. Food Sci.
6973-83.
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Total Phenolic Content of Canned Cherries Stored
at 22oC
Concentration (mg/100g FW)
Chaovanalikit and Wrolstad (2004) J. Food Sci.
6973-83.
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ORAC of Canned Cherries Stored at 22oC
Concentration (µmol TE/100g FW)
Chaovanalikit and Wrolstad (2004) J. Food Sci.
6973-83.
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Changes in Antioxidant Activity as Affected by
Heating
Nicoli et al. (1999) Trends Food Sci. Tech.
1094-100
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Changes in the Overall Antioxidant Properties of
Foods as Affected by Heating

• No changes
• No changes in naturally occurring AOX
• Loss of native AOX formation of compounds with
  novel or improved AOX
• Improvement of AOX properties of native compounds
• Formation of novel compounds having AOX
  properties (MRPs)

Nicoli et al. (1999) Trends Food Sci. Tech.
1094-100
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Changes in the Overall Antioxidant Properties of
Foods as Affected by Heating

• Decrease
• Loss of native AOX
• Formation of novel compounds having pro-oxidant
  activity (MRPs)

Nicoli et al. (1999) Trends Food Sci. Tech.
1094-100
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Conclusions

• Different unit operations and preservation
  methods markedly affect the retention of fruit
  and vegetable phytonutrients and antioxidant
  capacity
• Increased number of processing steps exacerbates
  phytonutrient losses
• Processing by-products are a potentially rich
  source of phytonutrients
• Water-soluble phytonutrients readily leach into
  liquid canning media

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Conclusions

• Fresh-cut produce may exhibit high antioxidant
  capacity due to the synthesis and accumulation of
  wound-induced phenolic compounds
• Mitigation strategies are needed to prevent
  losses of phytonutrients during processing
• More research is needed on the bioavailability of
  phytonutrients in processed foods

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