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Optimizing Processing Quality of Processing
Potatoes
2009 Australian Vegetable Industry Conference -
Growing a Healthy Australia
Steven B. Johnson, Ph.D. University of
Maine Cooperative Extension
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Potato processers pay for attributes they want
Specific gravity Colour Size profile
Potato processers penalize for attributes they
dont want
Bruises Foreign matter
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Atlantic
2000
2002
2001
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Data from Greg Porter, University of Maine
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Specific Gravity ResponseR. Burbank
1 point per 25 kg of K per hectare
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Data from Greg Porter, University of Maine
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2007 - 2008
Agtron values 2007 - 2008
12 February
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Agtron values 2007 - 2008
3 May
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Darkening of processed potato products
Accumulation of reducing sugars, mainly glucose,
from the Maillard reaction
Stress CO2 and ethylene Temperature
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Glucose levels 2007 2008
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Size profile
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Tuber size distributions of some seed lots lead
to GOOD cut seed piece size distribution. GOOD
cut seed piece size distribution leads to good
planting.
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Tuber size distributions of some seed lots lead
to poor cut seed piece size distribution. Poor
cut seed Piece size distribution leads to poor
planting.
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Seed Cutting Distribution
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Diseases cause quality losses
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Blackleg (Pectobacterium atrosepticum)
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Virus
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Common scab (Streptomyces spp.)
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Powdery scab (Spongospora subterranea f. sp.
subterranea. )
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Insects
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Potato processers penalize for attributes they
dont want
Bruises Foreign matter
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Bruise

• Impacts (drops, stones, hard surfaces)
• temperature
• Tuber Hydration
• Genetics
• wide range of varietal susceptibility
• Nutrient Management
• potassium -- strongest link
• other nutrients??

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Atlantic
2001
2000
2002
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Data from Greg Porter, University of Maine
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Snowden, Shepody, R. Burbank
Bruise free
Serious Bruise
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Data from Greg Porter, University of Maine
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Foreign matter
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Storage
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Optimizing Processing Quality of Processing
Potatoes
2009 Australian Vegetable Industry Conference -
Growing a Healthy Australia
Steven B. Johnson, Ph.D. University of
Maine Cooperative Extension
SBJ UMCE
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This is the end
http//www.umaine.edu/umext/potatoprogram/
SBJ UMCE