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e x t e n s i o n . u s u . e d u
Food MythsFact or Fiction?
Karin Allen, PhDUSU Extension Food Quality & Entrepreneurship
FCS Videocast SeriesSeptember 24, 2013
e x t e n s i o n . u s u . e d u
Fact or Fiction?
Alcohol evaporates out of foods during cooking.
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Fiction!
Alcohol evaporates out of foods during cooking.
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Ethanol or Ethyl Alcohol
• Hydrophobic and hydrophillic regions
• Stabilizes flavors and aromas
• Boiling point 170°F
Extract Flavor McCormick Watkins Massey
Vanilla Pure 41%Imit. 26% Pure 35% Pure 35%
Almond Pure 32%Imit. 32%
Pure 40%Imit. 45% Pure 90%
Orange Pure 79% Pure 89% Pure 90%
Peppermint Pure 89% Pure 91% Pure 83%
• Liqueurs (orange, berry, mint, etc.): typically 15-30%
• Wine (red, white, blush): 10-15%
• Liquor (rum, whiskey, vodka): 35-50%
Hydrogen Bonding in Ethanol
Hydrogen Bonding between Ethanol and Water
USDA Nutrient Retention Factors
Cooking Method Time % Alcohol Remaining
Flambée n/a 75%
Baked/simmered 15 min 40%
Baked/simmered 30 min 35%
Baked/simmered 1 hr 25%
Baked/simmered 1.5 hr 20%
Baked/simmered 2 hr 10%
Baked/simmered 2.5 hr 5%
Source: USDA Table of Nutrient Retention Factors, Release 6 (Dec. 2007)
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Fact or Fiction?
Freshly ground wheat shouldn’t be used for bread.
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Fact!
Freshly ground wheat shouldn’t be used for bread.
Gluten
Glutenins Gliadins
Gluten Formation
Gluten Requires Disulfide Bonding
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Fact!
Freshly ground wheat shouldn’t be used for bread.
Changes During Maturing
• Glutathione content decreases naturally after milling
• Chemical processing speeds this up
Why is Glutathione Bad?
Why is Glutathione Bad?
Glutathione
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Recommended Aging Time is 10 Days
• Research shows glutathione decreases by up to 43% after 10 days for some wheat types
• Bread volume increases roughly 10% using 10-day old flour
• Results between 10 and 40-day old flour are very similar
Source: Chen X. and Schofield J. D. (1996). “Changes in the Glutathione Content and Breadmaking Performance of White Wheat Flour During Short-Term Storage”. Cereal Chemistry 73(1):1-4.
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Fact or Fiction?
Freshly-squeezed is more nutritious than juice made from frozen concentrate.
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Fiction!
Freshly-squeezed is more nutritious than juice made from frozen concentrate.
Which apple would you choose?
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Blemished Foods in Food Processing
• The Food and Agriculture Organization reports post-harvest losses account for over 20% of total food waste world wide
• Fruits and vegetables used in processing must still meet USDA quality standards• Only 5% of apples for processing can have
worm holes
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But aren’t nutrients lost in processing?
• Frozen juice concentrates are no longer heated to evaporate water (they are still pasteurized for safety reasons)
• Water can be removed by freezing or membrane filtration
Freeze Concentration
Membrane Filtration
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But aren’t nutrients lost in processing?
• Frozen juice concentrates are no longer heated to evaporate water (they are still pasteurized for safety reasons)
• Water can be removed by freezing or membrane filtration
• Both techniques preserve sensitive nutrients such as Vitamin C
USDA Table of Nutrient Retention Factors, Release 6 (Dec. 2007)
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Fact or Fiction?
Red kidney beans should be boiled first, not added
dry to a slow-cooker.
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Fact!
Red kidney beans should be boiled first, not added
dry to a slow-cooker.
Phytohaemagglutinin
Levels of Protein Structure
PHA Activity in kidney beans
Variety Soak time
Cook conditions
Activity units before
Activity units after
Red kidney 18 hrs -- 53000 18000
Red kidney 18 hrs 100°C, 10 min 18000 6800
Red kidney 18 hrs 100°C, 20 min 18000 1300
White kidney 18 hrs -- 44000 28000
White kidney 18 hrs 100°C, 10 min 28000 0
White kidney 18 hrs 100°C, 20 min 28000 0
Red kidney 18 hrs 70°C, 20 min 28000 35000
Red kidney 18 hrs 80°C, 20 min 28000 215000
Adapted from Bender A.E. (1983). “Haemagglutinins (Lectins) in Beans”. Food Chemistry 11:309-320.
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FDA Recommendations
• Soak in water for at least 5 hours.
• Pour away the water.
• Boil briskly in fresh water, with occasional stirring, for at least 10 minutes.
Undercooked beans may be more toxic than raw beans!
Source: FDA Bad Bug Book 2nd Edition (2012)
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Fact or Fiction?
Pre-packaged roasts are safe even if cooked rare.
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It Depends…
Pre-packaged roasts are safe even if cooked rare.
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USDA Safe Cook Temps
ProductMinimum Internal
Temperature
Beef, Pork, Veal & Lamb
Steaks, chops, roasts 145°F
Ground 160°F
Poultry
Breasts, legs, thighs, wings 165°F
Ground 165°F
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Why is there a lower temperature for red meats?
• Intact muscles are sterile (bacteria cannot penetrate into the muscle)
• Meats become contaminated during harvest and processing
• Any cut surface can contain bacteria• Ground meats, cube steaks
• What about roasts?
Depends!!!Was it Injected or Tenderized?
So which pre-packaged meats are?
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How can I tell?
• As of June 2013, USDA requires all mechanically tenderized or injected meats to be labeled
• Must give cooking instructions, including a validated safe minimum internal temperature
• Consumers should follow similar recommendations when injecting roasts at home
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Questions or Comments?
Thank You!