Transcript Week 6 - Minerals

MINERALS
Chapter 7
Learning Objectives
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Describe the functions of minerals
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Identify food sources of minerals
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List minerals lacking in American diets
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List foods that are the best sources of these
minerals
Learning Objectives
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Give tips to ensure mineral intakes are
sufficient
Identify cooking techniques that
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promote retention of nutrients
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cause nutrient loss from foods
Minerals
• Essential for life and
health
• Must be obtained
from food
• Do not provide
energy
Minerals
• Needs are small
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measured in
milligrams
(1/1000 of a
gram) or
 micrograms
(1/1000 of a
milligram)

Minerals
• 15 are essential and must be from food
• Many minerals occur in nature
• All are inorganic elements
• no carbon in structure
• All are single elements
Shortfall Nutrients – or Nutrients of Concern
Many people do not get adequate amounts of:
Vitamins
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Minerals
Vitamin A
• Calcium*
Vitamin C
• Magnesium
Vitamin D*
• Potassium *
Vitamin E
• Sodium*
Vitamin K * Biggest nutrient gaps
Most diets also lacking dietary fiber
Choline
Most children and adults get too much sodium
Minerals
• Found in water and foods
• Remain intact during
digestion
• Stable, not easily
destroyed by heat, light,
oxygen
Two Groups of Minerals
Major Minerals (100 mg or more a
day)
Calcium
Chloride
Magnesium
Phosphorus
Potassium
Sodium
Sulfate
Biotin
Trace Minerals (less than 20 mg/day)
Iodine
Iron
Zinc
Selenium
Fluoride
Chromium
Copper
Manganese
Molybdenum
General Functions of Minerals
• Maintain the body’s fluid and acid/base
balance
• Provide structural components for blood,
bone, tooth cells
• Sustain immune system
General Functions of Minerals
• Co-factors in metabolic systems to repair
cells and protect from oxidative damage
• Participate in energy production, muscle
contraction, transmission of nerve impulses
Food Label for Nutrients
% daily value
 Goal 100%
 Good Source- 10-19% of daily value
 Excellent Source- 20% or more of daily value
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Calcium
• Most abundant mineral in the body
• 99% used to form and maintain teeth and
bones at all ages
• Calcium necessary throughout life for
bone mass and bone strength
Calcium
• Plays key role in blood clotting
• Aids muscle and nerve function
• Necessary for regular heartbeat, muscle
contraction
Calcium

DRI
 12-18 yo- 1300 mg/day
 19- 50 yo- 1000 mg/day
 Over 50- 1200 mg/day
 Older adults, 70+- 1500 mg/day
Calcium
• Higher absorption in
children and during
pregnancy
• Not all calcium
absorbed
• Deficiencies lead to
poor bones, teeth
and increased
fractures
Calcium - Sources
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Milk, milk alternatives
Yogurt
Cheese
Yogurt
Canned fish with bones
Calcium fortified orange
juice
Calcium - Sources
• Tofu set with
calcium
• Greens
• Rhubarb
• Legumes
Food Issues with Calcium
• Dairy products optimal source because
protein, vitamin D and lactose boost
absorption
• Tofu often processed with calcium to set.
Little calcium in other soy products.
• Foods fortified with calcium, calcium
citrate, well absorbed form
Food Issues with Calcium
• Full-fat dairy products high in cholesterol
and saturated fat
• Using a non-fat dried milk, evaporated
milk and yogurt in cooking boosts calcium
intake
• Canned salmon with bones, sardines are
rich sources of calcium
Osteoporosis
Calcium deficiency
 “brittle bones”
 Hip, spine, wrist
 Peak bone formation- first 3 decades
 Weight bearing exercise, calcium, vitamin D,
K, magnesium intake
 Risk- alcohol, smoking, high sodium
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Osteoporosis
and Calcium
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Age and bone calcium
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Maximizing bone mass
Potassium
• Less than 5% of Americans
get optimal potassium
intake
• Major role in
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Maintaining fluid balance
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Works opposite sodium
Acid/base balance
Healthy blood pressure
Heart beat
Bone health
Potassium
• DRI- 4700 mg/day
• Found in fruits, vegetables, milk, legumes
• Deficiencies linked to hypertension
• Low intake related to dehydration,
confusion, weakness
Sodium
• Daily Value – 2400 mg
• Dietary Guidelines for
Americans, 2010
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2300 mg
1500 mg for ages 51+,
African Americans.
hypertension, kidney
disease, diabetes
What Sodium Does in the Body
• Regulates body fluids
• Regulates acid-base balance
• Helps nerves and muscles function
properly
• Helps glucose and amino acids move from
blood into cells
Problem with Excess Sodium
• Can contribute to fluid retention
• May contribute to hypertension
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Sodium sensitive
Elderly
People with diabetes or kidney disease
African Americans
Sodium
• Filtered out of the blood by the kidneys
• Excreted in urine
• Lost through the skin via sweating
Sodium and Athletes
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Sodium lost through sweat
Replace fluids with water, but not sodium
Hyponatremia
 Muscle
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cramps
Clear sports drinks
 Exercise
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1 hour or longer
Consume plenty of sodium
Where is Sodium Found?
Table salt
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Salt (NaCl) is 40% sodium
1 gram of salt is 400 mg sodium
1 teaspoon of salt is 5.6 grams
1 teaspoon of salt adds about 2300 mg
of sodium to a dish
Where is Sodium Found?
• Flaked salts
weighs less than
5.6 grams per
teaspoon
• Less sodium per
teaspoon
Where is Sodium Found
• 75% salt from
manufacturers
• 15% from salt
added in cooking or
at the table
• 10% comes from
natural content
Where is Sodium Found?
Common ingredients
• Table salt
• Baking soda
• Baking powder
Where is Sodium Found?
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Monosodium glutamate (flavor enhancer)
Sodium benzoate (preservative)
Sodium caseinate (thicken, bind)
Sodium citrate (control acidity)
Sodium nitrite (Curing agent)
Sodium phosphate (emulsifer, stabilizer)
Where is Sodium Found?
Common condiments
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Fish sauce
Soy sauce
Soy sauce, low-sodium
Tamari sauce
Where is Sodium Found?
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Mustard
Capers
Catsup
Anchovies
Hoisin sauce
Where is Sodium Found
Processed foods
• Canned soups
• Pre-prepared sauces
• Cured, smoked and
deli meats
• Frozen foods, pizza
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Cheeses
Cereal, ready-to-eat
Breads
Snack foods
Sodium Issues in Food
• Salt biologically preferred flavor
• Sodium compounds perform many food
functions in processed foods
• Chefs should try to lower sodium sources as
much as possible. READ LABELS
Sodium
Magnesium
• Works with potassium to reduce blood
pressure
• In chlorophyll of green leafy vegetables
Magnesium
• Best food sources:
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Bran
Seafood
Green leafy vegetables
Legumes
Nuts
Iron
• Hemoglobin and Myoglobin
• in blood cells that carrys oxygen to cells
of body muscles
• Heme iron (from animal sources) better
absorbed than iron from plant foods
• Vitamin C- helps iron absorption from
plant foods; so does some heme iron
Iron
• Best food sources:
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Shellfish
Liver
Meats (especially red meats)
Fortified cereals, meatless protein sources
Legumes
Molasses
• Cooking in cast iron pans adds iron to
acidic foods. Useful for vegetarians
Iron Deficiency Anemia
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Low hemoglobin
Most common
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Breastfed infants, kids growth spurts
Pre-menopausal or pregnant women, female athletes
Chronic bleeding conditions
Poor diet
Symptoms
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Poor growth
Tired
Cold
Poor performance
Iron RDA’s
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Infants > 6 months: 11 mg/day
Teens: 11-15 mg/day
Adult males, post menopause: 8 mg/day
Women 19-50 yo: 18 mg/day
Pregnancy: 27 mg/day
Iodine
• Necessary to make the hormone thyroxin,
that regulates metabolic rate and body
temperature
• Food sources:
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Iodized salt
Fish
Shellfish
Foods grown in iodine rich soil
Iodine
• Residues of cleaning compounds on
foodservice equipment add to intake
• ? Increased need
• ? Inadequate intake
Disinfectants
• Dough conditioners
• Dairy industry
• Designer salts
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Fluoride
• For formation of teeth and bones and to
keep them strong, anti-bacterial
• Food sources:
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Fluoridated water
Toothpaste
Canned seafood
Tea
Fluoride
• Most community water is fluoridated at 1
part fluoride to 1 million parts water. This
level recommended by the dental society
and US government
• Excess can mottle teeth
• Controversy….
Adding Vitamins and Minerals
Fortification
• Vitamins and minerals are added
• Fortification common in breakfast cereals, milk
and dairy alternatives, fruit juices
Adding Vitamins and Minerals
Enrichment
• Vitamins and minerals are added to replace
nutrients lost in processing
• Enrichment is common in breads breakfast
cereals, and other grain products
Dangers of Excess Vitamins and Minerals
• Amounts found in foods are safe
• Regular intake of high-dose supplements
can be dangerous, stressing liver and
kidney
Bioavailability
• Bioavailability
is the degree
to which a
nutrient from
foods is
absorbed and
used by the
body.
Mineral Bioavailability Influenced By:
• Nutrients in high dose supplements
not used as well as nutrients in foods
• Binders such as oxylates and phytates decrease absorption
• Cooking can increase absorption breaks bonds between minerals and
binders
Oxalic and Phytic Acids
Oxalic Acid
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Binds some minerals
(calcium) so they are
partially absorbed
Found in:
 Spinach
 Oranges
 Rhubarb
 Tea
 Coffee
 Bananas
 Ginger
 Almonds
Phytic Acid
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Binds some minerals (iron
and zinc) so they are
partially absorbed
Found in:
 Cereals
 Nuts
 Sesame seeds
 Soybeans
 Wheat
 Pumpkin
 Beans
Nutrient Bioavailability is Enhanced By:
• Enzymes and bacteria in digestive tract can increase
amount of nutrients absorbed
• Vitamin C boosts absorption of iron present in plant
foods
• Protein and vitamin D boost calcium utilization
• Fermentation processes, such as those used to make
miso and tempeh, may improve iron bioavailability
Nutrient Bioavailability is Reduced By:
• Too much of one mineral can reduce the
absorption of another
• Polyphenols in regular and herbal teas,
coffee and red wine bind some iron
• Cooking softens cell walls of food so more
nutrients released
Raw Food
Pros
Vitamins and
minerals aren’t lost
from heat or
leaching into water
 No damage to
enzymes in
vegetables and
fruits
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Cons
Cooking destroys
salmonella and E.coli
 Cooked vegetables
may have more
bioavailable
nutrients
 More palatable
 Softens food for
easier digestion
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Nutrient Retention
• Minerals are more stable than vitamins
• Minerals cannot be destroyed by:
• Heat
• Light
• Oxygen
• Minerals can be destroyed by:
• Leaching into water that is discarded