Transcript small intestine

Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.

The balance of pH in the human body is critical for many life
processes.

The pH level of food DOES NOT affect the pH levels within the body.

Damage from gastric acids can be caused by:


Overeating – which can stretch the valve opening at the top of the stomach
allowing hydrochloric acid into the esophagus

Bulimia – induced, frequent vomiting washes strong gastric acids into the
esophagus, teeth, and mouth causing irreversible damage
A variety of pH levels are needed for digestion of food.
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.



Saliva (pH 6.5) in the
mouth begins the
digestive process.
Bile (pH 8.4) is produced
in the liver and stored in
the gall bladder until it is
released to help digestion
in the small intestine.
In the stomach,
hydrochloric acid, one of
nature’s strongest acids
(with a pH of 1.5 -1.7),
further digests food.

The pancreas releases
pancreatic juice, with a pH
of 8.0, to quickly raise the
pH as food leaves the
stomach.

In the small intestine, pH levels
out at 7.0.
Photo courtesy of LadyOfHats
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.

Blood pH must remain between 7.2 – 7.6. (7.4 is optimal)

Blood pH greater than 7.6 leads to alkalosis; less than 7.2
leads to acidosis. Both conditions are very dangerous
and may lead to:





Dull breathing reflex
Fatigue
Confusion
Coma
Death
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.

Buffers maintain the balance between hydrogen and
hydroxide ions in a solution, such as blood.

Carbon dioxide (CO2) plays a major role:

CO2 is a waste product of cell activity.

Carried by the blood to the lungs for expulsion

Gas is dissolved in the blood to form carbonic acid (H2CO3) and
keeps the blood from becoming too basic.

Concurrently, the blood molecules contain bicarbonate or
phosphate ions which neutralize the excess carbonic acid.
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.
Microorganisms growing and feeding on food
create food spoilage and often foodborne illnesses.
 A pH level of 5.0-7.0 is prime for growing bacteria
and other microorganisms.
 Understanding the pH environment when preserving
food products is important for the safety of the food.

Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.
Botulism grows in low-acid foods, such as corn, beans, other
vegetables, and meat, that have a pH above 4.6. These foods
must be preserved at very high temperatures to kill the sporeforming microorganism.
 High acid foods, such as berries, fruits, pickles, and tomatoes,
have a pH of less than 4.6 can use a much lower temperature for
preservation.

Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.



The freshness and pH of the leavening agents and other
ingredients will affect the appearance, flavor, and texture of
baked products.
Baking soda (NaHCO3), a base, will cause baked products to
rise when combined with an acid, such as buttermilk, lemon
juice, vinegar, or yogurt.
Baking powder is a mixture of baking soda, dry acids, and fillers.
Some of the dry acids react with baking soda to create an
immediate reaction during the mixing process. Fillers in the
baking powder prevent other dry acids, such as cream of
tartar, from reacting until heat is applied.
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.
Acids develop as fruit matures.
 During the ripening process, acids work to improve
flavor (by increasing sugar content) and color, as well
as the quality of the juice.
 Different fruits have different optimal acid levels.

Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.
 Citrus
fruits must have proper balance of sweetness and
acidity for palatability.
 Charts have been developed by food scientists showing
optimal ratios of sugar and acidity of various fruits.
Copyright © Notice: The materials are copyrighted © and trademarked ™ as the property of The Curriculum Center for Family and Consumer Sciences, Texas Tech University.