Transcript Vitamins and minerals

Food Biotechnology
Dr. Tarek Elbashiti
Food Biochemistry 4
Vitamins and minerals
Vitamins

Micronutrients

Minor components but essential constituents in
foods
 absence in diet affect the health of people
 absorption levels affects its bioavailability
which also affects cell function and thus
health
Categories
Fat-soluble
Dissolve in fat
Can be stored
Water-soluble
Dissolve in water
Carried in
bloodstream, not
stored
A, D, E, K
C and B-complex
vitamins
A and D excess can be Excess amounts may
harmful
cause extra work on
kidneys
E and K usually not
Thiamin (B1)

Functions:
 Helps produce energy
from carbohydrates
and amino acids
(Coenzyme)

Sources:
 Whole-grain and
enriched grain
products
 Beef
 Liver
Thiamine (B1)
Deficiency
 Decrease in activity of enzymes.
 Beriberi (neurological and cardiac symptoms
(severe) sources: legumes seeds, pericarp and
germ of cereals, yeast, milk and whole grain
bread
Loss
 in cooking water, due to heat, change in pH,
metal ions and ionic strength.
 Also destroyed by sulfites .(added to fruits & veg
to prevent browning)
Riboflavin (B2)

Functions:
 Produce energy
(cofactor)
 Changes tryptophan
(amino acid) into
niacin

Sources:
 Liver
 Yogurt and milk
 Enriched grains
 Eggs
 Green, leafy veggies
Riboflavin (B2)
Deficiency
 Lead to accumulation of amino acids so there is
decrease of glutathione reductase activity in red
cells
 Stomatitis including painful red tongue with sore
throat, chapped and fissured lips (cheilosis), and
inflammation of the corners of the mouth
Stability
 Unstable when exposed to UV light
Niacin (B3)


Functions:
Precursor of
NAD&NADP
 Helps body use
sugars/fatty acids
 Helps enzymes
function normally
 Produces energy

Sources:
 Foods high in protein
typically (poultry, fish,
beef, peanut butter,
legumes)
 Enriched and fortified
grains
Nicotinamide (Niacin)
Deficiency
 Serious is pellagra (affects skin, digestion and nervous system
– dermatitis, diarrhea and dementia)
Stability
 quite stable in heat and processing
Availability
 increases slightly during baking due to alkaline
conditions (baking powder)
Loss
 occurs in cooking water due to leaching.
Pyridoxine (B6)


Functions:
Cofactor in many enzyme
reactions in amino acid,
glucose, and lipid metabolism.
 Helps body make nonessential amino acids
 Helps turn tryptophan into
niacin and serotonin
 Help produce body
chemicals (insulin,
hemoglobin, etc)

Sources:

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
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Chicken
Fish
Pork
Liver
Whole grains
Nuts
Legumes
Pyridoxine (B6)
Deficiency
 Results in protein metabolic disorders eg haemoglobin
synthesis
Loss
 during cooking in cooking water
 extensive loss in dried milk due to interaction with
sulfhydryl groups of proteins
Vitamin B12 (cobalamin)

Functions:



Works with folate to make
RBC’s
In many body chemicals and
cells
Helps body use fatty
acids/amino acids

Sources:
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Animal products
Meat
Fish
Poultry
Eggs
Milk, other dairy
Cobalamin, B12
Stability

Quite stable to food processing and cooking at pH4-6

However, destroyed in alkaline media or in the presence of reducing
agents
 E.g. Ascorbic acid and SO2
Folate (folic acid) B9, M, Bc

Functions:

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Produces DNA and RNA,
making new body cells
Works with vitamin B12 to
form hemoglobin
May protect against heart
disease
Lowers risk of neural tube
defects in babies
Controls plasma
homocystine levels (related
to heart disease)

Sources:
 Fortified and enriched
grains and breakfast
cereals
 Orange juice
 Legumes
 Green, leafy veggies
 Peanuts
 Avocados
Folic acid (Folacin, B9)
Deficiency
 leads to anaemia
Loss
 vitamin C helps preserve folic acid in food, loss in milk due
to oxidative process.
 However, no destruction during blanching of vegetables.
Biotin (B7, H, coenzyme R)

Functions:
 Produces energy
 Helps body use
proteins, carbs, and
fats from foods
 Helps maintain steady
blood sugar level,
 Helps strengthen hair
and nails

Sources:
 Wide variety of foods
 Eggs
 Liver
 Wheat germ
 Peanuts
 Cottage cheese
 Whole grain bread
Biotin
Deficiency
 Rare except in people who eat large amounts of
raw egg (cooking releases biotin from protein).

Found to develop dermatitis and neuromuscular
dysfunction.

Stable vitamin-loss occurs during processing and
storage.
Pantothenic Acid (B5)




Synthesize coenzyme-A
(CoA)
Helps produce energy
Helps the body use
proteins, fat, and carbs
from food
Sources:
 Found in almost all
foods
 Meat, poultry, fish
 Whole grain cereals
 Legumes
 Milk
 Avocados
 Broccoli
Pantothenic acid, B5
Deficiency is rare
Loss
 10% during milk processing also during cooking of
vegetables due to leaching
Vitamin C


Functions:
Cofactor in at least eight
enzymatic reactions,
including several
collagen synthesis
reactions
 Keeps capillary walls,
blood vessels firm
 Helps body absorb
iron and folate
 Healthy gums
Heals cuts and wounds
 Protects from
infection, boosts
immunity
 Antioxidant
Sources
 Citrus fruits
 Other fruits, veggies


Ascorbic acid (C)
Deficiency
 leads to scurvy-failure of wounds to heal
Stability
 Very unstable-readily oxidised to dehydroascorbic
acid and then oxidized to 2,3-diketogulonic acid
which has no biological function.
 Alkaline pH increases loss, high temperatures
increases loss.
Fat Soluble Vitamins
 Stored
in the fatty tissues- eg. liver
 Accumulated
 Need fat to be absorbed in body and
can lead to toxicity
 Not required daily
Vitamin A (and carotenoids)

Functions:
 Normal vision
 Protects from infections
 Regulates immune
system
 Antioxidant
(carotenoids)
 Carotenoids Used in
food industry as a
colorant (orange) (label
friendly)

Food sources:
 Liver
 Fish oil
 Eggs
 Fortified milk or other
foods
 Red, yellow, orange,
and dark green veggies
(carotenoids)
Vitamin A
Loss


High temperatures and oxygen affect stability.
Quite stable in food processing and storage.
Vitamin D (the sunshine vitamin)

Functions:
 Promotes absorption
of calcium and
phosphorus
 Responsible for
calcium deposition in
bone matrix
 Regulates cell growth
 Plays role in immunity

Sources:
 Sunlight (10 – 15 mins
2x a week)
 Salmon with bones
 Milk
 Orange juice
(fortified)
 Fortified cereals
Calciferol, cholecalciferol (vitamin D)
Deficiency Impaired bone formation-increased secretion of Ca and
P leading to osteomalacia (weakening and softening)


Excessive intake
hypercalcaemia-calcium deposition in various organs.
Loss
 Sensitive to oxygen and light
Vitamin E

Functions:
 Antioxidant, may
lower risk for heart
disease and stroke,
some types of cancers
 Protects fatty acids
and vitamin A

Sources:
 Vegetable oils
 Foods made from oil
(salad dressing,
margarine)
 Nuts
 Seeds
 Wheat germ
 Green, leafy veggies
α –tocopherol, (vitamin E)
Stability
 Quite stable except for autoxidation.
 Loss in activity in commercial deep fried frozen
foods
Deficiency
 RBCs destruction
 Impaired of immune response
 Myopathies
 Peripheral neuropathy
Vitamin K

Functions:
 Helps blood clot
 Helps body make
some other proteins

Sources:
 Body can produce on
its own (from bacteria
in intestines)
 Green, leafy veggies
 Some fruits, other
veggies, and nuts
Vitamin K
Deficiency Reduced activity of prothrombin-leads to
haemorrhage
Loss
 Destroyed by light and alkali
 Stable to atmospheric oxygen and heat
What Are Minerals?
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Regulate body processes
Give structure to things in the body
No calories (energy)
Cannot be destroyed by heat
constituents which remain as ash after incineration of
plant and animal tissues
Categories of minerals

Major minerals


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
Calcium
Phosphorus
Magnesium
Electrolytes (sodium,
chloride, potassium)

Trace minerals

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Chromium
Copper
Flouride
Iodine
Iron
Manganese
Selenium
Zinc
Sodium
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
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Maintains osmotic pressure of extracellular fluid
Present mostly as an extracellular constituents
Activates enzymes such as amylase
Excess intake-hypertension
Food sources-(salt, meat, milk)
Deficiency-various disorders
Requirement-300-350mg
Potassium, K
Regulates osmotic pressure within cells,
involved in cell membrane transport
 Sources-major sources are potatoes and
molasses, white bread is potassium
deficient

Magnesium (mg)
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Roles:
Constituents and activator of many enzymes
including
Conversion of energy-rich phosphate compounds
Stabilizer of plasma, intracellular membranes and
nucleic acids
Life-supporting element
Requirement-300-350mg
Deficiency-various disorders
Calcium Ca

Essential nutrient:
 abundant in skeleton and other tissues
 building and maintenance of bones
 blood clotting and muscle contraction

Requirement is 0.8-1.0g

Major sources are milk and other dairy
products, however low in fruits and vegetables,
cereals, meat, fish and eggs
Chloride, Cl

Role
It serves as a counter ion for Na in
extracellular fluid and for hydrogen ions in
gastric juice
 Its absorption is rapid as its excretion in
urine
 Food sources-salt-NaCl

Phosphate, P
 Has
a role in metabolism
 Calcium: phosphate
in food
ratio should be 1
Trace elements
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Iron, Fe
Present in haemoglobin and myoglobin pigments
Present in other enzymes as peroxidase, catalase,
hydroxylases and flavine
Deficiency causes anemia
Iron from vegetable sources –poorly absorbed-called
non haem iron
Iron from animal sources-haem iron well absorbed
Vitamin C increases absorption
Phytates in bran impairs absorption.
Problems on fortification of
food with iron

Higher chance of oxidation in wheat
flour and decreased baking ability

Catalyses oxidation of fat or oil,
increased turbidity of wine and supports
growth of iron–requiring bacteria
Copper, Cu



Component of a no. of oxidoreductase (SOD,
tyrosinase, urinase, amine oxidase
Bound to ceruloplasmin (ferroxidase) in plasma
(catalyses oxidation of Fe2+ to Fe3+- form
transported by transferrin protein to Fe pool in
liver
Catalyses oxidative destruction of ascorbic acid
Zinc, Zn

Component of certain enzymes such as alcohol
dehydrogenase, lactate dehydrogenase,
malate dehydrogenase, etc

Zn poisoning due to food kept in Zn-plated metal
containers
Manganese (Mn)
 Metal
activator for pyruvate
carboxylase
 Activates enzymes as arginase, amino
peptidase, alkaline phosphatase, etc
 Relatively non-toxic
Cobalt, Co

Component of vitamin B 12
Chromium, Cr
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


Helps in the utilization of glucose
Activates phosphoglucomutase
Increase activity of insulin
deficiency cause
 decrease glucose tolerance
 Increase risk of CVD (cardiovascular disease)
Selenium, Se
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


Is an antioxidant
Enhance tocopherol activity
Component of glutathione peroxidase
Protect membranes from oxidative destruction
Fluorine
 Required
for growth and
reproduction
 Inhibits tooth decay by retarding
solubilization of tooth enamel and
inhibiting enzyme involved in dental
caries
Iodine, I


Utilised in thyroid gland in biosynthesis of hormone
thyroxine
Deficiency results in goiter (enlargement of thyroid
gland)

Good sources are sea foods

Fortification-Iodization of common salt (100μg to 110g NaCl – combat the deficiency

Higher amounts are toxic – affect reproduction and
lactation in animals