ANTIOXIDANTS

Presented ByShalvi SoniM.Sc. Food science $ nutritionBanasthali UniversityRajasthan

The Facts on antioxidants

Antioxidants in foods are important for our health and eating five to seven serves each day of fresh fruit and vegetables has been show to help protect against heart disease, cancers, and other disease.

Eating a large amount of fresh fruits and vegetables is the best source of antioxidants.

What are antioxidants

Antioxidants are naturally occurring chemicals in foods that help to counter the detrimental effects of oxygen free radicals , which form during normal metabolism and through external factors such as x-rays , ultra-violet radiation and pollution.

Antioxidants are phytochemicals , vitamins and nutrients that protect our cells from damage caused by free radicals.

Antioxidants can be found in most fruits and vegetables.

Antioxidants are capable of stabilizing or deactivating, free radicals before they attack cells.

Antioxidants are absolutely critical for maintaining optimal cellular and systemic health and well-being.

What are free radicals

In a human body the process of oxidation damages all cell membranes and other structures including cellular protein, lipids and DNA. When oxygen is metabolized it creats ‘free radicals’.

Free radicals are capable to attacking the healthy cells of the body, causing them to lose their structure and function.

The body can cope with some free radicals and needs them to function effectively. However, an over load of free radicals as been linked to certain diseases, including heart disease, liver disease and some cancers.

Oxidation can be accelerated by stress, cigarette smoking, alcohol, sunlight pollution and other factors.

The effect of free radicals

Deterioration of eye lens, which contribute to blindness.

Inflammation of joints (arthritis). Damage to nerve cells in the brain, which

contributes to condition such as Parkinson’s or Alzheimer’s disease.

Acceleration of the ageing process. Increased risk of coronary heart disease, since

free radicals encourage low density lipoprotein (LDL) cholesterol to adhere to artery walls.

Certain cancers, triggered by damaged cell DNA.

Types of antioxidants

β- carotene- Provitamin A, Ascorbic acid-Vitamin C Tocopherols Sulphar amino acids:

Cysteine Selenium Zinc

Carotenoids (Lycopene, Xanthophylis)

Lutein, α-and γ-carotenes (zeaxanthine)

Anthocyanins

Nutrient (Natural) Non-nutrient

Vitamin A and Beta-Carotene Vitamin A and Beta-Carotene are structurally

similar and they both function as antioxidant nutrients.

All vitamin A comes from the fatty tissues of animals whereas beta-carotene is found exclusively in plant foods with brightly colored (red and yellow) fruits and vegetables being the best sources.

Vitamin A was the first-soluble vitamin to be recognized.

It helps to :-

Improving immunity healthy eyes, soft and supple skin,

stronger bones and teeth Preventing calcification/kidney stones,

muscular weakness, acne and certain forms of cancer

Helping in the repair and replacement of old tissues

Delays ageing Lowers cholesterol

Ascorbic acid-Vitamin C

Vitamin certainly leads the list as one of the most important antioxidant nutrients.

Because it is water soluble, it can enter into and protect every cell in the human body.

It is synthesized in the liver by most animals, but not by man who depends on dietary sources for adequate supply.

It helps in :-

Protecting skin from UV damage

Providing resistance to infection

Promoting iron absorption from food, maintains healthy collagen and controls blood cholesterol

Increasing sperm counts esp. in smokers

Tocopherols- Vitamin E

Vitamin E is primary fat-soluble antioxidant nutrient.

Vitamin E resides in fatty tissues, especially cell walls and membranes.

It helps to protect the stability and integrity of cellular tissues membranes throughout the body by preventing free radical (lipid peroxidation) damage.

It helps in :-

Improving skin conditions

Improving appearance of scars

Protecting the body’s membrane

Maintaining healthy blood vessels

thinning blood in body

Sulphar amino acids

Cysteine- It is a semi-essential amino acid, which means that it can be biosynthesized in humans.

It can usually be synthesized by the human body under normal physiological conditions if a sufficient quantity of methioine is available.

It contains sulfur, which is said to work as an antioxidant, protecting the preserving the cells in the body.

It helps in :-

Protects the body against free radicals May help to reverse damage done by

smoking and alcohol abuse Produces white blood cells which boosts

immune system function. Reduces the effects of aging on the body

because of its detoxification properties. Helps the body absorb iron (ladies). Removes heavy metals like lead and mercury

by assisting and boosting the liver function.

Selenium

It is a trace element. It is a mineral that we need to consume in only very small quantities, but without which we could not survive.

It forms the active site of several antioxidant enzymes including glutathione peroxidase, which is one of the most important antioxidant enzyme in our antioxidant system.

It helps in :-

Maintaining healthy hair, skin as well as eyes

Promoting normal liver functions

Increasing male potency

Reducing the risk of heart disease as well as cancer

Improving mental fatigue and anxiety

Zinc

Zinc is a trace mineral that your body uses in small amounts. You need it for normal growth and healthy immune system function, as zinc is involved in protein production, DNA synthesis and cell division.

It's also necessary for hundreds of enzymes to function in many different chemical reactions in the body, and is also crucial for a normal sense of smell and taste.

It helps in :-

Strengthening the immune system Improving stress levels Preventing and shortening the duration

of cold Reducing appearance of acne Providing antimicrobial action in the

Gastro-intestinal tract

Carotenoids

Nature’s widespread pigments biosynthesis by ocean algae masked by dominant chlorophyll precursors of vitamin A All green vegetables contain carotenoids

but their color is masked by the green chlorophylls

All carotenoids are lipophilic compounds and thus are soluble in oils and organic solvents

Lutein Lutein is a yellow-to-orange pigment or phytochemical found

mostly in plants. It works as an antioxidant in your body to reduce the damage

done by free radicals.

Lutein is a carotenoid and is related to vitamin A.

Other carotenoids include beta carotene, alpha carotene.

Lutein is concentrated in the retinas of your eyes, so it's a necessary component of normal vision.

Eating a diet with lots of colorful fruits and vegetables that

contain lutein may also decrease your risk of cardiovascular disease.

Anthocyanins

Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue depending on the pH.

They belong to a parent class of molecules called flavonoids.

Anthocyanins occur in all tissues of higher plants, including leaves, stems, roots, flowers and fruits.

In photosynthetic tissues (such as leaves and sometimes stems), anthocyanins have been shown to act as a "sunscreen", protecting cells from high-light damage by absorbing blue-green and UV light.

Sources of AntiOxidants

Vitamin E is found in vegetable oils, walnuts, peanuts, almonds, seeds, olives, wheat germ, liver, and leafy green vegetables.

For good sources of vitamin C, look to citrus fruits (like oranges and grapefruit), broccoli, leafy green vegetables, tomatoes, peppers, potatoes, cantaloupe, and strawberries.

Common sources of beta-carotene include cantaloupe, mangoes, papaya, pumpkin, peppers, spinach, kale, carrot, squash, sweet potatoes, and apricots.

selenium in seafood, beef, pork, Brazil nuts, brown rice, and whole wheat bread.

Zinc - seafood, lean meat, milk and nuts.

Carotenoids (e.g., lycopene, lutein, zeaxanthin)

Flavonoids (e.g., anthocyanins, resveratrol, quercitin, catechins)

Glutathione Indoles Isoflavones (e.g., genistein,

daidzeins) Lignans Phenols, polyphenols,

phenolic compounds (e.g., ellagic acid, ferulic acid, tannins)

Saponins

Tomatoes, carrots, watermelon, kale, spinach

Grapes, blueberries, strawberries, cherries, apples, grapefruit, cranberries, raspberries, blackberries

Green leafy vegetables Broccoli, cauliflower, cabbage,

Brussels sprouts, Legumes (peas, soybeans) Seeds (flax seeds, sunflower

seeds) Grapes, blueberries, strawberries,

cherries, grapefruit, cranberries, raspberries, blackberries, tea

Beans, legumes

Phytochemical Food source

SYNTHETIC ANTIOXIDANTS

Butylated Hydroxy Anisole (BHA)

Butylated Hydroxy Toluene (BHT)

Tertiary Butyl Hydroquinone (TBHQ)

BHA (Butylated Hydroxyanisole) BHA has the ability of antioxidants is good on animal fats

in baked food systems.

BHA is fat soluble and water insoluble, solid white and is sold in tablets or flakes, are volatile, so useful for adding to the packing material.

BHA is frequently used for the preservation of coconut and palm kernel oil in cereal and confectionery products.

BHA is good in baking because of its stability to heat and

its mild alkaline conditions.

BHA is particularly useful in protecting the odor and flavor of essential oils.

FOOD USE

Bakery products Meat products Spices Cereals Yeast Vegetable oils Beverage mixes Dessert mixes Nuts

BHT (Butylated Hydroxytoluene)

BHT is a white crystalline solid with properties similar to BHA.

BHT is commonly used in combination with BHA to provide greater antioxidant activity.

BHT have a slight phenolic odor, and may impart undesirable odor in foods when used at high temperature for an extended period of time.

Antioxidant preservative; prevents oxidative rancidity development in oil-containing foods by terminating free radicals formed during autoxidation of unsaturated lipids.

It possesses antimicrobial activity as a phenolic compound.

FOOD USE

Breakfast cereals Baked goods Potato chips Vegetable Oils Snack foods Butter Margarine Frozen seafoods Chewing gum base

TBHQ (tert-Butylhydroquinone) It is an aromatic organic compound which is a

type of phenol. It is a highly effective antioxidant. In foods, it is

used as a preservative for unsaturated vegetable oils and many edible animal fats.

It is added to a wide range of foods, with the highest limit (1000 mg/kg) permitted for frozen fish and fish products. Its primary advantage is enhancing storage life.

Food Use

Dry cereals Edible fats Margarine Pizza toppings Potato chips Poultry Dried meats Sausages Beef patties Vegetable oils

Diet Tips

Try to limit or cut out the following: Processed Foods

Smoked Foods

Deep fried foods

High fat items such as pastries

Any items with added salt (check for sodium)

Items with added sugar

Try to limit your red meat intake

Try to increase: Fresh and unprocessed foods

Raw fruit and vegetables

The fiber content in your diet

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