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Onions- A Global Benefit to Health

Onions- A Global Benefit to Health. Gareth Griffiths, Laurence Trueman, Timothy Crowther, Brian Tomas and Brian Smith. Onion FAQ. Bulb onions likely originated in central Asia, but are not found in the wild. Onions are grown in every part of the world where plants are farmed.

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Onions- A Global Benefit to Health

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  1. Onions- A Global Benefit to Health Gareth Griffiths, Laurence Trueman, Timothy Crowther, Brian Tomas and Brian Smith

  2. Onion FAQ. • Bulb onions likely originated in central Asia, but are not found in the wild. • Onions are grown in every part of the world where plants are farmed. • Onion is the second most important horticultural crop world wide.

  3. Two Chemical Classes With Perceived Health Benefits. Flavonoids: -Anthocyanins (Red) -Quercetins (Yellow) Alkyl cysteine sulphoxides (ACSOs): -Flavor precursors cleaved by alliinase enzyme

  4. ACSOs and Associated Breakdown Products • Three ACSOs are present in intact onion tissue. • Upon hydrolysation by alliinase, and subsequent spontaneous reactions with each other and nearby compounds, ACSOs give rise to ~50 sulphur containing compounds. • This wide array of sulphur containing compounds contribute to onion flavor and are reported to provide benefits to human health.

  5. Factors Affecting final composition of ACSO breakdown products. • Initial concentration and ratios of the three ACSO species. • Availability of alliinase enzyme (tissue disruption). • Type and concentration of other compounds in the environment with witch ACSO breakdown products react. • pH & temperature of the environment.

  6. ACSO Breakdown

  7. Reported Health Benefits of ACSO breakdown products in Onion • Anticancer activity through modulation of enzymes involved in metabolization of carcinogenic compounds. • Possible lowering of serum cholesterol. • Lowering systolic blood pressure & thinning the blood (only compounds found in uncooked pungent cultivars). • Antiasthmatic activity, suppressing reactions leading to bronchial restriction. • Antifungal and antibacterial properties.

  8. Flavonoid Compounds in Onion Flavonols: • Yellow compounds concentrated in the skin of the onion. • Sixteen flavonol compounds have been identified in onion. Anthocyanins: • Red compounds. • Four anthocyanin compounds have been identified in onion.

  9. Reported Health Benefits of Flavonoids in Onion • Antioxidant effects of flavonoids help to protect cells from oxidative stress resulting from free radical damage, as well as reducing cancer rates by protecting DNA from oxidative damage. • Possible lowering of serum cholesterol by quercetin compounds. • Phenolic flavonoid compounds may provide some antibiotic activity.

  10. Garlic as an Antioxidant: The Good The Bad and The Ugly S.K. Banerjee, Pulok K. Mukherjee and S.K. Maulik

  11. Garlic Health FAQ. • Garlic has played an important dietary and medicinal role for centuries. • The sale of medicinal garlic preparations is on par with that of many prescription drugs. • A wide array of health claims are made for garlic and its various preparations.

  12. Health Benefits Attributed to Garlic • Prevention of Cardiovascular disease. • Reduced Cancer Risk. • Treatment of microbial infections. • Antidote for heave metal poisoning. • Hepatoprotective.

  13. Garlic and Human Health • Garlic consumption has been recognized in reducing rates of cancer and Cardiovascular disease. • This effect is thought to be largely due to the antioxidant properties of the many organosulphur compounds found in garlic preparations.

  14. Various Garlic Preparations Examined for Health Effects. • Raw Garlic • Heat Treated Garlic • Garlic Powder • Aged garlic Extract • Garlic Oil (steam distilled, oil macerated, ether extract) • Garlic Protein

  15. Garlic preparation method, effects on various oxidative stress conditions.

  16. Garlic Organosulphur Compounds • When Garlic is crushed Allinase enzyme acts on Alliin to form allicin. • Allicin has both antioxidant and oxidative properties. • The many breakdown products of Allicin vary across different preparation methods. • Different garlic preparations are reported to have varying antioxidant and disease fighting properties.

  17. Garlic Organosulphur Compounds

  18. Garlic Organosulphur Compounds Reported Effects. • Antioxidant (free radical scavenging) protecting DNA, Proteins, Lipids, and other compounds from oxidative damage. • Increased endothilial cell NO production, making blood vessels more elastic. • Decreased hepatic cytochrome P450, protecting the liver from toxin (acetominophen) induced injury.

  19. Negative Effects Resulting From large Doses of Garlic. • Bad Breath • Anemia. • Weight loss. • Lysis of red blood cells. • Altered cellular architecture in the heart, liver and kidneys.

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