Cadavid What are tannins Large molecular weight phenolic compounds Condensed and Hydrolyzable c hemistryaboutcom Chemistry of Tannins Hydrolyzable Tannins Mainly gallic acid and related compounds ID: 936015
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Slide1
Tannins
Stephanie Diamond, Emilee Landers, Andrea Sierra-
Cadavid
Slide2What are tannins?
Large molecular weight phenolic compounds
Condensed and
Hydrolyzable
c
hemistry.about.com
Slide3Chemistry of Tannins
Hydrolyzable
Tannins
Mainly
gallic acid and related compoundsHydrolyzed by acid, alkali, enzymes and hot water
Condensed Tannins
Also called
proanthocyaninsPolymerized flavan-3-ols
Fao.org
E.
Haslam
/ Chemistry of Vegetable Tannins. (1966)
Slide4Chemistry of Tannins
Astringency
Tannins bind carbohydrates and proteins and become insoluble
“roughness”
mouthfeelAntioxidants
Free-radical scavengers
Highly reactive phenols
Prevents oxidationLowers risk of CVD and cancerProoxidants
As with any antioxidant, at high levels can act as a prooxidant.
E.
Haslam
/ Chemistry of Vegetable Tannins. (1966)
Slide5Consumption of Tannins
Ubiquitous nature in foods
Fruits
Berries, pomegranate, persimmons, and more.
NutsHerbs and SpicesBeverages
Tea and wine
Consumption estimated between 1 and 1.1 g/day
Potential to be a main source of antioxidant in the human dietTraditionally used in herbal medicines and teas
Slide6Tannins as an anti-nutrient
Reduces the nutritional value of a food
Inhibition of digestive enzymes (due to protein binding ability)
Reduction in bioavailability of iron, vitamin A and B12
Anti-nutrient activity found only in in-vitro studiesInhibition not thoroughly understood
Caused by tannins or other mechanisms?
Absorption affected by glycosylation, conjugation, size, degree of polymerization, solubility
Contradictory researchBioavailability of iron in high and low tannin foods essentially the same
L. Bravo / Nutrition Reviews (1998)
Slide7Tannins as Carcinogens
Oral cancer
Betel nuts, containing 20% tannins
Esophageal cancerAssociated with hot tea consumption
May have actually been associated with the temperature of the waterPrevailing sentiment: Tannins exhibit primarily health-promoting properties
.
L. Bravo / Nutrition Reviews (1998)
Slide8Tannins in Nuts
Nuts more widely known for other health-promoting properties
High in unsaturated fatty acids
Cholesterol lowering
Condensed tannins
Almonds and hazelnuts
Hydrolyzable
tanninsWalnuts
Current research on nuts and tannins almost entirely quantificationKaramać (2009) looked at levels of antioxidant activity related to tannins in nutsWalnuts > hazelnuts > almonds
Huge research potential for nuts
M
.
Karamać
/ Eur. J. Lipid Sci. Technol. (2009)
Nutstop.com
Slide9Berries
Popular in USA
Exotic berries
Popular in other countries
Slide10Berries
Highly nutritious fruit:
Vit
A and Vit
C Ca, Fe, Mg
Good source of dietary fiber
High content of antioxidant compounds
Schwartz and others 2008
N.P.
Seeram
NP /
J.
Agric
.
Food
Chem
. 56 (2008) 627–629
Slide11Tannins in Berries
Different types of phytochemicals: One of the most important ones are
TANNINS
Condensed:
Proanthocyanidins
Hydrolyzables
: ellagitannis and gallotannis
N.
Seeram
et al. / Separation and Purification Technology 41 (2005) 49–55
Slide12Tannins in Berries
Bioavailability reported to be low!!
BUT
Addison Wesley Longman Inc
N.P.
Seeram
/
J.
Agric
.
Food
Chem
. 56 (2008) 627–629
Slide13Tannins in Berries
Type of tannins varies according to the specific berry and give each berry a different beneficial effect.
Proanthocyanidins:
Cranberries and blueberries.
Ellagitannins:
Strawberries, cloudberries and raspberries.
Slide14Tannins in Berries
Proanthocyanidins
from blueberry act on
striatum of the brain helping to keep the
memory
function while ageing.
Ellagitannins
from strawberry
act on
hippocampus
of the brain reducing the effect of aging on
spatial orientation
.
http://www.brainwaves.com/
B.
Shukitt
-Hale B
et al. /
Neurobilogy
of Aging, 20 (2007) 1187-1194.
Slide15Tannins in Berries
Proanthocyanidins from Cranberry have a protective effect against urinary track infections
Gunraj
S. 2013
A.B.
Howell
/
Critical
Reviews
in
Food
Science
and
Nutrition
, 42 (2008) 273-278
Slide16Tannins in Berries
Ellagitannins from cloudberry and raspberry may reduce the incidence of some foodborne diseases.
http://www.turbosquid.com/3d-models/3d-max-escherichia-coli-e/316273
R.
Puupponen-Pimiä
et al. /
J. Applied Microbiology 98 (2005) 991–1000.
Slide17Tannins in Berries
Ellagitannins from pomegranate may work as preventive agents for Arthritis Rheumatoid and Osteoarthritis
Block the signal transduction pathways and the response of pathogenic cells
Copeland 2013
M.
Shukla
et al. / Nutrition 24 (2008) 733–743
Slide18Tannins in Berries
Punicalagin
an ellagitannin
from pomegranate, inhibits cyclooxygenase enzyme COX-2, protein kinase B (AKT) and the nuclear factor kappa-B (NFκB)
mechanism in colon cells.
L.S.
Adams
et al. /
J. Agric. Food Chem. 54 (2006) 980-985
Slide19Red Wine Tannins
Belongs to Non-
hydrolyzable
group
Condensed tannin (aka
proanthocyanidins
) source is from grapes
Skins
: prodelphinidins and procyanidinsSeeds
: only procyanidins
Gomez-Plaza E, Hernandez- Jimenez A, Bautista-
Ortin
AB. 2011.
Proanthocyanindins
in Grapes and Wine: A Review. In: Petridis GK (editor). 2011. Tannins: Types, Food Containing, and Nutrition. Hauppauge, New York: Nova Science Publishers. 161-185 p.
Images from:
www.nature.com
and
www.intechopen.com
Slide20Red Wine Tannins
Contains 1.2-4.4g of condensed tannins per liter
Amount of tannins depends on various attributes
Fermentation of skins and seeds
Solubility of tanninsMaceration timeCalculate contribution
Berdanier
CD. 1998. CRC Desk Reference for Nutrition. Boca Raton, Florida: CRC Press LLC. 321 p.
Gomez-Plaza E, Hernandez- Jimenez A, Bautista-
Ortin AB. 2011. Proanthocyanindins in Grapes and Wine: A Review. In: Petridis GK (editor). 2011. Tannins: Types, Food Containing, and Nutrition. Hauppauge, New York: Nova Science Publishers. 161-185 p.
Slide21Red Wine Tannins
Health benefits
Antioxidant/cancer prevention
Scavenge free radical,
chelate transition ions
Cardiovascular disease prevention
Lowers plasma cholesterol levels, inhibits oxidation of LDLs, prevent blood clots
Bioavailability34mg
catechin/120mL red wine, and 0.072µM was the max concentration in human plasmaDue to larger structure that can bind other materials, believe that condensed tannins are better absorbed in the large intestineColon microbiota
Gomez-Plaza E, Hernandez- Jimenez A, Bautista-Ortin AB. 2011.
Proanthocyanindins
in Grapes and Wine: A Review. In: Petridis GK (editor). 2011. Tannins: Types, Food Containing, and Nutrition. Hauppauge, New York: Nova Science Publishers. 161-185 p.
Serrano J, et al./ Molecular Nutrition and Food Research.53: 310-329.
Donovan JL, et al./British J. Nutrition. 87: 31-37.
Slide22Tea Tannins
Green Tea
Fresh leaves that are steamed or pan-fried, then dried to deactivate enzymes
Black Tea
Withered leaves are crushed and polyphenol oxidase
can act on the
catechins
and gallocatechins to form oligomeric
theaflavins and polymeric thearubigensBabich H,
Gottesman RT, Liebling EJ, Schuck
AG. 2008. Theaflavin-3-gallate and Theaflavin-3'-gallate,
Polyphenols
in Black Tea with
Prooxidant
Properties. Basic & Clinical
Pharm
&
Tox
. 103:66-74.
Slide23Tea Tannins
Epidemiological studies: drinking tea regularly
Reducing risk for diseases (cancer & CVD) even subject is constantly exposed to toxic substances (consuming alcohol and smoking)
Bioavailability
Flavon-3-ol in green tea = 39% bioavailability in humans
Great differences in excretion, this may be due to difference in participants’
microbiota
Smiechowska
M, Dmowski P. 2011. Influence of Selected Factors on the Content of Tannins in Tea Extracts. In: Petridis GK (editor). 2011. Tannins: Types, Food Containing, and Nutrition. Hauppauge, New York: Nova Science Publishers. 161-185 p.Zhu M et al./
Planta medica 66: 444-447.Del Rio D at al./ Nutrition 26: 1110-1116.
Slide24Persimmon
Belong to non-
hydrolyzable
group of tannins Specific repeating units to form tannins within persimmonsCatechin
Catechin-3-gallate
Gallocatechin
Gallocatechin-3-gallate
Besada C, Salvador A. Tannins of Persimmon Fruit: Artificial Removal of Astringency. In: Petridis GK (editor). 2011. Tannins: Types, Food Containing, and Nutrition. Hauppauge, New York: Nova Science Publishers. 217-230p.
Slide25Persimmon
Health benefits
Antioxidant activity
Anti-inflammatory activity
Hypolipidemic
activity
Enzyme inhibiting
Detoxification of snake venom
Structure cause for health benefitsMonomeric flavan-3-ol unitsTypes of interflavan
bondsDegree of polymerizationLi et al./
Acta
Horticulturae
996:455-466.
Images from:
en.wikipedia.org
Slide26Conclusion
Large molecular weight
phenolic
compounds
Two categories: Condensed and Hydrolyzable
Wide variety of health benefits
Antioxidants
Lowers risk of CVD and cancerFound in a large variety of foods and beverages
Further research is neededUnderstand benefits and possible risks as an anti-nutrientUnderstand bioavailabilityColon microbiota
Slide27Thank you
Questions?