Proanthocyanidins (or condensed tannins) are a class of flavonoids widely present in the plants, second only to lignin as the most abundant phenol in nature.
Like Resveratrol, Procyanidins is a polyphenol. Both are find in good quantities in wine.
For many years Resveratrol has been the star in many discussions about why red wine was good for your health. The antioxydant that prevented many health problem.
Revesratrol is not alone anymore.
Now there is more, an other polyphenol that seems to play an even bigger role in the relationship between red wine and health benefit; the Procyanidins.
They are present in high concentrations in flowers, fruits, but most notably in:
maritime pine bark,
cinnamon, aronia fruit,
grape seed, grape skin, and red wines.
However, cranberry, black currant, green tea, black tea, and other plants also contain these flavonoids, as do cocoa beans.
Cocoa Beans has twive the number of antioxydant than wine.
Also compare to Blueberry who has a great reputation for containing a lot of Antioxydant here is the comparaison:
Blueberry: 32 - Cocoa Bean: 621
Açaí oil, obtained from the fruit of the açaí palm, is rich in numerous procyanidin oligomers.
Interesting fact: Apples contain on average per serving about eight times the amount of procyanidin found in wine, with some of the highest amounts found in the Red Delicious and Granny Smith varieties.
Here are some numbers:
- The major sources are some berries (blueberries, cranberries, and black currant) and plums (prunes), with a content of about 200 mg/100 g FW.
- Intermediate sources are apples, choke berries, strawberries, and green and red grapes (60-90 mg/100 g FW).
- In other fruits the content is less than 40 mg/100 g FW.
- On average, chocolate and apples contained the largest procyanidin content per serving (164.7 and 147.1 mg, respectively) compared with red wine and cranberry juice (22.0 and 31.9 mg, respectively).
- Foods with the highest proanthocyanidins content are cinnamon and sorghum, which contain respectively about 8000 and up to 4000 mg/100 g of fresh weight (FW).
*Coffee is not a good source.
Some good sources of proanthocyanidins are also some fruit juices.
Together with anthocyanins and their oxidation products, and catechins, they are the most abundant flavonoids in human diet and it has been suggested that they constitute a significant fraction of the polyphenols ingested in the Western diet.
Therefore, condensed tannins intake should be taken into consideration when analysis of various health issue.
Intestinal absorption of proanthocyanidins
Condensed tannins are poorly absorbed from the intestine; together with anthocyanins they are some of the least well-absorbed polyphenols.
Proanthocyanidins in grape seeds
A particularly rich source of proanthocyanidins is the seeds of grape.
Proanthocyanidins in grape seeds are only B-type procyanidins.
It is important to mention that although number of proanthocyanidin is relatively low in grapes vs an Apple, grape seed proanthocyanidins are potent antioxidants and free radical scavenger, being the more effective either than vitamin E and vitamin C
The interest on proanthocyanidins, and their content in foods, has increased as a result of the discovery, due to clinical and laboratory studies, of their anti-infectious, anti-inflammatory, cardioprotective and anticarcinogenic properties.
These protective effects have been attributed to their ability to:
- act as free radical scavenger;
- inhibit lipid peroxidation;
- act on various protein targets within the cell, modulating their activity.
Proanthocyanidins are not detectable in the majority of vegetables; they have been found in small concentrations in Indian pumpkin. They are not detectable also in maize, rice and wheat, while there are present in barley.
Oligomeric procyanidins have attracted increasing attention in the fields of nutrition and medicine due to their potential health benefits observed in vitro and in vivo. Most prominently, procyanidin oligomers have been shown to have potent antioxidant activity and the ability to scavenge reactive oxygen and nitrogen species (Ariga and Hamano 1990, Arteel and Sies 1999, Hagerman et al. 1998). In addition, recent research suggests these phytochemicals may modulate immune function and platelet activation
2 types of procyanidins:
Depending on the bonds between monomers, proanthocyanidins have a:
A-type procyanidins: Although many food plants contain high amounts of proanthocyanidins, only a few, such as plums, avocados, peanuts or cinnamon, contain A-type procyanidins, and none in amounts equal to cranberries (Vacciniun macrocarpon).
B-type procyanidins, consisting of catechin and/or epicatechin as constituent units, are the exclusive proanthocyanidins in at least 20 kinds of foods including blueberries (Vaccinium myrtillus), blackberries, marion berries, choke berries, grape seeds, apples, peaches, pears, nectarines, kiwi, mango, dates, bananas, Indian pumpkin, sorghum, barley, black eye peas, beans blacks, walnuts and cashews.