source of antioxidants

The dietary fiber is regarded as a non-digestible carbohydrate in the human small intestine that passes into the large intestine. Dietary Fiber is believed to play a significant role in maintaining the functional integrity of the human gastrointestinal tract.

Consuming high dietary fiber, largely dependent on the intake of dietary fiber is linked with reduced risk of diseases including atherosclerosis and colon cancer as well as body weight control. Consuming about 25-30g of dietary fiber in 24 hours had been recommended by the American Heart Association.

The most commonly consumed dietary fiber products are derived from cereals. Accordingly, over the past decades, high dietary fiber materials from fruits have frequently been introduced in the Western world. In all, the fruit dietary fiber concentrates have been a better nutritional quality when compared to those found in the cereals, as a result of their important contents of bioactive compounds – Carotenoids and flavonoids among others.

On the other hand, antioxidants are regarded as compounds that prevent and delay the oxidation of other molecules by preventing the initiation or perhaps the transmission of oxidizing chain reactions. Over time, numerous studies have shown that health issues associated with the consumption of synthetic antioxidants as well as with strict regulations presently control their use in food products. Hence, attention has been directed towards the enhancement of natural antioxidants.

fiber fruits

Similarly, foodstuffs rich in dietary fiber as well as dietary fiber ingredients are quite known in the food market, but their antioxidant capacities are insignificant. Just recently, the concept of Antioxidant Dietary Fiber (ADF) got introduced.

The major characteristics of ADF are the combination of both the physiological effects of dietary fiber and antioxidants in a single element. A gram of ADF is expected to have 2,2-diphenyl-1-picrylhdrazyl (DPPH) free radical scavenging capacity equivalent to at least 50mg Vitamin E as well as dietary fiber content quite higher than 50% dry matters from natural constituents.

While vegetables and fruit wastes originating from industrial food processing are normally thrown away or used as fertilizers and animal feeds, few studies have indicated that the so-called wasted products of nutritive plant originated foods are actually rich in Antioxidant dietary fiber. The aforementioned facts evoked the concept of utilizing the so-called wastes as food supplements or technological ingredients. The powders of numerous by-products including grape seed, cabbage leaves or perhaps extracts are now readily available in drugstores as supplements.

Best Sources Of Antioxidants Dietary Fiber

The amount of dietary fiber-enriched food products made known to the food market has really been on the increase as a result of its beneficial effects, mainly on the digestive system. Dietary fibers gotten from by-products of antioxidant-rich foodstuffs comprise of significant and healthy antioxidants like carotenoids and polyphenols. Thus, the sources of antioxidant dietary fiber are subsequently highlighted:


Cabbage is widely known and used for traditional medicine due to its antibacterial and inflammatory properties. The antioxidant capacity of the cabbage species has equally been analyzed. Experts have studied the production of Antioxidant dietary fiber from cabbage outer leaves which normally is separated as waste and used as fertilizers.

Results from the studies have, however, revealed that the crude fiber content of the cabbage outer leaves is very beneficial for human health. Containing 19.92-47g/100g DM, the studies revealed it’s very much similar to the results of a total dietary fiber which reads 40.48g/100g DM.


This fruit is well-known for its high phenolic content and Vitamin C. The orange juice is equally rich in these bioactive compounds effectively contributing to its antioxidant activity. Anyways, studies have also shown that the fruit itself contains higher flavone, Vitamin C as well as carotenoid contents as compared to orange juice. It’s confirmed that orange peel has a very high dietary fiber content of 71.62g/100g DM.



Recognized as one of the many good sources of antioxidant dietary fiber, the fruit possesses an antioxidant activity due to flavonols and phenolic acids. Similarly, the fruit chlorogenic acid, protocatechuic acid, quercetin derivative, as well hyperoside is largely related to its high antioxidant capacity.

Nevertheless, the apple peel was indicated to have a higher antioxidant capacity than the pulp itself. A recent study on the fruit showed that about 80-89% of the fruit contains water while the amount of dietary fiber is between 0.86-1.81%.

The apple pomace removed during the processing is reported to have about 51.10g/100g DM of total dietary fiber. 14.50g/100g is soluble and about 36.50g/100g DM is regarded as insoluble dietary fibers aside the total phenol content totaling 10.16mg/g.


It’s widely known that grapes are cultivated mainly as Vitis Vinifera for the production of wine. However, it is also reported that the total weight of grapes used for winemaking results in grape pomace, which is branded as waste during the process.

The grape pomace comprises skins, stems, and seeds and in several cases, this waste are used for the extraction of grape seed oil. The grape by-product is reported to a dietary fiber of 64.6% as well as free radical scavenging capacity. Some studies have equally reported a higher dietary fiber of 74-77%, while a white grape by-product and stem has a combined dietary fiber content of 715.6-790.5g/Kg DM.



Studies have successfully shown that Sharlyn melon peels as well as Watermelon rinds, usually discarded are good sources of Antioxidant Dietary Fiber with a crude fiber content of about 17-29%.


Tomato, which is a good source of ascorbic acid, flavonoids, phenols, β-carotene, and carotenoids lycopene is largely used in the food industry. The processing a tomato goes through has an effect on its antioxidant capacity. Peeling the back of a tomato was shown to cause serious loss in phenolic contents, β-carotene, lycopene, and ascorbic acid while removing the seed in tomatoes results in loss of phenolics and carotenoids. However, a tomato peel, highly rich in phenolics is reported to have a high dietary fiber content of 86.15%


Acai, Cactus, Carrot, Guava, Mango, Coffee beans, Cocoa beans, Passion fruit, and Pineapple are also significant sources of Antioxidant Fiber Dietary. The ADF has been proposed as the latest potential antioxidant ingredient that has proven to delay and prevent lipid oxidation in foods besides increasing the nutritive value of the product. It also brings in several benefits, including giving an opportunity to enrich food formulas. On the other hand, the use of waste as ingredients can also enhance both economic and environmental benefits.