Flaxseed: Phenolic Rich Superfood

Nutritionists have been intrigued by the potential health benefits offered by flaxseed (Linum usitatissimum L.). This versatile seed is a rich source of diverse phenolics, encompassing lignans, phenolic acids, flavonoids, phenylpropanoids, and tannins.

The inclusion of flaxseed in both food and food products has been consistently on the rise, fueled by its elevated levels of essential omega-3 fatty acid alpha-linolenic acid (ALA), dietary fiber, and natural phenolic antioxidants.

Antioxidants, whether synthetic or natural, possess the capability to postpone specific forms of cell damage and neutralize reactive radical species formed during oxidative reactions in metabolism. Primarily consisting of phenols, polyphenols, carotenoids, thocyanins, and tocopherols, antioxidants play a pivotal role as phytochemicals in plants.

Due to their safety, consumers tend to prefer natural antioxidants, such as those found in flaxseed, which have been linked to a reduced risk of cancer development.

A significant portion of the phenolic acids present in flaxseed, including p-hydroxybenzoic, trans-ferulic, and trans-p-coumaric acids, exists in an ester-bound state. Noteworthy is the accumulation of ferulic and p-coumaric acid glucosides in substantial concentrations within flaxseed. Additionally, phenolic acids like caffeic acid and their glucosides have been detected in flaxseed.

Caffeic acid, classified as a hydroxycinnamic acid, is widespread in plants and serves as a crucial intermediate in lignin biosynthesis, a fundamental component of woody plant biomass.

Flavonoids, a subgroup of polyphenols featuring a C6-C3-C6 structure comprising two aromatic rings connected by a three-carbon linkage, include diverse categories such as anthocyanins, flavanols, flavones, flavanones, and flavonols.

The flavonoid content in flaxseed, ranging from 0.3 to 0.71 g per kg of flaxseed, is contingent upon growth conditions and cultivar types. In flaxseed, flavonoids predominantly exist in glucoside forms, such as herbacetin 3, 8-O-diglucopyranoside, herbacetin 3, 7 O-dimethyl ether, and kaempferol 3, 7-O-diglucopyranoside.
Flaxseed: Phenolic Rich Superfood

Notes: Republished article

Antioxidants in flaxseed

Flaxseed (Linum usitatissimum L.) has been the focus of interest of nutritionists due to potential health benefits.

Flaxseed is a rich source of different types of phenolics such as lignans, phenolic acids, flavonoids, phenylpropanoids and tannins.

Day by day, incorporation of flaxseed in food and in food products has been increasing due to its high content of essential omega-3 fatty acid, alpha-linolenic acid (ALA), dietary fiber and natural phenolic antioxidants

Antioxidants are synthetic or natural compounds that can delay some types of cell damage and quench reactive radical species formed during oxidative reactions in metabolism. They include mainly phenols, polyphenols, carotenoids, thocyanins and tocopherols, which main groups of phytochemicals found in plants.

Natural antioxidants have been associated with cancer development are generally opted by consumers because of their safety.

Most of the flaxseed phenolic acids such as p-hydroxybenzoic, trans-ferulic and trans-p-coumaric acids are ester bound. Among these phenolic acids, ferulic and p-coumaric acid glucosides were accumulated at high concentrations in the flaxseed. In addition, phenolic acid like caffeic acid and their glucosides were also reported in the flaxseed.

Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. It is found in all plants because it is a key intermediate in the biosynthesis of lignin, one of the principal components of woody plant biomass and its residues.

Flavonoids are the polyphenols, with C6-C3-C6 skeleton that consists of two aromatic rings joined by a three-carbon link. Flavonoids generally include anthocyanins, flavanols, flavones, flavanones and flavonols.

Depending upon growing and cultivar conditions, flaxseed possesses about 0.3-0.71 g of total flavonoids per kg of flaxseed. In the flaxseed, flavonoids are in the form of their glucoside such as herbacetin 3, 8-Odiglucopynanoside, herbacetin 3, 7 O-dimethyl ether, and kaempferol 3, 7-O-diglucopyranoside.

Antioxidants in flaxseed

Oats antioxidant

Oats and their products have been known for many years to possess antioxidants properties. The epicatechin concentration is highest in the hull fraction supporting the link between phenolics and antioxidant activity.

Oats posses antioxidant capacity most of which is likely derived from polar phenolic compounds in the aleurone.

Phenolic compounds and tocols are mainly regarded as being responsible for oat antioxidant activity. Oat sterols have also been reported to have antioxidant properties. Study in 2001 found that the cultivar had significant impact on the antioxidant activity of oats. The antioxidant activity differences were likely due to the significant differences in phenolic composition of the cultivars.

The polyphenols of oats have also recently been found to exhibit anti-inflammatory, anti-proliferative and anti-itching activity, which may provide additional protection against coronary heart disease, colon cancer and skin irritation.

Oats contain unique antioxidant polyphenols called avenanthramides not found in other cereals. These metabolites are a unique group of antioxidants found almost exclusively in oats.
Oats antioxidant