3.1 Nutritional Importance of Polyphenols
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(h) Vegetables
(i) Virgin olive oil
(j) Wines.
3.1.1 Cereals
Barley, maize, wheat and rice, sorghum, oat, rye and buckwheat are the most
important cereals in terms of world annual production, according to the PhenolExplorer database on polyphenol content in foods.
1 Apart from being of international importance, the Mediterranean Dietary pattern includes a high intake of cereals, mainly wheat, as well as rice, maize and rye (desirably whole grains or coarsely
refined/milled flours).
Cereals are a source of dietary fibres, minerals, vitamins, essential fatty acids and
phytonutrients. The most abundant antioxidants in whole grains are phenolic acids,
which are highly concentrated in the bran and in the germ. The subclass of phenolic
acids depends on each cereal. Hence, barley mainly provides 4-hydroxybenzoic acid
and ferulic acid. This later phenolic acid is the most important in maize, with an
average content of 171 mg/100 g. Ferulic acid is also the principal phenol in wheat,
being present at about 47 mg/100 g in whole grain wheat flour, followed by sinapic
acid, p-coumaric acid, vanillic acid, caffeic acid and diferulic acids. Also, syringic, ocoumaric, gentisic acid and 2-hydroxybenzoic acids are available in minor amounts,
according to Phenol-Explorer database on polyphenol content in foods.
Yu and colleagues compared the content of polyphenols and their antioxidant
activity in both whole and refined wheat flour. The study carried confirms the general
judgement that bakery products from whole wheat are richer in antioxidant phytonutrients and consequently more beneficial to health than those made of refined flours.
In the same research, authors also observed that baking operations reduce the total
polyphenol’s content up to 28 and 33%, respectively, for unrefined and refined flours.
Results from high-performance liquid chromatography (HPLC) analyses which discriminate compounds showed an increase between 18 and 35% in ferulic acid after
baking of both, whole (dark) and refined (white) wheat bread.
3.1.2 Cloves, Other Spices and Aromatic Herbs
Several culinary herbs and spices are representative of the Med Diet: a brief list of
these common seasonings may be summarized as follows (Delgado et al. 2017a, b;
Barbieri et al. 2019; Shan et al. 2005):
1 This database is freely available at the following web address: http://phenol-explorer.eu/reports/4.
35
(h) Vegetables
(i) Virgin olive oil
(j) Wines.
3.1.1 Cereals
Barley, maize, wheat and rice, sorghum, oat, rye and buckwheat are the most
important cereals in terms of world annual production, according to the PhenolExplorer database on polyphenol content in foods.
1 Apart from being of international importance, the Mediterranean Dietary pattern includes a high intake of cereals, mainly wheat, as well as rice, maize and rye (desirably whole grains or coarsely
refined/milled flours).
Cereals are a source of dietary fibres, minerals, vitamins, essential fatty acids and
phytonutrients. The most abundant antioxidants in whole grains are phenolic acids,
which are highly concentrated in the bran and in the germ. The subclass of phenolic
acids depends on each cereal. Hence, barley mainly provides 4-hydroxybenzoic acid
and ferulic acid. This later phenolic acid is the most important in maize, with an
average content of 171 mg/100 g. Ferulic acid is also the principal phenol in wheat,
being present at about 47 mg/100 g in whole grain wheat flour, followed by sinapic
acid, p-coumaric acid, vanillic acid, caffeic acid and diferulic acids. Also, syringic, ocoumaric, gentisic acid and 2-hydroxybenzoic acids are available in minor amounts,
according to Phenol-Explorer database on polyphenol content in foods.
Yu and colleagues compared the content of polyphenols and their antioxidant
activity in both whole and refined wheat flour. The study carried confirms the general
judgement that bakery products from whole wheat are richer in antioxidant phytonutrients and consequently more beneficial to health than those made of refined flours.
In the same research, authors also observed that baking operations reduce the total
polyphenol’s content up to 28 and 33%, respectively, for unrefined and refined flours.
Results from high-performance liquid chromatography (HPLC) analyses which discriminate compounds showed an increase between 18 and 35% in ferulic acid after
baking of both, whole (dark) and refined (white) wheat bread.
3.1.2 Cloves, Other Spices and Aromatic Herbs
Several culinary herbs and spices are representative of the Med Diet: a brief list of
these common seasonings may be summarized as follows (Delgado et al. 2017a, b;
Barbieri et al. 2019; Shan et al. 2005):
1 This database is freely available at the following web address: http://phenol-explorer.eu/reports/4.