293
the shikimate-phenylpropanoids flavonoids pathways (Krzyzanowska et al. 2010).
Majority of the phenolic compounds show estrogenic activities, and defined as the
compounds having one or more aromatic ring along with hydroxyl substituents,
including many functional derivatives like esters, methyl ethers, glycosides, etc.
(Parsaeimehr et al. 2011). Polyphenolic compounds could be divided into two categories, firstly soluble phenols e.g. phenolic acids, flavonoids and quinones, secondly insoluble phenols e.g. condensed tanins, lignins and cell wall bounded
hydroxycinammic acids (Krzyzanowska et al. 2010).
Many types of compounds are included in polyphenolic compounds like furanocoumarins, lignin, flavonoids, isoflavonoids, and tannins. Another class of phenols
flavonoids comprised of large and varied units of polyphenolic compounds found in
plants. Among flavonoids vital group of compounds are flavonols comprised of
quercetin, kaempferol, and isorhamnetin, other important group is flavones for
example apigenin, luteolin, and chrysoeriol (Hounsome et al. 2008). Another class
called phenolic acids contains gallic and caffeic acids, vanillic acid, cinnamic acid
and coumaric acid (Krzyzanowska et al. 2010). Most commonly phenolic acids and
flavonoids are found in sprouted seeds which have recognized as anti-oxidant and
could be used as functional compounds (Fu et al. 2011). As germinated (sprouted)
are rich source of poylphenolic compounds and other bioactive compounds therefore, these seeds could be the best alternative of fruits and vegetables in our
healthy diets.
16.8 Germinated Grains and Polyphenols
Through several studies in cereal grains it was shown that germination process
could enhance the amount of solvent-extractable phenolic compounds (Tables 16.1
–16.3). Several authors suggested that increment of water soluble polyphenolic
compounds during sprouting process can be attributed to the de novo synthesis and
transformation (Kim et al. 2013; Tang et al. 2014). Negative impact of seed germination also observed, as many studies showed the reduction in polyphenolic content
in sprouted seeds. And this contradictory result associated with increment in moisture content during germination process, during which soluble phenols may be
wasted (Guo et al. 2012). These opposing results stated are mainly accredited to
difference in soaking, temperatures, germination time and methods of drying the
germinated grains. Increased phenolic contents and antioxidant activities has been
stated through different in vitro studies in cereal grains, like wheat (Van Hung et al.
2011), sorghum (Donkor et al. 2012), buckwheat (Alvarez- Jubete et al. 2010), and
rice (Imam et al. 2012).
Enhanced polyphenol oxidase activity (PPO) might be the reason of increased
polyphenol contents in germinated grains as compared with non-germinated grain
(Demeke et al. 2001). The increase in polyphenols during seed geminating could be
due to solubilization of condensed tannins during water soaking and its movement
to the outer layer during germination. During maize germination phytate contents
16 Effect of Germination Processing on Bioactive Compounds of Cereals and Legumes
the shikimate-phenylpropanoids flavonoids pathways (Krzyzanowska et al. 2010).
Majority of the phenolic compounds show estrogenic activities, and defined as the
compounds having one or more aromatic ring along with hydroxyl substituents,
including many functional derivatives like esters, methyl ethers, glycosides, etc.
(Parsaeimehr et al. 2011). Polyphenolic compounds could be divided into two categories, firstly soluble phenols e.g. phenolic acids, flavonoids and quinones, secondly insoluble phenols e.g. condensed tanins, lignins and cell wall bounded
hydroxycinammic acids (Krzyzanowska et al. 2010).
Many types of compounds are included in polyphenolic compounds like furanocoumarins, lignin, flavonoids, isoflavonoids, and tannins. Another class of phenols
flavonoids comprised of large and varied units of polyphenolic compounds found in
plants. Among flavonoids vital group of compounds are flavonols comprised of
quercetin, kaempferol, and isorhamnetin, other important group is flavones for
example apigenin, luteolin, and chrysoeriol (Hounsome et al. 2008). Another class
called phenolic acids contains gallic and caffeic acids, vanillic acid, cinnamic acid
and coumaric acid (Krzyzanowska et al. 2010). Most commonly phenolic acids and
flavonoids are found in sprouted seeds which have recognized as anti-oxidant and
could be used as functional compounds (Fu et al. 2011). As germinated (sprouted)
are rich source of poylphenolic compounds and other bioactive compounds therefore, these seeds could be the best alternative of fruits and vegetables in our
healthy diets.
16.8 Germinated Grains and Polyphenols
Through several studies in cereal grains it was shown that germination process
could enhance the amount of solvent-extractable phenolic compounds (Tables 16.1
–16.3). Several authors suggested that increment of water soluble polyphenolic
compounds during sprouting process can be attributed to the de novo synthesis and
transformation (Kim et al. 2013; Tang et al. 2014). Negative impact of seed germination also observed, as many studies showed the reduction in polyphenolic content
in sprouted seeds. And this contradictory result associated with increment in moisture content during germination process, during which soluble phenols may be
wasted (Guo et al. 2012). These opposing results stated are mainly accredited to
difference in soaking, temperatures, germination time and methods of drying the
germinated grains. Increased phenolic contents and antioxidant activities has been
stated through different in vitro studies in cereal grains, like wheat (Van Hung et al.
2011), sorghum (Donkor et al. 2012), buckwheat (Alvarez- Jubete et al. 2010), and
rice (Imam et al. 2012).
Enhanced polyphenol oxidase activity (PPO) might be the reason of increased
polyphenol contents in germinated grains as compared with non-germinated grain
(Demeke et al. 2001). The increase in polyphenols during seed geminating could be
due to solubilization of condensed tannins during water soaking and its movement
to the outer layer during germination. During maize germination phytate contents
16 Effect of Germination Processing on Bioactive Compounds of Cereals and Legumes