24
2 Polyphenols as Bioactive Compounds in Foods and Food Supplements
Beltran and coworkers, OO with light or no bitter taste corresponds to concentration
lower than 220 mg phenols/kg (Beltran et al. 2007). The same study has categorized
OO with a phenolic content from 220 to 340 mg/kg in the less bitter group. On the
other side, the bitter oils contained up to 410 mg/kg of polyphenols while the very
bitter OO may contain more than 410 mg/kg of polyphenols.
The implication and the role of each individual polyphenol to the total bitterness
are not yet clear. However, different researchers have linked the intensity of bitter taste
to the presence of polyphenols derived from the hydrolysis of oleuropein, a secoiridoid glucoside (Kiritsakis 1998; Soler-Rivas et al. 2000). Andrewes and colleagues
have demonstrated a strong correlation between the concentration of secoiridoid
derivates of hydroxytyrosol and bitterness (Andrewes et al. 2003).
Based on many studies, cited below, extra virgin olive oil (EVOO) with phenol’s content higher than 200 mg/kg can provide more health benefits than EVOO
with lower levels of phenols, strongly contributing to regulate blood pressure and
decrease the incidence of cardiovascular diseases (Castañer et al. 2011; Aranceta
Bartrina et al. 2016). EVOO is the only food known to independently increase highdensity lipoprotein (HDL)-cholesterol thanks to polyphenols, according to Casas and
coworkers (Casas et al. 2018). In addition, the EUROLIVE study reported that the
increase in high-density lipoprotein (HDL)-cholesterol concentrations and the concomitant reduction in low-density lipoprotein (LDL)-cholesterol and triglycerides are
dose-dependent with respect to the levels of phenolic content in OO. On these bases,
the EFSA declares that 5 mg of hydroxytyrosol per 20 g of OO should be consumed
daily. This declaration is published officially as a healthy claim that OO polyphenols
contribute to the protection of blood lipids against oxidative stress (EFSA Panel on
Dietetic Products, Nutrition and Allergies 2011; Reg EC 432-2012).
Polyphenols, with almost all their classes and subclasses, participate, with varying
intensity degrees to build up the sensorial attributes and nutritional features of the
food matrix they occupy.
Formerly, many phenolic compounds have been considered plant-based toxins.
However, nowadays, it became clear that they contribute to reduce the incidence
risk of many non-communicable diseases. The feeling of bitterness imparted by
phenolic compounds is not appreciated by a large number of consumers. To take
advantage of the benefits of these phytonutrients, the traditional kitchens, as well as
the food industry, have developed techniques to reduce the intensity of bitterness into
an acceptable level for most consumers. The table olive’s debittering stage (before
fermentation or other processing steps) is an example. This step aims to reduce the
excess of phenolic compounds which make up 2–3% (w/w) of olive flesh, mainly
oleuropein, which is a heterosidic ester of elenolic acid and hydroxytyrosol which is
primarily responsible for the bitter principle of olive fruits. Each combination of table
olive’s variety and preparation style results in a particular nutritional, nutraceutical
and sensorial profile. This wealth has led the IOC to the development of peculiar
evaluation standards. Based on the definition of the IOC, table olives mean (IOC
2004) ‘the product:
2 Polyphenols as Bioactive Compounds in Foods and Food Supplements
Beltran and coworkers, OO with light or no bitter taste corresponds to concentration
lower than 220 mg phenols/kg (Beltran et al. 2007). The same study has categorized
OO with a phenolic content from 220 to 340 mg/kg in the less bitter group. On the
other side, the bitter oils contained up to 410 mg/kg of polyphenols while the very
bitter OO may contain more than 410 mg/kg of polyphenols.
The implication and the role of each individual polyphenol to the total bitterness
are not yet clear. However, different researchers have linked the intensity of bitter taste
to the presence of polyphenols derived from the hydrolysis of oleuropein, a secoiridoid glucoside (Kiritsakis 1998; Soler-Rivas et al. 2000). Andrewes and colleagues
have demonstrated a strong correlation between the concentration of secoiridoid
derivates of hydroxytyrosol and bitterness (Andrewes et al. 2003).
Based on many studies, cited below, extra virgin olive oil (EVOO) with phenol’s content higher than 200 mg/kg can provide more health benefits than EVOO
with lower levels of phenols, strongly contributing to regulate blood pressure and
decrease the incidence of cardiovascular diseases (Castañer et al. 2011; Aranceta
Bartrina et al. 2016). EVOO is the only food known to independently increase highdensity lipoprotein (HDL)-cholesterol thanks to polyphenols, according to Casas and
coworkers (Casas et al. 2018). In addition, the EUROLIVE study reported that the
increase in high-density lipoprotein (HDL)-cholesterol concentrations and the concomitant reduction in low-density lipoprotein (LDL)-cholesterol and triglycerides are
dose-dependent with respect to the levels of phenolic content in OO. On these bases,
the EFSA declares that 5 mg of hydroxytyrosol per 20 g of OO should be consumed
daily. This declaration is published officially as a healthy claim that OO polyphenols
contribute to the protection of blood lipids against oxidative stress (EFSA Panel on
Dietetic Products, Nutrition and Allergies 2011; Reg EC 432-2012).
Polyphenols, with almost all their classes and subclasses, participate, with varying
intensity degrees to build up the sensorial attributes and nutritional features of the
food matrix they occupy.
Formerly, many phenolic compounds have been considered plant-based toxins.
However, nowadays, it became clear that they contribute to reduce the incidence
risk of many non-communicable diseases. The feeling of bitterness imparted by
phenolic compounds is not appreciated by a large number of consumers. To take
advantage of the benefits of these phytonutrients, the traditional kitchens, as well as
the food industry, have developed techniques to reduce the intensity of bitterness into
an acceptable level for most consumers. The table olive’s debittering stage (before
fermentation or other processing steps) is an example. This step aims to reduce the
excess of phenolic compounds which make up 2–3% (w/w) of olive flesh, mainly
oleuropein, which is a heterosidic ester of elenolic acid and hydroxytyrosol which is
primarily responsible for the bitter principle of olive fruits. Each combination of table
olive’s variety and preparation style results in a particular nutritional, nutraceutical
and sensorial profile. This wealth has led the IOC to the development of peculiar
evaluation standards. Based on the definition of the IOC, table olives mean (IOC
2004) ‘the product: