1.3 Phenols, Their Chemical Structures, Sourcing and Interactions …
9
On the other hand, the use of polyphenols as food additives (and coadjuvant agents
against food degradation) with controlled atmosphere packaging may be proposed.
The use of food additives, food compatible gases (namely used in controlled atmospheres) concomitantly with freezing techniques was tested for vegetable foods by
several authors (Laganà et al. 2017a, b, c, d, 2019a, b, c, d; Steinka et al. 2017a, b, c, d).
1.3.4 Phenols and Pedoclimatic Conditions
Undoubtedly, the genetic factor represented by cultivar has a high weight on phenolic
profiles and content as previously explained, but some other studies have demonstrated that same varieties have changed their phenolic content under different pedoclimatic conditions. This feature can be relevant and worth studying when considering
probable scenarios of climate change. Issaoui and coworkers have studied the effect
of the growing area conditions (regional specificities) on the differentiation between
Chemlali and Chétoui olive oils (Issaoui et al. 2010). These authors have found that
phenolics (total polyphenols and o-diphenols) have markedly increased from south to
north and from low altitude to a high altitude. Dabbou and colleagues have confirmed
these results and further showing an influence of the edafoclimatic conditions at the
growing area in the phenolic profiles (Dabbou et al. 2009). Thus, Chétoui cv grown
on Zaghouan region, (latitude 36° 24
00
N, longitude: 10° 09
00
E, altitude: 90 m,
humidity: 47%, annual mean temperature: 18 °C, annual mean rainfall: 350–550 mm)
has the highest level of 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4DHPEA-EDA) and similar polyphenols. However, cv Chétoui cultivated on Béja
area (latitude: 36° 44
N, longitude: 9° 11
E, altitude: 181 m, humidity: 44%, annual
mean temperature: 18 °C, annual mean rainfall: 600–1200 mm) has a high level
of 3,4-DHPEA and 2-(4-hydroxyphenyl)ethanol (p-HPEA). Different phenolic profiles have been noticed in Oueslati olive oils produced in Tunis and Kairouan area
(Dabbou et al. 2009).
On the other hand, Dabbou et al. (2010) have investigated the effect of irrigation
levels on the concentration of phenolic compounds in olive fruits (Olea europaea L.,
cv. Arbequina).
Authors found that different irrigation regimes applied to Arbequina cv. not only
affected the total amount of phenolic compounds present in virgin olive oil, but also
their phenolic profiles (Dabbou et al. 2010).
Regarding wines, and pedoclimatic variations, Soleas and coworkers have demonstrated that the expression of resveratrol may be climate-oriented (Soleas et al. 1997).
Authors studied Cabernet Sauvignon wines and observed varied resveratrol concentrations, which seem to depend on climate variations. Those plants in warm and
dry climates have reduced concentrations of resveratrol, while the plants from the
same cultivar (cv), in the colder and wetter climates (Bordeaux and Canada) produced wines with higher resveratrol levels. Other researchers confirmed such results
from Soleas and colleagues: grape’s phenols are produced in response to the stress
9
On the other hand, the use of polyphenols as food additives (and coadjuvant agents
against food degradation) with controlled atmosphere packaging may be proposed.
The use of food additives, food compatible gases (namely used in controlled atmospheres) concomitantly with freezing techniques was tested for vegetable foods by
several authors (Laganà et al. 2017a, b, c, d, 2019a, b, c, d; Steinka et al. 2017a, b, c, d).
1.3.4 Phenols and Pedoclimatic Conditions
Undoubtedly, the genetic factor represented by cultivar has a high weight on phenolic
profiles and content as previously explained, but some other studies have demonstrated that same varieties have changed their phenolic content under different pedoclimatic conditions. This feature can be relevant and worth studying when considering
probable scenarios of climate change. Issaoui and coworkers have studied the effect
of the growing area conditions (regional specificities) on the differentiation between
Chemlali and Chétoui olive oils (Issaoui et al. 2010). These authors have found that
phenolics (total polyphenols and o-diphenols) have markedly increased from south to
north and from low altitude to a high altitude. Dabbou and colleagues have confirmed
these results and further showing an influence of the edafoclimatic conditions at the
growing area in the phenolic profiles (Dabbou et al. 2009). Thus, Chétoui cv grown
on Zaghouan region, (latitude 36° 24
00
N, longitude: 10° 09
00
E, altitude: 90 m,
humidity: 47%, annual mean temperature: 18 °C, annual mean rainfall: 350–550 mm)
has the highest level of 3,4-dihydroxyphenylethanol-elenolic acid dialdehyde (3,4DHPEA-EDA) and similar polyphenols. However, cv Chétoui cultivated on Béja
area (latitude: 36° 44
N, longitude: 9° 11
E, altitude: 181 m, humidity: 44%, annual
mean temperature: 18 °C, annual mean rainfall: 600–1200 mm) has a high level
of 3,4-DHPEA and 2-(4-hydroxyphenyl)ethanol (p-HPEA). Different phenolic profiles have been noticed in Oueslati olive oils produced in Tunis and Kairouan area
(Dabbou et al. 2009).
On the other hand, Dabbou et al. (2010) have investigated the effect of irrigation
levels on the concentration of phenolic compounds in olive fruits (Olea europaea L.,
cv. Arbequina).
Authors found that different irrigation regimes applied to Arbequina cv. not only
affected the total amount of phenolic compounds present in virgin olive oil, but also
their phenolic profiles (Dabbou et al. 2010).
Regarding wines, and pedoclimatic variations, Soleas and coworkers have demonstrated that the expression of resveratrol may be climate-oriented (Soleas et al. 1997).
Authors studied Cabernet Sauvignon wines and observed varied resveratrol concentrations, which seem to depend on climate variations. Those plants in warm and
dry climates have reduced concentrations of resveratrol, while the plants from the
same cultivar (cv), in the colder and wetter climates (Bordeaux and Canada) produced wines with higher resveratrol levels. Other researchers confirmed such results
from Soleas and colleagues: grape’s phenols are produced in response to the stress