ethylhexan-1- ol, 3-methylbutanoic acid, benzaldehyde, hexan-2-ol, acetic acid, 2phenylethanol butan- 2-one, benzyl alcohol, gamma butyrolactone and butan-2,3dione) are also positively associated with the earthy flavor while five cold climate
positively linked compounds (namely, ethanol, dimethylsulfide, butan-2-one, 2methylfuran and acetone) are in direct relationship with fruity flavor. Some of
other major volatile compounds remained unaffected but play a critical role in
final cup quality, including 2-furanmethanol, ethanol, toluene, 3-methylfuran and
hexanal, 2-methylpropan-1-ol. The literature cited that high temperature (>23
C)
during fruit development brings about the changes in the expressions and activities
of genes and enzymes of these volatile compounds leading to disturb the “standard”
concentrations of these volatile compounds and eventually hampering the body and
sensory attributes of coffee [201]. Working with the cafés-terroir in Honduras,
Avelino et al. [31] noted that the effect of temperature is conditioned by the latitude
and altitude and that those attributes jointly favor coffee quality, producing the local
characteristics of taste and aroma. Bertrand and his coworkers also deduced that
temperature plays a more vital role in deciding the cup quality of coffee than rainfall
as rainfall linked to four (2-ethylhexan-1-ol, 3-methyl-2-butenoate, methane, and
gamma valerolactone). But, unlike their claims, rainfall always played its overall
indirect critical role in maintenance and keeping the temperature and humidity under
certain required limit all year round. Average daily temperature also found to alter
the “standard” concentrations of isomeric compounds of major coffee compositional
components (caffeine, chlorogenic acid, lipids, sucrose, polysaccharides) but keeping the overall net concentration of major component unaltered [202]. The isomers
of same compounds respond differently to the temperature, i.e., 5-CQA is negatively
correlated with temperature, but the reverse trend was observed for 3-caffeoyl
quinate (3-CQA) and 4-CQA content. Similarly in lipids, stearic acid (about 7%)
stored more in warmer conditions than linoleic and palmitic acids (35–45% each)
[202]. After the discoveries of Bertrand et al. [201] and Joet et al. [202] on coffee
volatile compounds and temperature role in controlling the biosynthetic pathways of
certain important fatty acids, Abreu et al. [203] in the same year work on unfolding
the relation of amino acid profile and proteinase activity with temperature as the
previous revelation from Montavon et al. [33, 197] and Ludwig et al. [196] has
showed the varying activity of proteinase and protease enzymes of coffee seeds from
hotter to cold coffee fields (immaturation stage to maturation) responsible for
varying quality due to variation in the ratios of free amino acids being taken part
in Maillard reaction liable for coffee aroma, color, and flavor. Abreu and his
colleagues noted a higher concentration of free amino acids at immature stage
(both from hotter and colder regions) of coffee seeds then at mature stage, but
seeds from hotter regions found to have higher amount of amino acid. Additionally,
hotter side coffee seeds found to have higher amount of asparagine (Asn), aspartic
acid (Asp), and lysine (Lys) at immature stage and at maturation stage more variety
of amino acids (i.e., methionine (Met), glutamic acid (Glu), Asn, Lys, leucine (Leu),
alanine (Ala), tyrosine (Tyr) and gamma-aminobutyric acid (GABA)) added to seeds
from hotter regions. Abiotic stresses (like drought, high temperature) also lead to
increase the production of nonprotein amino acid GABA due to higher dehydrin
676
A. Hameed et al.
positively linked compounds (namely, ethanol, dimethylsulfide, butan-2-one, 2methylfuran and acetone) are in direct relationship with fruity flavor. Some of
other major volatile compounds remained unaffected but play a critical role in
final cup quality, including 2-furanmethanol, ethanol, toluene, 3-methylfuran and
hexanal, 2-methylpropan-1-ol. The literature cited that high temperature (>23
C)
during fruit development brings about the changes in the expressions and activities
of genes and enzymes of these volatile compounds leading to disturb the “standard”
concentrations of these volatile compounds and eventually hampering the body and
sensory attributes of coffee [201]. Working with the cafés-terroir in Honduras,
Avelino et al. [31] noted that the effect of temperature is conditioned by the latitude
and altitude and that those attributes jointly favor coffee quality, producing the local
characteristics of taste and aroma. Bertrand and his coworkers also deduced that
temperature plays a more vital role in deciding the cup quality of coffee than rainfall
as rainfall linked to four (2-ethylhexan-1-ol, 3-methyl-2-butenoate, methane, and
gamma valerolactone). But, unlike their claims, rainfall always played its overall
indirect critical role in maintenance and keeping the temperature and humidity under
certain required limit all year round. Average daily temperature also found to alter
the “standard” concentrations of isomeric compounds of major coffee compositional
components (caffeine, chlorogenic acid, lipids, sucrose, polysaccharides) but keeping the overall net concentration of major component unaltered [202]. The isomers
of same compounds respond differently to the temperature, i.e., 5-CQA is negatively
correlated with temperature, but the reverse trend was observed for 3-caffeoyl
quinate (3-CQA) and 4-CQA content. Similarly in lipids, stearic acid (about 7%)
stored more in warmer conditions than linoleic and palmitic acids (35–45% each)
[202]. After the discoveries of Bertrand et al. [201] and Joet et al. [202] on coffee
volatile compounds and temperature role in controlling the biosynthetic pathways of
certain important fatty acids, Abreu et al. [203] in the same year work on unfolding
the relation of amino acid profile and proteinase activity with temperature as the
previous revelation from Montavon et al. [33, 197] and Ludwig et al. [196] has
showed the varying activity of proteinase and protease enzymes of coffee seeds from
hotter to cold coffee fields (immaturation stage to maturation) responsible for
varying quality due to variation in the ratios of free amino acids being taken part
in Maillard reaction liable for coffee aroma, color, and flavor. Abreu and his
colleagues noted a higher concentration of free amino acids at immature stage
(both from hotter and colder regions) of coffee seeds then at mature stage, but
seeds from hotter regions found to have higher amount of amino acid. Additionally,
hotter side coffee seeds found to have higher amount of asparagine (Asn), aspartic
acid (Asp), and lysine (Lys) at immature stage and at maturation stage more variety
of amino acids (i.e., methionine (Met), glutamic acid (Glu), Asn, Lys, leucine (Leu),
alanine (Ala), tyrosine (Tyr) and gamma-aminobutyric acid (GABA)) added to seeds
from hotter regions. Abiotic stresses (like drought, high temperature) also lead to
increase the production of nonprotein amino acid GABA due to higher dehydrin
676
A. Hameed et al.