factors, played a critical and significant role within and among the different vicinities
on physical quality and biochemical composition of brew. The extent and pattern of
irrigation and rainfall profoundly affects the nitrogenous compounds (e.g., amino
acids, proteins, protease, total nitrogen, and PPO) and contents and mass of coffee
beans while highest quantities of these nitrogenous compounds are detected in less
irrigated and restricted rainfall areas [189, 192]. There is direct relationship between
the extent of restriction of water supply and protein, lipids, crude fiber, chlorogenic
acid, and caffeine contents of coffee beans. The low to high (80 to 40 of FI) restricted
supply of water can increase the contents of protein, crude fate, and caffeine by
9.4–14.7%, 26–14.1%, and 15.5–18.3%, respectively [192]. The very high application of N in restricted supply of water may further aggravate the worsening of final
cup quality as the work of Liu et al. [192] showed that N application (low to high) in
restricted supply may further increase the protein and chlorogenic acid contents by
7.1–26.2% and 6.4–37%, respectively. Further, proteolytic activity involves the lysis
of proteins into smaller polypeptides, peptides, and amino acids in coffee seeds [196]
which in turn contributes in Maillard reaction along carbohydrates [197]. So any
variation in the rate of proteolytic activity can result in the variation of amino acids,
polypeptides, and peptide contents which in turn would upset the Maillard reaction
outcomes like its specific color or aroma and flavor, eventually deteriorating the cup
quality of coffee. The literature further indicates that despite good yield, full
irrigation (FI), with even high N fertilization, had lower contents of protein and
chlorogenic acids which harm the quality of coffee. But the combination of moderate
DI (80% of FI) with high N application cannot only give comparable high yield but
also improved nutritional quality of coffee [189, 192]. Some authors also claimed
low yield under full irrigation system [198] which may be due to waterlogging which
created the hypoxia or anoxia like conditions in soil in which aerobic metabolism of
plant suffer and consequently producing fermentative pathways products to fulfill
the energy needs.
Volatile compounds have pronounced impact on the sensory and organoleptic
characteristics of coffee. However, out of hundreds volatile compounds, only a few
are key to determine the final quality of coffee [199]. Nearly 300 volatile compounds
were detected in coffee green beans out which 200 still exist in coffee beans after
roasting [200]. These volatile compounds are the sources of body (i.e., aroma,
acidity, fruitiness earthiness, etc.) and sensory attributes of coffee. Bertrand et al.
[201] first time in literature determined the direct and detailed relationship of these
volatile compounds with climate (i.e., temperature, rainfall, solar radiation). Out of
44 volatile compounds, they enlisted 21 institutes to be in strong relationship with
changing temperature, rainfall, and solar radiation which belong to the alcohol,
aldehyde, ketone, lactone, furan, phenol, pyrazine, pyrrole, hydrocarbon, aliphatic
acid, and sulfide classes of chemicals. Alcoholic, aldehyde, ketonic, and sulfide class
of compound noticed to play generous roles in changing the body and sensory
quality of coffee with respect to changing temperature. Alcoholic and aldehydes
(except ethanol) compounds found to have direct relation with temperature, while
sulfides and ketones possess negative relation. The majority of temperature positively linked compounds (i.e., butan-2.3-diol, butan-1.3-diol, 2-butoxyethanol, 227 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
675
on physical quality and biochemical composition of brew. The extent and pattern of
irrigation and rainfall profoundly affects the nitrogenous compounds (e.g., amino
acids, proteins, protease, total nitrogen, and PPO) and contents and mass of coffee
beans while highest quantities of these nitrogenous compounds are detected in less
irrigated and restricted rainfall areas [189, 192]. There is direct relationship between
the extent of restriction of water supply and protein, lipids, crude fiber, chlorogenic
acid, and caffeine contents of coffee beans. The low to high (80 to 40 of FI) restricted
supply of water can increase the contents of protein, crude fate, and caffeine by
9.4–14.7%, 26–14.1%, and 15.5–18.3%, respectively [192]. The very high application of N in restricted supply of water may further aggravate the worsening of final
cup quality as the work of Liu et al. [192] showed that N application (low to high) in
restricted supply may further increase the protein and chlorogenic acid contents by
7.1–26.2% and 6.4–37%, respectively. Further, proteolytic activity involves the lysis
of proteins into smaller polypeptides, peptides, and amino acids in coffee seeds [196]
which in turn contributes in Maillard reaction along carbohydrates [197]. So any
variation in the rate of proteolytic activity can result in the variation of amino acids,
polypeptides, and peptide contents which in turn would upset the Maillard reaction
outcomes like its specific color or aroma and flavor, eventually deteriorating the cup
quality of coffee. The literature further indicates that despite good yield, full
irrigation (FI), with even high N fertilization, had lower contents of protein and
chlorogenic acids which harm the quality of coffee. But the combination of moderate
DI (80% of FI) with high N application cannot only give comparable high yield but
also improved nutritional quality of coffee [189, 192]. Some authors also claimed
low yield under full irrigation system [198] which may be due to waterlogging which
created the hypoxia or anoxia like conditions in soil in which aerobic metabolism of
plant suffer and consequently producing fermentative pathways products to fulfill
the energy needs.
Volatile compounds have pronounced impact on the sensory and organoleptic
characteristics of coffee. However, out of hundreds volatile compounds, only a few
are key to determine the final quality of coffee [199]. Nearly 300 volatile compounds
were detected in coffee green beans out which 200 still exist in coffee beans after
roasting [200]. These volatile compounds are the sources of body (i.e., aroma,
acidity, fruitiness earthiness, etc.) and sensory attributes of coffee. Bertrand et al.
[201] first time in literature determined the direct and detailed relationship of these
volatile compounds with climate (i.e., temperature, rainfall, solar radiation). Out of
44 volatile compounds, they enlisted 21 institutes to be in strong relationship with
changing temperature, rainfall, and solar radiation which belong to the alcohol,
aldehyde, ketone, lactone, furan, phenol, pyrazine, pyrrole, hydrocarbon, aliphatic
acid, and sulfide classes of chemicals. Alcoholic, aldehyde, ketonic, and sulfide class
of compound noticed to play generous roles in changing the body and sensory
quality of coffee with respect to changing temperature. Alcoholic and aldehydes
(except ethanol) compounds found to have direct relation with temperature, while
sulfides and ketones possess negative relation. The majority of temperature positively linked compounds (i.e., butan-2.3-diol, butan-1.3-diol, 2-butoxyethanol, 227 “Coffee Bean-Related” Agroecological Factors Affecting the Coffee
675