Coffee Parts Review

SOME TRUES CONCERNING COFFEE

ABSTRACT

Coffee is one of the most widely consumed beverages in the world due to its organoleptic properties and its ability to keep individuals alert. However, its consumption is frequently associated with negative health effects. This paper reviews the most recent information about the relation between coffee and health. A number of epidemiological studies carried out in the last decade consistently show that coffee intake is related to a lower risk of type-2 diabetes, liver damage, and neurodegenerative diseases such as Parkinson's. The mechanisms which could explain these observations are not clearly understood yet, but they could be related to the unique profile and high concentrations of antioxidants in coffee, particularly chlorogenic acid.

Key words: coffee, type-2 diabetes, Parkinson, cardiovascular diseases, antioxidant, chlorogenic acid.

SUMMARY

Coffee is one of the most consumed beverages worldwide, due to its organoleptic properties and its ability to keep individuals on their toes. However, its consumption is frequently associated with negative effects on health. This article reviews the latest information on the relationship between coffee consumption and health. Several epidemiological studies carried out in the last decade consistently show that coffee consumption is associated with a lower risk of type-2 diabetes, liver damage and neurodegenerative diseases such as Parkinson's. The mechanisms that could account for these observations are not yet fully understood but could be related to the specific antioxidant profile of coffee and the high concentrations of these, particularly chlorogenic acid.

Key words: Coffee, type 2 diabetes, Parkinson's, cardiovascular diseases, antioxidants, chlorogenic acid.

INTRODUCTION

Coffee is a very popular drink for its organoleptic characteristics, making it one of the most widely consumed in the world. It contains an immense variety of chemical compounds responsible for its sensory quality and its physiological effects, such as caffeine, which is a recognized stimulant of the central nervous system and that affects the alertness of the individual. The consumption of coffee, however, is frequently associated with unhealthy lifestyles such as smoking and staying up late, which sometimes gives it a negative image. On the other hand, there are beliefs or "myths", even at a medical level, regarding its potential adverse effects, which are not necessarily proven, but which lead to adopting precautionary positions regarding its use against certain health disorders. This work updates in a non-exhaustive way the most recent and novel bibliographic information on the relationship between coffee and health.

BACKGROUND

Coffee is called the drink prepared by infusion from the seeds of the fruit of the coffee trees duly processed and roasted. It is characterized by a pleasant aroma and flavor and is widely consumed worldwide.

The coffee tree is a tropical shrub with green leaves belonging to the Rubiaceae family and the genus Coffea spp. It grows in areas of moderate humidity at 600 to 1,200 meters high. It includes many species, however, only Arabica and Robusta are cultivated, which in turn present different varieties. It produces fleshy red or purple fruits called coffee cherries with two cores each containing a green coffee bean or bean (1).

Origin of coffee

There is almost unanimous consensus that coffee originated in its wild form known as Arabica in the highlands of Abyssinia (now Ethiopia) and a series of legends circulate regarding the discovery of its use as a drink. The most accepted refers to Kaldi, a shepherd from Abyssinia who observed that his goats leaped around very excited and full of energy after having eaten the leaves and fruits of a certain bush. Kaldi took fruits and branches of that bush to the Abbot of a monastery who would have discovered the drink of coffee by putting the cherries on the fire, which when roasted produced an exquisite aroma.

Coffee became popular around the 13th century as a stimulating drink, possibly as a result of the Islamic prohibition of alcoholic beverages. As early as the 15th century, Muslims introduced coffee to Persia, Egypt, and Turkey, where the first coffee shop, Kiva Han, opened in 1475 in Constantinople. Later, coffee reached Europe in the seventeenth century thanks to Venetian merchants, where it quickly became a favorite drink and circulated in different countries (Italy, 1645; England, 1650; France, 1660). The first coffee shop in London was opened in 1652 and in Paris in 1672. In the 18th century, large crops moved to Ceylon and Indonesia as well as South America, where the first plantation was established.

He went to Brazil in 1727 (2).

International Trade

The coffee tree is undoubtedly one of the most important vegetable products in global international trade and coffee is currently produced in different regions, with Brazil being the largest producing and exporting country. In 2005, world coffee production reached 108,222,000 bags (60kg each) of which 65% to 70% corresponded to Arabica and the rest to Robusta. The Arabica produces a fine and aromatic coffee, while the Robusta, which has a lower price, produces a drink rich in caffeine, strong and more acidic and is usually used for the manufacture of soluble or instant coffee.

The main world producers in 2005 were Brazil (30.4%), Colombia (10.2%), Vietnam (10.2%) and Indonesia (7.7%). In commercial terms, during the 2004/2005 period a global level of exports of US $ 8.9 billion was reached. In producing countries, this crop has a high economic and social impact since it mostly involves small farmers and a large labor force (3, 4).

Per capita coffee consumption is variable around the world. According to the latest data from FAO (2004), the Nordic countries of Europe have the highest apparent consumption expressed in kg / year / person of green coffee: Finland (11.8), Norway (9, 5) and Denmark (9, one). The largest producer, Brazil, shows a per capita consumption of 4.4 kg / year, the United States, 4.1 kg / year, Colombia 1.0 kg / year, Argentina 1.0 kg / year and Chile 0.6 kg / year, this last figure represents an apparent daily consumption of 1.64 grams per person (5).

Harvest and processing

Once the ripe cherries have been harvested, either by hand or by scraping or shaking the branches, they are subjected to dry processing (sun drying) or wet to separate and obtain the coffee beans, which are classified, They polish and package, constituting green coffee whose composition varies depending on the variety, origin, processing and climate.

Toasted

While roasting might not be considered within the coffee production flow itself, since world trade statistics refer to bags of green coffee, coffee reaches consumers already roasted. By applying temperatures (200 to 250 ° C), the grains change their structure, dehydrate and release oil, reduce their weight, take on a dark color and develop their characteristic aromas and flavors. There are coffees with a wide range of roasted colors that range from the lightest such as New England coffee to the darkest such as Italian coffee or espresso.

Types of coffee preparations

There are different ways to prepare coffee, such as using ground roasted coffee beans added with water that is then boiled and allowed to settle (Turkish coffee), or preparing coffee extracts by passing boiling water through the ground coffee beans and filtering (percolation) either by simple gravity (filter paper) or by pressure as in the case of espresso coffee. Instant coffee corresponds to an aqueous extract of spray-dried coffee. Each of these preparations varies in terms of its organoleptic qualities, chemical composition and eventually in its physiological effects.

Decaffeinated coffee

Decaffeinated coffee is obtained from green beans treated with pressure steam and subsequent extraction with organic solvents or by supercritical extraction. The beans are subsequently roasted, obtaining decaffeinated coffee with a maximum content of 0.1% caffeine on a dry basis. In the case of decaffeinated instant coffee, the maximum allowed caffeine content on a dry basis is 0.3% (1).

CHEMICAL COMPONENTS OF COFFEE

Coffee is made up of more than 1000 different chemical substances (6) including amino acids and other nitrogenous compounds, polysaccharides, sugars, triglycerides, linoleic acid, diterpenes (cafestol and kahweol), volatile (formic and acetic) and non-volatile (lactic, tartaric, pyruvic, citric), phenolic compounds (chlorogenic acid), caffeine, volatile substances (over 800 identified of which 60-80 contribute to the aroma of coffee), vitamins, minerals. Other constituents such as melanoidins are derived from non-enzymatic browning reactions or carbohydrate caramelization that occur during roasting. There are important variations in the concentration of these components depending on the variety of coffee and the degree of roasting.

Caffeine

Caffeine (1,3,7-trimethylxanthine) is one of the three methylxanthines present in coffee along with theophylline and theobromine. This alkaloid acts as a stimulant of the central nervous system and is also found naturally in tea and cocoa. It is also added in commonly consumed drinks such as cola (around 10 mg / 100mL) and energy drinks (reaching 34mg / ml).

Arabica and Robusta green coffees contain 1.16% (0.6-1.7%) and 2.15% (1.16-3.27%) of caffeine respectively (6) while it reaches levels of 3.1-3 , 9% in instant coffee powder (7, 8). In brewed coffee, caffeine levels vary between 29 and 176mg / cup (median 74) depending on the concentration and solubility of the coffee, among others (6). In the case of instant soluble coffee, an average caffeine content of 60 mg / 150 ml cup (range 30 - 120 mg) is estimated. The caffeine content in instant decaffeinated coffee is 0.12%, equivalent to around 3mg / cup (7).

Caffeine is rapidly and completely absorbed in the digestive tract, distributing itself to all tissues of the body. The maximum plasma concentration of caffeine reaches 50 µM after a habitual intake of coffee, and its half-life in the body is 2.5 to 10 hours. Caffeine metabolism occurs mainly in the liver, where cytochrome p450 accounts for 95% of its transformation, which generates more than 25 metabolites, while the remaining 5% is excreted in the urine.

Cafestol and Kahweol

These diterpenes are found in green coffee beans in free or esterified form as palmitate. They are considered responsible for the increase in total and LDL cholesterol levels observed in some populations that consume unfiltered coffee such as Turkish coffee, Scandinavian boiled coffee or cafetière that contain high levels of these diterpenes (6-12 mg / cup) ( 10, 11). Cafestol and kahweol are extracted in hot water but are retained by the filter paper. Espresso coffee has an average content of 1.5 mg / cup (11).

Chlorogenic acids

Coffee contains a series of characteristic phenolic esters called chlorogenic acids, which are derived from the ester bond between caffeic acid and quinic acid. Up to 11 chlorogenic acids have been identified in Robusta coffee. Chlorogenic acid is normally called the one that is present in the greatest amount (5-O-caffeoylquinic). Along with the also present feruloylquinic acids, esters of caffeic acid and ferulic acid are an important source of dietary phenols. The content of chlorogenic acids is 7% in green coffee and they partially decompose (30 to 70%) during roasting, reaching levels of the order of 4.0%. (6). Mattila et al. (13) measured the content of phenolic acids in food, concluding that coffee is the richest source among the drinks consumed, compared to apple juice, orange juice, red wine, beer, black tea, green tea and concentrated juice of berries. It is generally noted that 200 ml of roast and ground coffee could provide between 70 and 350 mg of chlorogenic acid.

Antioxidant activity

Chlorogenic acids are well recognized as antioxidants. The hydroxyl (OH) antiradical capacity of green and roasted coffee depends on 5-O-caffeoylquinic acid (14). The use of mixtures of caffeic acid with chlorogenic acids has been described as an alternative to the use of synthetic antioxidants (1). Likewise, it has been shown that instant coffee can act as a pro-oxidant for ascorbic acid and as a scavenger of superoxide free radicals (15).

The antioxidant activity of coffee is not only due to polyphenolic compounds but also to the presence of caffeine and compounds derived from roasting. Caffeine has the ability to inhibit lipoperoxidation induced by hydroxyl radicals (OH.), Peroxides (ROO.) And singlet oxygen, making it a potent antioxidant with glutathione-like capacity and superior to ascorbic acid (16, 17). On the other hand, the coffee roasting process induces the formation of high molecular weight compounds such as melanoidins as well as 

It is low molecular weight compounds that also possess antioxidant activity (14). This would compensate for the decrease in chlorogenic acids that occurs when roasting. The maximum antioxidant activity is observed in moderately roasted coffee (18).

Using different techniques for determining the total antioxidant activity, coffee appears as the greatest contributor to the total daily intake of antioxidants in Norwegian adults (19) and the greatest source of antioxidants in drinks in the Spanish (20) and Italian (21) diet. ) (Table 1). Halvorsen et al. (22) reported that, in a list of 1,113 foods consumed in the United States, prepared coffee was among the 50 richest in antioxidants and in sixth place in terms of antioxidant contribution per serving of consumption (250 ml). All this makes coffee a unique dietary source of antioxidants with a very specific profile and high total antioxidant capacity.