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instant coffee

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

instant coffee

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

instant coffee

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

http://instant.wikia.com/wiki/Instant_Wiki#Instant_coffee_manufacturers

instant coffee

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

instant coffee

 

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

instant coffee

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

instant coffee

 

instant coffee

instant coffee

“Instant coffee” was invented back in 1906 by George C. Washington. He was an Englishman living in Guatemala and a chemist by trade. An avid coffee-drinker, he noticed a powdery buildup on the spout of his favorite silver coffee pot. That prompted his curiosity and further experimentation followed. He eventually produced a dried coffee crystal much like we still have today. His brand was called Red E Coffee.

Bascially, instant coffee is just regularly brewed coffee with nearly all the water removed. It’s not that mysterious a process at all. There is no strange chemical adulteration that goes on. Instant coffee is still pure coffee.

There are two methods for producing instant coffee crystals: freeze-drying and spray-drying. The freeze-drying method preserved the most ‘coffee flavour’ but it’s a more involved procedure. First, the coffee is allowed to sit so the water evaporates naturally, leaving a concentrated coffee solution. This concentrate is then frozen to around -40 Celsius. The remaining water freezes into ice crystals. Sublimation (a natural process similar to evaporation) is used to remove the ice. What’s left is dry grains of coffee.

The second method is spray-drying. The water is again allowed to evaporate, forming a concentrate. The concentrated coffee is sprayed from a high tower in a large hot-air chamber. As the droplets fall, the remaining water evaporates. Dry crystals of coffee fall to the bottom of the chamber. The high temperatures involved in this method do tend to effect the oils of the coffee and more flavour is lost.

Even if you don’t care for a whole cup of instant brew, you can still use instant coffee to add a tasty touch to other drinks, or even cooking and baking.

History

Instant coffee was invented in 1901 by Satori Kato, a Japanese scientist working in Chicago. Kato introduced the powdered substance in Buffalo, New York, at the Pan-American Exposition.[1] George Constant Louis Washington developed his own instant coffee process shortly thereafter, and first marketed it commercially (1910). The Nescafé brand, which introduced a more advanced coffee refining process, was launched in 1938.

High-vacuum freeze-dried coffee was developed shortly after World War II, as an indirect result of wartime research into other areas. The National Research Corp. was formed in Massachusetts as a process-development company employing high-vacuum technology. It developed high-vacuum processes to produce penicillin, blood plasma and streptomycin for US military use. As the war ended, NRC looked to adapt its processes for peacetime uses. It formed Florida Foods Corp. to produce concentrated orange juice powder, and originally sold its product to the United States Army. That company later changed its name to Minute Maid.

 Use

Instant coffee is available in powder or granulated form contained in glass jars, sachets or tins. The user controls the strength of the resulting product, by adding more or less powder to the water, ranging from thin “coffee water” to very strong and almost syrupy coffee.

Instant coffee is also convenient for preparing iced coffee like the Greek frappé, which is popular in warmer climates and hot seasons.[citation needed]

In some countries such as Portugal, Spain and India, instant coffee is commonly mixed with hot milk instead of boiling water.

 Production

As with regular coffee, the green coffee bean itself is first roasted to bring out flavour and aroma. Rotating cylinders containing the green beans and hot combustion gases are used in most roasting plants. When the bean temperature reaches 165 °C the roasting begins, accompanied by a popping sound similar to that produced by popcorn. These batch cylinders take about 8–15 minutes to complete roasting with about 25-75% efficiency. Coffee roasting using a fluidized bed only takes from thirty seconds to four minutes, and it operates at lower temperatures which allows greater retention of the coffee bean aroma and flavor.

The beans are then ground finely. Grinding reduces the beans to 0.5–1.1-millimetre (0.020–0.043 in) pieces in order to allow the coffee to be put in solution with water for the drying stage. Sets of scored rollers designed to crush rather than cut the bean are used.

Once roasted and ground, the coffee is dissolved in water. This stage is called extraction. Water is added in 5-10 percolation columns at temperatures of 155 to 180 °C; this concentrates the coffee solution to about 15-30% coffee by mass. This may be further concentrated before the drying process begins by either vacuum evaporation or freeze concentration.

“Freeze drying”

The basic principle of freeze drying is the removal of water by sublimation.

Since the mass production of instant coffee began in post-WWII America, freeze-drying has grown in popularity to become a common method. Although it is sometimes more expensive, it generally results in a higher-quality product.

  1. Agglomerated wet coffee granules are rapidly frozen (slow freezing leads to large ice crystals and a porous product and can also affect the colour of the coffee granules).
  2. Frozen coffee is placed in the drying chamber, often on metal trays.
  3. A vacuum is created within the chamber. The strength of the vacuum is critical in the speed of the drying and therefore the quality of the product. Care must be taken to produce a vacuum of suitable strength.
  4. The drying chamber is warmed, most commonly by radiation but conduction is used in some plants and convection has been proposed in some small pilot plants. A possible problem with convection is uneven drying rates within the chamber, which would give an inferior product.
  5. Condensation – the previously frozen water in the coffee granules expands to ten times its previous volume. The removal of this water vapor from the chamber is vitally important, making the condenser the most critical and expensive component in a freeze-drying plant.
  6. The freeze-dried granules are removed from the chamber and packaged.Spray drying

Spray drying is preferred to freeze drying in some cases because of its economy, short drying time, usefulness when dealing with such a heat-sensitive product, and the fine, rounded particles it produces.

Spray drying produces spherical particles about 300 micrometres (0.012 in) size with a density of 0.22 g/cm³ (ref 2). To achieve this, nozzle atomization is used. Various ways of nozzle atomization can be used each having its own advantages and disadvantages. High speed rotating wheels operating at speeds of about 20,000 rpm are able to process up to 60,000 pounds (27 tonnes) of solution per hour (ref 3). The use of spray wheels requires that the drying towers have a wide radius to avoid the atomized droplets collecting onto the drying chamber walls.

One drawback with spray drying is that the particles it produces are too fine to be used effectively by the consumer; they must first be either steam-fused in towers similar to spray dryers or by belt agglomeration to produce particles of suitable size.

“Decaffeination”

In commercial processes the decaffeination of instant coffee almost always happens before the critical roasting process which will determine the coffee’s flavour and aroma processes.

Composition

The caffeine content of instant coffee is generally less than that of brewed coffee. One study comparing various home-prepared samples came to the result that regular instant coffee (not decaffeinated) has a median caffeine content of 66 mg per cup (range 30–120 mg per cup), with a median cup size of 225 ml (range 170-290 ml) and a caffeine concentration of 328 µl/ml (range 100-560 µl/ml).In comparison, drip or filter coffee was estimated to have a median caffeine content of 110 mg, with a median concentration of 620 µl/ml for the same cup size.

Regarding antioxidants, the polyphenol content of a 180 ml cup of instant coffee has been estimated to be approximately 320 mg, compared to approximately 400 mg in a cup of brewed coffee of the same size.

Health effects

Compared to overall health effects of coffee, instant coffee appears to be as efficient as filtered coffee in decreasing the risk of diabetes type 2.On the other hand, it has been associated with an increased risk of bladder cancer in women when compared to regular coffee, whereas for men both instant and regular coffee has been associated with an increased bladder cancer risk.[5] However, current review research suggests that there is no dose-response relationship between coffee drinking and bladder cancer, and that previous studies may have been confounded by unidentified risks of bladder cancer.

Instant coffee decreases intestinal iron absorption more than drip coffee. One study estimated that, when a cup of instant coffee was ingested with a meal composed of semipurified ingredients, intestinal absorption was reduced from 5.88% to 0.97%, compared to an absorption of 1.64% with drip coffee. It was also estimated that, when the strength of the instant coffee was doubled, intestinal iron absorption fell to 0.53%.Apparently, however, there is no decrease in iron absorption when instant coffee is consumed 1 hour before a meal, but the same degree of inhibition as with simultaneous ingestion occurs when instant coffee is taken 1 hour after a meal.

Animal experiments have indicated that instant coffee confers no risk related to reproduction, lactation, embryotoxicity or teratogenicity, but possibly a risk of a delay in bone calcification in high doses.

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