Why does lemon juice reduce the “fish” odor of sea food — specifically fish?
$begingroup$
In studying about amines, I read that lemon juice is also used to wash fish because it reacts with the amines on and in the fish to convert the amines to its salt, just reducing the "fishy smell".
I was thinking that it must be the citric acid in lemon juice that somehow reacts with the amines to convert them to their salts.
What is the general chemical reaction of citric acid with amines in fish, and why does this reaction actually reduce the "fishy" smell?
acid-base amines
edited May 13 at 5:50
andselisk♦
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
$endgroup$
add a comment |
$begingroup$
In studying about amines, I read that lemon juice is also used to wash fish because it reacts with the amines on and in the fish to convert the amines to its salt, just reducing the "fishy smell".
I was thinking that it must be the citric acid in lemon juice that somehow reacts with the amines to convert them to their salts.
What is the general chemical reaction of citric acid with amines in fish, and why does this reaction actually reduce the "fishy" smell?
acid-base amines
edited May 13 at 5:50
andselisk♦
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
$endgroup$
5
$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50
add a comment |
$begingroup$
In studying about amines, I read that lemon juice is also used to wash fish because it reacts with the amines on and in the fish to convert the amines to its salt, just reducing the "fishy smell".
I was thinking that it must be the citric acid in lemon juice that somehow reacts with the amines to convert them to their salts.
What is the general chemical reaction of citric acid with amines in fish, and why does this reaction actually reduce the "fishy" smell?
acid-base amines
edited May 13 at 5:50
andselisk♦
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
$endgroup$
In studying about amines, I read that lemon juice is also used to wash fish because it reacts with the amines on and in the fish to convert the amines to its salt, just reducing the "fishy smell".
I was thinking that it must be the citric acid in lemon juice that somehow reacts with the amines to convert them to their salts.
What is the general chemical reaction of citric acid with amines in fish, and why does this reaction actually reduce the "fishy" smell?
acid-base amines
acid-base amines
edited May 13 at 5:50
andselisk♦
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
edited May 13 at 5:50
andselisk♦
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
edited May 13 at 5:50
andselisk♦
20.9k773141
edited May 13 at 5:50
andselisk♦
20.9k773141
edited May 13 at 5:50
andselisk♦
20.9k773141
20.9k773141
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
asked May 13 at 1:22
Winter SoldierWinter Soldier
22417
22417
5
$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50
add a comment |
5
$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50
5
5
$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50
$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50
add a comment |
1 Answer
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oldest
votes
$begingroup$
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains trimethylamine-N-oxide $ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to trimethylamine $ce{(CH3)3N}$,
the source of ammonia-like fish odour.
Trimethylamine N-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure.TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.
TMAO is biosynthesized from trimethylamine, which is derived from choline.
In acidic environment, TMA forms water soluble, non volatile, odourless trimethylammonium salts, what eliminates the volatile smelly trimethylamine. (Similarly as ammonia forms ammonium salts.)
$$ce{(CH3)3N + H+ -> (CH3)3NH+ }$$
Another source of fishy smell/taste, especially of some sweet water species like carp or catfish, is geosmin, a polycyclic alcohol, being a derivate of decahydronaphthalene(decaline). It is released after death of some Streptomyces or cyanobacteria cells which gives a muddy or earthy taste, and the human smell sensors are extremely sensitive to it (5 ppt).
Geosmin is also responsible for smell of the soil after raining, of some beet roots and even of drinking water of surface origin. There is speculation the nose sensitivity for geosmin is a evolutionary response for the need of efficient searching for water.
Geosmin reportedly breaks down in acidic environments.
answered May 13 at 4:56
PoutnikPoutnik
3,056620
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add a comment |
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$begingroup$
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains trimethylamine-N-oxide $ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to trimethylamine $ce{(CH3)3N}$,
the source of ammonia-like fish odour.
Trimethylamine N-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure.TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.
TMAO is biosynthesized from trimethylamine, which is derived from choline.
In acidic environment, TMA forms water soluble, non volatile, odourless trimethylammonium salts, what eliminates the volatile smelly trimethylamine. (Similarly as ammonia forms ammonium salts.)
$$ce{(CH3)3N + H+ -> (CH3)3NH+ }$$
Another source of fishy smell/taste, especially of some sweet water species like carp or catfish, is geosmin, a polycyclic alcohol, being a derivate of decahydronaphthalene(decaline). It is released after death of some Streptomyces or cyanobacteria cells which gives a muddy or earthy taste, and the human smell sensors are extremely sensitive to it (5 ppt).
Geosmin is also responsible for smell of the soil after raining, of some beet roots and even of drinking water of surface origin. There is speculation the nose sensitivity for geosmin is a evolutionary response for the need of efficient searching for water.
Geosmin reportedly breaks down in acidic environments.
answered May 13 at 4:56
PoutnikPoutnik
3,056620
$endgroup$
add a comment |
$begingroup$
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains trimethylamine-N-oxide $ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to trimethylamine $ce{(CH3)3N}$,
the source of ammonia-like fish odour.
Trimethylamine N-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure.TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.
TMAO is biosynthesized from trimethylamine, which is derived from choline.
In acidic environment, TMA forms water soluble, non volatile, odourless trimethylammonium salts, what eliminates the volatile smelly trimethylamine. (Similarly as ammonia forms ammonium salts.)
$$ce{(CH3)3N + H+ -> (CH3)3NH+ }$$
Another source of fishy smell/taste, especially of some sweet water species like carp or catfish, is geosmin, a polycyclic alcohol, being a derivate of decahydronaphthalene(decaline). It is released after death of some Streptomyces or cyanobacteria cells which gives a muddy or earthy taste, and the human smell sensors are extremely sensitive to it (5 ppt).
Geosmin is also responsible for smell of the soil after raining, of some beet roots and even of drinking water of surface origin. There is speculation the nose sensitivity for geosmin is a evolutionary response for the need of efficient searching for water.
Geosmin reportedly breaks down in acidic environments.
answered May 13 at 4:56
PoutnikPoutnik
3,056620
$endgroup$
add a comment |
$begingroup$
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains trimethylamine-N-oxide $ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to trimethylamine $ce{(CH3)3N}$,
the source of ammonia-like fish odour.
Trimethylamine N-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure.TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.
TMAO is biosynthesized from trimethylamine, which is derived from choline.
In acidic environment, TMA forms water soluble, non volatile, odourless trimethylammonium salts, what eliminates the volatile smelly trimethylamine. (Similarly as ammonia forms ammonium salts.)
$$ce{(CH3)3N + H+ -> (CH3)3NH+ }$$
Another source of fishy smell/taste, especially of some sweet water species like carp or catfish, is geosmin, a polycyclic alcohol, being a derivate of decahydronaphthalene(decaline). It is released after death of some Streptomyces or cyanobacteria cells which gives a muddy or earthy taste, and the human smell sensors are extremely sensitive to it (5 ppt).
Geosmin is also responsible for smell of the soil after raining, of some beet roots and even of drinking water of surface origin. There is speculation the nose sensitivity for geosmin is a evolutionary response for the need of efficient searching for water.
Geosmin reportedly breaks down in acidic environments.
answered May 13 at 4:56
PoutnikPoutnik
3,056620
$endgroup$
There are 2 cases, both related to the acid-base reactions. Both are also partial reasons why so many fish recipes use lemon juice.
Fish, especially sea fish, naturally contains trimethylamine-N-oxide $ce{(CH3)3N-O}$,
that after fish death gets enzymatically reduced to trimethylamine $ce{(CH3)3N}$,
the source of ammonia-like fish odour.
Trimethylamine N-oxide is an osmolyte found in saltwater fishes, sharks, rays, molluscs, and crustaceans. It is considered as a protein stabilizer that may serve to counteract urea, the major osmolyte of sharks, skates and rays. It is also higher in deep-sea fishes and crustaceans, where it may counteract the protein-destabilizing effects of pressure.TMAO decomposes to trimethylamine (TMA), which is the main odorant that is characteristic of degrading seafood.
TMAO is biosynthesized from trimethylamine, which is derived from choline.
In acidic environment, TMA forms water soluble, non volatile, odourless trimethylammonium salts, what eliminates the volatile smelly trimethylamine. (Similarly as ammonia forms ammonium salts.)
$$ce{(CH3)3N + H+ -> (CH3)3NH+ }$$
Another source of fishy smell/taste, especially of some sweet water species like carp or catfish, is geosmin, a polycyclic alcohol, being a derivate of decahydronaphthalene(decaline). It is released after death of some Streptomyces or cyanobacteria cells which gives a muddy or earthy taste, and the human smell sensors are extremely sensitive to it (5 ppt).
Geosmin is also responsible for smell of the soil after raining, of some beet roots and even of drinking water of surface origin. There is speculation the nose sensitivity for geosmin is a evolutionary response for the need of efficient searching for water.
Geosmin reportedly breaks down in acidic environments.
answered May 13 at 4:56
PoutnikPoutnik
3,056620
edited May 14 at 14:53
answered May 13 at 4:56
PoutnikPoutnik
3,056620
answered May 13 at 4:56
PoutnikPoutnik
3,056620
answered May 13 at 4:56
PoutnikPoutnik
3,056620
3,056620
add a comment |
add a comment |
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$begingroup$
It's all about an acid-base reaction: amines are basic. And the amines found in fish are quite volatile. Addition of acid forms non-volatile salts (eg: aminium citrates)
$endgroup$
– The_Vinz
May 13 at 1:50