The importance of sulphur

Sulphur is an essential component of all living cells. Sulphur is a major inorganic element with biological importance across species. Found in protein molecules in muscles, hair, eyes, brain and other organs. It is abundant in human body and makes up about a quarter of a percentage of human weight.

Sulphur has an atomic weight 32.064, an atomic number of 16, and is represented by the chemical symbol “S”.

Sulphur is found in insulin and thus helps to regulate the metabolism of sugar. It assists in maintenance of oxygen balance necessary for brain function.

Most of the dietary sulphur is provided by the sulfur-containing amino acids methionine and cysteine, with an estimated requirement for young men of ~14 mg/day per kg body weight. Although cysteine is not an essential amino acid, it can be synthesized only from methionine, and it is conventional to consider the sum of methionine plus cysteine (the sulphur amino acids) in consideration of protein quality.

Proteins contain between 3 and 6% of sulfur amino acids. A very small percentage of sulfur comes in the form of inorganic sulfates and other forms of organic sulfur present in foods such as garlic, onion, broccoli, etc.

Allicin is a sulphur-containing compound (diallyl thiosulphinate; thio-2-propene-L-sulfinic acid-5-allyl ester), partially responsible for the flavor of garlic. Formed by the action of allinase on alliin (S-(2-propenyl)-L-cysteine sulphoxide) when the cells are disrupted, releasing the enzyme to act on the substrate. It has antibacterial properties.

Sulphur intake is directly correlational to protein intake source. Chicken, fish and beef proteins contain about 5% of sulphur -containing amino ccid. Dairy products contain around 4% because of casein’s lower sulphur -containing amino acid content.
The importance of sulphur

Methionine structural formula

Sulfur dioxide as food additive

Sulfur dioxide has been used since olden times in the form of 1-2% aqueous solutions as a disinfectant for equipment, barrels, bottles, corks and other ancillary items for the wine, drinks and food industries.

Fumes of burning sulfur were used as a sanitizing agent in wine-making by the ancient Egyptians and Romans. The practice is continued by the modern wine industry.

The compound is a colorless, nonflammable gas or liquid under pressure, with a suffocating, pungent odor.

Sulfur dioxide is used to prevent browning in certain dried fruits and to prevent wild yeast growth in wines used to make vinegar.

Sulfur dioxide also is used to control the growth of undesirable microorganism in soft fruits, fruit juices, wines, sausages, fresh shrimp, and acid pickles and using extraction of starches.

It is added to expressed grape juices used for making wines to inhibit molds, bacteria, and undesirable yeasts.

The most obvious drawback of sulfur dioxide is its intense pungent odor, which may be apparent in foods it is used to treat.
Sulfur dioxide as food additive

Methionine

Methionine, is a sulfur containing amino acid that is essential for human and animal nutrition. It is required for DNA-RNA structure, collagen and each cell’s protein syntheses function.

It has relatively low profile and is not present in high concentrations throughout the body.

Methionine is a nonpolar amino acid. Like other hydrophobic amino acids, it can play a role in binding or recognition of hydrophobic ligands such as lipids.

It is the most abundant sulfur containing amino acid and the principal supplier of sulfur to man and animals.

Methionine helps remove heavy metals from the tissues. For example, lead is one heavy metal which causes brain damage.

It helps in the breakdown of fat, thus helping ro prevent a buildup of fat in the liver and arteries that might obstruct blood flow to the brain, heart and kidney.

Methionine high sulfur content helps supply the body with the acidity it needs to stave off chronic disease states that may result when the body’s alkaline to acid is too high.

This amino acid helps the digestive system; helps to detoxify harmful agents such as lead and other heavy metals; helps diminish muscle weakness, prevent brittle hair and protect against radiation and it beneficial for people with osteoporosis or chemical allergies.

Methionine

Sulfur in amino acids

Sulfur is present in amino acids such as methionine, taurine, cysteine and cysteine. Except for methionine, all the sulfur rich amino acids can be synthesized by the body from methionine and sulfur.

There are two major source of human dietary sulfur containing amino acids. One them is L-cysteine, a sulfur containing amino acid with the thiol side-chain, which is involved in metal-binding in proteins.

L-methionine is another proteic amino acid that possesses sulfur in its molecule.

From L-cysteine and L-methionine the body builds the essential compounds coenzyme A, heparin, glutathione, lipoic acid and biotin.

The disulfide bonds of the sulfur containing amino acids are largely responsible or determining the tertiary structure of proteins.

Cystine 

Cystine is the stable form of the sulfur rich amino cysteine. The body is capable of converting one of the other as required.

The sulfur in cysteine molecules plays a crucial role in folding proteins into their correct shapes. For examples sulfur independent proteins are keratin – part of hair, skin and nails and collagen – part of connective tissue like cartilage.

Methionine 

Methionine, an essential amino acid, is an important source of sulfur. It is required for DNA-RNA structure, collagen and each cell’s protein syntheses function.

Methionine helps remove heavy metals from the tissues. For example, lead is one heavy metal which causes brain damage.

It helps to control fat levels in the blood and aids in preventing the buildup of cholesterol on the artery walls.

Sulfur in amino acids

Amino acid cysteine

Cysteine is found extensively in the plant foods human ingest. It is found plentifully in the grasses and thus in the meat of domesticated grazing animals.

Cysteine takes its name from cystine, named after the Greek kustis meaning bladder – cystine was first isolated for kidney stones.

Cystine is the stable form of the sulfur rich amino cysteine. The body is capable of converting one of the other as required.

The sulfur in cysteine molecules plays a crucial role in folding proteins into their correct shapes. For examples sulfur independent proteins are keratin – part of hair, skin and nails and collagen – part of connective tissue like cartilage.

Though sulfur itself does not improve nail growth it was found that cystine may have a positive effect on the growth of hypnochium cells.

The amino acid contains a sulfur group that help to function as antioxidant. Cysteine also can be combined with glutamic acid and glycine in liver cells to form glutathione, which is a principle water soluble antioxidant in cells and the blood.

The human body synthesizes the amino acid cysteine for homocysteine and it is part of human hair, skin and nails as the protein keratin.

Cysteine can be found in red pepper, garlic, onions, broccoli, brussel sprouts, oats and wheat germ.

Amino acid cysteine