Classification of dietary fibers

Dietary fibers are the indigestible portion of plant foods. Dietary fibers can be classified according to the degree of water solubility. There are two types of dietary fibers;

1. Water-soluble fibers, such as pectin and gums
2. Water-insoluble fibers, such as cellulose and hemicellulose

Pectin

Pectin is a structural heteropolysaccharide which is found in cell walls of plant cells. Common sources of pectin are Apples, guavas, quince, plums, gooseberries, oranges and other citrus fruits. The main use for pectin (vegetable agglutinate) is as a gelling agent, thickening agent and stabilizer in food.

Gums

Gum is a polysaccharide. Gum is useful as thickening agents, gelling agents, emulsifying agents, and stabilizers.

Cellulose

Cellulose is polysaccharide which is found in cell wall of plant cells. It is mainly used to produce paperboard and paper.

Hemicellulose

A hemicellulose is any of several heteropolymerssuch as arabinoxylans, present along with cellulose in almost all plant cell walls.


there are several ways of classifying the dietary fibers such as;

Chemical classification

1. Simple polysaccharides (cellulose)
2. Complex polysaccharides (Lignin, cutin)

Classification according to the physical properties

1. Water soluble Fibers(Cllulose)
2. Non-soluble fibers (Cutin)

The macromolecular constituents of plant cell wall material fall into 3 groups;

1. The fibrillar polysaccharides (cellulose)
2. The matrix polysaccharides ( hemicelluloses, glycoproteins)
3. The encrusting polysaccharides (lignin)

IMPORTANCE OF DIETARY FIBERS

Biosensors in cancer detection

A biosensor is a device for the detection of an analyte that combines a biological component with a physicochemical detector component. It should be able to convert a biological response into an electrical signal.

Development of biosensors to detect cancers is a developing in modern day. There are several biosensors tested for this purpose and results are very encouraging.

Cancer is a malignant tumor of potentially unlimited growth that expands locally by invasion and systemically by metastasis. Cancer can produce various substances. These substances can be used as markers to detect the cancer. There can be gene mutation which leads the production of cancer. Detection of these mutant genes is a way of detecting the cancers. Biosensors will play a big role in this detecting process.

Eg. Lectin-Based Biosensors are used to detect lung, liver and prostate cancers. These cancers produce a glycan called sialic acid. Lectin-Based Biosensor is used to detect this sialic acid.

Sgot sgpt ratio

Sgot and sgpt are liver enzymes. Measurement of blood levels of these enzymes provide valuable information regarding the state of one’s liver. Individual values of these enzymes are important and ratio between these two enzymes provides additional information. Most important aspect of the sgot sgpt ratio is that it gives a clue for the cause of the liver disease. Followings are few examples:

1. SGOT/SGPT ratio for alcoholic hepatitis and cirrhosis 2.85 +/- 0.2
2. SGOT/SGPT ratio for postnecrotic liver cirrhosis 1.74 +/- 0.2
3. SGOT/SGPT ratio for chronic hepatitis 1.3 +/- 0.17
4. SGOT/SGPT ratio for obstructive jaundice 0.81 +/- 0.06

Interpretation of these values should be done with the clinical history of the patients. An SGOT/SGPT ratio greater than 2 is highly suggestive of alcoholic hepatitis and cirrhosis