Pectin found in the main cell wall of all plants is basically a structural heteropolysaccharide (any polysaccharide formed from two or more different kinds of monosaccharide). Commercial production of pectin is generally done by means of extracting the peel of the citrus fruits which is later dehydrated to a powdery form having a white to pale brown color. Pectin has a number of uses in the food processing industry. It is made use of in food as a coagulating agent, especially in jams and jellies. In addition, pectin is also used in fillings, sweets, as preservatives in fruit juices and milk drinks as well as a natural resource of nutritional fiber.
Pectin is basically used as a condensing agent in cookery and is regarded as one of the most natural variety of edible coagulators available today. It is interesting to note that the pectin that was initially available in the market was actually obtained from apples and not citrus fruits. In addition to the citrus fruits and apples, other fruits that enclosed this gelling agent included several varieties of pears and plums. In fact, apples are very rich in pectin content, French chemist and pharmacist Henri Braconnot was the first to discover and recognize the properties of pectin. Soon after the discovery of the features of pectin by Henri Braconnot, there was a rush among numerous businessmen interested in production of pectin commercially to sign contracts with the apple juice manufacturers with a view to acquire the residues of the pressed apples, called pomace. In those days, pomace was mainly available in a liquid form.
Pectin constitutes a compound collection of polysaccharides in plant cells and is found in the majority of major cell walls and especially in profusion in all non-woody terrestrial plants. Pectin is found all through the primary cell walls and also in the middle lamella (a term for a plate like structure and appearing in multiples) between the plant cells where its primary function is to bind these cells together.
The quantity, arrangement as well as the chemical constitution of the pectin varies among different plants, inside a plant in the fullness of time and also in the different parts of a plant. When the fruits ripen or mature, the pectin contained in them is split or separated by two enzymes – pectinase and pectinesterase. This process, in turn, makes the fruits softer as the middle lamella of the fruit cells break down and they become detached from one another. A comparable process of cell separation induced by the break down of pectin takes place in the abscission zone (also called a separation zone) of the petioles of deciduous plant at the time of shedding their leaves.
It is important to mention here that although pectin forms a normal component of human diet, it does not have any noteworthy nutritional input. On an average, an individual’s daily ingestion of pectin from fruits and vegetable is very insignificant and is projected to be approximately 5 gram. This assumption is made on the basis of the fact that an individual eats around 500 grams fruits and vegetables every day. In the digestive process in humans, the pectin passes through the small intestine relatively unchanged. Hence, pectin is considered to be a soluble dietary fiber.
It has been found that eating fruits and vegetables rich in pectin content has helped to lower the intensity of cholesterol in blood. According to scientists, consumption of pectin augments the thickness in the intestinal tract and this causes lesser absorption of cholesterol from bile or other ingested foodstuff. On the other hand, microorganism present in the large intestine and colon break down pectin and free the short-chain fatty acids that have an encouraging impact on our health.
As discussed earlier, the major raw materials for manufacturing pectin include dried citrus peel and/ or apple pomace. Incidentally, the citrus peel as well as the apple pomace is both by-products in the process of producing these fruit juices. There are some manufacturers who even produce pectin from
sugar–beet pomace. However, the quantity of pectin produced from the last raw material is too insignificant.
Pectin is extracted from the above mentioned raw materials by adding hot watered down acid at pH values ranging between 1.5 and 3.5. The extraction process continues for a number of hours during which the protopectin gives up a few of its branching and chain-length and turns into a solution. After the solution is strained, the extract obtained from the raw materials is thickened in vacuum and after that the pectin is produced following the addition of either isopropanol or ethanol. Earlier, manufacturers used a method whereby pectin was precipitated with aluminum salts, but this technique is no longer in use.
After precipitating pectin using alcohol, pectin is later on separated, washed and dehydrated. When you treat the preliminary pectin with watered down/ dilute acid, it results in low esterified pectins. However, when this technique involves ammonium hydroxide, you are able to obtain amidated pectins. Pectin is normally homogenized with sugar and at time with calcium salts or even organic acids after drying and milling with a view to obtain the best performance in a specific application.
As discussed earlier, the primary use for pectin is in the food processing industry. It is used as a gelling agent, coagulating agent as well as a preservative in foods. Traditionally, pectin has been used to provide a jelly-like stability to jams or marmalades, if not these items would be similar to sweet juices. For domestic purposes, pectin is used as an element to crystallize sugar in cases where it is watered down to the proper concentration with sugar and a number of citric acid to regulate the pH. In fact, often you will find a product called ‘sugar with pectin’ in the market. In a number of countries, pectin is also sold in the market as a solution, an extract or even a blended powder for the purpose of preparing jams at home. It may be noted that usually high-ester pectins are used in the manufacture of traditional jams and marmalades enclosing more than 60 per cent sugar and other fruit solids that are soluble. On the other hand, diet products are usually made with low-ester pectins and amidated pectins that require less quantity of sugar. Pectin is also used to preserve acidic protein drinks, like drinking yogurt, and as an alternative of fat in many baked foods. The normal levels or proportion of pectin used as additives in edible matters range between 0.5 per cent and 1.0 per cent, which is approximately the same quantity of pectin present in fresh fruits.
Pectin also has a number of therapeutic uses. As pectin enhances the thickness as well as volume of stool, in medicine it is use to treat constipation and diarrhea. Along with kaolinite, pectin continued to be a major element used in Kaopectate till 2002. The demulcent feature of pectin has made it a valuable ingredient of many throat lozenges. In addition, pectin also finds widespread use in preparations for healing wounds and in the manufacture of special medical adhesives, for instance, colostomy devices. Pectin is also extensively used in the cosmetic industry, where it is basically made use of as a stabilizer.
Apart from the usefulness of pectin in the human food processing, it also serves as a nutrient in cattle fodder. As far as the cattle food is concerned, about 90 per cent of pectin is digestible by bacterial enzymes depending on the degree of deposits of lignin on the plant cell walls. Cattle food specialists suggest that it is possible to enhance digestibility as well as energy concentration by means of augmentation in the fodder.
It is interesting to note that pectin is also used in the cigar industry where it is regarded as a superb alternative for vegetable glue. Hence, it is not uncommon to find many cigar smokers as well as collectors using pectin to mend the broken tobacco covering leaves on their cigars.
Apart from what has been discussed earlier, pectin has numerous uses in protecting our body and ensuring a sound health. In fact, pectin has the capacity to reduce serum cholesterol, especially low density lipoprotein (LDL) cholesterol, enhance the resistance of insulin and to help in getting respite from diarrhea. In addition, pectin also functions as a detoxifying agent, helps in regulating as well as protecting the gastrointestinal tract, invigorates the immune system, and also functions as an anti-ulcer agent and is also antinephrotic and hence often used in the treatment of kidney diseases. Pectin along with other dietary fiber elements plays a crucial role in avoiding a spill over of the glucose levels in blood by means of supporting satiation and also most likely by lowering the absorption of glucose after ingestion of glycaemic carbohydrate. Hence, ingestion of pectin is considered to be beneficial for people suffering from diabetes. Ingestion of pectin is also said to be effective in lessening heart ailments as well as gallstones.
Findings of quite a number of researches have shown considerable decline in serum cholesterol, low density lipoprotein (LDL) cholesterol and augmentation or no alteration in the high density lipoprotein (HDL) cholesterol among people who have been taking their food along with pectin enhancements or fruits and vegetables, such as apples and carrots, which are high in pectin content. It may be noted here that scientists are of the view that the advantage of pectin in reducing serum cholesterol is possibly because of its function in augmenting fecal fat, fecal cholesterol, bile acids or sterols.
It has often been seen that diets enclosing pectin included in a food source, such as citrus fruits, seem to be accepted more favorably by our body that permits ingestion of more quantities of such foods in comparison to consumption of pectin in the powder or capsule forms.
Before concluding, it is worth mentioning that conventionally people have been extensively using pectin derived from Panax ginseng for its properties to heal wounds.