FOOD APPLICATIONS

Pectin is first and foremost a gelling agent used to impart a gelled texture to foods, mainly fruit based foods. the gelling ability is further utilized where stabilization of multiphase foods is required, either in the final product or at an intermediate stage in the process.

The thickening effect of pectin is utilized mainly where food regulations prevent the use of cheaper gums or where the "all natural" image of a product is essential.

Jams and Jellies

HM-pectin requires 55-85% sugar and pH 2.5-3.8 in order to gel. These requirements limit the possible uses of HM-pectin as a gelling agent to sweetened fruit products and about 80% of the world production of HM-pectin is used in the manufacture of jams and jellies, the pectin being added to make up for "deficiency of natural pectins."

The role of pectin is to impart a texture to the jam or jelly that allows transportation without changes, that gives a good flavor release and that minimizes syneresis. during manufacture of a jam the pectin must ensure a uniform distribution of fruit particles in the continuous jelly phase from the moment the mechanical stirring ceases, i.e. the pectin must set quickly after the filling operation. The use concentrations for pectin vary from 0.1-0.4% in jams and jellies.

Pectin gelation can be obtained in a cold process by mixing a pectin-sugar-syrup with soluble solids 60-65% and pH 3.8-4.2 with fruit acid solution to achieve pH 3.0. This process is used in Scandinavia by the bakers to make jelly-covered fruit tarts. A variation of the technique is mixing a pectin solution with pH 2.9 and soluble solids 25% with a liquid sugar to obtain soluble solids 53%.

These two processes can be used as a result of gelation of HM-pectin being time, as well as temperature. dependent.

The traditional application of LM-pectin is in jams with soluble solids below 55%, which is the limit for the use of HM-pectin. The calcium content of the fruit is normally sufficient to set an amidated LM-pectin, whereas acid demethylated LM-pectin requires addition of a calcium salt. The type of LM-pectin must be carefully selected according to the soluble solids/pH conditions in the application medium. In products with very low solids, as for instance sugar-free jams for diabetics, LM-pectin hardly has sufficient water binding and a carrageenan is better suited. In some instances combinations of LM-pectin and carrageenan offer advantages.

The heat reversibility of LM-pectin gels may be utilized in bakery jams and jellies for glazing purposes. A jam or jelly base with soluble solids of approx. 65% has a relatively good microbiological sterility, but the LM-pectin only imparts a paste-like texture to the product, due to pregelation. Prior to application, the base is diluted with water to approx. 40% solids and heated to remelt the LM-pectin gel. When poured on top of cakes and tarts, the LM-pectin gels optimally at the reduced solids to form a coherent and glossy glazing.

Fruit preparations for yogurt

Low ester pectins are often used in fruit preparations for yogurt to create a soft, partly thixotropic gel texture, sufficiently firm to ensure uniform fruit distribution but still allowing the fruit preparation to be easily stirred into the yogurt. The pectin may further - especially when combined with other plant gums - reduce color migration into the yogurt phase of the final product.

Fruit drink concentrates

Gelation of pectin may be used as a means of stabilizing a multiphase system if gelling conditions can be achieved at some stage in the process. Gelation provides the yield value which is required to obtain permanent stabilization of emulsions, suspensions and foams. HM-pectin is used in fruit drink concentrates, stabilizing any oil emulsions and fruit particle suspensions. In this application the gelation is apparent in the end product only as a thickening effect, as the coherent gel texture has been broken mechanically to obtain a smooth flow. Extensive homogenization must not be used, as sufficient yield value must still be present to ensure stabilization.

Fruit juice

The viscosity or mouthfeel creating properties of HM-pectin find use in recombined juice products to restore the mouthfeel of the juice to that of the fresh juice. Pectin is further used to provide a natural mouthfeel in instant fruit drink powders.

Fruit/milk desserts

The calcium response of LM-pectin may be utilized to obtain an instant gelation when adding calcium ions (milk) to a syrup containing LM-pectin. A canned fruit preparation containing 2% LM-pectin in a fruit syrup with 25-30% soluble solids and pH 4.0 is mixed with an equal amount of cold milk to quickly make a fruit flavored semi-gelled milk dessert.

LM-pectin has excellent stability at the conditions of fruit preparation manufacture, i.e. pH 4.0 and suitable pasteurization conditions. The LM-pectin solution remains fluid at room temperature as calcium content is insufficient to cause gelation. When the fruit preparation is mixed with milk, sufficient calcium is available to gel the LM-pectin.

Another version of this basic idea is a concentrated, sweetened and flavored LM-pectin solution, a paste to be mixed into three parts of cold milk. The ‘intermediate moisture food' properties of this concept imply a wider pH-range allowing vanilla or chocolate flavoring to be used.

A third versions is a powder to be dissolved in cold water prior to addition of milk.

Fermented and directly acidified dairy products

The ‘protective colloid' effect of HM-pectin is utilized to stabilize sour milk products either cultured or produced by direct acidification (fruit juice-milk combinations).

The pectin reacts with the casein, prevents the aggregation of casein particles at pH below the isoelectric pH (4.6) and allows pasteurization of the sour milk products to extend their shelf life.

The texture of yogurt may be improved by small amounts of LM-pectin which is added before the yogurt milk is heated. The LM-pectin does not prevent syneresis.

Gelled milk products

M-pectin is suited as a gelling agent in milk desserts, but less economical in use than carrageenan, which gels milk a much lower use concentrations.

LM-pectin may, however, be preferred as gelling agent for sour milk puddings or milk desserts combined with fruit. Unlike carrageenan, LM-pectin does not co-precipitate with casein at reduced pH-values and thus ensures a reasonable shelf life of the product.

Confectionery products

High ester pectin is mainly used within the confectionery industry for making fruit jellies and jelly centers, flavored with natural fruit constituents and/or synthetic flavors. In combination with whipping agents it is further used as a texturizer for aerated fruit flavored products.

Low ester pectin not requiring addition of acid for gel formation is used for jellies and centers in which the low pH-range necessary for HM-pectin gelation is not acceptable for flavor reasons (e.g. peppermint or cinnamon flavored jellies).

At low concentrations, LM-pectin may further impart a thixotropic texture to confectionery fillings. At higher concentrations a cold gelation can be obtained if calcium ions are allowed to diffuse into the filling.

Compared to other gelling agents commonly used for confectionery products, pectin requires strict observance of the recipe and production parameters, but offers the advantage of a very fine texture and mouthfeel, excellent flavor release and compatibility with modern continuous processing due to a fast and controllable gelation.

PHARMACEUTICAL APPLICATIONS

The ability of pectin to add viscosity and stabilize emulsions and suspensions is utilized in a number of liquid pharmaceutical preparations.

Pectin is further reported to possess a number of valuable biological effects - the most well-known being an anti-diarrhea effect. Anti-diarrhea suspensions, powders or tablets often contain a mixture of kaolin, pectin and a antibiotic.

Pectin is extensively used as a component in the adhesive part of ostomy rings. In this application the water binding effect and the ability to adhere to moist surfaces are utilized. Pectin is further non-irritating in contact with the skin, and certain bactericidal and wound healing effects have even been reported.