Pectin is a complex sugar molecule present in the plant cell wall. This compound is mainly composed of alpha-d-galacturonic acid; some of its acidic groups have been esterified with methanol. Sugars and other uronids often contain up to 20% of pectin.
Pectin is divided into two types of HMP with a degree of esterification above 50% and LMP with a degree of esterification below 50%.
The degree of esterification is a key factor in the rheological and physicochemical properties of pectin. The ability of pectin to form a gel depends on its degree of esterification. On the other hand, higher amounts of galacturonic acid show high purity.
High-ester or conventional pectin requires 65-70% sugar and 0.2 to 1.5% pectin and pH between 2.8 and 3.4 to form the gel. This pectin does not give a gel above pH 3.5. But at pH below 2.8 the gel is formed only at high temperatures.

Rapid Set Pectin
These pectins are esterified above 70% and form gels in hot temperatures (80 ℃). The optimum pH of their gel formation is 3 to 3.4.

Slow Set Pectin
The degree of esterification of these pectins is between 50 and 70%. The proper pH for them to form gel is 2.8 to 3.2. They should first be cooled to 50 and then gel forms. The gel strength of these pectins depends on the degree of esterification.

Low-ester pectins:
The degree of esterification of this group of pectins is less than 50% and as a result of controlled desterification, high-ester pectins are produced.
The pectins of this group do not require sugar or acid to form gels, they are used in the preparation of dietary jams and form in the pH range of 2.5 to 6.5.
The gel formation is similar to that of the high-ester gel, but the viscosity of the gel is lower than that of the high-ester pectin.

Pectin Application:

  • Gelling agent in vegetable jelly without animal gelatin
  • Pectin as a gelling agent in dietary jams
  • Pectin as a filler and stabilizer in pastries
  • Pectin as a stabilizer in the ice cream stabilizer combination
  • Pectin as a stabilizer of yogurt to prevent two-phase yogurt
  • Products containing low methoxyl pectin have been used to treat gastric and duodenal ulcers.
  • Pectin is used as an emulsifying agent in water emulsions in oil.
  • Pectins reduce blood cholesterol.