Pectin, an acidic polysaccharide occurring in the cell walls of a fruit, is a popular food additive for gelling, thickening and stabilizing. It is also widely used in the cosmetics industry in the manufacture of oils and creams, paints, toothpaste and shampoos, and in the manufacture of wound healing preparations and gel caps for the pharmaceutical industry as it has excellent water binding and gel forming properties even at low concentrations. Pectin market has an annual growth of about 6 % driven by the rising demand for functional foods products, which translates into expanded market for hydrocolloids, as well as increasing use by the cosmetic and pharmaceutical industry.
The major sources of pectin are citrus peels, the waste from extraction of lemon and orange juices, and apple pomace, the dry residue from the extraction of apple juice. Therefore, pectin is a by-product of either cider or juice production.
Although there are various alternative processes, most pectin is produced by the extraction from the raw material with hot aqueous mineral water. The process is known as acid hydrolysis and the most commonly used acid is hydrochloric acid (HCl). The acid hydrolysis results in a slurry containing a solid residue which is easily separated by filtration or centrifugation. After a concentrating step, the concentrated extract is treated to isolate the pectin, most commonly mixed with organic solvent.
The K-Patents Sanitary Process Refractometer PR-43-A is used to measure continuously the concentration of the liquid pectin extract to ensure optimum control and the highest product quality. A refractometer after the concentration step monitors that the target concentration of pectin extract is constantly achieved. The refractometer’s output signal can be used for automated control of the concentration step, and consequently for optimizing energy consumption and alcohol usage in the following precipitation step.
Application Note ref. 2.12.02 Pectin Extraction and Evaporation (PDF)