The pectin process from GEA Westfalia Separator provides today’s producers with an extraction process which is as gentle on the product as it is efficient.
Pectin (from the Greek “pektos” = gel) occurs in all higher terrestrial plants. Citrus fruits occupy a special position, as they have an unusually high concentration of pectin substances in the flavedo and albedo (about 25 percent moist mass of the whole citrus fruit). The pectin obtained from the citrus peel is used mainly as a setting agent in the food industry, but also for pharmaceutical and cosmetic products. Global production of pure pectin is estimated at approx. 35,000 tons of which 70 percent comes from citrus peel.
Following a special initial treatment of the fresh peel and storage in mechanized silos, the dried peel is milled and fed into the extraction process. The pectins are extracted by a variety of acids with a pH-value of 1 to 3, at a temperature between 65 ºC and 85 ºC and for an extraction period of 0.5 to 6 hours. Extraction delivers a raw extract with 0.3 to 1 percent pectin. Separating this viscous solution from the heavily swollen and in some cases disintegrated pomace cake is the key technical problem in the pectin industry.
In the pectin process from GEA Westfalia Separator shown in the flow chart, this task is managed by combining a number of decanters and a filter press. The extract then runs through the separator and precoat filtration before the pectin is precipitated using isopropanol. The excess precipitant is then separated by a gas-tight decanter until only dry pure citrus pectin with good storage properties remains.