Pectin is produced in an extraction process under acidic conditions. The peel is separated from the pectin and the protopectin present in the fruit is extracted by hydrolysis in an aqueous solution. After a filtration and clarification process, the pectin syrup is precipitated and isolated. A horizontal vacuum dryer from BHS is used for the subsequent drying step.
Stripping and contact drying
The cleaned pectin fibers are fed into the BHS vacuum dryer and heated by its jacket to evaporate alcohol and water. The BHS technology reduces the alcohol content (IPA) to less than 0.1% and the water content to less than 10%. The low alcohol content of 0.1% is achieved through an additional stripping process in which steam is injected into the product area via several nozzles. The alcohol-saturated vapors are led out of the product area via a vapour filter and separated in a condenser.
The drying process is made extremely difficult by the fibers of the pectin, as these tend to gel. Fast-rotating knives - so-called choppers - dissolve these fiber bonds and effectively support the drying process. This achieves short drying times of around three hours before the product is gravimetrically discharged into big bags.