Potato waste could produce new food ingredients

Danish researchers have developed a new method, which uses potato waste for the extraction of rhamnogalacturonan I (RG-I), a pectic polysaccharide, that could be used to produce new ingredients and functional hydrocolloids.

Although previous research has shown that potato fibre is rich in RG-I, it cannot be isolated by traditional industrial extraction procedures as they are often performed at a low pH level, causing degradation of the RG-I molecule, foodnavigator.com reported.

In order to extract RG-I, researchers subjected industrial potato waste to enzymatic starch removal using purified termamyl, enzymatic RG I solubilisation using a highly purified polygalacturonase, and finally purification using depth filtration and ultrafiltration.

The RG-I extracted via the new method was found to be in its native, intact form, and had high molecular weight and a monosaccharide composition comparable to RG-I extracted by analytical laboratory extraction procedures.

None of the functional properties of RG-I were lost, making it more suitable for further modifications and tailoring to suit specific desired pectic properties, such as stabilising and gelling capabilities, and as a viscosity aid, among others.

The research was conducted by a team led by Peter Ulvskov at the University of Copenhagen, Denmark.