Entering the hall of the Dutch potato cooperative AVEBE, one’s attention is immediately drawn to a large pane of stained glass, showing all products once produced from the potato, one hundred years ago. Building and pane belonged to ScholtenHonig, later acquired by AVEBE. Most side products have vanished over the years – often because of competition from cheaper petroleum based alternatives. But they might return, all of them, in the biobased economy.
For some time, AVEBE has successfully isolated potato proteins at low temperature, producing substances worth more per ton than the starch (see our interview with Marco Giuseppin). It is a promising development. And after the proteins comes the potato juice, the fraction without starch and with less proteins. AVEBE now looks for innovators for subsequent processing of this potato juice. It has published a special leaflet to draw the world’s attention to the potential value of this juice.
Upon evaporation, potato juice produces a kind of molasses, sold under the name of Protamylasse. ‘The amount of energy used to produce Protamylasse does not suit the sustainable company that AVEBE aims to be,’ says the leaflet. ‘We value being environmentally responsible. In addition to that, Protamylasse contains much more value than presently realised. Therefore, we are looking for partners that would like to invest with us to valorise potato juice to its inherent value.’
What does potato juice contain? It contains 2.5% of the potato’s solid fraction. Major components include: amino acids and organic acids (e.g. citric acid), minerals like potassium, and vitamins. ‘The potato juice contains all components required for growth,’ the leaflet continues; ‘when left to its own, lactic acid fermentation takes place spontaneously.’
An important class of compounds is that of the glycoalkaloids, substances specifically produced by the night shade family. These compounds are toxic, and they might be used for producing pesticides. Another product, available in large quantities from the juice, is the amino acid asparaginine. The company’s potato juice contains a yearly yield of 3.000 tons, whereas yearly world demand equals 5.000 tons. At present, the company has no way to valorise these substances. So far, talks with other companies have been unsuccessful.
‘Each year, AVEBE processes some 2 million tons of potatoes,’ the leaflet ends. ‘We are looking for partners that would fit precisely into this scale of production. Partners that could help us in valorising these streams, and in marketing the ensuing ‘new products’ as well. Of course, at AVEBE we have all the skills needed to process diluted streams.’ Innovators, step forward!