Potato is more sustainable source of protein than rivals

The potato could emerge as a serious player in the nutritional ingredients market and as a "far more sustainable" source of protein than many of its rivals, according to researchers gathered in Amsterdam for a seminar on the merits of vegetable vs animal protein.

The event was organised by starch giant Avebe, which has set up a subsidiary called Solanic to extract highly functional proteins from potato juice using mild separation technology (instead of the traditional heat- coagulation method).

While potato protein had the clean-label status, low allergenicity and functionality (gelation, foaming, emulsification) enabling it to give soy, eggs and milk proteins a run for their money, it also had exciting potential in gut health and weight management, said Dr Gertjan Schaafsma, a professor in nutrition and food science at Wageningen University.

Not only did potato protein stimulate the release of the appetite regulating hormone CCK, it also reduced plasma triglycerides, improved glucose homeostasis and helped preserve lean body mass, he said. It also stimulated the production of beneficial mucous lining the colon and had anti-inflammatory effects, owing to bioactives such as glutathione, taurine, threonine and glutamine, which were synthesised from amino acids in potato proteins, he added: "This is a promising area that should be explored further."

Despite the fact that the percentage of protein in potato was low, the amount it yielded per hectare was higher than rival sources, said Solanic: "Per hectare, you get 500-1,000kg of potato protein, versus 164-500kg of soy protein, 98-300kg of wheat protein and just 33kg of milk protein."

With respect to solubility, potato protein also had an advantage over soy at the slightly acidic pH typical of many food products, said professor Harry Gruppen, also from Wageningen University. “The full potential of potato protein has hardly been exploited.”

Solanic director Frank Goovaerts, who is talking to more than 150 potential customers about using the potato proteins, said they had superior functionality to other vegetable proteins and comparable or better functionality than animal proteins.

When the plant became fully operational in the autumn, three fractions would be available in liquid and dry formats, he said. “However, we could have 20 different fractions in five years’ time. It depends what customers want.”

The Solanic plant, which will be capable of producing more than 10,000t a year of proteins from the waste products of potato starch production, is the world’s largest industrial chromatography installation.