Spuds go for intensive care
In 2002, the kitchen at St Olav´s Hospital joined the national pilot scheme ‘Organic food in hospitals´, run by the research institute Bioforsk. A hospital consumer survey revealed that people were not satisfied with the potatoes that were served at the hospital. We decided to investigate whether introducing organic potatoes could be a means to improve potato quality and patient satisfaction.
Casualties arriving battered and bruised
A processing firm called Farmers based locally in Trondheim delivers all potatoes to the hospital kitchen. This firm was happy to supply organic certified potatoes from local producers as long as the excess costs were covered by the customer. We started a test production of organic potatoes which clearly showed big variations in quality. The most serious problem was darkening and discolouration of the potatoes after peeling and cooking.
During conventional production one would add sodium-bisulphite to the water in which peeled potatoes are stored. This hinders discolouration of raw and cooked potatoes but is not acceptable practice in organic production. A novel solution to this problem was required.
Excessive waste in the form of peel proved another problem related to the use of organic potatoes. The amount of waste varied widely between varieties and between batches brought to the processing unit. The relatively high price of organic potatoes made it particularly important to reduce the losses incurred during peeling.
By virtue of its good taste and strong resistance to potato blight, Troll is the dominant variety of organic potato produced in Norway. It was therefore a great surprise to the farmers to learn that this particular variety performed poorly in our test production in terms of excessive waste during peeling and susceptibility to discolouration.
An additional challenge facing farmers was that the processing unit was used to sourcing conventional potatoes at very low prices. This resulted in a wide gap between what the producers expected to receive for their organic potatoes and what the processor was willing to pay. The hospital catering manager stressed that since potatoes rarely contribute much the total cost of a meal, it was more important to him to strive for higher quality and secure patients satisfaction rather than the lowest price available.
Gases, warmth and love
Enzymatic discoloration of potatoes is caused by the oxidation of natural phenol substances. The oxidation is promoted by the polyphenol oxidiase (PPO) enzyme that is found in plants. In our search for alternatives to the sodium-bisulphite treatment, we came across the researcher Lene Kaaber at Matforsk. She had interesting results from lab trials using carbon dioxide to reduce PPO activity. The method is based on replacing oxygen in the storage water with carbon dioxide. At the processing unit this method yielded very good results in large scale trials. The processor rapidly adopted the practice and has since 2005 supplied the hospital kitchen with peeled potatoes stored in carbon dioxide enriched water.
Discoloration of potatoes can also be a result of impact damage (black spot bruising) or potassium deficiency during cultivation. The experience from our work is that black spot bruising is strongly associated with potatoes being handled and peeled at low temperatures. The optimum temperature for avoiding impact damage has been found to be 12 degrees C, and for storage is 4 degrees C. As a consequence of our research and dissemination of the findings, the processing unit is now conscious of the importance of handling their products at the correct temperatures.
And the winner is...
Several potato varieties have been tested in the project ‘Organic food in hospitals´. So far the Folva variety is our favourite. The waste during peeling is consistently about 25 % by weight and the variety is relatively resistant to black spot bruising. Compared to Troll, Folva has low dry matter content and is thus less susceptible to disintegrating during cooking. Folva is however much more challenging for the farmers to grow, because it is susceptible to both potato blight and greening.
Frequent project meetings which gathered together all sections of the potato production chain enabled us to jointly identify problems and their solutions. The organic producers quickly realised the need for cooperation and communication in order to secure supply contracts with the hospital. Eleven farmers formed a producers group and chose a coordinator. He manages production and delivery for the group, acts as their spokesman and feeds back valuable information from the processors and customers.
The processing unit sends samples of potatoes it suspects are of poor quality for independent quality control. The farmers recognise this method of assessing potato quality and it enables them to track the cause of problems. If the independent judgement confirms poor quality, the producer´s payment will be reduced, according to the initial contract.
Norwegian Agricultural Authorities encourage organic production and consumption of organic goods through sponsorship of contracts between producers, processors and consumers. This has been an incentive for binding cooperation and entering long-term contracts. St Olav´s Hospital has now signed a three-year contract for the supply of organic potatoes with local farmers and the processor.
Our work shows that Norwegian farmers can provide organic potatoes of consistently high quality. It demonstrates that at every stage from production to consumption quality must be scrutinised in order to achieve this. All stakeholders, including the hospital kitchen, have acquired valuable knowledge about potato varieties and quality requirements. Most importantly this progress reflects positively in terms of customer satisfaction. A survey in December 2005 demonstrated that 77 % of the patients responding were content or very content with the potatoes served at the hospital. It seems that potatoes as well as patients may benefit from a little intensive care.
Bakk, E. og S. Haglund, 2004. Storskala utprøving av alternativ metode (til sulfittløsning) til forhindring av svartfarging av forhåndsskrelte poteter. Sluttrapport per 31. desember 2004. Ref: BEDAH - 2004/005467. Innovasjon Norge.
Haglund, S, 2004. Økologisk potetdyrking i et helkjedeperspektiv. I: NORSØK-rapport 1-2004, pp 5-8. GAN forlag, Oslo, Norway.
Størvold, L., Vikhals, B. K. & Bakken, T. S. 2004. Økologiske poteter i sykehus. Hovedprosjekt 2003/2004, 45 s. Næringsmiddelteknologisk utdanning, Høgskolen i Sør-Trøndelag, Trondheim.