Comparison between protein yield in different spring-rape varieties : jämförelse av proteinutbyte mellan olika vårrapssorter

Abstract: The market for new protein sources for food has never been as popular as it is today. This is partly a response to the increased climate threat. One major contributing factor to the climate impact is food production and the huge waste that comes from both producer and consumer. Trying to develop new sources of protein is important since carbon dioxide emissions from the protein sources consumed today, often from animals, are very high. Plant protein has considerably lower carbon dioxide emissions and is therefore a good alternative. Rapeseed is a well-established oil plant that is grown both in Sweden and internationally, especially in Canada. In Sweden, about 108.000 ha are currently grown with rapeseed of both spring and autumn varieties. The crop can be grown on the major parts of southern Sweden and is relatively easy to grow. Rapeseed consists of 30–40% oil and 20–25% protein. The protein in rapeseed has a high-quality amino acid composition compared to other vegetable protein and animal protein as it contains several essential amino acids. Antinutrients such as glucosinolates, phytic acid and erucic acid have long been a problem in rapeseed but thanks to intensive plant breeding, the antinutrients have drastically decreased and are today under approved levels. Rapeseed contains high-grade protein and is suitable for further processing. Oil extraction is the most common human-consumed product of rapeseed, but the production also results in a by-product, a high-protein content press cake. The press cake is commonly used for animal feed. In this study, eleven spring rapeseed cultivars were examined, whose protein exchange in the press cake was compared. The study was a part of an extensive research project on rapeseed protein at Lund University. The results showed differences between the protein yield of the varieties and the variety SW Y2909 was found to be the highest yield with 33% crude protein and the lowest yield was Lennon with 13%. A conclusion based on the result is that rapeseed varieties have difference in protein yield.