Biorefinery of leafy legumes

Slides presented during "How legume science is enabling industry "

Webinar 6: European legumes in transition 4th May 2021

"Biorefinery of leafy legumes and grasses"

Presented by :  Associate professor Trine Kastrup Dalsgaard - Dalsgaard, Department of Food Science, Aarhus University, Denmark. Dept of Food Science - Interests in Alternative proteins and food stability

Leafy legumes (e.g., lucerne and clovers) and grasses are common protein-rich feed crops, which have potential to be used not only as ruminant feed but also as food protein, thereby bypassing the animals. The architecture of these plants is very different from other legumes such as pea, faba bean and soybean. Thus, they need to be processed in a completely different way. One of the barriers in the biorefinery of these leafy biomasses is the presence of highly active redox enzymes within the matrices. For example, red clover is well known for its polyphenol oxidase activity. Besides this, other redox enzymes are also present in the matrix, and will contribute to enzymatic browning, protein-phenol crosslinking, and potential decrease in protein digestibility. Procedures to overcome this challenge will be discussed. A common procedure for the processing of these crops is a double-screw pressing, followed by decantation and precipitation (heat, fermentation, or acid). While such procedures normally generate green protein extract with protein content of 40-60% of dry matter, the food industry demands for white protein isolate with protein content higher than 80%. Biorefinery methods to achieve this goal will be discussed.