Refining high-quality leaf protein and valuable co-products from green biomass of Jerusalem artichoke (Helianthus tuberosus L.) for sustainable protein supply

The present study evaluates the green biomass of Jerusalem artichoke (JA) as an alternative green protein. A leaf protein concentrate (LPC) was prepared from leafy shoots using biotechnological methods. Seven clones were compared to assess the importance of the genetic basis of JA, and alfalfa served as the control. The LPC content of JA was an average 39 g kg−1 of fresh biomass, while that of alfalfa was 32 g kg−1. The JA can produce up to 936 kg of protein ha−1 year−1 without fertilization under rainfed conditions. The crude protein content of the LPC varied from 24.2 to 31.4 m/m%, depending on clones and harvesting time, which was comparable to that of alfalfa LPC (~ 32.3%). The amino acid profile of the LPC of JA, particularly of the essential amino acids, was similar to alfalfa and soybean. In addition, our results confirmed that the polyunsaturated fatty acid (PUFA) content varied between 64 and 68% in the LPC fraction, regardless of the clone that was used, with linoleic acid and linolenic acid being the predominant PUFAs. In addition, unlike alfalfa, the content of arachidonic acid was 0.5% in the JA LPC. The tuber yield was significantly reduced because of the repeated harvesting of the shoot parts; however, the tubers obtained were sufficient to regenerate the plantation in the subsequent year, thus ensuring the renewable ability and sustainability of the green biomass of JA.