Identification of key parameters and phytochemical composition of fiber and brown juice by-products from green biomass of Jerusalem artichoke ( Helianthus tuberosus L.)

The investigation within the green biorefinery focused on value-measuring properties of by-products derived from leaf protein concentrate production, particularly from Jerusalem artichokes. Results showed fiber fractions ranged from 17 to 28% per 1 kg of fresh biomass, while brown juice fractions ranged from 57 to 68 %. Protein content varied from 7 to 14 m/m% for fiber and 0.3-1.4 m/m% for brown juice, with Rubik and Piri varieties exhibiting minimal differences in crude protein content between harvests. Amino acid analysis revealed significant amounts of leucine and lysine in both fractions. Phenolic compounds, notably hydroxy-methoxy flavones, were abundant in brown juice, with Rubik variety showing promising total phenolic content (TPC) and total flavonoid content (TFC). Qualitative determination identified chlorogenic acid and two isomers among cinnamic acid derivatives, suggesting potential medicine candidates. Brown juice fractions, especially from Rubik variety, hold promise for applications such as biostimulants. Further exploration of phenolic components in brown juice could yield valuable insights.