S25 - Session P1 - Comparative study of slicing methods for labdanum gum extraction from Cistus ladanifer

Authors: Pedro V. Mauri Ablanque, Celia Cano-Shaw *, José Plaza, Lorena Parra, Inés Bautista, Jaime Lloret, Sandra Sendra, Luis Saul Esteban, Irene Mediavilla

Labdanum gum is one of the most important bioproducts obtained from rockrose (Cistus ladanifer, L.), a shrub of the Mediterranean forests. Traditionally, labdanum gum is obtained by immersing the aerial parts of the rockrose in warm carbonated water, which is later acidified. With the cultivation, harvest methods such as commercial harvester baler are included, allowing a series of other processes such as slicing methods. In this paper, the comparison of labdanum gum extraction with two slicing methods is presented. Several individuals of rockrose were harvested on 17/08/2021 from two close locations in the north of Madrid (Spain). The two locations are characterized by similar climatology and have rockrose of different ages. For the gum extraction, 400 g of fresh biomass were used. Two different methods to slice the biomass are evaluated. As the first method, manual cutting using pruning shears is applied. On the other hand, simulating an industrial process, an industrial crusher is used. The objective is to evaluate if the slicing methods for biomass preparation impact the obtained bioproducts. The gum was extracted by immersing the biomass in warm water with sodium carbonate for 30 minutes; then, biomass was filtered, and the liquid was stored at environmental temperature. After 24 h, sulfuric acid is added. Three days after the addition of acid, the labdanum gum is collected and desiccated. Our preliminary results indicate that the slicing method has no impact on the amount of obtained gum for young individuals. Nonetheless, for old individuals, the amount of extracted gum increases with the industrial processing of biomass (6.31 g of gum per 100 g of fresh biomass) than for the manual cutting (4.49 g of gum per 100 g of fresh biomass). The ANOVA indicates that obtained results are statistically different with a p-value of 0.01.