Ultrasound-assisted extraction optimization of flaxseed mucilage using response surface methodology and evaluation of its anticoagulant activity

Abstract

This study investigated the optimization of ultrasound-assisted extraction (UAE) of mucilage from flaxseed was investigated through a Box-Behnken response surface design. The effects of the solid-to-liquid ratio (X1), extraction time (X2), and sonication amplitude (X3) on mucilage yield were evaluated. The structural characteristics (FTIR and SEM) and in vitro anticoagulant activity were also investigated. The maximum yield of flaxseed mucilage was 44.32 % under optimum conditions: a solid-to-liquid ratio of 1:30, an extraction time of 30 min, and an amplitude of 100 %. The predicted yield agreed well with the experimental yield (43.92 %), confirming the model reliability. Statistical analysis indicated that all coefficients were significant (p < 0.05), with the exception of the linear term of the solid-to-liquid ratio (X1), which was not significant (p > 0.05); this suggests that variables should be considered in combination rather than individually, hence the importance of experimental designs in process optimization. FTIR analysis revealed that the mucilage was a sulfated polyanionic polysaccharide, and SEM revealed a heterogeneous surface with compact, dense, and flaky structures. Furthermore, the flaxseed mucilage exhibited moderate anticoagulant activity via activated partial thromboplastin time (APTT) and prothrombin time (PT); maximum APTT and PT values of 16.1 s and 54.5 s, respectively, were observed at a concentration of 80 mg/mL This indicates that the mucilage interferes with both the intrinsic and extrinsic coagulation pathways, with a more pronounced effect on the extrinsic pathway as measured by PT. These results suggest that flaxseed mucilage could be a promising natural source of anticoagulant agents, with a potentially safer profile than heparin due to its moderate activity.