Analysis of Lepidium sativum L. (Garden cress) seed mucilage: A comprehensive characterization using XRD, DSC, and PSA techniques

crystallinity and thermal stability, of Lepidium sativum seed mucilage using particle size analysis (PSA), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) characterization.

Method: The mucilage extracted from Lepidium sativum seeds was obtained by utilizing distilled water as a solvent, followed by precipitation with 95% ethanol to isolate the mucilage effectively. To assess the size distribution and average particle size of the extracted mucilage, a Particle Size Analysis (PSA) was conducted. Crystallinity and crystal characteristics were investigated using X-ray Diffraction (XRD), which provided insights into the nature of the mucilage and detailed the size of its crystallites. Additionally, thermal stability was analyzed through Differential Scanning Calorimetry (DSC).

Results: The particle size distribution analysis results illustrated a range of particle sizes: 25% of the particles measured at 169.68 µm. In contrast, the median size (50th percentile) was determined to be 292.50 µm, and 75% of the particles reached a size of 408.64 µm. The average particle size was calculated to be 259.89 ± 0.24 nm, indicating a relatively fine particle size distribution. The average size of the crystallites calculated from the XRD data was found to be 47.47 nm, confirming the presence of crystalline regions within the mucilage. The DSC analysis provided a detailed thermogram, revealing two distinct thermal events: an endothermic peak recorded at 68.24 ºC, and an exothermic peak at 268.86 ºC. Furthermore, the latent heat of fusion was quantified at -161.86 J/g for the endothermic transition and 38.17 J/g for the exothermic transition.

Conclusion: The Particle Size Analysis (PSA) and X-ray Diffraction (XRD) revealed that L. sativum mucilage has an average particle size of 259.89 nm and a partially crystalline structure. Differential Scanning Calorimetry (DSC) showed a melting point of 68.24 ºC and decomposition at 268.86 ºC, indicating thermal stability with latent heats of -161.86 J/g and 38.17 J/g, respectively.