Extraction Methods and Their Influence on Yield When Extracting Thermo-Vacuum-Modified Chestnut Wood

Abstract

Improvements in the yield and solubility of chestnut wood extractives, by using different extraction methods and molybdenum catalysts as support, have rarely been reported in literature. Many studies focus on the different parts of trees, except for the chemical characteristics of the remaining extractives achieved from thermally modified (THM) chestnut (Castanea sativa Mill) wood. This research seeks to better understand the effects of extraction techniques and catalysts on the yield and solubility of extractives. GC-MS analysis of the chloroform soluble and insoluble fractions was also used. Accelerated Solvent Extraction (ASE) 110 °C, Soxhlet, and autoclave extraction techniques were used to obtain extractives from untreated and thermally modified (THM) chestnut wood (170 °C for 3 h). Ethanol/H2O, ethanol/toluene, and water were the solvents used for each technique. A polyoxometalate compound (H3PMo12O40) and MoO3 supported on silica were used as catalysts. The THM induced a change in the wood’s surface color (ΔE = 21.5) and an increase in mass loss (5.9%), while the equilibrium moisture content (EMC) was reduced by 17.4% compared to the control wood. The yields of the extractives and their solubility were always higher in THM and mainly used ASE as the technique. GC-MS analysis of the extractives, without catalyst support, showed different results for each extraction technique and type of wood (untreated and THM). Ultimately, the amount of extractive compound dissolved in each solvent will differ, and the choice of extraction technique will depend on the intended final application of the extracted chemical product.

Antioxidant, Antimicrobial, and Antiplasmodial Activities of Sonchus arvensis L. Leaf Ethyl Acetate Fractions

“…The yield of extract depended on the solvent and the methods of extraction. [19][20][21] In this study, group fractions IV were the highest yield. They were isolated by the n-hexane: ethyl acetate (40:60, 30:70, 20:80).…”

Green Extraction Techniques of Bioactive Compounds: A State-of-the-Art Review

“…Compared to other techniques reviewed in this article, the use of PLE seems to provide reduced extraction times, low solvent consumption, high selectivity, and highly biologically active extracts [57]. For instance, in both studies developed by D'auria et al [150] and Todaro et al [62] (Table 18), just 15 min of extraction time was needed; this is much quicker than that of the previously reviewed studies and extraction techniques. In addition, in the case of Castanea sativa Mill., PLE showed higher yields when compared to SC.…”

GC-MS and SPME Techniques Highlighted Contrasting Chemical Behaviour in the Water Extractives of Modified Castanea sativa Mill. and Fagus sylvatica L. Wood

“…The wood was dried at 0% humidity under vacuum (200 mbar) at 90 • C for 12 h. From an initial (pre-drying) temperature of 30 • C, the temperature was increased by 5 • C every hour to 90 • C. At the end of the drying cycle, the oven was shortly opened and the wood samples were quickly weighed [32].…”

“…A split injector was maintained at 250 • C and the detector was maintained at 230 • C. The oven was held at 80 • C for 2 min, gradually warmed at 8 • C/min, up to 250 • C, and held for 10 min. The tentative identification of aroma components was based on mass spectra and NIST (National Institute of Standards and Technology) 11 library comparison [32].…”