Petroleum ether

Nuclear magnetic resonance (NMR) spectra were recorded in dimethyl sulphoxide (DMSO)-d6 on a Bruker Avance 500 spectrometer operating at 500 MHz (1H) and 125 MHz (13C). Chemical shifts (δ, in ppm) were referenced to tetramethylsilane (TMS), and J was expressed in Hz. FAB-MS was taken on a Thermo Scientific TSQ 8000 Evo Triple Quadrupole mass (70eV) spectrometer (Thermo Fisher Scientific, USA). The UV-Vis spectrum was recorded in mEthanol on a Shimadzu UV-1800 spectrophotometer with silica gel column chromatography (Merck, 107734, Darmstadt, Germany). Ethanol, mEthanol, petroleum ether, ethyl acetate, and n-butanol were obtained from Panreac^® (Barcelona, Spain). All chemicals were of analytical reagent grade. A quantity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) in free radical form and acetylcholinesterase (AChE) was purchased from Sigma (Merck KGaA, Darmstadt, Germany).

Water (ultrapure grade) and ethanol (HPLC grade) were acquired from Merck (Madrid, Spain). Hexanal (98%), p-anisidine reagent (99%), 2,2-diphenyl-1-picrylhydrazyl (DPPH), sodium chloride, methanol (HPLC grade) and n-hexane (96%, GC grade) were supplied by Sigma-Aldrich (Madrid, Spain). Petroleum ether, sodium methylate, sulphuric acid (98%), acetic acid, potassium iodide, sodium thiosulfate (0.1 M), chloroform, isooctane were of analytical or chromatographic grade and were purchased from Panreac (Barcelona, Spain). Standard compounds such as linoleic (C18:2), oleic (C18:1), palmitic (C16:0), palmitoleic (C16:1), stearic (C18:0) and tridecanoic (C13) acid methyl esters; and 4-methyl-2-pentanone were acquired from Sigma-Aldrich (Madrid, Spain) in the purest available form. A commercial poly(ε-caprolactone) PCL-CAPA 6800 (Mn = 80,000, density = 1.1 g cm⁻³) was supplied in pellets by Perstorp Holding AB (Sweden). Guara almond skins (AS) were kindly supplied by Almendras Llopis (Alicante, Spain).

Ethanol (99.5%), mEthanol (99.9%), acetone (99.9%), sulfuric acid (96%), petroleum ether (40–60 °C), acetic acid glacial (99.8%), acetonitrile (99.9%), hydrochloric acid (37%) and sodium hydroxide (40%) were obtained from PanReac (Barcelona, Spain). α-Amylase, pepsin, pancreatin, porcine bile extract, electrolytes (CaCl₂, KCl, KH₂PO₄, NaHCO₃, MgCl₂ and (NH₄)₂CO₃), Folin Ciocalteu’s reagent, crystal violet staining, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, dimethyl sulfoxide, phosphate buffered saline solution and reference reagents for identification of phenolics and SCFAs were purchased from Sigma-Aldrich (Madrid, Spain). Microbial culture media was obtained from Scharlab (Barcelona, Spain), while pure culture probiotic strains were purchased from Spanish Type Culture Collection (CECT) (Valencia, Spain). Cell culture medium and reagents were obtained from Fisher Scientific (Madrid, Spain).