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Abstract: Recovery of the oil components of okara by ethanol-modified supercritical carbon dioxide extraction was investigated at 40–80°C temperature and 12–30MPa pressure. In a typical run (holding period of 2h, continuous flow extraction of 5h), results indicated that the oil component could be best obtained with a recovery of 63.5% at relatively low temperature of 40°C and mild pressure of 20MPa in the presence of 10mol% EtOH as entrainer. Based on gas chromatography–mass spectrometry (GC–MS) analysis, the extracts consisted mainly of fatty acids and phytosterols, and traces of decadienal. Folin–Ciocalteau estimates of total phenols showed that addition of EtOH as entrainer increased the yield and the amount of phenolic compounds in the extracts. The amounts of two primary soy isoflavones, genistein and daidzein, in the extracts also increased with increasing amount of EtOH. [Copyright &y& Elsevier]

This study involved the incorporation of useful compounds, such as repellents and antibacterial agents, at high concentrations in l-lactide (l-LA) random copolymers. The amount of α-pinene released in gas from the copolymers was also evaluated. Outstanding controlled release properties were developed using random copolymers of l-lactide (l-LA) with γ-valerolactone (VL), ε-caprolactone (CL), tetramethylene carbonate (TEMC) (1,3-dioxepan-2-one), and 1,5-dioxepan-2-one (DXO) using tin 2-ethyl-hexanoate [Sn(oct)2] as a catalyst at 150 °C for 24 h without solvent. Preparation of controlled release materials was accomplished using α-pinene from Japanese cypress oil and synthetic random copolymers of l-LA with cyclic monomers as base materials under supercritical carbon dioxide (scCO2). Poly(l-LA-ran-VL), poly(l-LA-ran-CL), poly(l-LA-ran-TEMC), and poly(l-LA-ran-DXO), which have lower Tm and ΔHm values than poly(l-LA) were used for the impregnation experiments. The oil content of the copolymers was greater than that in poly(l-LA). The content of oil into poly(l-LA-ran-TEMC) (80 : 20) was 8.1%, 2.1-fold greater than that in poly(l-LA) (Lacea H-100) (H-100), and 1.5-fold greater than that in poly(l-LA) (Lacea H-440) (H-440). Although a previous study showed that 3.2% d-limonene could be incorporated into poly(l-LA-ran-CL) (85 : 15) under the same conditions, results of this experiment showed that 5.8% and 6.6% oil could be incorporated into poly(l-LA-ran-CL) (81 : 19 or 91 : 9), respectively. Results from controlled release experiments demonstrated that the oil content in the polymer decreased upon copolymer degradation for all copolymers. In gas release tests, polymers H-440 and poly(l-LA-ran-VL) (85 : 15) released gas upon hydrolysis. Although the weight loss of H-440 was only 9% at 56 days, the calculated loss of oil in H-440 was 28%. [ABSTRACT FROM AUTHOR]

Outstanding controlled release materials were developed using statistically random copolymers of l-lactide ( l-LA) with ε-caprolactone (CL) using Sn(oct)2 as a catalyst at 150 °C for 24 h without solvent. Preparation of novel controlled release materials was carried out using useful organic compounds with low boiling points and synthetic random copolymers composed of l-LA and CL as base materials under supercritical carbon dioxide (scCO2). Low-boiling-point compounds such as d-limonene, hinokitiol, and trans-2-hexenal were used. In impregnation experiments using scCO2, the amounts of low-boiling-point compounds increased with an increase in l-LA content. When enzymatic degradation of poly( l-LA- ran-CL) was performed using lipase PS, copolymers with higher CL contents degraded more rapidly than did copolymers with higher l-LA content. In contrast, enzymatic degradation of copolymers occurred to a higher degree with increased l-LA content in enzymatic degradation by proteinase K. In a controlled release experiment with poly( l-LA- ran-CL) (=73/27), after 400 h of degradation by proteinase K, the remaining weight of the copolymer pellet was 6% and the amount of d-limonene remaining in the pellet was 15%. [ABSTRACT FROM AUTHOR]