A comparative study on physicochemical hydrolysis methods, including acid-catalyzed, base-catalyzed, and subcritical water hydrolysis, for glycerides removal prior to subsequent γ-oryzanol purification from rice bran acid oil (RBAO), is presented. The effects of hydrolysis conditions on the residual levels of glycerides and γ-oryzanol in RBAO were first investigated for each method. It can be concluded that the acid-catalyzed hydrolysis was not a suitable hydrolysis method for this application as it provided a low glycerides conversion level of ca. 30% using 2 N H₂SO₄ at 80–100 °C, despite the long reaction time (> 60 min). For the base-catalyzed hydrolysis, 100% glycerides removal was achieved at the most suitable condition, which was suggested to be at 2.5 N NaOH, 90 °C and 5–10 min. At this condition, a relatively high residual level of γ-oryzanol of ca. 57–66% was obtained. For the subcritical water hydrolysis, the results suggested that γ-oryzanol was hydrolyzed more rapidly than glycerides, and the most suitable condition for subcritical water hydrolysis was at 220 °C for 10 min. At this condition, high glycerides removal of > 95% was achieved while the remaining amount of γ-oryzanol was still acceptable (50%).

提出了一种物理化学水解方法的比较研究，包括酸催化，碱催化和亚临界水水解，用于在随后从米糠酸油（RBAO）中纯化γ-谷维素之前去除甘油酯。每种方法首先研究了水解条件对RBAO中甘油酯和γ-谷维素残留量的影响。可以得出结论，酸催化的水解方法不适用于该应用，因为它提供的甘油三酸酯转化率较低，约为1。30％使用2 NH ₂ SO ₄尽管反应时间长（> 60分钟），但仍可在80–100°C下使用。对于碱催化的水解，在最合适的条件下（建议在2.5 N NaOH，90°C和5-10分钟的条件下）可去除100％的甘油酯。在这种条件下，约γ-谷维素残留水平相对较高。获得57–66％。对于亚临界水水解，结果表明γ-谷维素的水解速度比甘油酯快，最适合亚临界水水解的条件是在220°C下进行10分钟。在此条件下，可以实现> 95％的高甘油酯去除率，而剩余的γ-谷维素含量仍然可以接受（50％）。