Hydrothermal Hydrolysis of Hesperidin Into More Valuable Compounds Under Supercritical Carbon Dioxide Condition

Abstract

Synergistic effects of utilizing subcritical water and supercritical carbon dioxide were investigated for the hydrolysis of hesperidin into more valuable compounds at a pressure range of 10−25 MPa and temperature of 110−140 °C. The effect of operating conditions such as pressure, temperature, reaction time, and addition of cosolvent such as ethanol were found to affect the hydrolysis rate. Higher yields were obtained at higher carbon dioxide pressure owing to an increase in formation of carbonic acid. Moreover, the rate of reaction was also found to increase with increasing temperature, obtaining higher yields of the main products, hesperetin-β-glucoside and hesperetin. Addition of ethanol as a cosolvent could increase solubility of hesperidin, however, it inhibited the reaction and formation of carbonic acid. At the maximum temperature of 140 °C and pressure of 25 MPa investigated in this work, the highest concentration of hesperetin-β-glucoside of 4.2 mol/L was obtained in a reaction time of 2 h, whereas for hesperetin the highest was 6.9 mol/L obtained in 3 h. Among the hydrolysis methods investigated, the proposed method was the most selective toward formation of the target compounds.

CO2‐Enabled Biomass Fractionation/Depolymerization: A Highly Versatile Pre‐Step for Downstream Processing

“…[165] For hydrolysis of polymericm aterials in Sc-CO 2 ,r eaction parameters, such as pressure, temperature, time, moisture, and catalyst/enzyme loading, were typically taken into consideration for the optimization of reaction processes,w hereas little attention was paid to structural changes of the used catalyst or enzyme under the sub-or supercritical conditions. [169][170][171][172] In fact, sub-or supercritical CO 2 was demonstrated to have anegligible impact on the primary structure of the enzyme( e.g., Candida rugosa Lip7), whereas its secondary andt ertiary structures were changed to ac ertain extent, closely depending on conditions such as CO 2 pressure, temperature, and time. [173] These alterations could be directly correlated to the activity of enzymatic hydrolysis, as well as the residual hydrolysis activity, and kineticc onstants.…”

In-line separation of multicomponent reaction mixtures using a new semi-continuous supercritical fluid chromatography system

“…We were pleased to note that the relatively harsh and nonanhydrous supercritical conditions within the separation system did not lead to any degradation of product, allaying concerns about the carbonic acid catalysed breakdown of the methyl ester protecting group. 28,29 Purification of a telescoped intermediate. One of the primary objectives of this project was to develop a system suitable for use as a downstream separation process in telescoped flow procedures.…”

Organic Acid-Catalyzed Subcritical Water Hydrolysis of Immature Citrus unshiu Pomace

“…This is because, in the subcritical region, the ionic product of water increases with temperature and an acidic medium favorable to hydrolysis reactions is formed [ 22 , 23 , 24 ]. Ruen-ngam et al [ 25 ] performed SW hydrolysis of hesperidin over 1–4 h at 110–140 °C, with a CO 2 pressure of 25 MPa. However, the high pressure limits industrial applications.…”