The kinetics of hydrolysis of olive oil,peanut oil,soybean oil,safflower oil in near-critical water was systematically determined in the temperature range from 170℃ to 240℃ and at pressure of 10 MPa.From the results,it could be seen that the vegetable oil hydrolysis in near-critical water was a typical self-catalyzed reaction.With a second-order kinetics equation,the activation energies evaluated were 41.8 kJ·mol-1 for olive oil,37.3 kJ·mol-1 for peanut oil,37.7 kJ·mol-1 for soybean oil,31.2 kJ·mol-1 for safflower oil respectively.The activation energies of different vegetable oils had a close relationship with their iodine values.With increasing iodine value,the activation energy of vegetable oil hydrolysis in near-critical water decreased.
In order to investigate the influencing factors of 5-hydroxymethyl-2-furaldehyde （5-HMF） content in Schisandra, confirm the theory of 5-HMF deriving mainly from Schisandra processing course, and give some suggestions about the Schisandra processing method, the 5-HMF contents in decoctions of Schisandra under different heating temperature, decocting time, soaking time, processing methods and treatment with different solvents before decocting the Schisandra were measured by RP-HPLC method. The results showed that there is great difference of 5-HMF level in decoctions from differently processed Schisandra and unprocessed Schisandra; decocting time of 60 rain has some effects on 5-HMF level in decoctions and there is certain quantity 5-HMF in processed Schisandra itself and very little 5-HMF in unprocessed Schisandra. Heating time, heating temperature and treating solvents all have effect on 5-HMF level in decoction of Schisandra. 5-HMF in Schisandra was mainly from processing course. Both long heating time and high heating temperature can increase 5-HMF level in Schisandra. The production of 5-HMF in Schisandra may have some relationships with some polar components, which can dissolve in water, ethanol and acetone, especially in ethanol. To control processing temperature, processing time and treatment with some solvent is very important for controlling 5-HMF level in Schisandra.
Two novel and environmentally benign solvent systems, organic acids-ennchea high temperature liquid water （HTLW） and NH3-enriched HTLW, were developed, which can enhance the reaction rate of acid/base-catalyzed organic reactions in HTLW. We investigated the decomposition of fructose in organic acids-enriched HTLW, hydrolysis of cinnamaldehyde and aldol condensation of phenylaldehyde with acetaldehyde in NH3-enriched HTLW. The experimental results demonstrated that organic acids-enriched or NH3-enriched HTLW can greatly accelerate acid/base-catalyzed organic reactions in HTLW.
Xiu Yang LU Qi JING Zhun LI Lei YUAN Fei GAO Xin LIU
