Synthesis of Glycerides of Fatty Acids by Inorganic Solid Catalysts: A Review

Molecular networking and Paterno-Büchi reaction guided glycerides characterization and antioxidant activity assessment of Ganoderma lucidum spore oil

Ganoderma lucidum spore oil (GLSO) is a dietary supplement, with glycerides (GLs) recognized as its important active component. However, comprehensive profiling and accurate structural characterization of GLs in GLSO remain underexplored. In this study, 59 GLs from GLSO were identified by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF MS) and molecular networking (MN). The double bond isomers of these compounds were further resolved by the Paterno-Büchi (PB) reaction coupled with UPLC-Q-TOF MS, resulting in the identification of 36 unsaturated GLs, including 5 pairs of positional isomers. In summary, 64 GLs were characterized, consisting of 9 diacylglycerols (DGs) and 55 triacylglycerols (TGs). Additionally, the compositional variations, antioxidant activities, and relative isomer ratios of CC positional isomers of GLSO from eight different manufacturers were revealed, with 11 GLs correlating with antioxidant activity. This study enhances the understanding of the nutritional value of GLSO and lays a foundation for future quality standard formulation.

Enhanced Glycerolysis of Fatty Acid Methyl Ester by Static Mixer Reactor

This study investigates the synthesis of monoglycerides (MGs) and diglycerides (DGs) from glycerol (G) and fatty acid methyl ester (FAME) using a static mixer reactor (SMR), which combines a static mixer (SM) with a reactor tank. The SMR integrates Kenics static mixers (KSM) and low-pressure drop static mixers (LPDSM) with varying length-to-diameter ratios (L/D = 1.0 and 1.5). Keys glycerolysis parameters, including the G:FAME molar ratio of 2:1-3:1, 2-3 wt % potassium hydroxide (KOH), and reaction time of 30-90 min at 150 °C were systematically explored. The SMR design allows precise control over the reaction time without altering the feed flow rate or tube length and avoiding agitator leakage. The optimal operating conditions, determined through a face-centered central composite design, resulted in 71.35% MGs and 14.20% DGs at a 3:1 molar ratio of G to FAME, 3 wt % KOH, 60 min, and 150 °C using an LPDSM with an L/D of 1.5. In comparison, an LPDSM with an L/D of 1 achieved 79.28% MGs and 10.17% DGs under the same conditions. When applied to purified crude glycerol, these conditions yielded 61.09% MGs and 23.44% DGs. The study found that a lower L/D ratio improved the mixing efficiency but increased the pressure drop. The SMR demonstrated superior performance in glycerolysis compared with conventional stirred tank reactors and ultrasonic probe reactors, indicating its potential for enhanced industrial application.

Lipase-catalyzed solvent-free synthesis of monoglycerides from biodiesel-derived crude glycerol: Optimized using response surface methodology

The growth of the biodiesel industry has resulted in significant quantity of crude glycerol. It is necessary to explore the synthesis of high-value-added products from crude glycerol. In this study, the enzymatic synthesis of monoglycerides under solvent-free conditions, employing crude glycerol as the primary feedstock, had been investigated. The analysis showed that the highest yield of monoglycerides was obtained after 12 h, and Novozym 435 showed the highest monoglyceride yield of 18.41 % among the three lipases tested, followed by Lipozyme TL IM and Lipozyme RM IM. Monoglycerides were synthesized from biodiesel-derived crude glycerol using Novozym 435 as the catalyst under solvent-free conditions at different parameters, which were catalyst concentration, substrate molar ratio, and temperature. The yield of monoglycerides was examined in single-factor experiments. Response surface methodology (RSM) was subsequently employed to optimize the synthesis conditions based on the single-factor experimental results. The optimal conditions were at an enzyme concentration of 12.7 wt% and a molar ratio of crude glycerol:oil of 5.7:1 at a reaction temperature of 65.2 °C. The experimental yield of monoglycerides under the optimal conditions was 28.93 %, which is close to the value predicted from the RSM model (29.02 %).

New Technology for the Synthesis of Glycerol Monooleate

Herein, a new approach for glycerol monooleate (GMO) was developed. GMO was synthesized via the esterification method using self-made sodium oleate and 3-chloro-1,2-propanediol as reactants, tetrabutylammonium bromide as the catalyst, and toluene as the solvent. The effects of the reaction molar ratio, type and amount of catalyst, and reaction temperature and time on the yield were investigated. Results showed that the optimal process conditions for synthesizing GMO were as follows. The molar ratio of sodium oleate to 3-chloro-1,2-propanediol was 1:2, the reaction temperature was 115°C, the reaction time was 6 h, weight of toluene was 25 g, and the catalyst dosage was 3.5%. Under these conditions, high-purity GMO was synthesized with a yield of 89.02%.