E-mail: 2007025@email.zzuli.edu.cn
Abstract: The potentially wide application of
Phenolic acids (PAs) in industries
was severely limited by their inadequate solubility and stability in
polar/non-polar media. To overcome these limits, studies on the
enzymatic esterification of PAs with glycerol were carried out to reach
a yield of 95% of phenolic acid
glycerols (PAGs) under the following reaction conditions: 1:150 molar
ratio of caffeic acid (CA) to
glycerol; 25% of Lipozyme 435
relative to the weight of total substrates; temperature 80oC, 500 rpm; 86.7 kPa and reaction time 10 h. Three
resulting PAGs including caffeoyl
glycerol (CG), feruloyl glycerol (FG) and p -hydroxycinnamoyl
glycerol (p -HCG) were confirmed by MS, 1H NMR
and 13C NMR. Among
them, CG showed a comparative free radical scavenging ability to CA,
indicating its potential use as a water-soluble antioxidant alternative
to CA for food and cosmetic applications. Moreover, the direct
esterification of PAs with glycerol decrease the product cost and
increase the feasibility of industrial production compared with the
previous transesterification sythesis methods of PAGs.
Keywords Enzymatic
esterification; Phenolic acid glycerols; Free radical scavenging
ability; Antioxidant capacity