Solvent-Free Synthesis of Modified Pectin Compounds Promoted by Microwave Irradiation

Microwave-assisted solvent-free modification of pectin was successfully
accomplished, consisting in the esterification of several fatty acids by pectin alcoholic
functions. The reaction was performed by simply mixing the reagents with a catalytic
amount of the inorganic base (potassium carbonate) and irradiating the obtained mixture
with microwaves for a short time (3-6 min). The replacement of the traditional heating
with a microwave source allowed the development of a new synthetic protocol which
provided increased yield of the final products, since it eliminates the small amount of
degraded polysaccharide produced during traditional oil bath heating. The desired esters
were fully characterized by FT-IR spectroscopy and thermogravimetric analysis.