Article 1 Betaine 1 Betaine methyl ester Catalysis 1 Esterification 1 Magnetic Resonance Spectroscopy 1 Microscopy, Electron, Scanning 1 Oxidation-Reduction 1 Starch 1 Starch betainate 1 Transesterification 1 acid 1 acidity 1 alcohol 1 alkalinity 1 betaine 1 betaine derivative 1 carbon nuclear magnetic resonance 1 catalysis 1 catalyst 1 chemical reaction 1 chemistry 1 degradation 1 degree of substitution 1 depolymerization 1 dimethyl sulfoxide 1 esterification 1 infrared spectroscopy 1 methanol 1 methyl betainate 1