Abstract:

This article presents investigations into the modification of potato starch with the use of pullulanase, an enzyme which hydrolyses the α-1,6-glycoside bonds. We tested the effect of the enzymatic reaction time and the amount of the enzyme used on the amylose content in biomodified starch, and investigated the molecular characteristics of starch. The structural changes which occurred in the starch were identified by FTIR and NMR spectroscopy. We established that an increase in the modification time and in the enzyme/substrate module causes an decrease in the average molecular weight, as well as increases in polydispersion and in the amylose content in biomodified starch. Both native and biomodified starch are characterised by a B-type crystalline structure. Biomodified starch is characterised by a lower share of the ordered phase in comparison to native starch. Biomodified potato starch with an increased amylose share in relation to native starch may find application in manufacturing films and fibres.