Page 25 - InnoRenew CoE International Conference 2023
P. 25
Chemical and enzymatic starch modification for various
sustainable applications
Marica Mikuljan1*, Matthew Schwarzkopf1,2, Jaka Gašper Pečnik1,2,
Mariem Zouari1,2, Tania Langella 1,2
1 InnoRenew CoE, Livade 6a, 6310 Izola, Slovenia; marica.mikuljan@innorenew.eu; matthew.schwarzkopf@innorenew.eu;
jaka.pecnik@innorenew.eu; mariem.zouari@innorenew.eu; tania.langella@innorenew.eu
2 Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia
* Corresponding author
Starch is one of the most abundant biopolymers. Like cellulose, starch can be considered a condensation polymer
because its hydrolysis yields glucose molecules. It is completely biodegradable, inexpensive, and renewable.
Unmodified starch can takes up water very easily, swell rapidly, rupture, lose viscosity, produce cohesive pastes,
and are is not stable to in acidic conditions, at high temperatures, or under mechanical action. We can change
overcome these shortcomings by chemical, physical, and enzymatic modificationying of starch methods. In this
study, the effect of chemical and enzymatic modification on the properties of wheat starch were investigated.
The chemical modifications were accomplished by the addition of suitable reagents to aqueous starch slurries
while controlling the pH and the temperature. Forenzymatic modification, extracellularstarch-degrading enzyme
complexes from the fungi Morchella esculenta, Pleurotus ostreatus, Ganoderma lucidum, Trametes versicolor,
and Fomes Iinzengae were used in the study. In both modification methods, iodine paper was used to determine
the residual starch after modification. Iodine forms a blue to -black complex with starch. After modification, the
modified starch was washed four times with clean water and dried in a fan oven at 45°C for 48 hours. It was then
ground in an IKA grinder and stored in sealed containers. The zeta potential, pH value, and thermal properties
of the modified starch for use in emulsion and suspension were determined. Results showindicate that a pH
greater than 7.,5 and particles with positive zeta potentials with more positive than +30 mV or more negative
zeta potentials more than –30 mV are important indicators of the stability of colloidal dispersion. The thermal
degradation of starch bellow 300°C involves the dehydration of the OH from the glucose monomers followed
by main chain secession to produce volatile compounds. The replacement of the starch OH components with
oxides improves the thermal stability. Starch and its derivatives will be used in as biodegradable alternatives to
conventional petroleum-based material.
Keywords: wheat starch, modification, enzyme, properties
Acknowledgement: The authors gratefully acknowledge receiving funding from funding source ARRS,
N2-0225.
REFERENCES
Hartig, T., Evans, G.W., Jamner, L.D., Davis, D.S., Gärling, T., 2003. Tracking restoration in natural and urban
field settings. J. Environ. Psychol. 23, 109–123. https://doi.org/10.1016/S0272-4944(02)00109-3
K. Laird, Plastics Today, Packaging Materials, Nov. 23, 2015
13–14 SEPTEMBER 2023 I IZOLA, SLOVENIA 25
sustainable applications
Marica Mikuljan1*, Matthew Schwarzkopf1,2, Jaka Gašper Pečnik1,2,
Mariem Zouari1,2, Tania Langella 1,2
1 InnoRenew CoE, Livade 6a, 6310 Izola, Slovenia; marica.mikuljan@innorenew.eu; matthew.schwarzkopf@innorenew.eu;
jaka.pecnik@innorenew.eu; mariem.zouari@innorenew.eu; tania.langella@innorenew.eu
2 Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Glagoljaška 8, 6000 Koper, Slovenia
* Corresponding author
Starch is one of the most abundant biopolymers. Like cellulose, starch can be considered a condensation polymer
because its hydrolysis yields glucose molecules. It is completely biodegradable, inexpensive, and renewable.
Unmodified starch can takes up water very easily, swell rapidly, rupture, lose viscosity, produce cohesive pastes,
and are is not stable to in acidic conditions, at high temperatures, or under mechanical action. We can change
overcome these shortcomings by chemical, physical, and enzymatic modificationying of starch methods. In this
study, the effect of chemical and enzymatic modification on the properties of wheat starch were investigated.
The chemical modifications were accomplished by the addition of suitable reagents to aqueous starch slurries
while controlling the pH and the temperature. Forenzymatic modification, extracellularstarch-degrading enzyme
complexes from the fungi Morchella esculenta, Pleurotus ostreatus, Ganoderma lucidum, Trametes versicolor,
and Fomes Iinzengae were used in the study. In both modification methods, iodine paper was used to determine
the residual starch after modification. Iodine forms a blue to -black complex with starch. After modification, the
modified starch was washed four times with clean water and dried in a fan oven at 45°C for 48 hours. It was then
ground in an IKA grinder and stored in sealed containers. The zeta potential, pH value, and thermal properties
of the modified starch for use in emulsion and suspension were determined. Results showindicate that a pH
greater than 7.,5 and particles with positive zeta potentials with more positive than +30 mV or more negative
zeta potentials more than –30 mV are important indicators of the stability of colloidal dispersion. The thermal
degradation of starch bellow 300°C involves the dehydration of the OH from the glucose monomers followed
by main chain secession to produce volatile compounds. The replacement of the starch OH components with
oxides improves the thermal stability. Starch and its derivatives will be used in as biodegradable alternatives to
conventional petroleum-based material.
Keywords: wheat starch, modification, enzyme, properties
Acknowledgement: The authors gratefully acknowledge receiving funding from funding source ARRS,
N2-0225.
REFERENCES
Hartig, T., Evans, G.W., Jamner, L.D., Davis, D.S., Gärling, T., 2003. Tracking restoration in natural and urban
field settings. J. Environ. Psychol. 23, 109–123. https://doi.org/10.1016/S0272-4944(02)00109-3
K. Laird, Plastics Today, Packaging Materials, Nov. 23, 2015
13–14 SEPTEMBER 2023 I IZOLA, SLOVENIA 25
