https://doi.org/10.17113/ftb.58.01.20.6239

Application of Spectrophotometric Fingerprint in Cluster Analysis for Starch Origin Determination

Nikola Sakač¹*, Maja Karnaš², Jasminka Dobša³, Marija Jozanović⁴*, Vlatka Gvozdić⁴, Elvira Kovač-Andrić⁴, Marija Kraševac Sakač⁴ and Bojan Šarkanj⁵

¹University of Zagreb, Faculty of Geotechnical Engineering, Hallerova 7, HR-42000 Varaždin, Croatia

²Josip Juraj Strossmayer University of Osijek, Faculty of Agriculture, Vladimira Preloga 1, 31000 Osijek, Croatia

³University of Zagreb, Faculty of Organization and Informatics, Pavlinska 2, 42000 Varaždin, Croatia

⁴Josip Juraj Strossmayer University of Osijek, Department of Chemistry, Cara Hadrijana 8/A, 31000 Osijek, Croatia

⁵University North, Dr Žarko Dolinar Square 1, 43000 Koprivnica, Croatia

Article history:

Received: 7 February 2019

Accepted: 10 March 2020

Key words:

starch botanical origin, starch-triiodide complex, cluster analysis

Summary:

The botanical origin of starch is of importance in industrial applications and food processingbecause it may influence the properties of the final product. Current microscopicmethods are time-consuming. Starch consists of an origin-dependent amylose/amylopectinratio. Triiodide ions bind characteristically to the amylose and amylopectin dependingon the botanical origin of the starch. The absorbance of the starch-triiodide complex wasmeasured for wheat, potato, corn, rye, barley, rice, tapioca and unknown origin starch,and within the different cultivars. Each starch sample had specific parameters: starch-triiodidecomplex peak wavelength maximum (λmax/nm), maximum absorbance change atλ_max (ΔA) and λ_max shift towards the unknown origin starch sample values. The visible absorptionspectra (500-800 nm) for each starch sample were used as a unique fingerprint,and then elaborated by cluster analysis. The cluster analysis managed to distinguish dataof two clusters, a cereal type cluster and a potato/tapioca/rice starch cluster. The cerealsubclusters extensively distinguished wheat/barley/rye starches from corn starches. Datafor cultivars were mostly in good agreement within the same subclaster. The proposedmethod that combines cluster analysis and visible absorbance data for starch-triiodidecomplex was able to distinguish starch of different botanical origins and cultivars withinthe same species. This method is simpler and more convenient than standard time-consumingmethods.