The effects of glycerol and guar-xanthan mixture on mechanical and barrier properties of starch based edible films--chemometric analysis/Uticaj glicerola i smese guar-ksantana na mehanicka i barijerna svojstva jestivih filmova od skroba--hemometrijska analiza

The aim of this work was to evaluate the simultaneous effect of glycerol (30, 40 and 50%) and guar-xanthan gum addition (0.1, 0.3 and 0.5%) effect on starch based edible film mechanical and barrier properties. According to Response Surface Methodology, the most influential parameter in the second order polynomial models calculation was the percentage of glycerol, while the linear term of guar-xanthan content was important only for second order polynomial model calculation for tensile strength and water vapor permeability. According to principal component analysis, samples grouping along the first component are primarily due to the content of glycerol, which is also confirmed by ANOVA analysis. According cluster analysis, two separate clusters are observed on the dendrogram, which includes the right (with the increased value of tensile strength) and the left cluster (with the increased value of elongation break and water vapor permeability). The observed distance of the two clusters is considerable (approx. 80). Keywords: edible films, plasticizers, characteristics, pattern recognition techniques. Ispitivanje funkcionalnih karakteristika jestivih hidrokoloida sa ciljem unapredenja svojstava predstvalja znacajan izazov. U radu je ispitan uticaj dodatka plastifikatora glicerola i smese guar-ksantana na mehanicke (zatezna jacina i izduzenje pri kidanju) i barijerne karakteristike (propustljivost vodene pare) jestivih skrobnih filmova. Jestivi skrobni filmovi su izuzetno aplikativni u prehrambenoj industriji zbog niza prednosti: niska cena, ekoloska podobnost, inertnost prema upakovanom sadrzaju. Ipak, njihovu primenu najvise ogranicva krta priroda filma i visoka propustljivost vodene pare, koja je posledica hidrofilne prirode skroba. Dodatak glicerola ima zadatak da redukuje intermolekularne sile i poveca mobilnost biopolimernih lanaca cime se povecava fleksibilnost filmova. Dokazano je da ksantan pozitivno utice na ponasanje skroba u smislu poboljsanja stabilnosti, viskoziteta filmova, stepena rastvorljivosti i bubrenja. Guar guma, takode, ima funkciju zgusnjivaca i stabilizatora, pomaze odrzavanju homogenosti i strukture, funkcionise kao vezujuce sredstvo. Obzirom da su obe komponente kompatibilne sa skrobom i odobrene za primenu u prehrambenoj industriji u postupku proizvodnje jestivih filmova aplicirali smo i smesu guar-ksantana, kako bi se ispitao uticaj na osobine dobijenih filmova. Potvrdeno je da dodatak glicerola unapreduje mehanicke osobine filmova.