| Abstract | Cilj je bio pripremiti biopolimerni materijal od škroba s dodanim polifenolima aronije te ispitati kinetiku otpuštanja polifenola. Polifenoli su ekstrahirani vodom pomoću ultrazvuka, karakterizirani (visokodjelotvorna tekućinska kromatografija) te adsorbirani na škrob. Materijal je pripremljen od škroba s adsorbiranim polifenolima aronije te od čistog škroba s ekstraktom aronije. U ekstraktu aronije identificirani su antocijanini, fenolne kiseline i flavonoli. Polifenoli aronije su se adsorbirali na škrob, no adsorpcijski kapacitet bio je nizak (0,33 mg g-1). Polifenoli koji su se nalazili u većem postotku u ekstraktu, adsorbirali su se u većem postotku na škrob (r2 = 0,9967). Materijali od škroba s adsorbiranim polifenolima (5 i 10 % škroba, glicerol 0,5, 1, 2 i 2,5 g) pokazali su nešto veće postotke vode i topljivost u vodi, a količina otpuštanih polifenola bila je niska. Materijali pripremljeni od čistog škroba s ekstraktom aronije (5 i 10 % škroba, glicerol 2,5 i 5 g) pokazali su nešto veće postotke vode i topljivost u vodi no puno bolje otpuštanje polifenola (0,645 do 2,700 mg g-1 ) (bolja aktivna funkcija). Vrijeme polureakcije (t1/2) iznosilo je 30-87 min (prvi red) te 38-130 min (drugi red), a maksimalna količina otpuštenih polifenola 0,9-2,4 mg g-1 (prvi red), 1,1-3,1 mg g-1 (drugi red). |
| Abstract (english) | The goal was to prepare a biopolymer material from starch with added aronia polyphenols, and to examine the kinetics of polyphenol release. Polyphenols were extracted with water (ultrasound), characterized (high performance liquid chromatography) and adsorbed onto starch. The material was prepared from starch with adsorbed polyphenols and from pure starch with aronia extract. Anthocyanins, phenolic acids and flavonols were identified in aronia. Aronia polyphenols were adsorbed on starch, but the adsorption capacity was low (0.33 mg g-1). Polyphenols, which were found in a higher percentage in the extract, were adsorbed in a higher percentage on starch (r2=0.9967). Materials with adsorbed polyphenols onto starch (5 and 10% starch, glycerol 0.5, 1, 2 and 2.5 g) showed higher percentages of water and water solubility, and the amount of released polyphenols was low. Materials prepared from pure starch with aronia extract (5 and 10% starch, glycerol 2.5 and 5 g) showed higher percentages of water and water solubility, but a much better release of polyphenols (0.645 to 2.700 mg g-1 ) (better active function). The half-life of reaction (t1/2) was 30-87 (first-order) and 38-130 min (second-order), and the maximum amount of released polyphenols was 0.9-2.4 mg g-1 (first order), 1.1-3.1 mg g-1 (second order). |
