20.500.12556/RUL-188051 Vpliv temperature na hidrolizo škroba v izbranih hidratiziranih mokah z endogenimi encimi Effect of temperature on starch hydrolysis in selected hydrated flours with endogenous enzymes V okviru magistrske naloge smo preučevali vpliv temperature na hidrolizo škroba z endogenimi encimi v hidratiziranih polnozrnatih mokah iz kaljenih in nekaljenih zrn pšenice, pire in ajde. Hidrolizo smo izvajali pri temperaturah od 50 do 70 °C in masnem razmerju med moko in vodo 1 : 2 ter jo vrednotili po 15 minutah, 2,5 ure in 18 urah inkubacije. Nastanek sladkorjev in oligosaharidov smo določali kromatografsko, vsebnost reducirajočih sladkorjev pa spektrofotometrično po reakciji z dinitrosalicilno kislino. Rezultati so pokazali, da na obseg hidrolize škroba in sestavo nastalih sladkorjev pomembno vplivajo vrsta moke, kaljenje zrn, temperatura in čas inkubacije. Glavni produkt hidrolize v pšeničnih in pirinih mokah je bila maltoza, v ajdovih mokah pa glukoza. Optimalna temperatura hidrolize je bila glede na vrsto moke 60 ali 65 °C. Obseg hidrolize se je praviloma povečeval s časom inkubacije, medtem ko pri 70 °C podaljšanje inkubacije v večini primerov ni povzročilo značilnega povečanja hidrolize, kar kaže na zmanjšano aktivnost oziroma inaktivacijo endogenih encimov pri tej temperaturi. Kaljenje je povečalo obseg hidrolize pri vseh preučevanih vrstah žit oziroma psevdožit. Največja stopnja hidrolize škroba v pšenični moki se je s kaljenjem povečala z 28 % na 32 %, pri pirini moki pa z manj kot 15 % na 37 %, kar predstavlja največji obseg hidrolize med preučevanimi vzorci. Hidroliza je bila najmanj izrazita v ajdovih mokah, kjer je največja stopnja hidrolize znašala 4,3 % pri moki iz nekaljenih in 14,7 % pri moki iz kaljenih zrn. Sprememba masnega razmerja med moko in vodo z 1 : 2 na 1 : 1 oziroma 1 : 3 je pri daljših časih inkubacije pri 65 °C le malo vplivala na obseg hidrolize škroba v moki iz nekaljenih pšeničnih zrn. As part of this master’s thesis, we investigated the effect of temperature on starch hydrolysis by endogenous enzymes in hydrated whole-grain flours from germinated and non-germinated wheat, spelt, and buckwheat grains. Hydrolysis was performed at 50–70 °C using a flour-to-water mass ratio of 1:2 and evaluated after 15 min, 2.5 h, and 18 h of incubation. Sugars and oligosaccharides were determined chromatographically, while reducing sugars were quantified spectrophotometrically using the dinitrosalicylic acid method. The extent of starch hydrolysis and the composition of the resulting sugars were significantly affected by flour type, germination, temperature, and incubation time. Maltose was the predominant hydrolysis product in wheat and spelt flours, whereas glucose predominated in buckwheat flours. Depending on the flour type, the optimal hydrolysis temperature was 60 or 65 °C. Hydrolysis generally increased with incubation time, whereas at 70 °C prolonged incubation caused no significant increase in most cases, indicating reduced activity or inactivation of endogenous enzymes. Germination increased starch hydrolysis in all investigated cereals and pseudocereals. The maximum degree of hydrolysis in wheat flour increased from 28 % to 32 % following germination. The effect was more pronounced in spelt flour, where hydrolysis increased from less than 15 % to 37 %, the highest value among the investigated samples. Buckwheat flours showed the lowest hydrolysis, reaching 4.3 % in non-germinated and 14.7 % in germinated samples. Changing the flour-to-water mass ratio from 1:2 to 1:1 or 1:3 had only a minor effect on starch hydrolysis in non-germinated wheat flour during longer incubation at 65 °C. encimska hidroliza pšenična moka pirina moka ajdova moka kaljenje temperatura stopnja hidrolize amilaze škrob maltoza tekočinska kromatografija visoke ločljivosti HPLC enzymatic hydrolysis wheat flour spelt flour buckwheat flour sprouting temperature degree of hydrolysis amylases starch maltose high-performance liquid chromatography HPLC true false false [P. Jakša] Slovenski jezik Angleški jezik Magistrsko delo/naloga 2026-09-18 07:17:20 2026-09-18 07:17:27 2026-09-19 04:29:53 0000-00-00 00:00:00 2026 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 664.2.0:577.15 289815 291613443 61878.pdf 61878.pdf 1 4569EAFC1B0D96559C0F413C65DCFCC8 674538aef6c9dcb5bf25a1eaeca53319218ec20549a44b3fec2cddd810c37d0c 36832ef1-b320-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=248044 Biotehniška fakulteta 0 0 0