Antioksidativna učinkovitost rženega slada

Klemenčič, Bojana (author), Terpinc, Petra (mentor), Pogačnik da Silva, Lea (reviewer)

V diplomskem delu smo želeli proučiti vpliv pogojev slajenja na antioksidativno učinkovitost (AU) rženega (Secale cereale L.) slada. Kaljena zrna smo vzorčili vsakih 24 ur in jih sušili pri temperaturi 60 ºC oz. 100 ºC. Sposobnost lovljenja prostih radikalov smo določili z metodo DPPH• in rezultate podali kot ekvivalent troloksa. Rezultati so pokazali, da namakanje zrn negativno vpliva na količino prisotnih antioksidantov. AU slada je pri etanolnih ekstraktih naraščala ves čas poskusa (96 ur), medtem ko smo pri metanolnih ekstraktih zadnji dan kaljenja zabeležili manjši upad, vendar samo, če smo slad sušili pri 100 ºC. Ugotovili smo, da je učinkovitost antioksidantov v sladu, sušenem pri 100 °C boljša kot v sladu, sušenem pri 60 °C, ter da je AU spojin, ekstrahiranih z metanolom, višja od tistih, ki so ekstrahirane z etanolom, neodvisno od časa kaljenja in pogojev sušenja. Najvišjo AU smo določili v metanolnem ekstraktu slada, ki je bil podvržen 72-urni biološki aktivaciji in temperaturi sušenja 100 °C (0,89 mg troloks/g suhi vzorec), ko je prirast AU znašala 106 % v primerjavi z AU neslajene rži. Zaključimo lahko, da daljši čas kaljenja poveča AU rženega slada ter da temperatura sušenja in pogoji ekstrakcije znatno vplivajo na AU ekstraktov.

• Language: Slovenian
• Keywords: rž, Secale cereale L., rženi slad, fenolne spojine, antioksidativna učinkovitost, metoda DPPH•, metanol, etanol
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [B. Klemenčičl]
• Year: 2017
• PID: 20.500.12556/RUL-98320
• UDC: 663.4:633.14:66.094.3.097.8
• COBISS.SI-ID: 4857464
• Publication date in RUL: 26.11.2017

Secondary language

• Language: English
• Title: Antioxidant efficiency of rye malt

Abstract

The purpose of the thesis was to examine the influence of malting on the antioxidant efficiency (AE) of rye (Secale cereale L.) malt. Germinated grains were sampled every 24 hours and kilned at a temperature of 60 ºC and 100 ºC. The free radical scavenging activity was determined by DPPH• method and the results were expressed as trolox equivalent. The results showed that steeping of the grain has a negative effect on the amount of antioxidants present. AE of ethanolic malt extracts increased throughout the experiment (96 hours), while in the case of methanolic extracts a smaller decrease on the last day of germination was observed, but only if the malt was kilned at 100 °C. The efficiency of antioxidants in malt dried at 100 °C was found to be better than those from malt dried at 60 °C. Furthermore AE of compounds extracted with methanol was found to be higher than those extracted with ethanol, regardless to the germination time and kilning conditions. The highest AE was observed for the methanolic extract of the malt that was subjected to 72-hour biological activation and kilning temperature of 100 °C (0.89 mg Trolox/g dw). When AE was increased for the 106 % compared to the AE of unmalted rye. It can be concluded that longer germination time increases the AE of rye malt and that the kilning temperature and extraction conditions significantly affect the AE of the extracts.

• Keywords: rye, Secale cereale L., rye malt, phenolic compounds, antioxidative efficacy, method DPPH•, methanol, ethanol