Vpliv različnih načinov priprave na vsebnost fenolnih spojin v alkoholnih ekstraktih plodov hruške (Pyrus communis L.)

Ivanušič, Mojca (author), Mikulič Petkovšek, Maja (mentor)

Z magistrskim delom smo želeli preveriti, kateri dejavniki ekstrakcije vplivajo na vsebnost fenolnih spojin pri pripravi hruškovega likerja, iz plodov sorte 'Viljamovka'. V poskusu smo imeli šest različnih obravnavanj: tehnološko zrele hruške v 70 % etanolu, tehnološko zrele hruške v 40 % etanolu, užitno zrele hruške v 70 % etanolu, užitno zrele hruške v 40 % etanolu, pire pripravljen iz užitno zrelih hrušk v 40 % etanolu ter suhi krhlji užitno zrelih hrušk v 40 % etanolu. Med analiziranimi fenolnimi spojinami je pri vseh obravnavanjih bilo izmerjene največ klorogenske kisline, sledijo epikatehin in derivati izoramnetina. Ugotovili smo, da se je izmed vseh obravnavanj, pri katerih smo uporabili 40 % etanol, največ fenolnih spojin izločilo iz suhih krhljev užitno zrelih plodov (926 µg/10 ml), vendar razlika v vsebnosti fenolnih spojin glede na užitno zrele hruške ni bila značilna. Najmanj fenolnih spojin se je ekstrahiralo iz pireja užitno zrelih hrušk (440 µg/10 ml), vendar se vsebnost ni značilno razlikovala od vsebnosti fenolnih spojin, ekstrahiranih iz tehnološko in užitno zrelih plodov. Vrsta topila (70 % in 40 % etanol) in zrelost plodov (tehnološka in užitna zrelost) sta prav tako vplivali na vsebnost skupnih fenolnih spojin, ki jih je bilo značilno več v tehnološko zrelih plodovih, ki smo jih ekstrahirali s 70 % etanolom (253 g/kg). Za čim večjo vsebnost skupnih fenolnih spojin v domačih likerjih hruške (40 % etanol) bi bilo torej najboljše uporabiti suhe krhlje.

• Language: Slovenian
• Keywords: hruška, različni načini priprave, alkoholni ekstrakti, fenolne spojine
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [M. Ivanušič]
• Year: 2019
• PID: 20.500.12556/RUL-113222
• UDC: 634.13:543.61:547.56(043.2)
• COBISS.SI-ID: 9374329
• Publication date in RUL: 14.12.2019

Secondary language

• Language: English
• Title: Influence of different methods of preparation on phenolic compounds in alcohol extracts of pear fruit (Pyrus communis L.)

Abstract

With this thesis we wanted to check what extraction factors affect the content of phenolic compounds in the preparation of pear liqueur from pear fruits of 'Williams' variety. The experiment had six different treatments: technological ripe pears in 70 % ethanol, technological ripe pears in 40 % ethanol, edible pears in 70 % ethanol, edible pears in 40 % ethanol, puree prepared from edible pears in 40 % ethanol and dried slices of edible pears in 40 % ethanol. Among the identified phenolic compounds, the highest content of chlorogenic acid was measured in all treatments, followed by epicatechin and isoramnetin derivatives. We found that, irrespective to the all treatments and using of 40 % ethanol, the majority of phenolic compounds were extracted from the dry pear slices (926 µg / 10 mL), but the differences in the content of phenolic compounds compared to the edible ripe fruits were not significant. The lowest values of phenolic compounds were extracted from puree of edible pears (440 µg / 10 mL), but the content was not significantly different compared to the phenolic compounds extracted from technological and edible fruits. The type of solvent (70% and 40% ethanol) and fruit maturity (technological and edible maturity) also influenced the content of total phenolic compounds, which contents were significantly higher in technological ripe fruits, which were extracted with 70 % ethanol (253 g / kg). To maximize the content of total phenolic compounds in homemade pear liqueurs (40 % ethanol), the dried pear slices should be used.

• Keywords: pear, different preparation methods, alcoholic exstracts, phenolic compounds