diplomsko delo
Iztok Stegovec (Author), Tatjana Košmerl (Reviewer), Mojca Korošec (Mentor)

Abstract

Terjak je živilo, ki se tradicionalno pripravlja iz soka bezgovih jagod. V ljudski medicini se mu pripisuje številne za zdravje ugodne učinke, zato v predelih Slovenije, kjer ga izdelujejo, ni manjkal v domači lekarni. Namen dela je bil senzorično oceniti vzorce terjaka in določiti vrednosti nekaterih parametrov, povezanih s preprečevanjem procesov oksidacije. Senzorično ocenjevanje je obsegalo ocenjevanje terjaka in pripravljenega napitka iz terjaka in sicer smo z metodo kvalitativne opisne analize opisali značilne lastnosti arome terjaka, s pomočjo hedonske lestvice ugotavljali ugajanje tega izdelka iz bezgovih jagod in razvrščali napitke iz analiziranih vzorcev, po intenzivnosti sladkega in kislega okusa. Analizirali smo šest vzorcev terjaka. Poleg senzorične analize smo s spektrofotometričnima metodama določili antioksidativno učinkovitost in skupne fenolne spojine, izmerili pH vrednost, ter vsebnost vode in parametre barve v sistemu CIE L*a*b*. Za terjak je značilna aroma po karamelu, zažganem sladkorju in suhih slivah. V napitku iz terjaka je bil najbolj izrazit kisel okus in trpka aroma. Povprečno vsebuje 28 % vode, ima kisel pH (3,81), parametri barve znašajo povprečno 20,04 (L*), 1,01 (a*), 0,85 (b*). Izmerili smo visoko antioksidativno učinkovitost, povprečno 726 mgtrolox/100 g, in vsebnost skupnih fenolov, 1588 mgGAE/100 g. Zastavljeni hipotezi smo ovrgli, saj nismo dokazali negativne korelacije med pH vrednostjo in antioksidativno učinkovitostjo, prav tako nismo potrdili povezave med vsebnostjo skupnih fenolnih spojin in nižjo hedonsko oceno, saj vzorec z najvišjo vsebnostjo teh spojin ni bil najslabše ocenjen.

Keywords

bezgove jagode;črni bezeg;Sambucus nigra;terjak;fizikalnokemijske lastnosti;senzorične analize;senzorične lastnosti;antioksidanti;antioksidativna učinkovitost;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [I. Stegovec]
UDC: 615.89:634.747:543.92
COBISS: 4837752 Link will open in a new window
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Downloads: 406
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Other data

Secondary language: English
Secondary title: Characterization of some chemical and sensory properties of terjak
Secondary abstract: Terjak is a home remedy, which is traditionally prepared from elderberry juice. Based on folk medicine, it supposably has a lot of health benefits, that is why it was a vital part of every home pharmacy in the regions of Slovenia, where it is produced. The purpose of our work was sensory analysis of the samples of terjak, and to determine the values of some parameters, affecting the antioxidant activity. Sensory analysis was done on raw samples as well as on the drink prepared with them. With the qualitative descriptive method we determined the characteristics of the aroma of terjak, with the hedonic scale we determined the liking levels of samples, and we ranked the prepared drink samples according to their intensity of the sweet and sour taste, respectively. We analyzed six samples. Alongside of the sensory analysis, we determined the antioxidant capacity and total phenolic content, using a spectrophotometric method. We measured the pH values, determined the water content and the colour parameters in the CIE L*a*b* system. The aroma of terjak is characterized by caramel, burnt sugar and dried prunes. In a drink from terjak sour taste and astringency were the most intensively perceived. The product contains on average 28 % water, has acidic pH value (3.81), and colour parameteres 20.04 (L*), 1.01 (a*), 0.85 (b*). Terjak has high antioxidant capacity, on average 726 mgtrolox/100 g, and content of total phenolic, 1588 mgGAE/100 g. The set hypothesis turned out to be wrong, as there was no negative correlation between the pH values and the antioxidant capacity, as well as no connection between the total phenolic content and a lower score on the hedonic scale, as the sample with the highest content of these compounds, did not receive the lowest score.
Secondary keywords: elderberry;black elder;Sambucus nigra;terjak;physicochemical properties;sensory analysis;sensory properties;antioxidants;antioxidant potential;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VIII, 21 f., [2] f. pril.
ID: 10910304