Fenolni profil slovenskega matičnega mlečka

Rak, Marjeta (author), Polak, Tomaž (mentor), Bertoncelj, Jasna (comentor)

V sklopu magistrske naloge smo v matičnem mlečku želeli določiti vsebnost skupnih fenolnih spojin (SFS), njegovo antioksidativno učinkovitost, vsebnost 10-hidroksi-2-decenojske kisline (10-HDA) in fenolni profil ter ugotoviti, če med obravnavanimi parametri obstajajo povezave. V analizo smo vključili 10 vzorcev matičnega mlečka slovenskega porekla ter 2 vzorca matičnega mlečka tujega porekla. Vsebnost SFS v vzorcih matičnega mlečka smo izrazili v ekvivalentih treh standardnih spojin: galne kisline, hesperetina in hesperidina. Ugotovili smo, da uporaba Folin-Ciocalteu reagenta v kombinaciji z UV-VIS spektrofotometrijo ter predhodno ekstrakcijo na trdni fazi predstavlja primerno metodo za določanje vsebnosti SFS v matičnem mlečku, saj so bili dobljeni rezultati primerljivi z rezultati tujih avtorjev. Antioksidativno učinkovitost matičnega mlečka smo določili na dva načina, kot sposobnost lovljenja radikala DPPH∙ in kot sposobnost redukcije železovega iona. Med metodama smo potrdili linearno povezavo in dokazali, da so vsi vzorci matičnega mlečka antioksidativno učinkoviti. Vsebnost 10-HDA je v skoraj vseh vzorcih nad predpisano mejo 1,4 g/100 g, izstopal je le vzorec matičnega mlečka tujega izvora, ki ni dosegal standarda kakovosti glede vsebnosti te maščobne kisline. S tekočinsko kromatografijo, sklopljeno z masnim spektrometrom (LC-MS), smo določili vsebnost posameznih fenolnih spojin in ugotovili, da se v raziskovanih vzorcih matičnega mlečka v največji meri nahajajo fenolne kisline in flavonoidi. Potrdili smo, da pridelovalec matičnega mlečka statistično značilno vpliva na večino raziskovanih parametrov.

• Language: Slovenian
• Keywords: matični mleček, skupne fenolne spojine, flavonoidi, antioksidativna učinkovitost, 10-HDA, fenolni profil, pridelovalec matičnega mlečka
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [M. Rak]
• Year: 2018
• PID: 20.500.12556/RUL-105723
• UDC: 638.17:547.56:66.094.3.097.8
• COBISS.SI-ID: 5007480
• Publication date in RUL: 08.12.2018

Secondary language

• Language: English
• Title: Phenolic profile of Slovenian royal jelly

Abstract

The aim of the master thesis was to determine the total phenolic content (TPC), antioxidant activity, 10-hydroxy-2-decenoic acid (10-HDA) content, and phenolic profile of royal jelly, and to investigate relationships among analysed parameters. Ten samples of Slovenian royal jelly and two samples of royal jelly of foreign origin were included in the study. The TPC in royal jelly samples was expressed in the equivalent of three standard compounds: gallic acid, hesperetin and hesperidin. The use of the Folin-Ciocalteu reagent in combination with UV-VIS spectrophotometry and solid phase extraction was found as an appropriate method for determination of TPC in royal jelly, as the results obtained were comparable with the results of foreign authors. The antioxidant activity of royal jelly was determined with two methods, such as DPPH∙ radical scavenging activity and ferric reducing antioxidant power (FRAP) assay. We confirmed the linear relationship among the methods used and proved that all samples of royal jelly were antioxidant effective. The 10-HDA content was in almost all samples above the prescribed limit of 1.4 g/100 g, only a sample of royal jelly of foreign origin did not meet the quality standard for the content of this fatty acid. By liquid chromatography-mass spectrometry, the content of individual phenolic compounds was determined and the results showed that phenolic acids and flavonoids were the most prevalent in the analysed samples of royal jelly. We have confirmed that the producer statistically significantly influence most of the parameters investigated.

• Keywords: royal jelly, total polyphenols, flavonoids, antioxidant activity, 10-HDA, phenolic profile, royal jelly producer