Količina kalija i magnezija u mandarini na tržištu grada Zagreba

master's thesis

• Title (english): Potassium and magnesium content in mandarin on market of city of Zagreb
• Author: Morana Rehak
• Mentor: Marko Petek (mentor)
• Committee member: Marko Petek (predsjednik povjerenstva)
• Committee member: Tomislav Karažija (član povjerenstva)
• Committee member: Goran Fruk (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Plant Nutrition); Zagreb
• Defense date and country: 2021-09-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Mandarina je biljna vrsta koja pripada skupini zimskog sezonskog voća. Vrlo je cijenjena zbog
visokog sadržaja vitamina C te minerala kalija i magnezija. Potrošači nemaju informacije o
točnom mineralnom sastavu mandarina prilikom kupnje, stoga je provedeno istraživanje s
ciljem utvrđivanja količine makroelemenata kalija i magnezija u mandarini te usporedbe
rezultata s obzirom na mjesto kupnje pojedinih uzoraka. Uzorkovanje mandarine provedeno
je u gradu Zagrebu na 3 tržnice, u 3 trgovačka lanca i 3 trgovine ekološkim proizvodima.
Nakon digestije koncentriranom HNO3 i HClO4 u mikrovalnoj peći, kalij je određen
plamenfotometrijski, a magnezij atomskom apsorpcijskom spektrometrijom. Suha tvar
određena je gravimetrijski sušenjem do konstantne mase. Količina suhe tvari u uzorcima
mandarine kretala se u rasponu od 7,86 % do 8,70 %. Količina kalija u suhoj tvari mandarine
kretala se u rasponu od 2,04 % do 2,33 %, a količina magnezija od 0,101 % do 0,110 %.
Količina kalija u svježoj tvari mandarine kretala se u rasponu od 235 do 297 mg K/100 g
svježe tvari, a količina magnezija od 11,6 do 14,0 mg Mg/100 g svježe tvari.

Abstract (english)

Mandarin is a plant species which belongs to the group of winter seasonal fruit. It is highly
valued for its vitamin C, potassium and magnesium content. When buying mandarins,
consumers do not have the information on the exact mineral composition of mandarins so a
study was conducted to determine the content of macroelements potassium and
magnesium in mandarins as well as to compare the results with regards to the place of
purchase of individual samples. Mandarin sampling was carried out in the city of Zagreb at 3
markets, 3 retail chains and 3 organic product stores. After digestion with concentrated
HNO3 and HClO4 in microwave oven, potassium was determined by flame photometry and
magnesium by atomic absorption spectrometry. Dry matter was determined gravimetrically
by drying until constant mass. The content of dry weight in the mandarin samples ranged
from 7,86 % to 8,70 %. The content of potassium in dry weight of mandarin ranged from
2,04 % to 2,33 %, and the content of magnesium from 0,101 % to 0,110 %. The content of
potassium in the fresh weight of mandarin ranged from 235 to 297 mg K/100 g fresh weight,
and the content of magnesium ranged from 11,6 to 14,0 mg Mg/100 g fresh weight.

• Keywords: makroelementi; minerali; uzorkovanje; vitamini; voće
• Keywords (english): fruit; macroelements; minerals; sampling; vitamins
• Language: croatian
• URN:NBN: urn:nbn:hr:204:289147
• Study programme: Title: Agroecology; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka agroekologije (magistar/ magistra inženjer/inženjerka agroekologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2021-11-26 12:44:57