Utjecaj uvjeta skladištenja na održivost bučinog i sojinog ulja i njihovih mješavina

master's thesis

• Title (english): Influence of the storage conditions on the stability of pumpkin seed and soybean oil and their mixtures
• Author: Tanja Ptiček
• Mentor: Desanka Rade (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Oil and Fat Technology); Zagreb
• Defense date and country: 2006-04-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovome radu određivana je stabilnost bučinog i sojinog ulja te bučinog ulja uz dodatak 2, 5 i 10% sojinog ulja tijekom 30 dana skladištenja na svjetlu u prozirnoj i zelenoj staklenoj ambalaži, te skladištenja u mraku u staklenoj ambalaži. Oksidacija ulja bila je najveća u uljima koja su se skladištila u prozirnoj staklenoj ambalaži na svjetlu, nešto manja kod onih koja su bila u zelenoj ambalaži na svjetlu, a mala kod ulja koja su bila skladištena u mraku. Na svjetlu se najbrže kvarilo čisto bučino ulje, a najsporije čisto sojino, dok je u mraku bilo obrnuto. Uzorcima ulja je određen i sastav masnih kiselina. U bučinom i sojinom ulju najzastupljenije masne kiseline su linolna i oleinska, pa je sličan sastav i u miješanim uljima, na osnovu kojeg se nije moglo dokazati patvorenje bučinog ulja. Snimljene su i apsorbancijske krivulje u vidljivom dijelu spektra iz kojih se vidjelo da uvjeti skladištenja na svjetlu utječu na gubitak boje u nekim uzorcima. Provedeno je i ubrzano kvarenje pri 98 ºC tijekom 24 sata, te su se oksidacijske promjene pratile povećanjem mase i određivanjem peroksidnog broja. Najmanje promjene bile su kod bučinog čistog ulja, a najveće kod sojinog ulja, dok su kod miješanih ulja ove promjene u korelaciji s dodanim udjelima sojinog ulja.

Abstract (english)

In this work the stability of pumpkin seed oil, soybean oil and pumpkin seed oil with the 2, 5 and 10% addition of soybean oil was determined during 30 day storage period in clear and green glass containers in the daylight and in glass containers in the dark. In the daylight, the oxidation of oil was the greatest in the oils stored in clear containers and somewhat lower in those stored in green containers. The oxidation was small in the oils stored in the dark. In the light the deterioration of pure pumpkin seed oil was the fastest and of the pure soybean oil the slowest, while in the dark it was the other way around. The content of fatty acids was also determined for the samples. Linoleic and oleic acids represent the biggest part of the total fatty acids in pumpkin seed and soybean oil. The composition was similar in the mixed oil samples so the adulteration of the pumpkin oil couldn't be proven. The absorption curves were recorded in the visible part of the spectrum from which can be seen that the storage conditions in the daylight influence the loss of color in some samples. The deterioration process was also accelerated at 98 ºC during 24 hours. The changes in oxidation were observed through the increase of the mass and the determination of the peroxide value. Smallest changes were present in the pure pumpkin seed oil and the greatest in the soybean oil while trough the mixed oils these changes were in correlation with the added quantity of soybean oil.

• Keywords: bučino ulje; održivost; patvorenje; skladištenje; sojino ulje
• Keywords (english): adulteration; pumpkin seed oil; soybean oil; stability; storage
• Language: croatian
• URN:NBN: urn:nbn:hr:159:745713
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-08 12:25:35