Utjecaj uvjeta skladištenja na održivost bučinog i suncokretovog ulja

master's thesis

• Title (english): Impact of storage conditions on the stability of pumpkin and sunflower oil
• Author: Sonja Glumbić
• 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: 2006-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Određivana je stabilnost bučinog i suncokretovog ulja te bučinog ulja uz dodatak 2, 5 i 10% suncokretovog ulja tijekom skladištenja na svjetlu u prozirnoj i tamnoj ambalaži te skladištenja u mraku. Provedeno je i ubrzano kvarenje istih uzoraka pri 98° C. Oksidacija ulja praćena je određivanjem peroksidnog broja, a kod ubrzanog kvarenja i određivanjem porasta mase. Snimljene su i apsorbancijske krivulje svih uzoraka u vidljivom dijelu spektra kako bi se vidjelo da li uvjeti skladištenja utječu i na boju ulja. Svi ispitivani uzorci, na svjetlu u prozirnoj i tamnoj ambalaži, pokazali su nakon 30 dana skladištenja veliko povećanje peroksidnog broja. Na svjetlu se najbrže kvarilo čisto bučino ulje, bez obzira na ambalažu, ali nešto jače u prozirnim bočicama. Suncokretovo ulje se u ovim uvjetima kvarilo najsporije, ali istom brzinom i u prozirnoj i tamnoj ambalaži. Dodatkom suncokretovog ulja u bučino ulje (u sve tri koncentracije) neznatno je porasla stabilnost bučinog ulja u ovim uvjetima. Istovremeno je kod uzoraka skladištenih u mraku najmanji porast peroksidnog broja bio kod bučinog ulja, a najveći kod suncokretovog. Kod bučinog ulja kojem je dodano suncokretovo, peroksidni broj je rastao u korelaciji s povećanjem dodanog suncokretovog ulja. Oksidacijske promjene kod ubrzanog kvarenja pri 98° C bile su najmanje kod čistog bučinog ulja, a najveće kod čistog suncoketovog, dok su kod mješavine uzoraka ove promjene također u korelaciji s udjelom dodanog suncokretovog ulja. U svim uzorcima osim čistog suncokretovog ulja došlo je tijekom skladištenja na svjetlu do većeg ili manjeg gubitka boje.

Abstract (english)

The stability was determined in pumpkin and sunflower oil and in mixture of pumpkin oil with 2, 5, and 10% of sunflower oil, during the storage in transparent and dark bottles in the daylight and in the dark. The samples were heated at 98°C. Oxidation of oil was indicated by determination of the peroxide value, and in quick spoilage by determination of increase in mass. The absorption lines were noted down for all the samples in visible part of spectrum to see if the conditions of storage influence the colour of oil. All the samples in transparent and dark bottles stored for 30 days in the daylight showed a large increase in peroxide value. Pumpkin seed oil had the quickest spoilage in the light, regardless of the colour of the bottles, but more in transparent bottles. Under these conditions sunflower oil had the slowest grade of spoilage, but it spoiled at the same rate in transparent and dark bottles. In the mixtures of sunflower and pumpkin oil (in all three concentrations), the stability of pumpkin seed oil has risen insignificantly under these conditions. At the same time in the samples that were stored in the dark the smallest increase in the peroxide value was in pumpkin seed oil and the biggest increase was in sunflower oil. In the mixture of sunflower and pumpkin oil, the peroxide value increased in correlation with an increase of sunflower oil concentration. During the heating at 98°C the changes in oxidation were the smallest in the pure pumpkin seed oil and the largest in the pure sunflower oil, while in the mixtures of these samples the changes were in correlation with the amount of sunflower oil in the mixture. During the storage, in all the samples, except from the pure sunflower oil, the loss of colour in higher or lower degree was noted.

• Keywords: bučino ulje; suncokretovo ulje; skladištenje; održivost; peroksidni broj
• Keywords (english): pumpkin seed oil; sunflower oil; storage; stability; peroxide value
• Language: croatian
• URN:NBN: urn:nbn:hr:159:318761
• 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: 2017-09-11 08:15:31