professional thesis
Oxidative stability of vegetable oils with added propyl gallate and rosemary extract

Katica Volmut (2010)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Food Engineering
Metadata
TitleOksidacijska stabilnost biljnih ulja s dodatkom propil galata i ekstrakta ružmarina
AuthorKatica Volmut
Mentor(s)Tihomir Moslavac (thesis advisor)
Abstract
Oksidacijska stabilnost je važan parametar za procjenjivanje kvalitete ulja i masti, daje dobru procjenu stanja njihove osjetljivosti za oksidacijsko kvarenje. Cilj ovog rada bio je ispitati oksidacijsku stabilnost različitih vrsta biljnih ulja i njihovih kombinacija, te utjecaj ekstrakta ružmarina (StabilEnhance® OSR i OxyLess® CS udjela 0,1% i 0,3%) i propil galata (0,01%) na produženje oksidacijske stabilnosti ulja. Za ispitivanje oksidacijske stabilnosti korištene su sljedeće vrste biljnih ulja: suncokretovo ulje, visokooleinsko suncokretovo ulje, ulje kukuruznih klica, ulje pšeničnih klica, bademovo ulje, ulje koštica grožđa, suncokretovo ulje sa dodatkom gljiva, ulje šafranike i orahovo ulje. Određivanje oksidacijske stabilnosti ulja, njihovih kombinacija, te utjecaja antioksidansa (ekstrakta ružmarina i propil galata) provedeno je testom ubrzane oksidacije ulja - Rancimat testom. Rezultat oksidacije ulja izražen je indukcijskim periodom (IP), zaštitnim faktorom (PF) i antioksidacijskom aktivnošću antioksidansa (AA). Stabilnost smjese ulja proporcionalna je indukcijskom periodu. Također je spektrofotometrijski praćena boja ulja pri 492 nm (transparencija). Iz dobivenih rezultata može se zaključiti da dodatak pojedinih biljnih ulja (25% i 50%) u suncokretovo ulje dovodi do promjene oksidacijske stabilnosti smjese ulja izražene indukcijskim periodom. Dodatkom visokooleinskog suncokretovog ulja kao i ulja kukuruznih klica u suncokretovo ulje produžuje se stabilnost smjese ulja prema oksidacijskom kvarenju. Prirodni antioksidans ekstrakt ružmarina OxyLess® CS značajno povećava oksidacijsku stabilnost smjese suncokretovog ulja i pojedinih ispitivanih ulja (50:50) u odnosu na StabilEnhance® OSR i propil galat.
Keywordsoil oxidative stability rosemary extract propyl gallate
Parallel title (English)Oxidative stability of vegetable oils with added propyl gallate and rosemary extract
Committee MembersAndrija Pozderović
Tihomir Moslavac
Antonija Perl Pirički
Vedran Slačanac
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Food Engineering
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Food Safety and Quality
Study programme typeuniversity
Study levelpostgraduate specialist
Study programmeFood Safety and Quality
Academic title abbreviationuniv. spec. techn. aliment.
Genreprofessional thesis
Language Croatian
Defense date2010-07-09
Parallel abstract (English)
Oxidative stability is an important parameter in evaluation the quality of oils and fats, as it gives a good estimation of their susceptibility to oxidative deterioration. The aim of this study was to investigate oxidative stability of different types of vegetable oils and their combinations, and an effect of rosemary extract and propyl gallate to a prolong oxidative stability of oils. The following types of vegetable oils were used to test the oxidative stability: sunflower , high oleic acid sunflower, corn, wheat germ, almond, grapeseed , sunflower oil with the addition of dried porcini mushrooms, safflowerseed and walnut. A determination of oxidation stability of oils and their combination, and the effect of antioxidants (rosemary extract and propyl gallate) was conducted by a test of rapid oxidation of oil – Rancimat test. The result of oil oxidation was expressed by the induction period (IP), a protective factor (PF) and by antioxidant activity of antioxidants (AA). The stability of blends of oil is proportional to the induction period. The colour of oil also followed up with spectrophotometer at 492 nm (transparency). From these results it can be concluded that an addition of certain vegetable oils (25% i 50%) in sunflower oil led to changes in the oxidation stability of oil blends expressed within the induction period. The addition of high oleic acid sunflower oil and corn oil in sunflower oil prolongs the stability of blends of oil degradation by oxidation. The natural antioxidant rosemary extract OxyLess CS® significantly increases the oxidative stability of sunflower oil blends and some oils tested (50:50) compared to StabilEnhance® OSR, and propyl gallate.
Parallel keywords (Croatian)ulje oksidacijska stabilnost ekstrakt ružmarina propil galat
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:323377
CommitterIvana Šuvak