professional thesis
Oxidative stability of vegetable oils with added tert- butylhydroquinone and natural antioxidants

Melita Horvat (udano Pašić) (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 tert-butilhidrokinona i prirodnih antioksidansa
AuthorMelita Horvat (udano Pašić)
Mentor(s)Tihomir Moslavac (thesis advisor)
Abstract
Jedan od glavnih problema prilikom proizvodnje, primjene i prerade jestivih ulja je oksidacija lipida, ona uzrokuje važnu promjenu kemijskih, senzorskih i nutritivnih svojstava. Kako bi se spriječila oksidacija lipida u primjeni su razni sintetski i prirodni antioksidansi. U ovom radu istraživan je utjecaj sintetskog antioksidansa tert-butilhidrokinona (0,01 %) i prirodnih antioksidansa ekstrakta ružmarina Oxy´Less®Clear (0,5 % i 1,5 %) i ekstrakta zelenog čaja (0,1 % i 0,3%) na oksidacijsku stabilnost smjese suncokretovog ulja i ostalih vrsta biljnih ulja (50:50). Za ispitivanje oksidacijske stabilnosti korištene su sljedeće vrste biljnih ulja: suncokretovo ulje, sojino ulje, ulje uljane repice, rižino ulje, ekstra djevičansko maslinovo ulje, laneno ulje, kikirikijevo ulje te orahovo ulje. Određivanje oksidacijske stabilnosti ulja, njihovih kombinacija, te utjecaj antioksidansa (tert-butilhidrokinona, ekstrakta ružmarina i ekstrakta zelenog čaja) provedeno je testom ubrzane oksidacije ulja - Rancimat testom (3,0 g, temperatura 120 oC, protok zraka 9 L/h). Rezultat oksidacije ulja izražen je indukcijskim periodom (IP), zaštitnim faktorom (PF) i antioksidacijskom aktivnošću antioksidansa (AA). Stabilnost smjese ulja proporcionalna je indukcijskom periodu. Uz navedeno, spektrofotometrijski je praćena i 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. Prirodni antioksidansi ekstrakt ružmarina OxyLessClear (1,5 %) i ekstrakt zelenog čaja (0,3 %) efikasnije štite smjesu ulja od oksidacijskog kvarenja u odnosu na dodatak sintetskog antioksidansa TBHQ (0,01 %).
Keywordsoil vegetable oil extract oxidative stability antioxidants
Parallel title (English)Oxidative stability of vegetable oils with added tert- butylhydroquinone and natural antioxidants
Committee MembersAndrija Pozderović (committee chairperson)
Tihomir Moslavac (committee member)
Antonija Perl Pirički (committee member)
Vedran Slačanac (committee member)
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
Engineering
Study programme typeuniversity
Study levelpostgraduate specialist
Study programmeFood Safety and Quality
Academic title abbreviationuniv. spec. techn. aliment.
Genreprofessional thesis
Language Croatian
Defense date2010-10-06
Parallel abstract (English)
One of the major problems during production, application and processing of edible oils is oxidation of lipids, it causes an important change in the chemical, sensory and nutritional properties. In order to prevent oxidation of lipids in the application is various synthetic and natural antioxidants. In this paper, monitored the influence of synthetic antioxidants tertbutylhydroquinone (0,01%) and natural antioxidant: extracts of rosemary Oxy'Less ® Clear (0,5% and 1,5%) and green tea extract (0,1% and 0,3% ), on the oxidative stability of sunflower oil mixtures and other types of vegetable oil (50:50). To test the stability of oxidation were used the following types of vegetable oils: sunflower oil, soybean oil, rapeseed oil, rice oil, extra virgin olive oil, linseed oil, and walnut oil. Determination of oxidation stability of oils and their combination, and the impact of antioxidant (tert- butyl hydroquinone, extracts of rosemary and green tea extract) conducted with a test of rapid oxidation of oils - Rancimat test (3.0 g, temperature 120 °C, air flow 9 L/h). The result of oil oxidation expressed induction period (IP) protection factor (PF) and the antioxidant activity of antioxidants (AA). Stability of mixtures of oil is proportional to the induction period. They also monitored spectrophotometrically and the color of oil at 492 nm (transparency). From these results it can be concluded that the addition of certain vegetable oils (25% and 50%) in sunflower oil led to changes in the oxidation stability of oil mixtures. Natural antioxidant extracts of rosemary OxyLessClear (1,5%) and the green tea extract (0,3%) protect oil mixture more efficiently from the oxidative deterioration as compared to the addition of synthetic antioxidants TBHQ (0,01%).
Parallel keywords (Croatian)ulje biljna ulja ekstrakti oksidacijska aktivnost antioksidansi
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:109:723088
CommitterSanda Hasenay