master's thesis
Influence of different antioxidants on oxidative stability of a mixture of vegetable oils

Josipa Vadas (2013)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Metadata
TitleDjelovanje različitih antioksidansa na oksidacijsku stabilnost smjese biljnih ulja
AuthorJosipa Vadas
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. U ovom radu istraživan je utjecaj dodatka pojedinog ispitivanog biljnog ulja (25 %, 50 %, 75 %) u rižino ulje na promjenu oksidacijske stabilnosti smjese ulja, te utjecaj prirodnih antioksidansa ekstrakta zelenog čaja (0,1 % i 0,3 %), ekstrakta ružmarina OxyLess.CS (0,1 % i 0,3 %) i ekstrakta nara 10 (0,1 % i 0,3 %) na oksidacijsku stabilnost smjese rižinog ulja i ostalih vrsta biljnih ulja (50:50). Za ispitivanje oksidacijske stabilnosti korištene su sljedeće vrste biljnih ulja: rižino ulje, suncokretovo ulje, repičino ulje i sezamovo ulje. Određivanje oksidacijske stabilnosti ulja, njihovih kombinacija, te utjecaj antioksidansa provedeno je testom ubrzane oksidacije ulja – Oven testom (63 °C). Rezultat oksidacije ulja izražen je peroksidnim brojem (Pbr) tijekom 4 dana testa. Dodatkom suncokretovog i repičinog ulja u rižino ulje dolazi do smanjenja oksidacijske stabilnosti smjese ulja, dok dodatkom sezamovog ulja dolazi do porasta oksidacijske stabilnosti u odnosu na stabilnost čistog rižinog ulja. Dodatkom ekstrakta zelenog čaja i ekstrakta ružmarina u smjese ispitivanih biljnih ulja došlo je do porasta stabilnosti smjese ulja prema oksidacijskom kvarenju. Dodatkom ekstrakta nara u smjesu rižinog i suncokretovog ulja došlo je do malog sniženja vrijednosti peroksidnog broja, dok je dodatkom ekstrakta nara u smjesu rižinog i repičinog te rižinog i sezamovog došlo do prooksidacijskog djelovanja. Najveću efikasnost zaštite s obzirom na korištene antioksidanse pokazuje ekstrakt ružmarina OxyLess.CS u koncentraciji 0,1 %.
Keywordsvegetable oil oxidative stability extract green tea extract rosemary extract pomegranate extract
Parallel title (English)Influence of different antioxidants on oxidative stability of a mixture of vegetable oils
Committee MembersAndrija Pozderović
Tihomir Moslavac
Vedran Slačanac
Jurislav Babić
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2013-05-17
Parallel abstract (English)
One of the major problems during production, application and processing of edible oils is lipid oxidation; it causes an important change in chemical, sensory and nutritional properties. This paper explores the influence of adding certain tested vegetable oil (25%, 50%, 75%) to rice oil, in order to determine a change in the oxidation stability oil mixture, and the influence of natural antioxidants: green tea extract (0,1% and 0,3%), rosemary extract OxyLess.CS (0,1% and 0,3%) and pomegranate extract (0,1% and 0,3%) in order to observe oxidation stability of rice oil mixture and other types of vegetable oils (50:50). The following types of vegetable oils were used in order to test the oxidation stability: rice oil, sunflower oil, rapeseed oil and sesame oil. The determination of oxidation stability of oils, their combinations, and the impact of antioxidants was conducted with a test of rapid oil oxidation – Oven test (63 °C). The result of oil oxidation is expressed by peroxide value (PV) during 4 days of testing. The addition of sunflower and rapeseed oil to rice oil leads to decrease of oxidation stability of oil mixture, while the addition of sesame oil leads to increase of oxidation stability when related to the pure rice oil stability. The addition of green tea extract and rosemary extract to mixtures of tested vegetable oils led to the increase of oil mixture stability towards oxidation degradation. The addition of pomegranate extract to a mixture of rice and sunflower oil led to a small decrease in peroxide number value, while the addition of pomegranate extract to rice and rapeseed mixture, as well as rice and sesame oil led to pro-oxidation activity. Regarding the used antioxidants, the highest protection efficiency is displayed by rosemary extract OxyLess.CS in concentration 0,1%.
Parallel keywords (Croatian)ulje biljna ulja oksidacijska stabilnost ekstrakt ekstrakt zelenog čaja ekstrakt ružmarina ekstrakt nara
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:109:621868
CommitterSanda Hasenay