Access restricted to higher education institution's students and staff
master's thesis
UTJECAJ TALKA I SOLI NA UČINKOVITOST PROCESA PROIZVODNJE, O-DIFENOLE I BOJU DJEVIČANSKIH MASLINOVIH ULJA SORTI BUŽA, OBLICA I ROSINJOLA

Toni Biskupović (2015)
Metadata
TitleUTJECAJ TALKA I SOLI NA UČINKOVITOST PROCESA PROIZVODNJE, O-DIFENOLE I BOJU DJEVIČANSKIH MASLINOVIH ULJA SORTI BUŽA, OBLICA I ROSINJOLA
AuthorToni Biskupović
Mentor(s)Olivera Koprivnjak (thesis advisor)
Abstract
Kod određenih sorti izdvajanje ulja iz maslinovog tijesta je otežano zbog nastanka emulzije i gela. Takva tijesta nazivaju se “teška” tijesta, a njihovom nastanku pogoduje visok udio vode u plodu (> 50 %) i nizak udio bezmasne suhe tvari (˂ 25 %). Kako bi se povećali prinosi ulja, Međunarodno vijeće za masline preporučuje dodatak pomoćnih tvari za vrijeme miješenja maslinovog tijesta. Talk kao pomoćna tvar potiče ujedinjavanje sitnih kapljica ulja u veće i olakšava ekstrakciju ulja, dok NaCl povećava gustoću i elektrostatsku nabijenost vodene faze maslinovog tijesta te na taj način olakšava izdvajanje uljne faze procesom centrifugiranja. Primjena ovih pomoćnih tvari u proizvodnji nije uobičajena praksa kod hrvatskih uljara. Stoga je u ovom radu istražen utjecaj pomoćnih tvari s fizikalnim djelovanjem (talka i natrijevog klorida, u masenim udjelima 1,5 % i 3,0 %) na pokazatelje uspješnosti laboratorijske prerade (randman, ekstraktabilnost i udio ulja u suhoj tvari komine), o-difenole i boju djevičanskih maslinovih ulja sorti Buža, Oblica i Rosinjola. O-difenoli su ekstrahirani na krutoj fazi i određeni kolorimetrijski, a boja ulja je određena spektrofotometrijski. Dodatak 1,5 % te 3,0 % talka je povećao ekstraktabilnost ulja kod Buže i Oblice, dok kod Rosinjole nije imao učinka. Udio o-difenola u ulju Buže se smanjio ispod granice detekcije analitičke metode s dodatkom talka. Suprotno tomu, dodatak 3,0 % talka povećao je udio o-difenola u ulju Rosinjole za 37 %. Primjena talka nije značajno utjecala na boju ulja niti jedne sorte. Natrijev klorid (3,0 %) statistički je značajno povećao ekstraktabilnost kod Buže i Oblice, te udio o-difenola u uljima Buže i Rosinjole (prosječno za 58%). Dodatak 3,0 % natrijevog klorida doveo je do promjene boje ulja na način da je smanjio zelenu komponentu, a povećao žutu te potamnio ulje.
Keywordsvirgin olive oil talc sodium chloride extractability orto-diphenols oil colour.
Committee MembersDražen Lušić
Branka Blagović
Jasenka Mršić-Pelčić
GranterSveučilište u Rijeci
Medicinski fakultet
Lower level organizational unitsKatedra za tehnologiju i kontrolu namirnica
PlaceRijeka
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Food Chemistry
Study programme typeuniversity
Study levelgraduate
Study programmeStudy of Sanitary Engineering
Academic title abbreviationmag. sanit. ing.
Genremaster's thesis
Language Croatian
Defense date2015
Parallel abstract (English)
In specific cultivars of olives, oil extraction from olive paste is complex as emulsion and gels can be generated during the process. High percentage of water in fruit (> 50 %) and low percentage of non-fat dry matter (˂ 25 %) are contributing to creation of such “difficult” pastes. In order to increase oil yield, International Olive Council recommends addition of coadjuvans while mixing the oil paste. Talc stimulates unification of tiny oil drops into bigger masses and eases oil extraction, while sodium chloride increases the ionic charge and density of the aqueous phase, therefore making it easier to extract oil phase by centrifugation. Usage of such supplements usually isn’t practiced by Croatian oil manufacturers. This paper exhibits the effect of coadjuvans with physical activity (talc and NaCl, in concentrations of 1,5 % and 3,0 %) on oil process yield, o-diphenols and colour in extra-virgin olive oil cultivars Buža, Oblica and Rosinjola. O-diphenols are extracted in solid phase and determined by colorimetry, while the oil colour is determined spectrophotometrically. The addition of 1,5 % and 3,0 % talc enhances extractability of Buža and Oblica oils, however there is no effect with Rosinjola. While in Buža talc reduced o-diphenols to be undetectable under the threshold of analytical method, in Rosinjola they were increased by 37 %. Neither oils were significantly effected in terms of colour. Statistically, addition of 3,0 % NaCl substantially increased the extractability in Buža and Oblica. Concentrations of o-diphenols in Buža and Rosinjola were also affected (58 % in average). 3,0 % NaCl also altered the oil colours by diminishing its lightness and green tones, and enhanced the yellow tones.
Parallel keywords (Croatian)djevičansko maslinovo ulje talk natrijev klorid ekstraktabilnost orto-difenoli boja
Resource typetext
Access conditionAccess restricted to higher education institution's students and staff
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:184:629898
CommitterBosa Licul