Utjecaj ultrazvuka i pulsirajućeg električnog polja na aktivnost lipoksigenaze u plodu masline

master's thesis

• Title (english): Effect of ultrasound and pulsed electric field on the lipoxygenase activity of olive fruits
• Author: Ivana Hojka
• Mentor: Klara Kraljić (mentor)
• Mentor: Katarina Filipan (pomoć pri izradi, neposredni voditelj)
• Committee member: Dubravka Škevin (predsjednik povjerenstva)
• Committee member: Zoran Herceg (član povjerenstva)
• Committee member: Sandra Balbino (član povjerenstva)
• 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: 2024-12-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Mogućnost inkorporacije inovativnih tehnologija, poput ultrazvuka (UZV) i pulsirajućeg električnog polja (PEP), u suvremenu proizvodnju djevičanskog maslinovog ulja (DMU) predmet je brojnih istraživanja u posljednjem desetljeću. Navedene tehnologije, zbog svog djelovanja na staničnu strukturu, mogu povećati iskorištenje proizvodnje ulja, ali mogu djelovati i na kvalitetu, nutritivnu vrijednost i senzorska svojstva DMU. Cilj ovog rada bio je ispitati utjecaj UZV i PEP na aktivnost lipoksigenaze u maslinama hrvatskih autohtonih sorti. Korištene su masline sorti rosulje, levantinke, oblice i istarske bjelice. Lipoksigenaza je izolirana iz tijesta tretiranog UZV-om (256 do 640 W, 3 do 17 min) ili PEP-om (1 do 8 kV/cm, 18 do 102 s), a njezina aktivnost određivana je mjerenjem količine hidroperoksida formiranih u reakciji enzima s linolenskom masnom kiselinom. Aktivnost lipoksigenaze u najvećoj je mjeri uvjetovana sortom masline. Od istraživanih sorti, rosulja posjeduje najveću aktivnost lipoksigenaze i njezina se aktivnost značajno smanjuje primjenom obje inovativne tehnike. Ostale istraživane sorte pokazuju različit odgovor na primijenjene tretmane a povećanje, odnosno smanjenje aktivnosti lipoksigenaze ovisi o primijenjenim parametrima.

Abstract (english)

The possibility of incorporating innovative technologies such as ultrasound (US) and pulsed electric field (PEF) in the modern production of virgin olive oil (VOO) has been the subject of numerous studies over the last decade. These technologies can increase oil yield due to their effect on cell structure, but they can also affect the quality, nutritional value and sensory properties of VOO. The aim of this study was to investigate the influence of US and PEF on lipoxygenase activity in olives from Croatian autochthonous varieties. The olive varieties used were Rosulje, Levantinka, Oblica and Istarska bjelica. Lipoxygenase was isolated from olive paste treated with US (256 to 640 W, 3 to 17 min) or PEF (1 to 8 kV/cm, 18 to 102 s) and its activity was determined by measuring the amount of hydroperoxides formed during the reaction of the enzyme with linolenic fatty acid. The results show that the lipoxygenase activity depends on the olive variety. Of the varieties studied, Rosulja variety has the highest lipoxygenase activity, which is significantly reduced by the two innovative techniques. Other varieties used in this study respond differently to the applied treatments, and the increase or decrease in lipoxygenase activity depends on the parameters applied.

• Keywords: lipoksigenaza; maslina; ultrazvuk; pulsirajuće električno polje; hrvatske autohtone sorte
• Keywords (english): lipoxygenase; olives; ultrasound; pulsed electric field; Croatian autochthonous varieties
• Language: croatian
• URN:NBN: urn:nbn:hr:159:110038
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-01-08 13:36:38