Utjecaj predtretmana inovativnim tehnologijama na aktivnost polifenol oksidaze i peroksidaze u tijestu maslina sorte levantinka

undergraduate thesis

• Title (english): The effect of pretreatment of olive paste with innovative technologies on the activity of polyphenol oxidase and peroxidase in Levantinka variey
• Author: Sandra Kupfer
• Mentor: Klara Kraljić (mentor)
• 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: 2024-07-16, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Polifenol oksidaza i peroksidaza endogeni su enzimi ploda masline koji prilikom proizvodnje djevičan skog maslinovog ulja kataliziraju nepoželjne reakcije oksidacijske degradacije fenolnih spojeva. Cilj o voga rada bio je ispitati utjecaj inovativnih tehnologija (ubrzanog toplinskog tretmana, ultrazvuka, pulsi rajućeg električnog polja i kombinacije ovih tehnologija) te miješenja na aktivnost polifenol oksidaze i peroksidaze. Aktivnost ova dva enzima određena je spektrofotometrijski, mjerenjem koncentracije na stalog o-kinona za polifenol oksidazu te nastalog tetragvajakola za peroksidazu. Pokazalo se kako je ubrzani toplinski tretman najefikasniji u inaktivaciji polifenol oksidaze, dok je aktivirao peroksidazu. Predtretman pulsirajućim električnim poljem doveo je također do smanjenja aktivnosti polifenol oksi daze, i povećanja aktivnosti peroksidaze. Ultrazvuk je povećao aktivnost oba enzima. U fazi miješenja značajno se smanjila aktivnosti oba enzima, ali to je smanjenje izraženije kod polifenol oksidaze. Stati stičkom obradom potvrđeno je kako i primijenjene tehnologije i faza miješenja imaju značajan utjecaj na aktivnost ova dva enzima.

Abstract (english)

Polyphenol oxidase and peroxidase are endogenous enzymes in the olive fruit that are responsible for the undesirable reactions of oxidative degradation of phenolic compounds in the production of virgin olive oil. The aim of this study was to investigate the effect of innovative pretreatment technologies (flash thermal treatment, ultrasound, pulsed electric field and their combinations) and the effect of malaxation on the activity of polyphenol oxidase and peroxidase. The activity of these two enzymes was determined spectrophotometrically by measuring the amount of o-quinone for polyphenol oxidase and the amount of tetraguaiacol for peroxidase. The flash thermal treatment was most effective in inac tivating the polyphenol oxidase, while it increased the activity of the peroxidase. Pretreatment with pulsed electric fields also decreased the activity of polyphenol oxidase and increased the activity of peroxidase. Ultrasound increased the activity of both enzymes. The malaxation process significantly decreased the activity of both enzymes, with the decrease being more pronounced for polyphenol oxi dase.

• Keywords: peroksidaza; polifenol oksidaza; inovativne tehnologije; miješenje; djevičansko masli novo ulje
• Keywords (english): peroxidase; polyphenol oxidase; inovative technologies; malaxation process; virgin olive oil
• Language: croatian
• URN:NBN: urn:nbn:hr:159:442425
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-09-02 11:19:42