Fizikalne i kemijske metode u praćenju oksidacije maslinovog ulja

undergraduate thesis

• Title (english): Monitoring of oxidative stability of olive oils using physical and chemical methods
• Author: Mihaela Severec
• Mentor: Marko Obranović (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: 2021-08-17, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Maslinovo ulje prepoznato je zbog svojih jedinstvenih senzorskih karakteristika te brojnih istraživanjima koje ga povezuju s pozitivnim učincima na ljudsko zdravlje. Iako je zbog svog sastava relativno stabilno i manje podložno oksidaciji, ipak je jedna od najčešćih uzroka kvarenja tijekom prerade i skladištenja. Svrha ovog istraživanja je usporediti parametre oksidacije svježeg ekstra djevičanskog i termooksidiranog maslinovog ulja kroz određene vremenske intervale s mjerenjima dobivenim putem diferencijalne skrenirajuće kalorimetrije. U ovom radu uzorcima koji su bili podložni termooksidaciji u različitim vremenskim intervalima određivao se peroksidni broj, K – brojevi te je uzorak podvrgnut diferencijalnoj motridbenoj kalorimetriji. Peroksidni brojevi kreću se od 4,74 za svježe, pa sve do 12,19 za maslinovo ulje koje je najduže bilo izloženo termooksidaciji. K₂₃₂, K₂₇₀ i ΔK vrijednosti također su najviše za uzorak koji je najduže bio izložen povišenoj temperaturi. Diferencijalno skenirajuća motridbena krivulja hlađenja pokazuje glavni egzotermni pik oko – 50 °C koja predstavlja temperaturu kristalizacije triglicerida.

Abstract (english)

Olive oil is recognized for its unique sensory characteristics and numerous studies that link it to improving human health. Although due to its composition it is relatively stable and less susceptible to oxidation, it is still one of the most common causes of spoilage during processing and storage. The purpose of this study is to compare the oxidation parameters of fresh and thermooxidized extra virgin olive oil over certain time intervals with measurements obtained by differential scanning calorimetry. In this paper, samples that were subject to thermal oxidation in different time periods is determined peroxide and K – numbers. Samples were also subjected to differential scanning calorimetry. Peroxide numbers range from 4.74 for thermally untreated, to 12.19 for olive oil which has been subject to thermal oxidation for the longest time. K₂₃₂, K₂₇₀ and ΔK values are also the highest for the sample that has been exposed to elevated temperature for the longest time. The DSC cooling curve shows the main exothermic peak at approximately - 50°C which represents the crystallization temperature of the triglycerides.

• Keywords: maslinovo ulje; oksidacija; DSC
• Keywords (english): olive oil; oxidation; DSC
• Language: croatian
• URN:NBN: urn:nbn:hr:159:854111
• 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: 2021-09-28 13:09:25