Stabilnost napitka od lista masline tijekom skladištenja pri povišenoj temperaturi

undergraduate thesis

• Title (english): The stability of olive leaf drink during storage at high temperature
• Author: Ivana Hajdinjak
• Mentor: Branka Levaj (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2017-07-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je ispitati stabilnost napitka od lista masline tijekom 12 tjedana skladištenja u nepovoljnim uvjetima i to na temperaturi od 30 °C, a provedene su sljedeće analize: odreĎivanje koncentracije ukupnih fenola pomoću Folin-Ciocalteu reagensa, odreĎivanje antoksidacijskog kapaciteta DPPH metodom, odreĎivanje boje CIELAB metodom, odreĎivanje mikrobiološke ispravnosti i odreĎivanje senzorskih svojstva kvalitativnom deskriptivnom analizom. Koncentracija ukupnih fenola skladištenjem se smanjuje, ali ne značajno. Antioksidacijski kapacitet ostao je pribliţno jednak tijekom skladištenja. Mjerenje boje ukazalo je na smanjenje L i H vrijednosti, te porasta a, b, C i ΔE vrijednosti. Vezano za senzorska svojstva skladištenjem napitka dolazi do smanjenja ţute boje, mirisa na list masline, okusa na list masline, trpkog okusa, gorkog okusa, arome svojstvene na list masline i arome na zeleno, te se povećava udio smeĎe boje i harmoničnog okusa. Strani miris, okus i aroma su manje zastupljeni ili ih uopće nema. Mikrobiološka ispitivanja ukazuju na zadovoljavajuću stabilnost napitka tijekom skladištenja.

Abstract (english)

The purpose of this study was to examine the stability of olive leaf drink during 12 weeks of storage under unfavorable conditions, at 30 ° C. The following analyzes were carried out: determination of total phenol concentration by Folin-Ciocalteu reagent, determination of antioxidant capacity using DPPH method, color determination using CIELAB method, determination of microbiological accuracy and determination of sensory properties by qualitative descriptive analysis. During storage, concentration of total phenol was not significantly reduced, while the antioxidant capacity remained approximately unchanged. Color measurement indicated a decrease in values L and H, while values a, b, C and ΔE were increased. Sensory tests showed reduction of yellow color, smell of olive leaf, olive leaf taste, sourness, bitterness, olive leaf aroma and green aroma, while estimated values of brown color and harmonious taste increased. Sensory tests report that strange smell, taste and aroma are less present or not present at all. Microbiological studies indicate satisfactory drink stability during the trial period.

• Keywords: antioksidacijski kapacitet; fenoli; list masline; napitak; skladištenje
• Keywords (english): antioxidant capacity; phenol; olive leaf; drink; storage
• Language: croatian
• URN:NBN: urn:nbn:hr:159:607374
• Study programme: Title: Nutrition; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-07-10 06:42:47