Utjecaj ultrazvuka visokog intenziteta na fizikalna svojstva soka od jabuke

undergraduate thesis

• Title (english): Influence of high intensity ultrasound on physical properties of apple juice
• Author: Sven Knechtl
• Mentor: Tomislav Bosiljkov (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2018-09-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj rada bio je ispitati pozitivan utjecaj ultrazvuka visokog intenziteta na promjenu fizikalnih svojstava soka od jabuke. Promatrana je promjena sljedećih fizikalnih svojstava soka od jabuke: apsorbancija, indeks stabilnosti soka od jabuke (ISS), gustoća, prividna viskoznost, raspodjela veličine čestica i temperatura. Pratio se utjecaj ultrazvuka konstantne frekvencije od 30 kHz i nominalne snage od 100 W pri amplitudama od 20, 60 i 100 %, vremenu obrade od 2, 6 i 10 minuta sa sondama promjera 7 i 10 mm. Rezultati dobiveni u ovom istraživanju obrađeni su pomoću programskog paketa „Statistica 12“. Ultrazvuk visokog intenziteta pokazuje statistički značajan utjecaj na sva promatrana fizikalna svojstva soka i njegovu stabilnost. Najstabilniji sokovi dobiveni su pri nižim vrijednostima amplitude (20 %) i vremena obrade (2 i 6 minuta) s vrijednostima ISS od 100 – 600 sati koje prati interval učestalosti raspodjele čestica od 0,05 – 3 μm.

Abstract (english)

The main goal of this research was to examine the positive effect of high-intensity ultrasound on the changes in physical properties of the apple juice. The changes of the following physical properties were observed: absorbance, juice stability index (ISS) density, apparent viscosity, particle size distribution, and temperature. The effect of 30 kHz constant frequency ultrasonic waves with a nominal power of 100 W, amplitudes of 20, 60 and 100 % and with 2 different probe sizes (7 and 10mm) was observed at different time intervals od 2, 6 and 10 minutes. The results acquired by this study were processed by the program „Statistica 12“. High-intensity ultrasound shows a statistically significant effect on the physical properties of apple juice and its stability. The most stable juice was observed at lower amplitudes (20 %) and at (2 and 6 minutes) with ISS values of 100 – 600 hours. The interval of particle size distribution was at 0,05 – 3 μm.

• Keywords: ultrazvuk visokog intenziteta; sok od jabuke; fizikalna svojstva; raspodjela veličine čestica
• Keywords (english): apple juice; high – intensity ultrasound; physical properties; particle size distribution
• Language: croatian
• URN:NBN: urn:nbn:hr:159:054196
• 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: 2018-10-04 12:04:49