Utjecaj obrade visokim hidrostatskim tlakom na reološka i mehanička svojstva soka iz voća kaki (Diospyros kaki)

undergraduate thesis

• Title (english): Influence of high hydrostatic pressure on the rheological and mechanical properties of the juice from the fruit Japanese Persimmon (Diospyros kaki)
• Author: Vlatka Poturica
• Mentor: Damir Ježek (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Unit Operations); Zagreb
• Defense date and country: 2016-06-30, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu ispitivan je utjecaj obrade visokim hidrostatskim tlakom na reološka i mehanička svojstva soka iz voća kaki (Diospyros kaki). Određivani parametri su pH, gustoća, viskoznost, raspodjela veličine čestica, boja i tekstura. Nakon mjesec dana mjerenja su ponovljena, kako bi potvrdili upotrebu tlaka kao alternativnu metodu sterilizaciji temperaturom. Pripremljeni uzorci tretirani su visokim hidrostatskim tlakom od 200, 300 i 400MPa u trajanju od 4 i 8 minuta. Ispitivanjem utjecaja visokog hidrostatskog tlaka na reološka i mehanička svojstva soka voća kaki utvrđeno je da nema značajnije promjene u navedenim svojstvima. Tijekom skladištenja ista svojstva su uglavnom održana. Najbolja održivost svojstava ostvarena je djelovanjem tlaka od 300MPa u trajanju od 8min. Primjenom većeg tlaka dolazi do veće degradacije boje. Na temelju rezultata, može se zaključiti da je visoki hidrostatski tlak dobra metoda tretiranja soka pri čemu izvorna reološka i mehanička svojstva ostaju očuvana, a trajnost je produljena. Najučinkovitijim pokazao se tretman tlakom od 300MPa kroz 8min.

Abstract (english)

The aim of this thesis was to examine the effect of treatment with high hydrostatic pressure on the rheological and mechanical properties of the juice from the fruit Japanese Persimmon (Diospyros kaki). Determined parameters are pH, density, viscosity, particle size distribution, color and texture. After a month the measurements are repeated to confirm the use of pressure as an alternative method of temperature sterilization. The prepared samples were treated with high hydrostatic pressure of 200, 300 and 400MP in duration of 4 and 8 minutes. By examining the impact of high hydrostatic pressure on the rheological and mechanical properties of fruit juice Japanese Persimmon it is determined that there are no significant changes in these properties. During storage the same properties are mainly held. Best sustainability of characteristics is achieved by pressure of 300 MPa for an 8min. Using a higher pressure leads to higher degradation of colors. Based on the results, it can be concluded that the high hydrostatic pressure is a good method of treating juice with whom original rheological and mechanical properties remain intact, and durability is prolonged. The most effective treatment has proven to be a pressure of 300MPa through 8min.

• Keywords: visoki hidrostatski tlak; reološka i mehanička svojstva; pH-vrijednost; boja
• Keywords (english): high hydrostatic pressure; rheological and mechanical properties; pH-value; color
• Language: croatian
• URN:NBN: urn:nbn:hr:159:554893
• 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: 2017-04-24 12:52:49