Utjecaj hladne plazme na kvalitetu 100%tnog soka jabuke tijekom skladištenja

undergraduate thesis

• Title (english): Effect of cold plasma to the quality of 100% apple juice during storage
• Author: Tihana Žugčić
• Mentor: Zoran Herceg (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Food Processes Engineering); Zagreb
• Defense date and country: 2015-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu ispitivan je utjecaj hladne plazme na kvalitetu 100%-tnog soka jabuke tijekom skladištenja od 10 dana. Praćena je mikrobiološka aktivnost, sadržaj vitamina C, pH te promjena boje. Pripremljeni uzorci tretirani su hladnom plazmom pri frekvenciji od 60, 90 i 120 Hz. Tretmani su se provodili u trajanju od 3, 6 i 9 min pri temperaturi od 30, 40 i 50 °C. Ispitivanjem utjecaja hladne plazme na kvalitetu 100 %-tnog soka jabuke tijekom skladištenja utvrđeno je da se najveća redukcija mikroorganizama ostvaruje dužim tretiranjem hladnom plazmom. Učinak je veći primjenom veće temperature. Dužim tretmanom ostvaruje se veća degradacija boje i vitamina C. Utjecaj hladne plazme na promjenu pH-vrijednosti nije značajan. Na temelju rezultata, može se zaključiti da je hladna plazma dobra metoda za produljenje roka trajnosti. Duži tretman pri većoj temperaturi i frekvenciji rezultirao je boljom inaktivacijom mikroorganizama, dok se za očuvanje vitamina C i boje soka najučinkovitijim pokazao kraći tretman.

Abstract (english)

The aim of this thesis was to examine the effect of cold plasma to the quality of 100% apple juice during 10 days storage. Quality parameters such as vitamin C content, pH, color, and changes of microbial activity were monitored during storage time. Juice samples were treated by cold plasma with applied frequencies of 60, 90 and 120 Hz. The experiments were conducted at different treatment times (3, 6 and 9 min) and temperature variations (30, 40 and 50 °C). This study of the effect of cold plasma to the quality of 100% apple juice during storage showed that the combined treatment had the most influence, depending on temperature and treatment time. Longer treatment time showed greater microbial reduction, but also vitamin C and color degradation. The effect of cold plasma on pH measurement was not significant. In conclusion, cold plasma is a promising new technique for prolonging juice shelf-life. Longer treatment time, higher frequencies and higher temperature are optimal parameters for microbial inactivation, but on the other hand, shorter treatment time are more effective for vitamin C and color preservation.

• Keywords: hladna plazma; vitamin C; pH-vrijednost; boja; mikrobiološka aktivnost
• Keywords (english): cold plasma; vitamin C; pH measurement; color; microbial activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:060046
• 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: Access restricted to students and staff of home institution
• Created on: 2017-04-26 07:26:11