diplomsko delo
Klara Kozamernik (Author), Barbara Jeršek (Reviewer), Rajko Vidrih (Mentor)

Abstract

Uporaba različnih načinov pasterizacije sadnih sokov različno vpliva na kakovost sadnih sokov. S toplotno obdelavo se kakovost proizvodov lahko močno zmanjša, zato so poleg termične pasterizacije začeli uporabljati netermične metode. Eden izmed teh je uporaba hladne plazme s katero lahko zmanjšamo negativne posledice toplotne obdelave, kot so zmanjšanje hranilne vrednosti in poslabšanje senzoričnih lastnosti. Tretiranje s hladno plazmo v kratkem času (5 s) ne zmanjša vsebnosti vitamina C, lahko pa pride do zmanjšanja, ko čas obdelave podaljšamo (npr. 20 s). Vsebnost antocianinov v sadnem soku se po tretiranju le-tega s hladno plazmo spreminja glede na vrsto sadnega soka, npr. v soku granatnega jabolka so antocianini stabilni, v borovničevem soku se vsebnost močno zmanjša. Vsebnost polifenolov in flavonoidov se lahko poveča, pri predolgi izpostavljenosti pa lahko začnejo razpadati. Barva sadnih sokov se po obdelavi s hladno plazmo ne spreminja tako kot pri toplotni obdelavi, ko lahko nastanejo nezaželjeni rjavo obarvani pigmenti. Mikroorganizme lahko s hladno plazmo popolnoma inaktiviramo, vendar moramo pri tem upoštevati tudi kakovost sadnega soka in empirično določiti optimalne parametre obdelave. Pri obdelavi sadnega soka s hladno plazmo moramo upoštevati tlak, napetost, čas obdelave in vrsto plina ter te parametre prilagajati sadnim sokovom in željenim rezultatom.

Keywords

sadni sokovi;podaljšanje obstojnosti;netermične metode;hladna plazma;inaktivacija mikroorganizmov;vitamin C;hranilna vrednost;senzorične lastnosti;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL BF - Biotechnical Faculty
Publisher: [K. Kozamernik]
UDC: 663.81:664.8/.9:579.67.08:543.9
COBISS: 32123139 Link will open in a new window
Views: 473
Downloads: 124
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Other data

Secondary language: English
Secondary title: Use of cold plasma for treatment of fruit juices
Secondary abstract: Application of different ways of fruit juice pasteurization might impact differently the quality of the products. As thermal processing can drastically diminish the quality of the product, alternative non-thermal means of pasteurization are being tested. One of them is cold plasma, which has no negative consequences on product nutritional and sensory quality. Cold plasma treatment used in a short period of time (5 s) does not diminish the content of vitamin C, although with an increase of the processing time (20 s) quality deterioration might take place. The stability of anthocyanins after the application of cold plasma depends on the type of fruit juice. The content of anthocyanins in pomegranate juice remains stable, while their content in blueberry juice diminishes considerably. The content of polyphenols and flavonoids can increase with the use of cold plasma, but might decompose if the exposure time is too long. The colour of fruit juices does not change after the application of cold plasma as it happens with thermal processing, where unwanted brown pigments form. Microorganisms can be completely inactivated with cold plasma but we also have to consider the quality of the product and empirically set optimal parameters. Pressure, tension, processing time and gas type are the parameters that must be taken into consideration and adjusted according to the type of juice and required results.
Secondary keywords: fruit juices;shelf-life extension;non-thermal methods;cold plasma;microbial inactivation;vitamin C;nutritional value;sensorial characteristics;
Type (COBISS): Bachelor thesis/paper
Study programme: 0
Embargo end date (OpenAIRE): 1970-01-01
Thesis comment: Univ. v Ljubljani, Biotehniška fak., Oddelek za živilstvo
Pages: VII, 17 f.
ID: 12029437