Utjecaj sorte i procesa proizvodnje na parametre kvalitete i biološki aktivne spojeve soka višnje

master's thesis

• Title (english): Effect of cultivar and processing on quality parameters and biologically active compounds in sour cherry juice
• Author: Josipa Kušt
• 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: 2014-07-18, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada bio je odrediti utjecaj procesa proizvodnje koncentriranog soka na parametre kvalitete (topljiva suha tvar, pH vrijednost i ukupna kiselost), boju te biološki aktivne spojeve višnje. Utjecaj se pratio na 2 sorte, Maraska i Oblačinska, a uzorci koji su izuzimani iz procesa proizvodnje iz industrije bili su plodovi na početku, sokovi nakon preše, sokovi nakon filtracije i koncentrirani sokovi. Provedena je i senzorska analiza koncentriranih sokova. Prema rezultatima izraţenim na svježi uzorak, vrijednosti za koncentracije fenola i antocijana kao i za antioksidacijski kapacitet rastu slijedom: plod, sok nakon preše, sok nakon filtracije te koncentrirani sok, za uzorke Maraske i Oblačinske. Prema rezultatima izraženim na suhu tvar, za sve parametre trend je isti osim za antocijane koji se tijekom koncentriranja smanjuju i to nešto manje u soku Maraske u odnosu na sok Oblačinske. Obzirom na sortu, svi uzorci Maraske imali su više suhe tvari i sadrže više ukupnih fenola, ukupnih i pojedinačnih antocijana te imaju veću antioksidacijsku aktivnost.

Abstract (english)

The aim of this study was to determine the effects of processing of sour cherry juices on quality parameters (soluble dry matter, pH value, total acidity), color parameters and biologically active compounds. From industrial juice production factory, fresh fruit at the beginning, juices after presses, juices after filtration and concentrated juices were sampled during the processing. Two varieties, Maraska and Oblaĉinska, were investigated. Sensory analysis of concentrated juices was also conducted. According to results expressed on fresh sample values, concentrations of phenols and anthocyanins as well as antioxidant capacity, increased in order: fruit, juice after presses, juice after filtration and concentrated juice, for both Maraska and Oblaĉinska. When expressed on a dry weight, the trend is the same for all parameters, except for anthocyanins which reduced during concentration. Reduction of anthocyanins was lesser in Marasca juice in relation to Oblaĉinska juice. Given the variety, all samples of Maraska had more soluble dry matter and contained more total phenols, total and individual anthocyanins and had higher antioxidant capacity.

• Keywords: višnja; sok; koncentrirani sok; antocijani; antioksidacijska aktivnost
• Keywords (english): sour cherry; juice; concentrated juice; anthocyanins; antioxidant activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:351716
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-02 09:28:22