Utjecaj sorte i uvjeta uzgoja na kvalitetu svježih jagoda te postupaka proizvodnje na kvalitetu marmelada

master's thesis

• Title (english): Variety and cultivar influence on the quality of fresh strawberries and processing treatments on marmelade's quality
• Author: Sanja Paljević
• 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: 2005-12-21, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu ispitivan je fizikalno – kemijski sastav i antioksidativna aktivnost kaša jagoda i niskokaloričnih marmelada od jagoda sorti Maya i Queen Elisa iz konvencionalnog i ekološkog uzgoja. Metodom kvantitativne deskriptivne analize ocijenjena su senzorska svojstva svježih plodova i kaša jagoda navedenih sorti. Marmelade su kuhane u vakuum – kuhaču i pri atmosferskom tlaku u laboratorijskim uvjetima. U analiziranim kašama ekološkog i konvencionalnog podrijetla količina topljive suhe tvari i pH vrijednosti bile su podjednake. Utvrđeno je da kaše ekološkog podrijetla imaju veću količinu pektina. Količina ukupnih fenola i neflavonoida bila je veća u kašama ekološkog podrijetla. Preradom kaša u marmelade došlo je do smanjenja količine ukupnih fenola, naročito antocijana, ali to nije utjecalo na smanjenje antioksidativne aktivnosti. Način kuhanja i vrsta dodanog šećera ne utječu na fizikalno – kemijski sastav marmelade. Svježe jagode iz konvencionalnog uzgoja imale su bolje ocijenjen intenzitet obojenosti, mirisa i arome po voću. Kaše ekološkog podrijetla imale su bolje ocijenjen okus i miris po jagodama.

Abstract (english)

The aim of the study was to examine physical and chemical composition and antioxidative acivity of purees and low – calorie marmelades of strawberry varieties, Maya and Queen Elisa, grown in conventional and organic cultivation. Using quantitative descriptive analysis sensoric attributes of fresh strawberries and their purees were estimated. Marmelades are prepared under vacuum conditions and under atmosfere pressure in laboratory conditions. Total soluble solids and pH values were almoust similar in analyzed purees from ecological and conventional source. Purees made of strawberries grown in organic cultivation had much more pectins. Amounts of total phenolics and flavonoids were higher in purees and marmelades from organic cultivation. During the processing of purees into marmelades the amount of total phenolics, especially of anthocyanins, were decreased, but there were no influence on the antioxidative activity, which was still remarkable. Different processing conditions and type of aded sugar didn`t affected on the physical and chemical composition of marmelades. Fresh strawberries from conventional cultivation were better evaluated in colour, flavour and fruit aroma. Purees made of strawberries grown in organic cultivation were better evaluated in taste and strawberry flavour.

• Keywords: antioksidativna aktivnost; antocijani; jagode; marmelade; QDA
• Keywords (english): antioxidative activity; anthocyanins; strawberries; marmelades; QDA
• Language: croatian
• URN:NBN: urn:nbn:hr:159:081501
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-11 14:01:52