Utjecaj sorte, načina uzgoja i uvjeta proizvodnje na kvalitetu marmelade od jagoda

master's thesis

• Title (english): Variety, cultivar and processing influence on the quality of strawberry marmelade
• Author: Tajana Popović
• 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: 2006-07-14, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

U ovom radu ispitivan je fizikalno – kemijski sastav, fenolni sastav i antioksidativna aktivnost kaša jagoda i niskokaloričnih marmelada od jagoda sorti Marmolada i Elsanta iz konvencionalnog i ekološkog uzgoja. Marmelade su kuhane u vakuum – kuhaču i pri atmosferskom tlaku u laboratorijskim uvjetima. U analiziranim kašama konvencionalnog i ekološkog 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 i marmeladama 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. Metodom kvantitativne deskriptivne analize ocijenjena su senzorska svojstva svježih plodova i kaša jagoda navedenih sorti. Svježe jagode iz ekološkog uzgoja imale su bolje ocijenjen intenzitet obojenosti. Kaše ekološkog podrijetla imale su bolje ocijenjen intenzitet obojenosti, aromu po voću, slatkoću okusa i viskoznost.

Abstract (english)

The aim of the study was to examine physical and chemical composition, phenolic composition and antioxidative acivity of purees and low – calorie marmelades of strawberry varieties, Marmolada and Elsanta, grown in conventional and organic cultivation. Marmelades were prepared under vacuum conditions and under atmosfere pressure in laboratory conditions. Total soluble solids and pH values were similar in analyzed purees from both conventional and organic sources. Purees made from 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, was decreased. However, there was no influence on the antioxidative activity, which was still high. Different processing conditions and type of aded sugar made no effect on the physical and chemical composition of marmelades. Using quantitative descriptive analysis sensoric attributes of fresh strawberries and their purees were estimated. Fresh strawberries from organic cultivation were better evaluated in colour. Purees made of strawberries grown in organic cultivation were better evaluated in colour, fruit aroma, sweetness and viscosity.

• Keywords: antioksidativna aktivnost; antocijani; jagode; marmelade; QDA
• Keywords (english): antioxidative activity; anthocyanins; strawberries; marmelades; QDA
• Language: croatian
• URN:NBN: urn:nbn:hr:159:500984
• 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: 2017-09-07 12:01:36