Usporedba fizikalnih i kemijskih svojstava višnje Maraske sa svojstvima drugih odabranih sorata i ekotipova višnje te njihovih proizvoda

doctoral thesis

• Title (english): Comparison of physical and chemical properties of Marasca and other selected sour cherry varieties or ecotypes and their products
• Author: Maja Repajić
• Mentor: Branka Levaj (mentor)
• Committee member: Verica Dragović-Uzelac (predsjednik povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; Zagreb
• Defense date and country: 2015-07-24, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology
• Universal decimal classification (UDC): 633/635 - Horticulture. Fruit growing. Viticulture. Gardening

Abstract

Cilj ovog istraživanja bio je ispitati utjecaj sorte/ekotipa i lokacije na fizikalno-kemijska i senzorska svojstva te aromu višnje Maraske i drugih sorata/ekotipova višnje. U tu svrhu ispitano je 5 sorata, odnosno ukupno 7 ekotipova višnje s dvije lokacije (okolica Zadra i Osijeka) uzgojenih kroz tri vegetacijske godine. U svim uzorcima određeni su fizikalno-kemijski parametri, boja (L*, a*, b*), udio biološki aktivnih spojeva te antioksidacijski kapacitet FRAP metodom. Za analizu arome primijenjena je mikroekstrakcija na čvrstoj fazi (HS-SPME) i plinska kromatografija uz masenu spektrometriju (GC-MS), a senzorsko ocjenjivanje provedeno je metodom kvantitativne deskriptivne analize (QDA). Također, ispitan je utjecaj skladištenja plodova 6 mjeseci na -18 °C te proizvodnje koncentriranog soka na fizikalno-kemijski sastav i aromu sorata Maraska i Oblačinska. Utvrđeno je da su sve sorte/ekotipovi imali viši udio topljive suhe tvari i tamniju boju na području Zadra. U sorti Maraska određena je gotovo najviša topljiva suha tvar na području Zadra i najviša topljiva suha tvar na području Osijeka, najmanja pH vrijednost i najviša ukupna kiselost na oba područja uzgoja. Najviši udio ukupnih fenola i antocijana te najviše antioksidacijski kapacitet određeni su u sortama Maraska, Rexelle i Heimann konzervna. Sorte/ekotipove s područja Zadra karakterizirao je viši udio benzaldehida, a sorte s područja Osijeka uz benzaldehid i viši udjeli D-limonena. Sorta Maraska se prema senzorskim svojstvima izdvojila od drugih sorata/ekotipova, a karakterizira je tamnija boja, izraženi kiselo-trpki okus, okus i miris na višnju, veća viskoznost i manja homogenost. Skladištenjem 6 mjeseci na -18 °C zadržana je kvaliteta plodova ispitivanih sorti, a procesiranjem u koncentrirani sok, proizvedeni su koncentrati s oko 60 % topljive suhe tvari i različitog aromatičnog sastava u odnosu na plodove, što nije utjecalo na senzorsku prihvatljivost, osobito koncentriranog soka sorte Maraska koji je senzorski ocijenjen višom ocjenom.

Abstract (english)

The objective of this study was to investigate the influence of the variety/ecotype and growing area on physico-chemical and sensory properties as well as aroma of sour cherry Marasca and other sour cherry varieties/ecotypes. Therefore, 5 varieties, or a total of 7 sour cherry ecotypes from two growing areas (Zadar and Osijek area) grown in three growing seasons were investigated. Physico-chemical parameters, colour (L*, a*, b*), content of biologically active compounds and antioxidant capacity by FRAP method were determined. Aroma analysis was carried out by headspace-solid phase microextraction (HS-SPME) and gas chromatography mass spectrometry (GC-MS) and for the sensory evaluation quantitative descriptive analysis (QDA) was applied. Also, the influence of storage at -18 °C for 6 months as well as processing into concentrated juice on the physico-chemical properties and volatile compounds in Marasca and Oblačinska sour cherries were investigated. It was found that all varieties/ecotypes had a higher total soluble solids and darker colour in the Zadar area. Marasca had almost the highest total soluble solids in the area of Zadar and the highest total soluble solids in the Osijek area, the lowest pH value and the highest total acidity in both growing areas. The highest amounts of total phenols and anthocyanins, and the highest values of antioxidant capacity were determined in Marasca, Rexelle and Heimann conserved varieties. The varieties/ecotypes from the Zadar area were characterized with higher amounts of benzaldehyde, while the varieties/ecotypes from Osijek area along with benzaldehyde, had much higher amounts of D-limonene. According to sensory characteristics, Marasca distinguished from other varieties/ecotypes by darker colour, expressed sour-bitter taste, sour cherry taste and odour, higher viscosity and lower homogeneity. Fruit quality of investigated varieties/ecotypes maintained with storing at -18 ° C for 6 months and concentrated juice processing resulted with concentrates containing about 60 % of total soluble solids and different aromatic composition regarding to raw material, which did not affect its sensory acceptability, especially of Marasca concentrated juice, which was sensory higher graded.

• Keywords: višnja; Maraska; fizikalno-kemijska svojstva; boja; senzorika; aroma; zamrzavanje; koncentrirani sok
• Keywords (english): sour cherry; Marasca; physico-chemical properties; colour; sensory analysis; aroma; freezing; concentrated juice
• Language: croatian
• URN:NBN: urn:nbn:hr:159:526286
• Promotion: 2016-04-17
• Study programme: Title: Food Technology; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti (doktor/doktorica znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2018-05-18 08:05:44