master's thesis
Influence of sugar addition and pH on pigment stability in red beet puree before and after freeze drying

Martina Marić (2009)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Food Technologies
Sub-department of Fruits and Vegetables Technology
Metadata
TitleUtjecaj dodatka šećera i pH na stabilnost pigmenata u kaši cikle prije i nakon liofilizacije
AuthorMartina Marić
Mentor(s)Nela Nedić Tiban (thesis advisor)
Abstract
Betalaini su stoljećima upotrebljavani kao prirodna bojila a jedan od najvažnijih komercijalnih izvora danas su koncentrat soka cikle i prah cikle. Cikla je relativno jeftin i bogat izvor crvenih pigmenata betacijana, među kojima je najzastupljeniji betanin. Na stabilnost pigmenata cikle tijekom pripreme, procesiranja i skladištenja utječe nekoliko čimbenika. Neki od njih su pH, toplina, aktivitet vode, kisik, svjetlost, metali i druge tvari. Cilj ovog istraživanja bio je utvrditi utjecaj pH (3 i 5) dodatkom askorbinske (AA) i limunske kiseline (LK) i različitih šećera (glukoze, fruktoze i saharoze) na stabilnost pigmenata u soku i kaši cikle. Ispitivan je i utjecaj spomenutih dodataka na stabilnost betacijana u kaši cikle nakon liofilizacije te rehidratacije. Dobiveni rezultati nisu pokazali značajniju degradaciju betacijana, odnosno boje u ispitivanim uzorcima cikle, u uvjetima u kojima je provedeno istraživanje. Koncentracija betacijana u soku cikle dodatkom LK (pH 3 i 5) nije se značajno promijenila u odnosu na sok bez dodataka, dok se dodatkom AA koncentracija betacijana u soku smanjila, posebno u soku zakiseljenom na pH 3. U uzorcima soka i kaše cikle je dodatkom šećera došlo do neznatnog smanjenja koncentracije betacijana, s izuzetkom liofiliziranih i rehidratiranih uzoraka kaše sa dodatkom fruktoze. Također je praćena promjena boje kaše cikle prije i nakon liofilizacije. Najmanju ukupnu promjenu boje ( E) nakon liofilizacije imali su uzorci kaše sa dodatkom glukoze (11.79-12.09), a najveću uzorak kaše zakiseljen s LK na pH 3 (18.73).
Keywordsred beet colour betacyanins sugars acid freeze drying
Parallel title (English)Influence of sugar addition and pH on pigment stability in red beet puree before and after freeze drying
Committee MembersVlasta Piližota (committee chairperson)
Nela Nedić Tiban (committee member)
Drago Šubarić (committee member)
Mirela Kopjar (committee member)
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Food Technologies
Sub-department of Fruits and Vegetables Technology
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2009-03-19
Parallel abstract (English)
Betalains have been widely used as natural colorants for many centuries. The main commercial sources of betalains are concentrates and powders of red beet. Red beet is cheep and excellent source of red pigments betacyanins, among which the most important one is betanin. Several factors including pH, heat, water activity, oxygen, light, metals and other chemicals, affect the stability of beet pigments during preparation, processing, and storage. In this work, the influence of pH with addition of ascorbic and citric acid and different sugars (glucose, fructose and sucrose) on pigment stability of red beet juice and puree was investigated. Also, influence of mentioned additives on betacyanin stability of red beet puree after freeze drying and rehydration was observed. The results did not show significant degradation of pigments and colour in investigated conditions. Betacyanin concentration in red beet juice with addition of citric acid (pH 3 and 5) did not significantly change in comparison with red beet juice, while addition of ascorbic acid caused decrease of betacyanin content, especially at pH 3. Sugar addition caused decrease of betacyanin content in red beet juice and puree with exception of freeze dried and rehydrated purees with addition of fructose. Colour change of puree before and after freeze drying was also observed. The lowest colour change after freeze drying had samples with glucose addition (11.79-12.09), while the highest colour change was in samples with citric acid at pH 3 (18.73).
Parallel keywords (Croatian)cikla boja betacijani šećeri kiseline liofilizacija
Resource typetext
Access conditionAccess restricted to students and staff of home institution
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:409178
CommitterSanda Hasenay