Optimizacija konvencionalne ekstrakcije polisaharida iz smeđe alge Cystoseira barbata

master's thesis

• Title (english): Optimization of conventional polysaccharide extraction from brown alga Cystoseira barbata
• Author: Erika Dobroslavić
• Mentor: Verica Dragović-Uzelac (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for drying Technologies and monitoring of biologically active compounds); Zagreb
• Defense date and country: 2020-07-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Smeđa alga Cystoseira barbata izvor je brojnih bioaktivnih molekula od kojih je sulfatirani polisaharid fukoidan među značajnijima. Fukoidanu se pripisuju brojna biološka svojstva i aktivnosti te stoga ima značajnu primjenu u prehrambenoj i farmaceutskoj industriji. Cilj rada bio je optimizirati uvjete konvencionalne ekstrakcije fukoidana iz smeđe alge Cystoseira barbata. Ekstrakcija je provedena primjenom klasičnih postupaka uz kontinuirano miješanje otapala i uzorka, a istražen je utjecaj otapala (destilirana voda i 0,1M HCl), temperature (40, 60 i 80 °C) i vremena (1, 2 i 3 h) ekstrakcije na degradaciju alge (gubitci algalne mase tijekom ekstrakcije), prinos fukoidana, koncentraciju ukupnih ugljikohidrata, koncentraciju sulfatnih grupa i antioksidacijsku aktivnost. Najmanja degradacija alge postignuta je u vodi pri 40°C i 1 h s trendom porasta povećanjem temperature i produljenjem vremena ekstrakcije. Optimalni uvjeti pri kojima se dobivaju najveći prinosi fukoidana i koncentracija ukupnih ugljikohidrata bili su otapalo 0,1M HCl, temperatura 80 °C i vrijeme ekstrakcije 3 h. Najveća koncentracija sulfatnih grupa dobiva se uz primjenu 0,1M HCl, pri temperaturi 40 °C i vremenu ekstrakcije 1 h. Antioksidacijska aktivnost najveća je u vodenim ekstraktima dobivenim pri temperaturi 60 °C i vremenu ekstrakcije 2 h. Veća koncentracija sulfatnih grupa rezultirala je manjom antioksidacijskom aktivnosti.

Abstract (english)

The brown alga Cystoseira barbata is a source of many bioactive molecules among which the sulfated polysaccharide fucoidan is a significant one. Fucoidan is used by the food and pharmaceutical industry due to its many biological activities. The aim of this study was to optimize the conditions of conventional extraction of fucoidan from the brown alga Cystoseira barbata. Extraction was performed using classical procedures with continuous mixing of the solvent and sample. The influence of solvents (distilled water and 0.1M HCl), temperature (40, 60 and 80 °C) and extraction time (1, 2 and 3 h) on algal degradation (loss of algal mass during extraction), fucoidan yield, concentration of total carbohydrates, concentration of sulfate groups and antioxidant activity was investigated. The lowest percent of algal degradation was achieved in water at 40 °C and 1 h with a tendency to increase with increasing temperature and prolonging the extraction time. The optimal conditions for the highest yield of fucoidan and the concentration of total carbohydrates were 0.1M HCl as a solvent, temperature of 80°C and extraction time of 3 h. The highest concentration of sulphate groups was achieved in 0.1M HCl, at temperature of 40 °C and an extraction time of 1 h. Antioxidant activity was highest in water extracts at temperature of 60 °C and 2 h extraction time. A higher concentration of sulfate groups resulted in lower antioxidant activity.

• Keywords: smeđe alge; Cystoseira barbata; sulfatirani polisaharidi; fukoidan; ekstrakcija
• Keywords (english): brown algae; Cystoseira barbata; sulphated polysaccharides; fucoidan; extraction
• Language: croatian
• URN:NBN: urn:nbn:hr:159:531028
• Study programme: Title: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra nutricionizma (magistar/magistra nutricionizma)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2020-07-22 10:44:52