Primjena otpada nastalog konzumiranjem espresso kave pri izradi pektinskih biofilmova

undergraduate thesis

• Title (english): Appliance of espresso coffee waste in preparing pectin biofilms
• Author: Angela Vujnović
• Mentor: Antonela Ninčević Grassino (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Analytical Chemistry); Zagreb
• Defense date and country: 2019-09-09, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Ekstrakcija fenola i flavonoida iz espresso kave i otpada nastalog nakon njena konzumiranja provedena je pomoću mikrovalova pri T = 50 i 70 °C, t = 5 i 10 minuta i φ (etanol) = 50 i 70 %. Spektrofotometrijskom analizom je utvrĎeno da espresso kava sadrži 38,75 do 51,40 mg/g, a otpad 4,55 do 6,90 mg/g ukupnih fenola. Budući da temperatura od 70 °C, vrijeme od 5 minuta i 70 %-tni etanol dovode do optimalne ekstrakcije fenola iz otpada kave, navedeni parametri su korišteni kod pripreme 5, 10 i 20 %-tnih ekstrakata, koji su zatim inkorporirani u pektinske biofilmove. Njihovom karakterizacijom je utvrĎeno da dodatak ekstrakata otpada utječe na promjenu boje, čvrstoće i elastičnosti biofilmova, pa tako uzorak s 20 %-tnim ekstraktom u odnosu na 5 i 10 %-tne pokazuje najveću čvrstoću i elastičnost. Time je pokazano da se i otpad kave može efikasno iskoristiti pri izradi jestivih i funkcionalnih biofilmova.

Abstract (english)

Extraction of phenols and flavonoids from espresso coffe and its waste remained after consumption was assisted by microwave irradiaton at T = 50 and 70 °C, t = 5 and 10 minutes and φ (etanol) = 50 and 70 %. Spectrophotometric analysis has shown that content of total phenols in espresso coffee is 38,75 to 51,40 mg/g and in waste 4,55 to 6,90 mg/g. Since temperature of 70 °C, time of 5 minute and φ (etanol) = 70 % leaded to optimal extraction of phenols from coffee waste, these parameters have been applied for preparation of 5, 10 and 20 % extracts, which subsequently have ben incorporated in pectin biofilms. Their analyses have shown that addition of coffee waste extracts affects colour, strenght and elasticity of biofilms, and sample with 20 % extract in comparison to 5 and 10 %% showed the highest strenght and elasticity. This has been shown that coffee waste can be used for preparation of edible and functional biofilms.

• Keywords: biofilm; ekstrakcija potpomognuta mikrovalovima; pektin; polifenoli; teksturalna svojstva; UV/Vis spektrofotometrija
• Keywords (english): biofilm; microwave assisted extraction; pectin; polyphenols; textural properties; UV/Vis spectrophotometry
• Language: croatian
• URN:NBN: urn:nbn:hr:159:938631
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2019-09-10 11:27:46