Utjecaj sastava čokolade i udjela etanola na antioksidacijski kapacitet i reološka svojstva čokoladnih likera

master's thesis

• Title (english): Effect of chocolate composition and content of ethanol on antioxidative capacity and rheological properties of chocolate liqueurs
• Author: Sanja Ćosić
• Mentor: Draženka Komes (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Chemistry and Technology of Carbohydrates and Confectionery Products); Zagreb
• Defense date and country: 2012-06-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Zadnjih nekoliko godina, kakaovi proizvodi poprimaju sve veći interes istraživača zbog svog zanimljivog bioaktivnog sastava, a ponajprije visokog udjela polifenolnih spojeva, za koje je poznato da imaju pozitivan učinak na ljudsko zdravlje. Čokoladni likeri, osim što imaju poželjna senzorska svojstva, također mogu biti i dobar izvor polifenolnih spojeva. Budući da je poznato da na udio bioaktivnih komponeti u različitim proizvodima utječe način proizvodnje i udio korištenih sirovina, cilj ovog rada bio je utvrditi utjecaj sastava čokolade i udjela etanola, korištenih u proizvodnji, na antioksidacijski kapacitet čokoladnih likera. Analizirani likeri napravljeni su od 4 različite vrste čokolade različitog udjela kakaovih dijelova (30, 32, 50, 72%) s udjelima od 20%, 25% i 30% etanola za svaku vrstu čokolade. Udjeli polifenolnih spojeva (ukupni fenoli, neflavonoidi i flavonoidi, proantocijanidini i flavan-3-oli) određeni su UV/VIS spektrofotometrijskim metodama, dok je antioksidacijski kapacitet utvrđen reakcijama s radikalima 2,2'-azino-bis(3-etilbenzotiazolin-6-sulfonskom kiselinom) (ABTS) i 1,1'-difenil-1-pikrilhidrazilom (DPPH). Reološka svojstva određena su na rotacionom reometru Rheometric Scientific RM–180. Rezultati su pokazali da među istraživanim likerima liker pripremljen kombinacijom čokolade sa 72% kakaovih dijelova i 30% etanola, sadrži najveći udio polifenolnih spojeva i ima najveći antioksidacijski kapacitet.

Abstract (english)

In the last few years, cocoa products have received increased scientific attention due to their interesting phytochemical composition, especially high content of polyphenols which have positive health effects. Chocolate liqueurs are known for having desirable sensory properties but they could also be a good source of polyphenol compounds. Since the processing parameters and the content of compounds can influence the content of bioactive compounds in the final product, the purpose of this study was to determine how the type of chocolate and the content of ethanol used, in chocolate liqueur production, can influence on their antioxidative capacity. Analyzed liqueurs were made of 4 types of chocolate with different cocoa content (30, 32, 50, 72%) with 20%, 25% and 30% of ethanol content for each type of chocolate. Content of polyphenolic compounds (total phenols, nonflavonoids and flavonoids, proantocyanidins and flavan-3-ols) were determined by UV/VIS spectrophotometric methods, while antioxidant capacity was evaluated using DPPH (1,1-diphenyl-1-picrylhydrazyl) and ABTS (2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)) assays. Rheological properties were determined using a Rheometric Scientific RM-180 rotational rheometer. Results have shown that among investigated liqueurs, chocolate liqueur prepared with chocolate containing 72% cocoa solids and 30% of ethanol, has the highest content of polyphenols and the highest antioxidative capacity.

• Keywords: antioksidacijski kapacitet; čokoladni likeri; etanol; polifenolni spojevi; reološka svojstva
• Keywords (english): antioxidative capacity; chocolate liqueur; ethanol; polyphenolic content; rheological properties
• Language: croatian
• URN:NBN: urn:nbn:hr:159:886690
• Study programme: Title: Food Technology; specializations in: Nutrition; Course: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-17 09:26:36