Reološka i antioksidacijska svojstva čokoladnih likera nakon jednomjesečnog odležavanja

master's thesis

• Title (english): Rheological and antioxidant properties of chocolate liqueurs after a month maturation
• Author: Bojana Banjeglav
• 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: 2012-09-20, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Posljednjih godina povećalo se zanimanje za alkoholna pića čija umjerena konzumacija može pozitivno utjecati na ljudsko zdravlje. U tom pogledu čokoladni likeri posebno su interesantni zbog kakaovih dijelova u svom sastavu budući da je poznato da se polifenoli kakaovca vezuju uz antioksidacijske i antikancerogene učinke. Cilj rada bio je odrediti utjecaj sastava četiri vrste čokolade (mliječna čokolada s 30% kakaovih dijelova i 24% mliječnog udjela, bitter čokolada s 72% kakaovih dijelova, desertna čokolada s 50% kakaovih dijelova i mliječna čokolada s 32% kakaovih dijelova i 20% mliječnog udjela) i udjela etanola (20%, 25% i 30%) na udjel ukupnih fenola, flavonoida, flavan-3-ola, proantocijanidina te antioksidacijski kapacitet i reološka svojstva čokoladnih likera. Udjel ukupnih fenola, flavonoida, flavan-3-ola i proantocijanidina određeni su primjenom spektrofotometrijskih metoda. Antioksidacijski kapacitet čokoladnih likera određen je ABTS metodom (reakcija s 2,2'-azinobis(3-etilbenzotiazolin-6-sulfonska kiselina) radikalom) i DPPH metodom (reakcija s 1,1-difenil-2-pikrilhidrazil radikalom). Reološka svojstva određena su na rotacionom reometru Rheometric Scientific RM – 180. Najveći udjel ukupnih fenola, flavonoida, flavan-3-ola i proantocijanidina određen je u čokoladnim likerima pripremljenim s čokoladom s 72% kakaovih dijelova, dok se u ostalim likerima udjeli fenolnih spojeva smanjuju proporcionalno udjelu kakaovih dijelova. Najveći antioksidacijski kapacitet određen je u čokoladnom likeru s 30% alkohola i čokoladom s 72% kakaovih dijelova. Potvrđene su dobre korelacije između antioksidacijskog kapaciteta i udjela flavan-3ola u čokoladnim likerima inducirajući da bi upravo flavan-3-oli mogli najviše utjecati na antioksidacijski kapacitet čokoladnih likera.

Abstract (english)

Increasing attention is drawn to alcoholic beverages which, with moderate consumption, may have a positive impact on the human health. Chocolate liqueurs are particularly interesting because of the cocoa solids they contain. It is generally known that cocoa polyphenols are associated with antioxidant and anticancer properties. The aim of this study was to determine the influence of the composition of four types of chocolate (milk chocolate with 30% cocoa parts and 24% of milk, bitter chocolate with 72% cacao parts, dessert chocolate with 50% cocoa parts and milk chocolate with 32% cocoa parts and 20% of milk) and different concentrations of ethanol (20%, 25% and 30%) on the content of total phenols, flavonoids, flavan-3-ols, proanthocyanidins, antioxidant capacity and rheological properties of chocolate liqueur. Content of total phenol, flavonoids, flavan-3-ols and proanthocyanidins were determined spectrophotometrically. Antioxidant capacity of chocolate liqueur was determined by the 2.2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS method) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH method). Rheological properties were determined by the rotational rheometer Rheometric Scientific RM – 180. The total content of phenol, flavonoid, flavan-3-ol and proanthocyanidin was determined in the chocolate liqueurs prepared with chocolate containing 72% cocoa solids, while in other liqueurs content of phenolic compounds was proportional to cocoa solids content. The highest antioxidant capacity was determined in chocolate liqueur with 30% alcohol and chocolate with 72% cocoa parts. Good correlations between antioxidant capacity and flavan-3-ol content in chocolate liqueur were confirmed, indicating that it is in fact flavan-3-ols that could most affect the antioxidant capacity of chocolate liqueur.

• Keywords: antioksidacijska svojstva; čokoladni likeri; flavan-3-oli; reološka svojstva
• Keywords (english): antioxidant properties; chocolate liqueurs; flavan-3-ols; rheology
• Language: croatian
• URN:NBN: urn:nbn:hr:159:182919
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-10 09:47:54