Utjecaj dodataka ekstrakta lista maline na bioaktivni potencijal čokolade

master's thesis

• Title (english): The effects of addition of extracts of yarrow leaves on the bioactive potential of chocolate
• Author: Doroteja Đurđek
• 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: 2011-12-19, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog rada je odrediti udjel ukupnih fenola, flavonoida, flavan-3-ola i proantocijanidina te antioksidacijski kapacitet tri vrste čokolade različitog udjela kakaovih dijelova (30, 38, 72 %) obogaćenih ekstraktom lista maline. Udjel ukupnih fenola i flavonoida određen je reakcijom s Folin-Ciocoalteau reagensom, udjel flavan-3-ola određen je reakcijama s vanilinom i s p-dimetilamino-cinamaldehidom (p-DAC), a udjel ukupnih proantocijanidina kiselinskom hidrolizom s klorovodičnom kiselinom. Antioksidacijski kapacitet određen je reakcijama sa željezo(III)-tripiridiltriazinom (FRAP) te 2,2’-azino-bis-(3-etilbenzotiazolin-6-sulfonske kiseline) (ABTS). Najveći udjel ukupnih fenola određen je u čokoladi sa 72% kakaovih dijelova uz dodatak 1% liofiliziranog ekstrakta lista maline, a najniži u čokoladi sa 30% udjela kakaovih dijelova uz dodatak 1% liofiliziranog ekstrakta lista maline. Najveći udjel flavonoida određen je u čokoladi s 38% kakaovih dijelova uz dodatak 3% listića maline, a najniži u čokoladi s 30% kakaovih dijelova uz dodatak 1% listića maline. Najveći udjel flavan-3-ola određen metodom s vanilinom, određen je u čokoladi s 72% kakaovih dijelova obogaćenoj s 3% koncentriranog ekstrakta lista maline, dok je najniži udjel određen u čokoladi s 30% kakaovih dijelova obogaćenoj sa 1% listića maline. Dodatak ekstrakta lista maline doprinosi povećanom antioksidacijskom kapacitetu čokolade. Najučinkovitiji je koncentrirani ekstrakt lista maline, dodan u 3%-tnom udjelu u svaku vrstu čokolade

Abstract (english)

Therefore, the objective of this work is to determine the content of the total phenols, flavonoids, flavan-3-ols and procyanidins as well as antioxidant capacityof three types of chocolate (various content of cocoa solids) enriched with the extract of raspberry. The concentration of total phenols and flavonoids was determined by using a reaction with the Folin-Ciocalteau reagent, while the content of flavan-3-ols was determined by using vanilin and p-dimethylaminocinamaldehyde (p-DAC) and the content of total procyanidins acid hydrolysis with hydrochloric acid. Antioxidant capacity was determined by using reactiona with iron (III)-tripyridyiltirazine (FRAP) and radicals 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The highest content of total phenols was determined in chocolate with 72% of cocoa solids with the addition of 1% freeze-dried extract of raspberry, and the lowest in chocolate with 30% of cocoa solids with the addition of 1% freeze-dried extract of raspberry. The highest content of flavonoids was detected in chocolate with 38% of cocoa solids with the addition of 3% of raspberry leaves, and the lowest in chocolate with 30% of cocoa solids with the addition of 1% of raspberry leaves. The highest content of flavan-3-ols, detected the method with vanilla, was determined in chocolate with 72% of cocoa solids enrichedwith 3% concentrated extract of raspberry, and the lowest in chocolate with 30% of cocoa solids enriched with 1% raspberry leaves. Presence of additives in all types of chocolate significantly affects their antioxidant capacity. The addition of raspberry extract contribute to the higher antioxidant capacity of all types of chocolate. The most effective is freeze-dried extract of raspberry added in the content of 3% to the all kinds of chocolate.

• Keywords: antioksidacijski kapacitet; polifenoli; čokolada
• Keywords (english): antioxidant capacity; polyphenols; chocolate
• Language: croatian
• URN:NBN: urn:nbn:hr:159:324239
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-06-01 10:18:57