Nutritivni doprinos buče u borbi protiv oksidacijskog stresa

master's thesis

• Title (english): Nutritional contribution of pumpkins while fighting oxidative stress
• Author: Sonja Međimurec
• Mentor: Jasenka Gajdoš Kljusurić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory for Measurement, Regulation and Automatisation); Zagreb
• Defense date and country: 2014-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Antioksidansi su tvari prirodno prisutne u hrani koje pomažu u borbi protiv štetnih učinaka slobodnih radikala. Unos antioksidanasa nužan je za zdravlje cijelog organizma. Buče su bogate prirodnim antioksidansima flavonoidima, karotenoidima, vitaminom C. β-karoten, kao najpoznatiji predstavnik skupine karotenoida, daje bučama narančastu boju. Cilj rada bio je primjenom Briggs-Rauscher-ove reakcije i blisko infracrvene spektrometrije usporediti antioksidacijski kapacitet svježih buča i termički obrađenih kuhanjem, mikrovalovima i prženjem. Iz rezultata je vidljivo da uzorci buče Hokkaido imaju znatno veće vrijeme inhibicije (IT), što upućuje i na proporcionalno veću antioksidacijsku aktivnost. Ekstrakcija se provela dvjema metodama: klasičnom ekstrakcijom i ekstrakcijom u ultrazvučnoj kupelji. Provedena je i kolorimetrijska analiza uzoraka. Rezultati t-testa pokazuju da ne postoje signifikantne razlike između uzoraka dobivenih različitom metodom ekstrakcije (p > 0,05). Multivarijatni modeli omogućili su uspješnu predikciju antioksidacijske aktivnosti (BRAI) i parametra boje (a*) na blisko-infracrvenog apsorpcijskog spektra uzorka.

Abstract (english)

Antioxidants are substances naturally present in foods and help fight the harmful effects of free radicals. Intake of antioxidants is essential for the health of the whole organism. Pumpkins are rich in natural antioxidants, flavonoids, carotenoids, vitamin C. β-carotene, as most representative group of carotenoids, gives pumpkins an orange color. The aim of this work study was using the Briggs-Rauscher's method and near-infrared spectroscopy to compare the antioxidant capacity of fresh pumpkins and prepared by boiling, frying and microwave. The results show that the samples Hokkaido pumpkin had significantly greater inhibition time (IT), suggesting the proportionally higher antioxidant activity. In the extraction were used two methods with reflux and using ultrasound. Also was conducted a colorimetric analysis of samples. The results of t-test showed no significant differences between the sample extractions (p > 0.05). Multivariate models enabled the successful prediction of antioxidant activity (Braila) and color parameters (a *) in the closely-infrared absorption spectrum of the sample.

• Keywords: buča; antioksidansi; β-karoten; BR reakcija; NIR
• Keywords (english): pumpkins; antioxidants; β-carotene; BR reaction; NIR
• Language: croatian
• URN:NBN: urn:nbn:hr:159:314781
• 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: Access restricted to students and staff of home institution
• Created on: 2017-05-02 08:40:59