Primjena Briggs-Rauscher reakcije i blisko-infracrvene spektroskopije u analizi biljnih napitaka od orašastih plodova

master's thesis

• Title (english): Application Briggs-Rauscher reactions and near-infrared spectroscopy the analysis of plant beverages of nuts
• Author: Tena Gikić
• 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: 2015-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Nutrition

Abstract

Nutritivne alergije i intolerancije predstavljaju sve veći javno-zdravstveni problem. Posljednjih godina na tržištu su postali dostupni novi napitci kao alternativa za konzumaciju kravljeg mlijeka, koji su zapravo vodeni ekstrakti žitarica ili orašastih plodova. Budući da su orašasti plodovi svojim kemijskim sastavom izuzetno nutritivno bogate namirnice koje pokazuju blagotvoran učinak na ljudsko zdravlje, ovi napitci postali su popularni kod osoba s navedenim problemima, ali i u općoj populaciji. U istraživanju su korišteni pripremljeni uzorci napitka od lješnjaka, indijskog oraščića i oljuštenog i neoljuštenog badema, te kupljeni napitci od badema i lješnjaka. Antioksidacijski kapacitet uzoraka određen je Briggs-Rauscher-ovom metodom, a također je provedena analiza NIR spektra. Cilj ovog rada bio je usporediti dobivene podatke za pripremljene i kupljene uzorke napitaka, te pratiti kakvoću ispitivanih uzoraka tijekom 7 dana, pomoću bliske infracrvene spektroskopije te uz pomoć predikcijskih modela predvidjeti očekivanu antioksidacijsku aktivnost uzoraka na osnovu NIR spektara. Utvrđena je razlika u antioksidacijskom kapacitetu i NIR spektrima pripremljenih i kupljenih napitaka, te u svježini tijekom čuvanja uzoraka. Najveću antioksidacijsku aktivnost pokazuje uzorak pripremljenog napitka od lješnjaka (BRAI=1,25 mg GAE.100 g-1), dok je najmanju vrijednost pokazao uzorak kupovnog napitka od badema (BRAI=0,36 mg GAE.100 g-1). Predikcijski modeli su pokazali čvrstu vezu između NIR spektra i antioksidacijske aktivnosti (R2>0,95).

Abstract (english)

Food allergy and intolerance represent a growing public health problem. In recent years, the market became available to new drinks as an alternative to cow's milk, which are actually aqueous extracts of grains or nuts. Chemical composition of nuts showed that this food is nutritionally very rich with beneficial effect on human health and the drinks from such food have become popular also in the general population. The study used samples that were (i) prepared in the laboratory (beverage from hazelnuts, cashews and almonds-shelled and unpeeled) and (ii) bought on the market – almond and hazelnut drinks. Antioxidant capacity of the samples was determined by the Briggs-Rauscher's method, and all samples were analysed by use of the NIR spectrum. The aim of this study was to compare the data obtained from the self-prepared samples and bought drinks; to monitor the quality of the samples for 7 days, using near infrared spectroscopy and with the help of predictive models to predict the expected antioxidant activity patterns based on NIR spectra. There was a difference in the antioxidant capacity and NIR spectra of prepared and bought drinks, and the freshness of samples during storage. The highest antioxidant activity showed the self-prepared drink of hazelnut (BRAI = 1.25 mg GAE.100 g-1), while the lowest value showed the buyed almond beverage (BRAI = 0.36 mg GAE .100 g-1). Predictive models have shown a strong link between the NIR spectrum and antioxidant activity (R2> 0.95).

• Keywords: napitak od orašastih plodova; BR reakcija; NIR spektroskopija; modeliranje
• Keywords (english): beverages of nuts; BR reaction; NIR spectroscopy; modelling
• Language: croatian
• URN:NBN: urn:nbn:hr:159:801962
• 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: 2017-05-03 12:34:42