Određivanje vitamina C u soku od naranče

undergraduate thesis

• Title (english): Determination of vitamin C in orange juice
• Author: Tina Krištić
• Mentor: Branka Levaj (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Technology of Fruits and Vegetables Preservation and Processing); Zagreb
• Defense date and country: 2013-07-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj istraživanja bio je odrediti i usporediti udjel vitamina C u pet industrijski proizvedenih sokova naranče i tri soka priređena u laboratoriju te u jestivom dijelu ploda od naranče. Vitamin C određen je tekućinskom kromatografijom. Također je provedena senzorska analiza uzoraka hedonističkom skalom. Industrijski sokovi nabavljeni su iz trgovačke mreže, a laboratorijski pripremljen na sokovniku te pasteriziran 5 i 10 minuta u vodenoj kupelji pri 85oC. Rezultati analize pokazali su da je udio vitamina C u industrijskim sokovima bio od 0,1607 mg/g soka (Cappy premium – 100% naranča sa komadićima naranče) do 0,3238 mg/g soka (Juicy – 100% naranča sok). Udio vitamina C u plodu naranče iznosi 0,2578 mg/g soka a u svježem soku 0,3188 mg/g soka. Pasterizacijom 10 minuta došlo je do vrlo malog smanjena udjela vitamina C (0,2959 mg/g soka). Pasterizirani sokovi senzorski nisu dobro ocjenjeni zbog pojave gorčine, a svježi sok i industrijski sokovi bili su dosta dobro ocjenjeni s tim da je najbolje ocijenjen Juicy – 100 % naranča sok.

Abstract (english)

The objective of this work was to determine and compare the quantity of vitamin C in five industrially manufactured samples of orange juice, three juices produced in laboratory and in edible part of orange fruit. Vitamin C was determined with liquid chromatography. Also, a sensory analysis with hedonistic scale was conducted. Industrially manufactured juices were purchased from the market and laboratory juices were prepared on the juice extractor and pasteurized for five and ten minutes in water bath on 85oC. The results of analysis show that the part of vitamin C in industrial juices was from 0,1607 mg/g juice (Cappy premium – 100% orange with bits of orange) to 0,3238 mg/g juice (Juicy – 100% orange juice). Part of vitamin C in fruit is 0,2578 mg/g juice and in fresh juice 0,3188 mg/g juice. Pasteurization for ten minutes led to slight decrease of vitamin C (0, 2959 mg/g juice). Pasteurized juices did not have good sensory characteristics due to the appearance of bitterness. Fresh and industrial juices were evaluated very well and the best rated was Juicy – 100% orange juice.

• Keywords: naranča; voćni sok; vitamin C; HPLC
• Keywords (english): orange; fruit juice; vitamin C; HPLC
• Language: croatian
• URN:NBN: urn:nbn:hr:159:782547
• Study programme: Title: Food Technology; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije (sveučilišni/a prvostupnik/prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka prehrambene tehnologije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-04 09:21:17