Promjene fizikalno-kemijskih i senzorskih svojstava pektinskih i agar-agar žele bombona tijekom skladištenja

master's thesis

• Title (english): Observing of physical-chemical and sensory properties of pectin and agar-agar jelly confections during storage
• Author: Helena Pap
• 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: 2007-12-06, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj rada bio je usporedno praćenje fizikalno-kemijskih i senzorskih svojstava žele bombona proizvedenih na različitim polisaharidnim bazama – pektinu i agar-agaru. U tu svrhu ispitivano je šest različitih vrsta aroma (limun, naranča, jagoda, malina, višnja i limeta) pektinskih i agar-agar žele bombona. Fizikalno-kemijska svojstva praćena su određivanjem aktiviteta vode, udjela suhe tvari, udjela vode i pH vrijednosti nepaniranih i paniranih korpusa neposredno nakon proizvodnje, nakon 24, 48, 72, 96, 480 i 720 sati. Provedena je i UV-Vis spektrofotometrijska karakterizacija prirodnih prehrambenih bojila upotrebljenih tijekom proizvodnje. Na osnovu dobivenih rezultata utvrđeno je da pektin zbog svoje sekundarne molekularne strukture čvršće veže vodu u svoju strukturu i zadržava je tijekom roka uporabe proizvoda, pa proizvodi s pektinom duže ostaju svježi i sporije mijenjaju svoja senzorska svojstva. Za razliku od proizvoda na bazi pektina, proizvodi s agar-agarom s vremenom otpuštaju vodu (sinereza) te su stoga skloniji isušivanju i poprimanju neželjenih senzorskih svojstava.

Abstract (english)

The aim of this study was a parallel observing of physical-chemical and organoleptic properties of jelly confections produced on different polysaharid bases – pectin and agar-agar. For this purpose, six different kinds of aromas (lemon, orange, strawberry, raspberry, cherry and lime) of pectin and agar-agar jelly confections were tested. Physical-chemical properties were observed by determining the water activity, the portion of dry matter, the portion of water and pH value of sugar coated and uncoated jellies directly after the production and after 24, 48, 72, 96, 480 and 720 hours. The UV-Vis spectofotometry characterization of natural food colorants used during the production was also conducted. On the basis of obtained results, it was determined that pectin, because of its secundary molecular structure, binds water more strongly and retains it during the shelf life of products. Therefore, the products with pectin remain longer fresh and they change their organoleptic properties more slowly. As opposed to the products based on pectin, the products with agar-agar release water (syneresis) and therefore are prone to drying out and obtain unwanted organoleptic properties.

• Keywords: agar-agar; aktivitet vode; pektin; prirodna bojila; žele bomboni
• Keywords (english): agar-agar; jelly confections; natural colorants; pectin; water activity
• Language: croatian
• URN:NBN: urn:nbn:hr:159:574734
• 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: 2017-09-05 09:56:13