Utjecaj sušenja raspršivanjem na fizikalno kemijske parametre soka indijske smokve

master's thesis

• Title (english): The effect of spray drying on physico-chemical parameters of prickly pear 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: 2015-11-04, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Cilj ovog istraživanja bio je provesti sušenje raspršivanjem uz pomoć tri različita nosača, maltodekstrina, arapske gume i chitosana te mješavine ova tri sredstva kako bi ispitali utjecaj na fizikalno-kemijske parametre. Prije sušenja raspršivanjem, uzorci soka su karakterizirani vrijednostima pH (3.5-4.7), °Brix (4.5-13) viskoznosti, boja (L*20.30-21.04, a*0.52-2.12, b*-1.14-1.52), reducirajući šećeri (6.15-9.76 g/100g soka) i sadržaj ukupnih fenola (96.97-236.88 mg/100g soka). Vlažnost (prah sa 10% AG, niska vlažnost), aktivitet vode (prah mješavina najniže vrijednosti), veličina čestica, topljivost i boja (L*31.35-35.93, a*21.84-35.61, b*-7.27-10.29), iskorištenje (50.2-69.8), reducirajući šećeri (39.42-61.45 g/100g praha) i sadržaj ukupnih fenola (783.63-1953.38 mg/100g praha) analizirani su u dobivenom prahu. Sok indijske smokve sadrži 9.76 mg/100g reducirajućih šećera i 236.9 mg/100g ukupnih fenola. Na veličinu čestica praha utječe odabir enkapsulirajućeg sredstva. Prah sa 10% arapske gume je najtopljiviji. Prah sa 1.25% chitosana sadrži najveći udio reducirajućih šećera i ukupnih fenola. Dobiveni prahovi bi se mogli upotrebljavati kao bojila i/ili visokovrijedni prehrambeni aditivi u razvoju novih proizvoda i na taj način promovirati proizvode sa visokim udjelom bioaktivnih tvari.

Abstract (english)

The aim of this thesis was to conduct spray drying of prickly pear juice with maltodextrin, Arabic gum, chitosan and a mixture of the three encapsulating agents and to study the effect on physico-chemical parameters. Before spray drying, juice solutions were characterized in terms of pH (3.5-4.7), °Brix (4.5-13), viscosity, color (L*20.30-21.04, a*0.52-2.12, b*-1.14-1.52), reducing sugars (6.15-9.76 g/100g juice) and total phenolic content (96.97-236.88 mg/100g juice). Humidity (powder with 10% AG, low humidity), water activity (mixture powder showed lowest values) particle size, solubility and color (L*31.35-35.93, a*21.84-35.61, b*-7.27-10.29), yield (50.2-69.8), reducing sugars (39.42-61.45 g/100g powder) and total phenolic content (783.63-1953.38 mg/100g powder) were analyzed in the obtained powders. Prickly pear juice presented values of 9.76 mg/100g of juice and 236.9 mg/100g of reducing sugars and total phenolic content, respectively. Particle size showed to be affected by type of encapsulating agents. In terms of solubility the powder with 10% Arabic gum showed to be the most soluble. Powder with 1.25% chitosan showed the highest amount of reducing sugars and total phenolic content. The obtained powders can be used as colorants and/or valuable food additives in the development of new food product formulations and thus promote products with high content of bioactive compounds.

• Keywords: indijska smokva; sušenje raspršivanjem; enkapsulirajući agensi
• Keywords (english): prickly pear; spray drying; encapsulating agents
• Language: croatian
• URN:NBN: urn:nbn:hr:159:999095
• Study programme: Title: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka prehrambenog inženjerstva (magistar/magistra inženjer/inženjerka prehrambenog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-04-27 12:53:15