Vremensko praćenje fizikalno kemijskih svojstava bagremnovog meda s dodacima oraha i peludi

master's thesis

• Title (english): Monitoring of physico-chemical characteristics of acacia honey with addition of walnuts and pollen during time
• Author: Goran Lončarević
• Mentor: Ljerka-Marija Lalić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Physical Chemistry and Corrosion); Zagreb
• Defense date and country: 2006-03-03, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Bagremovom medu kontinentalnog područja Hrvatske i uzorcima ovog meda s dodatkom oraha i peludi masenih udjela 5 i 10% (w/w) određeni su fizikalno kemijski parametri (viskoznost i elektroprovodljivost).Viskoznost uzoraka određena je pri temperaturi 10ºC, 20ºC, 30ºC, 40ºC i 50ºC. Za određivanje elektroprovodljivosti pripravljene su 20% otopine. Elektroprovodljivost meda određena je na 20ºC. Sva mjerenja fizikalno-kemijskih parametara obavljena su nakon vrcanja te nakon 10, 30 i 210 dana skladištenja. Za sve ispitivane uzorke se vrijednosti viskoziteta s povećanjem temperature signifikantno smanjuju, a na svim tempraturama s vremenom rastu. Dodaci umješani u med povećavaju vrijednost viskoziteta.Utvrđen je linearan slijed između logaritamske vrijednosti viskoznosti i recipročne vrijednosti temperature. Vrijednosti energija aktivacije za uzorke s dodacima su niže u odnosu na čisti med. Svim se ispitivanim uzorcima vrijednost električne provodljivosti tijekom skladištenja smanjivala. Dodatak peludi i oraha, oba masena udjela (5 i 10%) povisuje vrijednost elektroprovodljivosti. Uzorci su čuvani na temperaturi od 10ºC (283,15 K), bez svijetla u staklenoj ambalaži volumena 1000 ml zatvorenoj plastičnim poklopcima.

Abstract (english)

Acacia honey from continental part of Croatia and samples of this honey with addition of walnuts and pollen in mass parts 5% and 10 % (w/w) were determined by physico-chemical parameters (viscosity and electric conductivity). Viscosity of samples were determined at temperatures of 10ºC, 20ºC, 30ºC, 40ºC and 50ºC. For determination of electric conductivity was prepared 20% solutions. Electric conductivity of honey was determined at 20ºC. All physico-chemical parameters were determined on fresh honey and during storage period of 10, 30, and 210 days. For all tested honey samples, values of viscosity were decreased with temperature, and increased with storage time.Addition of walnuts and pollen increased value of viscosity.High degree of correlation has been established between logarithmic values of viscosity and opposite temperature values. Values of activation energy for samples with adds were lower than for pure honey. Electric conductivity of all samples was decreased during storage time. Pollen and walnuts of both mass parts (5% and 10 %) increase value of electric conductivity. Samples were kept in capped glass jars (volume 1000ml) on temperature of 10°C (283,15 K), without sunlight.

• Keywords: elektroprovodljivost; med; orah; pelud; temperatura i viskoznost
• Keywords (english): electric conductivity; honey; pollen; temperature; viscosity; walnuts
• Language: croatian
• URN:NBN: urn:nbn:hr:159:519569
• Study programme: Title: Food Technology; specializations in: Nutrition; Course: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-11 08:11:50