Utjecaj blanširanja na kemijski sastav i sposobnost rehidratacije osušenih listića jabuke

master's thesis

• Title (english): Effects of blanching on chemical composition and rehydration capability of dried apple slices
• Author: Milna Tudor
• Mentor: Vesna Lelas (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Food Processes Engineering); Zagreb
• Defense date and country: 2005-03-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Sušenje je jedna od najstarijih metoda konzerviranja kojom se iz prehrambenih proizvoda uklanja veći dio vode. Smanjenjem udjela vode usporava se mikrobiološka aktivnost, čime se sprečava kvarenje namirnica i omogućuje njeno dugotrajno čuvanje. Ovisno o vrsti namirnice postoje brojni tipovi sušara. U ovom radu provedeno je sušenje jabuka izrezanih u listiće u poluindustrijskoj komornoj sušnici kod temperature od 75 °C u vremenu od 240 minuta. Jabuke su prije sušenja blanširane na 4 različita načina, u 30%-tnoj otopini saharoze uz dodatak 0,1% limunske kiseline, u 30%-tnoj otopini saharoze uz dodatak 0,1% limunske kiseline i 2% inulina, u 40%-tnoj otopini saharoze uz dodatak 0,1% limunske kiseline, u 20%-tnoj otopini saharoze uz dodatak 0,1% limunske kiseline i 1% sorbitola pri temperaturi 80 °C u vremenu 20 minuta. Svježim, blanširanim i suhim jabukama određivana je suha tvar, prirodni i ukupni invert, vitamin C i ukupna kiselost. Određivana je i sposobnost rehidratacije osušenog proizvoda. Utvrđeno je povećanje suhe tvari, prirodnog i ukupnog inverta, smanjenje vitamina C i ukupne kiselosti kod svih uzoraka. Najbolju sposobnost rehidratacije ima uzorak koji je blanširan u 30%-tnoj otopini saharoze uz dodatak 0,1% limunske kiseline.

Abstract (english)

Dehydration is one of the oldest preservation methods. By reducing the water content of a food product to very low levels, the microbiological activity is reduced to minimum, and because of that keeping is more longer. Depend on type of food there are many type of drying systems. In this work drying was carried out in a cabinet-type tray dryer on temperature of 75 °C in duration of 240 minutes. Before drying apples were blanched on four different ways, in 30% solution of sucrose with 0,1% citric acid, in 30% solution of sucrose with 0,1% citric acid and 2% inulin, in 40% solution of sucrose with 0,1% citric acid, in 20% solution of sucrose with 0,1% citric acid and 1% sorbitol, on temperature of 80 °C in time of 20 minutes. Natural and total invert, dry matter, vitamin C and acidity was tested and defined on raw, blanched and dried apples. It was also defined rehydration of dried apples. Results are increasing value of dry matter, natural and total invert, and decreasing value of vitamin C and acidity. The sample that was blanched in 30% solution of sucrose with 0,1% citric acid has the best rehydration capability.

• Keywords: dehidratacija; jabuka
• Keywords (english): apple; dehydration
• Language: croatian
• URN:NBN: urn:nbn:hr:159:428606
• 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: 2017-09-13 07:44:29