Utjecaj djelovanja ultrazvuka pri sušenju jabuka

undergraduate thesis

• Title (english): The impact of ultrasound on apple drying
• Author: Petra Badenić
• Mentor: Mladen Brnčić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory of Thermodynamics); Zagreb
• Defense date and country: 2017-09-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Svrha ovog rada je utvrditi kako ultrazvuk visokih intenziteta koji se koristi kao predtretman prilikom klasičnog postupka sušenja utječe na senzorska svojstva (boju i teksturu) uzoraka jabuke. Uzorci se tretiraju u ultrazvučnoj kupelji pri različitim vremenima (10, 30 i 50 min), uz konstantne parametre temperature (20°C), frekvencije (37 kHz) i amplitude (100%). Uzorci se zatim suše u konvekcijskoj sušari pri temperaturama 40, 55 i 70°C u vremenima 60, 120 i 180 min. Uzorci koji nisu bili predtretirani sušeni su pri istim temperaturama 60, 120, 180 i 240 min. Ultrazvuk visokih intenziteta znatno skraćuje vrijeme sušenja, a sušenje se korištenjem ultrazvuka kao predtretmana može odvijati pri nižim temperaturama te se na taj način racionalnije raspolaže energentima. Tretirani uzorci sušeni pri 40 i 55°C manje su tvrdoće nego ne-tretirani uzorci, što pogoduje zahtjevima potrošača, dok temperatura od 70°C uzrokuje preveliku tvrdoću sušenih uzoraka. U svim slučajevima sušenja, pokazalo se kako predtretman ultrazvukom u trajanju od 10 minuta djeluje najpovoljnije na parametar ΔE*, odnosno uzrokuje najmanju razliku u boji.

Abstract (english)

The purpose of this paper is to determine how high intensity ultrasound used as a pre-treatment during a classic drying process affects the sensory properties (color and texture) of apple samples. Samples are treated in the ultrasonic bath at different times (10, 30 and 50 min), with constant temperature parameters (20°C), frequency (37 kHz) and amplitude (100%). The samples were then dried in a convection dryer at 40, 55 and 70°C for 60, 120 and 180 minutes. Samples that were not pre-treated were dried at the same temperatures for 60, 120, 180 and 240 min. High intensity ultrasound significantly shortens the drying time, and drying can be done at lower temperatures, which includes more rational energy using. Pre-treated samples dried at 40 and 55°C are less hard than untreated samples, favoring consumer demands, while the temperature of 70°C causes excessive hardness of the dried samples. In all cases, it has been shown that the 10-minute ultrasound treatment works best on the ΔE* parameter, causing the slightest difference in color.

• Keywords: jabuke; sušenje; ultrazvuk
• Keywords (english): apples; drying; ultrasound
• Language: croatian
• URN:NBN: urn:nbn:hr:159:636668
• 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: Open access
• Created on: 2017-09-11 09:36:19