Utjecaj direktnog ultrazvučnog predtretmana na utrošak energije, vrijeme sušenja, boju i teksturalna svojstva muškatne buče "Cucurbita moschata"

master's thesis

• Title (english): Influence of direct ultrasound pretreatment on energy consumption, drying time, color and textural properties of pumpkin "Cucurbita moschata"
• Author: Nikolina Krnjić
• Mentor: Filip Dujmić (mentor)
• Committee member: Sven Karlović (član povjerenstva)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Process Engineering); (Laboratory of Thermodynamics); Zagreb
• Defense date and country: 2021-11-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Sušenje je jedan od najstarijih načina konzerviranja voća i povrća kojim se izdvaja voda iz namirnice čime se produljuje rok trajanja hrane. Prilikom tradicionalnog načina sušenja (sušenje na suncu), može doći do neželjenih promjena boje, teksture, gubitka nutritivnih sastojaka te enzimskog posmeđivanja. Kako bi se takve promjene spriječile, sve se više koristi ultrazvuk kao predtretman prilikom sušenja hrane. Cilj ovog rada je odrediti najprikladniji predtretman primjenom direktnog ultrazvučnog postava u postupku sušenja muškatne tikve (butternut) pri sniženom tlaku (100 mBar) i atmosferskom tlaku te utjecaj na teksturu, boju, vrijeme sušenja i utrošak energije. Najkraće vrijeme sušenja postignuto je primjenom ultrazvučnog predtretmana amplitude od 60 % i vremena trajanju od 6 minuta čime je postignuto skraćenja vremena od 40,17 %, uz uštedu energije od 32,63 %. Predtretirani i osušeni uzorci buče očuvali su svoja teksturalna svojstva. Boja uzoraka bila je vizualno prihvatljiva, iako je instrumentalno određeno odstupanje boje osušenih predtretiranih uzoraka od velikih (3,0 - 6,0) do vrlo velikih (6,0 – 12,0).

Abstract (english)

Drying is one of the oldest ways of preserving fruits and vegetables, which separates water from food, thus extending the shelf life of food. During the traditional method of drying (drying in the sun), there may be unwanted changes in color, texture, loss of nutrients and enzymatic browning. To prevent such changes, ultrasound is increasingly being used as pretreatment when drying food. The aim of this study is to determine the most appropriate pretreatment using direct ultrasonic setup in the process of drying pumpkin (butternut) at reduced pressure (100 mBar) and atmospheric pressure as well as the impact on texture, color, drying time and energy consumption. The shortest drying time was achieved by applying an ultrasonic pretreatment with amplitude of 60 % and a duration of 6 minutes, thus achieving a time reduction of 40.17 %, with energy savings of 32.63 % compared to untreated samples. Pretreated and dried pumpkin samples preserved their textural properties. The color of the samples was visually acceptable, although the color deviation of the dried pretreated samples from large (3.0-6.0) to very large (6.0-12.0) was instrumentally determined.

• Keywords: buča; sušenje; ultrazvuk visokog intenziteta; boja; tekstura
• Keywords (english): pumpkin; drying; high intensity ultrasound; color; texture
• Language: croatian
• URN:NBN: urn:nbn:hr:159:749704
• 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: 2021-12-01 10:57:17