Preželatinizirano brašno kao sirovina za pekarsku industriju

master's thesis

• Title (english): Pregelatinization corn flour as raw material for bakery industry
• Author: Davorka Rajčan
• Mentor: Duška Ćurić (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Food Engineering); (Laboratory for Cereal Chemistry and Technology); Zagreb
• Defense date and country: 2005-07-13, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Food Technology

Abstract

Za ispitivanje u ovom radu korišteno je nativno kukuruzno brašno.Kukuruznom brašnu je određen udio vlage, indeks apsorpcije vode, indeks topljivosti u vodi, stupanj želatinizacije, broj padanja po Hagbergu, granulacija, te enzimatska aktivnost.Nakon toga brašno je podvrgnuto procesu ekstruzije na dvopužnom ekstruderu, ekstrudati su samljeveni, te prosijani kroz sito od 450 μm.Promatran je utjecaj masenog udjela vode u ekstruderu, broja okretaja pužnica, temperature ekstruzije i ukupne dobave sirovine na: indeks ekspanzije, vlagu ekstrudata (%), volumnu masu (g/L), indeks apsorpcije vode (g/gs.t.), indeks topljivosti u vodi (%) i stupanj želatinizacije (%).Pri stalnoj dobavi suhe tvari (57,75 kg/h), temperaturi ekstruzije (135°C), masenom udjelu vode (17,55%), te broju okretaja pužnica (200 i 310 o/min) moguće je proizvesti ekstrudat veličine čestica >450 μm čiji je stupanj želatinizacije približno 14%, te ekstrudat veličine čestica < 450 μm čiji je stupanj želatinizacije približno 14% pri temperaturi ekstruzije (155°C), masenom udjelu vode (22,39%), te broju okretaja pužnica (400 o/min).

Abstract (english)

In this work the analyses were carried out on raw corn flour.In corn flour was determined moisture value, water apsorption index, water solubility index, degree of gelatinization, falling number, and enzymatic activity.The twin screw extruder was used for extrusion.The extrudates were milled and sifted through the sieve of 450 μm.The influence of moisture content in extruder, screw speed, temperature of extrusion, feed rate on: expansion ratio, moisture of extrudates (%), bulk density (g/L), water apsorption index (g/g), water solubility index (%), degree of gelatinization (%), was observed.At permanent supply of dry base (57,75kg/h), temperature of extrusion (135°C), moisture content (17,55%) and screw speed (200 and 310 rpm) is possible made extrudates (size of particles <450μm) whose degree of gelatinization is nearly 14%, and extrudates (size of particles>450μm) whose degree of gelatinization is nearly 14% at temperature of extrusion (155°C), moisture content (22,39%) and screw speed (400 rpm).

• Keywords: ekstruzija; indeks apsorpcije vode; indeks topljivosti u vodi; kukuruzno brašno; želatinizacija
• Keywords (english): corn flour; extrusion cooking process; gelatinization; water apsorption index; water solubility index
• Language: croatian
• URN:NBN: urn:nbn:hr:159:615289
• Study programme: Title: Food Technology; specializations in: Food Engineering; Course: Food Engineering; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo (diplomirani inženjer prehrambene tehnologije; smjer prehrambeno inženjerstvo)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-09-11 09:22:27