doctoral dissertation
Urban Feguš (Author), Željko Knez (Mentor)

Abstract

The aim of the research project was to develop encapsulated flavourings suitable for the final food applications such as chewing gums, instant teas and confectionary products. For this purpose that water soluble particles with particle size distribution 400-1500 µm and flavour loading up to 30 wt. % should be developed. In order to produce encapsulates with desired physical properties research work was divided into three project phases. The scope of Phase 1 was to select suitable carrier materials and to perform preliminary experiments using laboratory scale process set-up. Different carbohydrates (maltodextrin, simple sugars and sugar syrups) were tested and selected according to their physical characteristics and their process performance. Afterwards preliminary experiments were performed by using laboratory scale set-up. Observations were used for defining process parameters for the design and construction of the pilot plant. Phase 2 covered design and development of the pilot plant for flavour encapsulation while In Phase 3 different process parameters were tested. In the first part influence of the process parameters (processing temperature, homogenizing pressure, mass flow, temperature of the cooling media, retention time in the cooling media and ratio between cooling media and product) on the encapsulation efficiency was investigated. Experiments were performed according to the Design of Experiments (DoE) analysed using analysis of covariance (ANCOVA). Process temperature, pressure at second homogenization step and residence time in cooling media had significant effect on the encapsulation efficiency while pressure at first homogenizing step, mass flow, temperature of the cooling media and ratio between product and cooling media were nonsignificant. Increase in the process temperature (T>130 °C) resulted in paste-like product with increased moisture content up to 13,3 wt.% which was not suitable for further processing. On the other hand samples processed at lower temperature (T<130 °C) resulted in crystalline-like structure with low moisture content. Low flavour retention (<4,5 %) was observed within all samples. Results obtained by ANCOVA were used for further optimization of the process parameters (e.g. homogenizing pressure and the retention time in the cooling media). Maximum flavour load of 3,5 % was observed regardless the homogenizing pressure. Low encapsulation efficiency (η<35 %) was related to poor emulsion stability. Additionally, effect of expansion pressure on the particle size distribution was investigated. It was observed that particle size distribution was little affected by varying expansion pressure (nozzle diameter). All formulation showed similar particle size distribution in-between 40-440 µm. In the last section effect of the emulsifier, flavouring properties and carrier were studied. Emulsifiers with different HLB values were tested in order to increase encapsulation efficiency. Flavourings were selected on the basis of their composition (polarity and volatility). For the encapsulation experiments mentha arvensis oil, orange oil and compounded pineapple flavouring were used. As an alternative carrier material erythritol was used. Addition of emulsifier improved flavour retention for samples containing mentha arvensis oil, while no affect was observed within samples containing orange oil and pineapple flavouring due to the volatility and diffusion of active compounds from matrix to surrounding environment.

Keywords

encapsulation;carbohydrate melts;flavouring;chigh pressure homogenizer;

Data

Language: English
Year of publishing:
Typology: 2.08 - Doctoral Dissertation
Organization: UM FKKT - Faculty of Chemistry and Chemical Engineering
Publisher: [U. Feguš]
UDC: 615.014.6:663.051(043.3)
COBISS: 19685142 Link will open in a new window
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Other data

Secondary language: Slovenian
Secondary title: Razvoj pilotne naprave za enkapsulacijo aromatičnih substanc v talino ogljikovih hidratov z uporabo visokotlačnega homogenizatorja
Secondary abstract: Cilj raziskovalnega projekta je bil razviti enkapsulirane aromatične substance, primerne za uporabo pri živilih, kot so žvečilni gumiji, instant čaji in slaščice. V ta namen je bilo potrebno razviti vodotopne delce z velikostno porazdelitivjo delcev 400-1500 µm in z vsebnostjo aktivne komponente do 30 %. Za proizvodnjo enkapsulatov z želenimi fizikalnimi lastnosti je bilo raziskovalno delo razdeljeno na tri projektne faze. Namen prve faze je bil izbrati primerne nosilne snovi in izvesti preliminarne poskuse z uporabo laboratorijske opreme. Testirani in izbrani so bili različni ogljikovi hidrati (maltodekstrin, enostavni sladkorji in sladkorni sirupi) glede na njihove fizikalne lastnosti in stabilnost tekom procesiranja. Nato je sledila sama izvedba enkapsulacijskih eksperimentov. S pomočjo pridobljenih ugotovitev so bili definirani procesni parametri za projektiranje in izdelavo pilotne naprave. Druga faza raziskovalne naloge je zajemala oblikovanje in razvoj pilotne naprave za enkapsulacijo aromatičnih substanc, medtem ko so bili v tretji fazi testirani različni procesni parametri. V prvem delu so bili raziskani vplivi procesnih parametrov, kot so temperatura obdelave, homogenizacijski tlak, masni pretok, temperatura hladilnega medija, retencijski čas v hladilnih medijih in razmerje med hladilnim medijem in produktom, na učinkovitost enkapsulacije. Poskusi so bili izvedeni z uporabo statistične metode načrtovanja poskusov (DoE) in analizirani s pomočjo analize kovariance (ANCOVA). Procesna temperatura, tlak na drugi homogenizacijski stopnji in retencijski čas v hladilnem mediju so imeli pomemben vpliv na učinkovitost enkapsulacije, medtem ko je bil vpliv ostalih parametrov zanemarljiv (tlak na prvi homogenizacijski stopnji, masni pretok, temperatura hladilnih medijev in razmerje med hladilnim medijem in produktom). Rezultat zvišanja procesne temperature (T> 130 ° C) je bil pasti podoben produkt s povečano vsebnostjo vlage do 13,3 mas.%, ki ni bil primeren za nadaljnjo obdelavo. Pri nižji temperaturi (T <130 ° C) je nastala kristalinična snov z nizko vsebnostjo vlage. Pri vseh vzorcih je bilo opaziti nizko končno vsebnost aromatičnih substanc (<4,5%). Statisčni rezultatso bili uporabljeni za nadaljnjo optimizacijo procesnih parametrov (npr. homogenizacijski tlak in retencijski čas v hladilnem mediju). Maksimalna končna vsebnost aromatičnih substanc (3,5%) je bila dosežena ne glede na homogenizacijski tlak. Nizka učinkovitost enkapsulacije (η <35%) je bila povezana s slabo stabilnostjo emulzije. Poleg tega je bil raziskan vpliv ekspanzijskega tlaka na porazdelitev velikosti delcev, pri čemer je bilo ugotovljeno, da premer šobe nima bistvenega vpliva na velikosti delcev, saj se je le-ta pri vseh formulacijah gibala med 40-440 µm. Zadnji del raziskave je proučeval vpliv emulgatorja, aromatičnih lastnosti in nosilcev. Testirani so bili emulgatorji z različnimi HLB vrednostmi. Aromatične substance so bile izbrane na podlagi njihove sestave (polariteta in obstojnost). Kot aromske komponente so bili uporabljeni mentolovo in pomarančno olje ter sestavljena aroma ananasa, kot alternativni nosilec pa eritritol. Dodajanje emulgatorja je izboljšalo enkapsulacijo arome pri vzorcih procesiranih zuporabo mentolovega olja, medtem ko pri ostalih aromskih komponentah, pomarančnem olju in aromi ananasa, ni bilo opaziti vpliva izboljšanja učnikovtosti enkapslacije difuzije aktivnih spojin iz matrice ogljigovih hidratov v okolico.
Secondary keywords: enkapsulacija;talina ogljikovih hidratov;aroma;visokotlačni homogenizator;doktorske disertacije;Ogljikovi hidrati;Disertacije;Aromatične substance;
URN: URN:SI:UM:
Type (COBISS): Doctoral dissertation
Thesis comment: Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages: XIII, 101 str.
ID: 9136032