Title
Optimizacija i modelovanje kinetike ekstrakcije rezinoida i mineralnih materija iz belog ivanjskog cveća (Galium mollugo L.)
Creator
Milić, Petar S. 1966-
Copyright date
2014
Object Links
Select license
Autorstvo-Nekomercijalno-Bez prerade 3.0 Srbija (CC BY-NC-ND 3.0)
License description
Dozvoljavate samo preuzimanje i distribuciju dela, ako/dok se pravilno naznačava ime autora, bez ikakvih promena dela i bez prava komercijalnog korišćenja dela. Ova licenca je najstroža CC licenca. Osnovni opis Licence: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/deed.sr_LATN. Sadržaj ugovora u celini: http://creativecommons.org/licenses/by-nc-nd/3.0/rs/legalcode.sr-Latn
Language
Serbian
Cobiss-ID
Theses Type
Doktorska disertacija
description
Datum odbrane: 07.06.2014.
Other responsibilities
mentor
Veljković, Vlada 1953-
član komisije
Stanković, Mihajlo
član komisije
Stamenković, Olivera 1973-
član komisije
Milojević, Svetomir 1958-
Academic Expertise
Tehničko-tehnološke nauke
University
Univerzitet u Nišu
Faculty
Tehnološki fakultet
Group
Katedra za hemijsko-inženjerske nauke
Alternative title
Optimization and modeling of the kinetics of resinoid and minerals extraction from white lady's bedstraw (Galium mollugo L.)
Publisher
[P. Milić]
Format
122 lista
description
Biografija autora: list [123]
description
Technological engineering, Chemical engineering
Abstract (en)
This doctoral dissertation deals with the extraction of total extractive (resinoid) and
some minerals (potassium, calcium and magnesium) from ground, dried aerial parts of
white lady’s bedstraw (Galium mollugo L.) using an aqueous ethanolic solution (50 % vol.)
at the solvent-to-plant material ratio of 20 g/g and different temperatures. Both maceration
and indirect ultrasound-assisted extraction were employed. The main goals were the
optimization, kinetic modeling and thermodynamic analysis of the maceration and
ultrasound-assisted extraction of resinoid and minerals from aerial parts of G. mollugo.
For the purpose of modeling the extraction conditions, the relationships of resinoid
and the minerals on extraction temperature and extraction time were modeled by using the
parametric response surface methodology (RSM) in the form of a quadratic equation and
the non-parametric method of artificial neural network (ANN). Both models were found
acceptable for predicting yields of resinoid and the minerals in the temperature ranges of
23-80 oC and 23-40 oC, respectively. However, having higher values of coefficient of
determination ( R2 ) and smaller values of mean relative percentage deviation (MRPD), the
ANN model appears to be better than the quadratic equation, but the latter model is more
reliable in predicting the yields within the applied temperature ranges. The RSM showed
that both temperature and time had a statistically significant impact on yields of resinoid
and the minerals at the 95% confidence level, extraction temperature being more
significant than extraction time.
To maximize the yield of resinoid and minerals the extraction conditions were
optimized by using the quadratic model and the combination of the ANN coupled with a
genetic algorithm (GA). Maximum yields of resinoid and minerals predicted by the two
models are very close to each other and agree with the corresponding actual maximum
v
yields. Also, both models provide similar optimal extraction conditions for both techniques
applied.
According to the ANN-GA model, the optimal extraction conditions (80 oC and
190 min for maceration and 40 oC and 56 min for ultrasound-assisted extraction)
maximized the resinoid yields to 21.3 and 26.0 g/100 g, respectively which agree with the
actual maximum resinoid yields (20.8 i 25.7 g/100 g) achieved under the same extraction
conditions. The optimal extraction conditions as well as the maximum yield and extraction
selectivity of minerals depended on the extraction technique and the type of mineral. For
both techniques applied, the extraction selectivity of the minerals decreased with increasing
temperature. At a constant temperature, the higher mineral extraction selectivity was
achieved by maceration than by ultrasound-assisted extraction.
The extraction of resinoid and minerals from aerial parts of G. mollugo by the
aqueous ethanolic solution in the absence of ultrasound than in its presence includes two
simultaneous processes, namely washing and diffusion of extractive matters. This
mechanism was assumed in modeling the kinetics of resinoid and minerals extraction
through the phenomenological model. The derived kinetic models for resinoid and minerals
are reliable and accurate in representing the variations of resinoid and minerals yields with
time at different temperatures in the absence and the presence of ultrasound. The
parameters of the models depend on the extraction technique, temperature, the type of plant
material and the type of extractive matters. Ultrasound affects the washing of resinoid and
minerals but not the diffusion of extractive matters through plant particles.
The thermodynamic analysis of resinoid and minerals extraction from aerial parts of
G. mollugo shows that both maceration and ultrasound-assisted extraction are spontaneous,
irreversible and endothermic. Spontaneity of resinoid and mineral extraction is favored by
increasing the extraction temperature. The higher extraction degree in the presence of
ultrasound is explained by the increased change of entropy of the extraction system. The
minerals yield increased by a factor of 1.02–1.06 and 1.14–1.27 in the absence and the
presence of ultrasound, respectively for every 10 oC rise in temperature.
vi
Based on the higher maximum yields of resinoid and minerals, the lower extraction
temperature and the shorter extraction time ultrasound-assisted extraction is more favorable
than maceration. However, resinoid obtained in the presence of ultrasound shows lower
antioxidative activity. Also, ultrasound-assisted extraction is characterazed by poorer
extraction selectivity of minerals. Furthermore, ultrasonic extractors are more complex and
more expensive than extractors for maceration. Therefore, further investigations and
techno-economic analysis are needed to choose the better technique for resinoid and
mineral extraction from aeruial parts of G. mollugo.
Authors Key words
Belo ivanjsko cveće, Galium mollugo L., maceracija, ultrazvučna
ekstrakcija, kinetika, modelovanje, optimizacija, termodinamika
Authors Key words
White lady’s bedstraw, Galium mollugo L., maceration, ultrasound-assisted
extraction, kinetics, modeling, optimization, thermodynamics
Classification
66.061.34:582.936.1:66.011(043.3)
Type
Elektronska teza
Abstract (en)
This doctoral dissertation deals with the extraction of total extractive (resinoid) and
some minerals (potassium, calcium and magnesium) from ground, dried aerial parts of
white lady’s bedstraw (Galium mollugo L.) using an aqueous ethanolic solution (50 % vol.)
at the solvent-to-plant material ratio of 20 g/g and different temperatures. Both maceration
and indirect ultrasound-assisted extraction were employed. The main goals were the
optimization, kinetic modeling and thermodynamic analysis of the maceration and
ultrasound-assisted extraction of resinoid and minerals from aerial parts of G. mollugo.
For the purpose of modeling the extraction conditions, the relationships of resinoid
and the minerals on extraction temperature and extraction time were modeled by using the
parametric response surface methodology (RSM) in the form of a quadratic equation and
the non-parametric method of artificial neural network (ANN). Both models were found
acceptable for predicting yields of resinoid and the minerals in the temperature ranges of
23-80 oC and 23-40 oC, respectively. However, having higher values of coefficient of
determination ( R2 ) and smaller values of mean relative percentage deviation (MRPD), the
ANN model appears to be better than the quadratic equation, but the latter model is more
reliable in predicting the yields within the applied temperature ranges. The RSM showed
that both temperature and time had a statistically significant impact on yields of resinoid
and the minerals at the 95% confidence level, extraction temperature being more
significant than extraction time.
To maximize the yield of resinoid and minerals the extraction conditions were
optimized by using the quadratic model and the combination of the ANN coupled with a
genetic algorithm (GA). Maximum yields of resinoid and minerals predicted by the two
models are very close to each other and agree with the corresponding actual maximum
v
yields. Also, both models provide similar optimal extraction conditions for both techniques
applied.
According to the ANN-GA model, the optimal extraction conditions (80 oC and
190 min for maceration and 40 oC and 56 min for ultrasound-assisted extraction)
maximized the resinoid yields to 21.3 and 26.0 g/100 g, respectively which agree with the
actual maximum resinoid yields (20.8 i 25.7 g/100 g) achieved under the same extraction
conditions. The optimal extraction conditions as well as the maximum yield and extraction
selectivity of minerals depended on the extraction technique and the type of mineral. For
both techniques applied, the extraction selectivity of the minerals decreased with increasing
temperature. At a constant temperature, the higher mineral extraction selectivity was
achieved by maceration than by ultrasound-assisted extraction.
The extraction of resinoid and minerals from aerial parts of G. mollugo by the
aqueous ethanolic solution in the absence of ultrasound than in its presence includes two
simultaneous processes, namely washing and diffusion of extractive matters. This
mechanism was assumed in modeling the kinetics of resinoid and minerals extraction
through the phenomenological model. The derived kinetic models for resinoid and minerals
are reliable and accurate in representing the variations of resinoid and minerals yields with
time at different temperatures in the absence and the presence of ultrasound. The
parameters of the models depend on the extraction technique, temperature, the type of plant
material and the type of extractive matters. Ultrasound affects the washing of resinoid and
minerals but not the diffusion of extractive matters through plant particles.
The thermodynamic analysis of resinoid and minerals extraction from aerial parts of
G. mollugo shows that both maceration and ultrasound-assisted extraction are spontaneous,
irreversible and endothermic. Spontaneity of resinoid and mineral extraction is favored by
increasing the extraction temperature. The higher extraction degree in the presence of
ultrasound is explained by the increased change of entropy of the extraction system. The
minerals yield increased by a factor of 1.02–1.06 and 1.14–1.27 in the absence and the
presence of ultrasound, respectively for every 10 oC rise in temperature.
vi
Based on the higher maximum yields of resinoid and minerals, the lower extraction
temperature and the shorter extraction time ultrasound-assisted extraction is more favorable
than maceration. However, resinoid obtained in the presence of ultrasound shows lower
antioxidative activity. Also, ultrasound-assisted extraction is characterazed by poorer
extraction selectivity of minerals. Furthermore, ultrasonic extractors are more complex and
more expensive than extractors for maceration. Therefore, further investigations and
techno-economic analysis are needed to choose the better technique for resinoid and
mineral extraction from aeruial parts of G. mollugo.
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