FORMULATION, PREPARATION AND CHARACTERIZATION OF NANOEMULSIONS FOR PARENTERAL NUTRITION : doctoral disertationDušica Mirković
, 2019, doktorska disertacija
Opis: The aim of this doctoral research was to develop and optimize parenteral nanoemulsions as well as the total parenteral nutrition (TPN) admixture containing a nanoemulsion obtained in the course of the optimization process (hereinafter referred to as optimal nanoemulsion), and to examine their physicochemical and biological quality as well. In addition, the quality of the prepared nanoemulsions was compared with the quality of the industrial nanoemulsion (Lipofundin® MCT/LCT 20%), and, in the end, the TPN admixture initially prepared was also compared with the admixture into which the industrial emulsion was incorporated.
Parenteral nanoemulsions that were considered in this dissertation were prepared by the high-pressure homogenization method. This method is the most widely applied method for the production of nanoemulsions due to the shortest length of homogenization time, the best-obtained homogeneity of the product and the smallest droplet diameter.
For the nanoemulsion formulation, preparation and optimization purposes, by using, firstly, the concept of the computer-generated fractional design, and, after that, the full experimental design, the assessment of both direct effects of different formulation and process parameters (the oil phase type, the emulsifier type and concentration, a number of homogenization cycles and the pressure under which homogenization was carried out) as well as the effects of their interactions on the characteristics of prepared nanoemulsions was performed.
Monitoring the nanoemulsion physical and chemical stability parameters was carried out immediately after their preparation, and then after 10, 30 and 60 days. It included the visual inspection, the measurement of the droplet diameter (the mean and volume droplet diameter), the polydispersity index, the ζ-potential, the pH value, the electrical conductivity, and the peroxide number. After the preparation and after 60 days, the biological evaluation (the sterility test and the endotoxic test) of the prepared nanoemulsions was carried out. As far as the characterization of the TPN admixture is concerned, it included practically the same parameters. The dynamics of monitoring the characteristics of the TPN admixture was determined on the basis of practical needs of hospitalized patients (0h, 24h and 72h).
The scope and comprehensiveness of this issue indicated the need to divide the doctoral dissertation into three basic stages. The first stage was preliminary. Using the 24-1 fractional factorial design, nanoemulsions for the parenteral nutrition were prepared. They contained either a combination of soybean and fish oil, or a combination of medium chain triglycerides and fish oil. In addition, the type and the amount of an emulsifier used, a number of high-pressure homogenization cycles, and the homogenization pressure, were also varied. The measurement of the above-mentioned parameters for the industrial nanoemulsion was parallely carried out (Lipofundin® MCT/LCT 20%). The objective of this part of the research was to identify critical numerical factors having the most significant effect on the characteristics that define the prepared parenteral nanoemulsions. Parameters that were singled out as the result of this stage of the research (the emulsifier concentration and a number of homogenization cycles) were used as independent variables in the second stage of the research.
Ključne besede: nanoemulsions, total parenteral nutrition admixtures, high pressure homogenization, design of experiments, optimization, analysis of variance, artificial neural networks
Objavljeno v DKUM: 07.06.2019; Ogledov: 11487; Prenosov: 11
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Grain amaranth as an alternative and perspective crop in temperate climateSilva Grobelnik Mlakar
, Matjaž Turinek
, Manfred Jakop
, Martina Bavec
, Franc Bavec
, 2010, pregledni znanstveni članek
Opis: As a consequence of globalisation and industrialisation of agriculture, global food security has become increasingly dependent on only a handful of fertilisation and energy high demanding plant species. This involution has increased the vulnerability of agriculture, reduced genetic diversity, provoked some environmental problems and impoverished the human diet. The mentioned facts stimulate the retrieving of alternative crops into the production. The present paper briefly describes crop importance, botany, nutritional value and utilisation of grain amaranth (Amaranthus spp.), one of the alternative crops discussed in the book Organic Production and Use of Alternative Crops. The immediate objective of this paper is to present information gained as a result of a national project on grain amaranth.
Ključne besede: grain amaranth, nutrition value, utilisation
Objavljeno v DKUM: 29.03.2018; Ogledov: 1066; Prenosov: 130
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The effect of dietary fibre content on skatole and indole production in faeces of immunocatrsted male pigsMartin Škrlep
, Nina Batorek Lukač
, Maja Prevolnik Povše
, Urška Tomažin
, Etienne Labussière
, Marjeta Čandek-Potokar
, 2015, objavljeni znanstveni prispevek na konferenci
Opis: The effect of dietary fibre content on intestinal production of indolic compounds was studied in immunocastrated pigs (IC). In addition, entire males (EM) and IC were compared on control diet (with low fibre content). For the study 32 crossbred pigs were assigned, within a litter to 4 treatment groups; 24 pigs were immunocastrated (at the age of 77 and 112 days) and 8 pigs were kept as entire males (EM). IC were split into three groups (IC_H, IC_M and IC_L) fed three diets differing in crude fibre (34, 60 and 80 g/kg dry matter, respectively) and net energy (NE) (10.0, 9.3, 8.5 MJ NE/kg/DM, respectively). EM were fed high NE i.e. low fibre diet. The experiment started when pigs were 84 days old and finished at the age of 172 days, when pigs were sent to slaughter. Skatole and indole concentrations were determined in the samples of intestinal content taken from caecum (CE), ascending (AC) and descending colon (DC). The concentration of indole was the highest in CE and proximal part of the colon, while skatole concentration increased in the distal parts of the large intestine. Concentrations of indolic compounds did not differ between EM and IC that were fed the same diet. Lowering dietary NE by inclusion of high fibre ingredients reduced the production of indole in the intestinal content of IC pigs, whereas the production of skatole was not affected.
Ključne besede: indole, skatole, dietary fibres, pig, entire males, immunocastrates, pig nutrition, immunocastration
Objavljeno v DKUM: 20.07.2017; Ogledov: 756; Prenosov: 145
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Influence of fertirigation with nitrogen on iron, copper and boron content in leaf and cropping of 'Jonagold' and 'Golden Delicious' apple treesZlatko Čmelik
, Stanislav Tojnko
, 2001, izvirni znanstveni članek
Opis: Two apple (Malus domestica Borkh) cultivars grafted on M9 rootstock were grown on high density ('Jonagold' 2500 trees/ha, 'Golden Delicious' 3000 trees/ha). There were five treatments for each cultuvar (fertirigation with 45kg N/ha, 60 kg N/ha, 120 kg N/ha, irrigation without fertilisers, and control- without irrigation and without fertilisers), and two timing variants (treatments during vegetation period from 1 May to 20 June - variant A, and treatments from 1 May to 1 August - variant B). The treatments were impossed beginning in the second year after planting and lasted seven years (1992-1998). Concentration of microelements in leaf was determined over the 7th and 8th growing season. During the season 1997/98 effects of the applied treatments on leaf mineral content were notable, but these effects often were not consistent. There were no significant timing effect on leaf nutrient concetration of both cultivars. During the cropping years (1993-1998) there were no consistent treatment effects for cumulative yield and cumulative yield efficiency. The highest cumulative yield achieved 'Jonagold' in the control, while 'Golden Delicious' performed best when it was fertilised with 45 and 60 kg N/ha.__
Ključne besede: Malus domestica, mineral nutrition, Fe, Cu, B, Malus domestica, mineralna ishrana, Fe, Cu, B
Objavljeno v DKUM: 10.07.2015; Ogledov: 1079; Prenosov: 39
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