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Aleksieva K.,Chungnam National University | Lagunov O.,Chungnam National University | Dimov K.,Institute of Cryobiology and Food Technologies | Yordanov N.D.,Chungnam National University
Radiation Physics and Chemistry | Year: 2011

The results of EPR studies on herbal pills of marigold, hawthorn, yarrow, common balm, tutsan, nettle and thyme before and after gamma-irradiation are reported. Before irradiation all samples exhibit one weak singlet EPR line with a g-factor of 2.0048±0.0005. After irradiation herbal pills could be separated in two groups according to their EPR spectra. Radiation-induced free radicals in pills of marigold, yarrow, nettle, tutsan and thyme could be attributed mainly to saccharide excipients. Tablets of hawthorn and common balm show "cellulose-like" EPR spectrum, superimposed on partly resolved carbohydrate spectrum, due to the active part (herb) and inulin, which is present in the pills as an excipient. Fading study of the radiation-induced EPR signals confirms that sugar radicals are more stable than cellulose species. The reported results show that the presence of characteristic EPR spectra of herbal pills due to excipients or active part can be used as unambiguous proof of radiation processing within 35 or more days after irradiation. © 2011 Elsevier Ltd.


Leiber F.,ETH Zurich | Tsvetkova V.,Institute of Cryobiology and Food Technologies | Petrova I.,Institute of Cryobiology and Food Technologies | Kreuzer M.,ETH Zurich | Scheeder M.R.L.,Bern University of Applied Sciences
Milchwissenschaft | Year: 2010

Within two groups of lactating Karakachan sheep, grazing mountain pastures in the Bulgarian Rhodope region, respectively one ewe produced milk containing extraordinarily high amounts of c9f11-C18:2 and f10-C18:1. The deviations from the group averages ranged up to about 20 standard deviations for the fl 0-C18:1 isomer in both cases. For one of the two sheep also f11-C18:1 proportion in total fatty acids was increased. Proportions of C18:0 and c9-C18:1 were very low. As the deviating sheep did not receive any treatment differing from that of the other seven and nine animals of the respective groups, it is hypothesized that these changes are due to an inhibition of the terminal step of biohydrogenation in the rumen, possibly by ingestion of an unknown, effective plant species.


Tsvetkova V.,Institute of Cryobiology and Food Technologies | Angelov L.,Institute of Cryobiology and Food Technologies | Jahreis G.,Institute of Nutrition science
Bulgarian Journal of Agricultural Science | Year: 2013

The aim of the study concerns an estimation of the lipids and their fatty acid composition of the grass associations occupying natural and cultivated pastures at 1200m altitude. Plant samples are taken from the region of the Middle Rhodopes from natural meadows containing mainly Nardus stricta and cultivated meadows predominantly with Fastuca fallax, Lolium perenne L. and Poa pratensis during the period from 15 May to 15 July. The established differences in the molar concentration of SFA, MUFA and PUFA, as well as the changed proportions of the main fatty acids (palmitic, oleic, linoleic and linolenic) are supposed to have influence on the milk fat in the ruminant animals. The content of SFA increases from May to July and reaches from 39.90mol% to 45.31mol% in the natural and from 31.19mol% to 40.86mol% in the cultivated grass. It is mostly due to the molar concentration of the 16:0 and 22:0 (p<0.05) which varies between 21.91mol% - 27.57 mol% and 0.88 mol% -1.47 mol%, respectively in the cultivated grasses. The study shows that the total content of MUFA is increased (p<0.01) during the experiment from 8.60mol% to 14.08 mol% in the cultivated meadows, while the differences are not significant in the grasses of the natural meadows. The concentrations of PUFA (60% - 45%) in the plant lipids at the examined altitude in the region of the Middle Rhodopes in May, June and July are connected with relatively higher levels of 18:3n-3 (24mol% - 42mol%) and 18:2 (13mol% - 21 mol%). It has to be noted that the high PUFA level during the whole vegetation period is favorable for providing an optimal supply of essential fatty acids to grazing animals, especially for productive ruminants, as well as for the increased synthesis and secretion of CLA in milk lipids, which prevent human beings from atherosclerosis, obesity, diabetes and other diseases and stimulate the immune system.


Aleksieva K.I.,Bulgarian Academy of Science | Dimov K.G.,Institute of Cryobiology and Food Technologies | Yordanov N.D.,Bulgarian Academy of Science
Radiation Physics and Chemistry | Year: 2014

The results of electron paramagnetic resonance (EPR) study on commercially available juices from various fruits and different fruit contents: 25%, 40%, 50%, and 100%, homemade juices, nectars and concentrated fruit syrups, before and after gamma-irradiation are reported. In order to remove water from non- and irradiated samples all juices and nectars were filtered; the solid residue was washed with alcohol and dried at room temperature. Only concentrated fruit syrups were dried for 60. min at 40. °C in a standard laboratory oven. All samples under study show a singlet EPR line with g=2.0025 before irradiation with exception of concentrated fruit syrups, which are EPR silent. Irradiation of juice samples gives rise to complex EPR spectra which gradually transferred to "cellulose-like" EPR spectrum from 25% to 100% fruit content. Concentrated fruit syrups show typical "sugar-like" spectra due to added saccharides. All EPR spectra are characteristic and can prove radiation treatment. The fading kinetics of radiation-induced EPR signals were studied for a period of 60 days after irradiation. © 2014 Elsevier Ltd.


Vassileva S.,Bulgarian Academy of Science | Mileva S.,Institute of Cryobiology and Food Technologies
Biotechnology and Biotechnological Equipment | Year: 2010

Brewing fermentation is among the most well studied processes in the food industry. Nevertheless, the process still provides challenges to the brewers. It is subject to alteration stemming from the variation in the yeast, a living organism, and due to the complex raw materials of biological origin. With a reliable predictors- artificial intelligence (AI)-based software tools as well as software analyzers for the fermentation monitoring and control one could manage with fewer measurements especially when an early warning gives the operators time to make corrective actions. Our work summarizes research results obtained in intelligent software tools design for beer manufacturing carried out in the Institute of Control and System Research and Institute of Cryobiology and Food Technologies as an answer of world trend in nowledge-based bio-economy establishment.


Marinova G.,Institute of Cryobiology and Food Technologies | Batchvarov V.,Institute of Cryobiology and Food Technologies
Bulgarian Journal of Agricultural Science | Year: 2011

The survey of the methods for determination of free radical scavenging activity by DPPH has been done. The differences between methods conditions and their evaluation are presented. It was determined the effect of methods conditions by ruggedness testing of methods. It was specified that the accuracy of the method for determination of free radical scavenging activity is effected by the solvent used (ethanol or methanol) and the sample/reagent DPPH volume ratio. The coefficient of variation of the method with ethanol is twice lower that the respective one determined with using of methanol. The calibration curves with ascorbic acid (Vitamin C) and α-Tocopherol (Vitamin E) and solvent ethanol and methanol were plotted. They are characterized with very high regression coefficients. Based on the analysis and evaluation of the methods, the results of ruggedness testing of methods, coefficient of variations of determination with solvent ethanol and methanol and recommendations of some authors it was proposed modification of the method for determination of free radical scavenging activity of beer and beverages with DPPH. The modification of the method includes: 0.06 mM solution of DPPH in ethanol, reaction mixture 1.5 ml diluted sample and 1.5 ml DPPH solution, 30 minutes time of reaction in dark, measurement of absorbance at 517 nm, presentation of the results as equivalent of Vitamin C antioxidant activity. It was investigated the effect of malt and hops on the antioxidant activity of wort and beer. It was established that the main free radical scavenging activity of beer is attributed by the malt used. The hopping increases additionally the values of the parameter. During the different stages of the brewing process the free radical scavenging activity is changed. The differences between the free radical scavenging activity of laboratory and production beers indicated the very important role of raw materials and technology used. The free radical scavenging activity of beers determined by ethanol is higher (an average 8,2 - 38.9 % for the used beer samples) than the values obtained by solvent methanol.


Ivanova S.,Institute of Cryobiology and Food Technologies
Bulgarian Journal of Agricultural Science | Year: 2011

The present study aims to investigate the trace element composition of fresh and lyophilized ewe's milk from sheep of the Karakachan breed raised in the region of the Middle Rhodopes. The analysis of trace elements in the native and lyophilized ewe's milk was made after ashing with atomic-absorption photometer AES-ICP "Varian- Liberty II". In the course of lactation a decrease of the content of the trace elements boron, barium, chromium, copper, iron, zinc, selenium and iodine and a good availability of manganese was observed in the native and freeze-dried milk.


Tsvetkova V.,Institute of Cryobiology and Food Technologies | Angelow L.,Institute of Cryobiology and Food Technologies
Bulgarian Journal of Agricultural Science | Year: 2010

The investigation is related to a study of the lipid content and fatty acid profile of the grass associations containing mainly Gramineae species and Fabaceae species from the region of Middle Rhodopes. Plant samples are taken from the meadows at 800m, 1000m and 1200m altitudes and results show a low lipid content in the grasses during the spring period April - June. The established differences in the concentrations of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids as well as the changed proportions of the main fatty acids (palmitic, oleic, linoleic and linolenic) are supposed to have influence on the milk fatty acid profile. The content of saturated fatty acids increases from April to June and reaches 22.5mol%, 27.5mol% and 26.3mol%, respectively at 800m, 1000m and 1200m, predominantly due to the molar concentration of the palmitic acid which varies between 16 and 20mol%, while the level of monounsaturated fatty acids doesn't change during the experiments. The higher concentrations of polyunsaturated fatty acids (64-72 mol %) at three altitudes are due to 18:3 (48-61mol%; 48-56mol% and 50-57 mol %) and 18:2 (from 13 to 18 mol%). It has to be noted that the high polyunsaturated fatty acids levels during the whole vegetation period are favorable for providing an optimal supply of essential fatty acids to grazing animals as well as for the increased synthesis and secretion of conjugated linoleic acid in milk lipids, which prevent human beings from atherosclerosis, obesity, diabetes and stimulate the immune system.


Todorov Y.,Institute of Cryobiology and Food Technologies | Nacheva I.,Institute of Cryobiology and Food Technologies | Metodieva P.,Institute of Cryobiology and Food Technologies | Doneva M.,Institute of Cryobiology and Food Technologies | Tsvetkov T.S.V.,Institute of Cryobiology and Food Technologies
Bulgarian Journal of Agricultural Science | Year: 2013

This paper describes the potentials of the application of modern soft computing techniques into development stage of contemporary food products. Recently, soft computing has been extensively studied and applied for scientific research and engineering purposes. In biological and food engineering, researchers have developed methods of fuzzy logic, artificial neural networks, genetic algorithms, decision trees, and support vector machines to study complex characteristics of many products in order to be adopted cost effective measures satisfying the production constraints and consumer expectations.


Tsvetkova V.,Institute of Cryobiology and Food Technologies
Bulgarian Journal of Agricultural Science | Year: 2014

The experiments are carried out with castrated male pigs fed individually from 20 kg to 100 kg live weight. The animals from the control group (12 pigs) are fed with standard soybean-corn feedstuff and these from the experimental group (12 pigs) – with soybean-barley mixture. The pigs are fed with rations equal in content of protein and energy. The objective of the investigation is to establish the level of the main plasma metabolites, participating in the cholesterol transport and the possibility to affect them in fattening pigs by the effect of barley included in the feed content. The blood plasma is analyzed for content of total protein, cholesterol, phospholipids, triacylglycerols and lipoprotein classes: chylomicrons, low density lipoproteins, very low density lipoproteins and high density lipoproteins. The obtained concentrations of the main plasma metabolites in the control and experimental group according to the biological norms and show a presence of a full value synthesis and secretion of liver proteins, phospholipids, cholesterol, triacylglycerols and lipoproteins. The main lipoprotein classes in the blood plasma of both animal groups are in the physiological optimum range and don’t show differences obligated to the feeding factor. The ratio high density lipoproteins/ low density lipoproteins for the two groups increases from 0.81 for 20 kg up to 1.04 and 1.18 for 50 kg and reaches values from 1.45 and 1.57 for 100 kg animals, for the control and experimental group respectively. © 2014 Bulgarian Journal of Agricultural Science.

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