... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrad... more ... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrade, Nemanjina 6, PO Box 127, 11081 Belgrade Zemun, Yugoslavia. b Department of Chemical Engineering, Faculty of Technology, University ...
... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrad... more ... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrade, Nemanjina 6, PO Box 127, 11081 Belgrade Zemun, Yugoslavia. b Department of Chemical Engineering, Faculty of Technology, University ...
In this study, the potential of application of non-aggressive LentiKat® technique for brewer&... more In this study, the potential of application of non-aggressive LentiKat® technique for brewer's yeast immobilization on polyvinyl alcohol was assessed. High cell loads of about 109cells/ml were achieved by this procedure and immobilization procedure had no adverse effect on cell viability. The stability and activity of obtained immobilized biocatalyst was tested in the growth studies and fermentations. Immobilized cells exhibited
A novel antioxidative assay based on direct current polarography has been developed. Quantificati... more A novel antioxidative assay based on direct current polarography has been developed. Quantification of antioxidative (AO) activity has been based on a decrease of hydrogen peroxide anodic current in the presence of antioxidants. An efficient experimental procedure, without any special pretreatment of analyzed samples, has been applied. Antioxidative activity of different kinds of commercial beers (dark, blond, and alcohol-free), some small-scale made special beers with medicinal herbs and mushroom extracts, extracts themselves, as well as individual phenolic components present in beer has been measured. In addition, changes of AO activity during the full-scale industrial process of beer production have been monitored. A strong correlation between results obtained and total phenolics content has been observed. The assay can be recommended for application in brewing industry, either to survey a process with the aim to optimize relevant technological factors or to analyze quality of final product.
Genoderma lucidum among all other cultivated mushrooms is unique for its medicinal, rather than n... more Genoderma lucidum among all other cultivated mushrooms is unique for its medicinal, rather than nutritional value. A woody mushroom for centuries highly regarded in oriental folk medicine in recent years came in to focus of numerous pharmacological and medical researchers. The paper gives a brief overview of the obtained results and state of the art of knowledge about its bioactive
World Journal of Microbiology & Biotechnology, 1993
The physiological characteristics of two strains of brewery ale yeasts,Saccharomyces cerevisiae, ... more The physiological characteristics of two strains of brewery ale yeasts,Saccharomyces cerevisiae, with sedimentation abilities, were investigated to see if the strains were suitable for lager beer production. Compared with typical industrial ale strains ofS. cerevisiae and lager strains ofS. uvarum (nowS. cerevisiae), the investigated strains differ in fermentation dynamics, as well as in biological properties. The differences, however, particularly between the two strains and the lager brewing yeasts, were not significant.
The industrial application of dialysis for the de-alcoholization of beer is based on a diafiltrat... more The industrial application of dialysis for the de-alcoholization of beer is based on a diafiltration method, because a small positive transmembrane pressure on the beer side of the membrane is neces sary to prevent ingress of water by osmosis and resulting dilution of the beer. This pressure difference introduces the new driving and convective mass transfer mechanism, which takes place simul taneously with the diffusive mechanism (specific for dialysis). The question is the influence which it has on the overall mass transfer phenomenon and selectivity of the alcohol/extract separation. An experimental Investigation of beer diafiltration using two different membranes (cellulose based Cuprophane and polysulfone) was performed at different transmembrane pressure differences and flow rates. On the basis of the experimentally measured inlet and outlet concentrations the convective components of the alcohol and extract mass fluxes as well as the overall separation factor were determined. This data was analysed and compared. The results indicate that convective mass transfer stimulated extract transfer and losses and thus diminished the efficiency of selective alcohol/extract separation in beer dialysis.
Using experimental results of chemical composition of initial beer, dialysed beer and dialysate, ... more Using experimental results of chemical composition of initial beer, dialysed beer and dialysate, obtained in laboratory scale equipment for dialysis, basic parameters for mass transfer kinetics were determined. It was found that absolute pressure in the system under the medium flow rate of 300 ml/min increased alcohol separate selectivity. As the result of the specific two-phase character of beer, the working pressure in the system for beer dialysis did not fall below 3-4 bar.
... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrad... more ... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrade, Nemanjina 6, PO Box 127, 11081 Belgrade Zemun, Yugoslavia. b Department of Chemical Engineering, Faculty of Technology, University ...
... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrad... more ... a Institute of Food Technology and Biochemistry, Faculty of Agriculture, University ofBelgrade, Nemanjina 6, PO Box 127, 11081 Belgrade Zemun, Yugoslavia. b Department of Chemical Engineering, Faculty of Technology, University ...
In this study, the potential of application of non-aggressive LentiKat® technique for brewer&... more In this study, the potential of application of non-aggressive LentiKat® technique for brewer's yeast immobilization on polyvinyl alcohol was assessed. High cell loads of about 109cells/ml were achieved by this procedure and immobilization procedure had no adverse effect on cell viability. The stability and activity of obtained immobilized biocatalyst was tested in the growth studies and fermentations. Immobilized cells exhibited
A novel antioxidative assay based on direct current polarography has been developed. Quantificati... more A novel antioxidative assay based on direct current polarography has been developed. Quantification of antioxidative (AO) activity has been based on a decrease of hydrogen peroxide anodic current in the presence of antioxidants. An efficient experimental procedure, without any special pretreatment of analyzed samples, has been applied. Antioxidative activity of different kinds of commercial beers (dark, blond, and alcohol-free), some small-scale made special beers with medicinal herbs and mushroom extracts, extracts themselves, as well as individual phenolic components present in beer has been measured. In addition, changes of AO activity during the full-scale industrial process of beer production have been monitored. A strong correlation between results obtained and total phenolics content has been observed. The assay can be recommended for application in brewing industry, either to survey a process with the aim to optimize relevant technological factors or to analyze quality of final product.
Genoderma lucidum among all other cultivated mushrooms is unique for its medicinal, rather than n... more Genoderma lucidum among all other cultivated mushrooms is unique for its medicinal, rather than nutritional value. A woody mushroom for centuries highly regarded in oriental folk medicine in recent years came in to focus of numerous pharmacological and medical researchers. The paper gives a brief overview of the obtained results and state of the art of knowledge about its bioactive
World Journal of Microbiology & Biotechnology, 1993
The physiological characteristics of two strains of brewery ale yeasts,Saccharomyces cerevisiae, ... more The physiological characteristics of two strains of brewery ale yeasts,Saccharomyces cerevisiae, with sedimentation abilities, were investigated to see if the strains were suitable for lager beer production. Compared with typical industrial ale strains ofS. cerevisiae and lager strains ofS. uvarum (nowS. cerevisiae), the investigated strains differ in fermentation dynamics, as well as in biological properties. The differences, however, particularly between the two strains and the lager brewing yeasts, were not significant.
The industrial application of dialysis for the de-alcoholization of beer is based on a diafiltrat... more The industrial application of dialysis for the de-alcoholization of beer is based on a diafiltration method, because a small positive transmembrane pressure on the beer side of the membrane is neces sary to prevent ingress of water by osmosis and resulting dilution of the beer. This pressure difference introduces the new driving and convective mass transfer mechanism, which takes place simul taneously with the diffusive mechanism (specific for dialysis). The question is the influence which it has on the overall mass transfer phenomenon and selectivity of the alcohol/extract separation. An experimental Investigation of beer diafiltration using two different membranes (cellulose based Cuprophane and polysulfone) was performed at different transmembrane pressure differences and flow rates. On the basis of the experimentally measured inlet and outlet concentrations the convective components of the alcohol and extract mass fluxes as well as the overall separation factor were determined. This data was analysed and compared. The results indicate that convective mass transfer stimulated extract transfer and losses and thus diminished the efficiency of selective alcohol/extract separation in beer dialysis.
Using experimental results of chemical composition of initial beer, dialysed beer and dialysate, ... more Using experimental results of chemical composition of initial beer, dialysed beer and dialysate, obtained in laboratory scale equipment for dialysis, basic parameters for mass transfer kinetics were determined. It was found that absolute pressure in the system under the medium flow rate of 300 ml/min increased alcohol separate selectivity. As the result of the specific two-phase character of beer, the working pressure in the system for beer dialysis did not fall below 3-4 bar.
Uploads
Papers by Ida Leskosek