DIAFILTRATION OF ULTRAFILTRATION RETENTATE OF WHEY FROM WHITE BRINED CHEESE

Whey diafiltration was carried out with a UF25-PAN polyacrylnitrilic membrane with 25 kDa molecular weight cut-off at volume reduction factors (VRF) VRF=2, VRF=4, VRF=6, VRF=8, VRF=10. The values of the principal components dry matter, protein, lactose and mineral substances in the retentates and permeate obtained were established. The relative shares of protein, lactose and mineral substances in the dry matter, the concentration factor (CF) values for dry matter, protein, lactose and mineral substances, and the protein retention factor (RF) were determined. Linear models were created for the CF of each investigated component according to the VRF, and a logarithmic model was developed for the protein RF according to the VRF. The results obtained demonstrated the efficiency of diafiltration for deep treatment aimed at a further elimination of lactose and mineral substances and subsequent utilization of the diafiltration concentrates low in lactose and mineral substances as a liquid supplement in the manufacture of extruded cereal products

Comparative study of quality characteristics of Kashkaval cheese from fresh and chilled curd

The influence of chilledcurd on Kashkavalcheese microbiological, functional, textural and sensorial characteristics was studied. It was found that salting the curd in a hot solution influenced to a greater degree the microflora reduction from the starter culture in Kashkaval cheese obtained fromfresh curd. In terms of species composition, Streptococcusssp. had a higher survival rate compared to Lactobacillusssp. During maturation, this trend changed and the number of Lactobacillusssp. increased, while that of Streptococcus ssp. remained constant and even slightly decreased in both studied samples. Melting and textural characteristics of the two studied cheese samples did not differ significantly at the end of the maturation process. The overall scores of the sensory profile were higher in the cheese obtained from fresh curd but no statistical differences (p>0.05) between separate sensory indices were established. The obtained results indicated that "Cagliata"can be successfully used as an alternative raw material for fresh curd in the production of Kashkaval cheese.publishedVersio

Moisture Sorption Isotherms of Sesame Flour at Several Temperatures

Moisture equilibrium data (adsorption and desorption) of sesame flour were determined using the static gravimetric method of saturated salt solutions at three temperatures, 10, 25 and 40 °C. The range of water activities for each temperature was between 0.11 and 0.85. Equilibrium moisture content decreased with the increase in storage temperature at any given water activity. The experimental data were fitted by five mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost, modified Henderson and Guggenheim-Anderson-de Boer (GAB)). The GAB model was found to be the most suitable for describing the sorption data. The monolayer moisture content was estimated using the Brunauer-Emmett-Teller equation

Izoterme vlaženja sezamovog brašna pri različitim temperaturama

Moisture equilibrium data (adsorption and desorption) of sesame flour were determined using the static gravimetric method of saturated salt solutions at three temperatures, 10, 25 and 40 °C. The range of water activities for each temperature was between 0.11 and 0.85. Equilibrium moisture content decreased with the increase in storage temperature at any given water activity. The experimental data were fitted by five mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost, modified Henderson and Guggenheim-Anderson-de Boer (GAB)). The GAB model was found to be the most suitable for describing the sorption data. The monolayer moisture content was estimated using the Brunauer-Emmett-Teller equation.Ravnoteža vlage (adsorpcije i desorpcije) u sezamovom brašnu određena je gravimetrijom zasićenih otopina soli na temperaturama od 10, 25 i 40 ºC. Aktivitet vode iznosio je 0,11-0,85 pri svim temperaturama. Ravnotežni udjel vlage smanjio se s povećanjem temperature skladištenja bez obzira na vrijednost aktiviteta vode. Podaci dobiveni istraživanjem uskladeni su uz pomoć pet matematičkih modela (modificirani Oswinov, Halseyev, Ching-Pfostov, Hendersonov i Gugenheim-Anderson-de-Boerov (GAB) model). GAB model bio je najprikladniji za opisivanje vrijednosti sorpcije. Udjel vlage u jednom sloju određen je Brunauer-Emmett-Tellerovom jednadžbom

Izoterme vlaženja sezamovog brašna pri različitim temperaturama

Moisture equilibrium data (adsorption and desorption) of sesame flour were determined using the static gravimetric method of saturated salt solutions at three temperatures, 10, 25 and 40 °C. The range of water activities for each temperature was between 0.11 and 0.85. Equilibrium moisture content decreased with the increase in storage temperature at any given water activity. The experimental data were fitted by five mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost, modified Henderson and Guggenheim-Anderson-de Boer (GAB)). The GAB model was found to be the most suitable for describing the sorption data. The monolayer moisture content was estimated using the Brunauer-Emmett-Teller equation.Ravnoteža vlage (adsorpcije i desorpcije) u sezamovom brašnu određena je gravimetrijom zasićenih otopina soli na temperaturama od 10, 25 i 40 ºC. Aktivitet vode iznosio je 0,11-0,85 pri svim temperaturama. Ravnotežni udjel vlage smanjio se s povećanjem temperature skladištenja bez obzira na vrijednost aktiviteta vode. Podaci dobiveni istraživanjem uskladeni su uz pomoć pet matematičkih modela (modificirani Oswinov, Halseyev, Ching-Pfostov, Hendersonov i Gugenheim-Anderson-de-Boerov (GAB) model). GAB model bio je najprikladniji za opisivanje vrijednosti sorpcije. Udjel vlage u jednom sloju određen je Brunauer-Emmett-Tellerovom jednadžbom

Thermodynamics of moisture sorption in tobacco (

In this study, the thermodynamic characteristics of tobacco seeds were investigated, based on experimental data from equilibrium moisture isotherms at desorption. An empirical exponential relationship was found for the decrease of the net isosteric heat and the differential entropy, based on the Clausius-Clapeyron equation, in response to the increase in moisture content; the values of the two parameters varied from 31.09 to 1.46 kJ.mol-1 and from 91.53 to 4.29 J.mol-1.K-1, respectively. The linear relationship between the enthalpy and the entropy in the moisture desoption of tobacco seeds supported the validity of the enthalpy-entropy theory. The value of Gibbs free energy was positive and the harmonic temperature (297.5 K) was lower than the isosteric temperature (339.6 K). The outcomes from the study provide for the deeper insight into the process of moisture desorption of tobacco seeds

Sorption isotherms of tobacco (

The moisture sorption capacity of tobacco seeds is decisive for their safe long-term storage; therefore, the analysis of the sorption isotherms, in a wide temperature and water activity range, is essential for seed quality maintenance in storage. In this study, the equilibrium sorption isotherms of tobacco (N. tabacum L.) seeds, “Kroumovgrad 90” variety of Oriental tobacco, were determined. The experimental data were obtained by the static gravimetric method at different temperatures and water activities. Sorption isotherms showed a typical Type II sigmoidal profile, with a significant hysteresis effect and a decrease of seed sorption capacity with the increase of temperature. The best fitting with tobacco seed sorption isotherms were the modified Chung-Pfost (desorption) and Oswin (adsorption) models. The monolayer moisture content, important for the safe storage of tobacco seeds, was also determined. The outcomes from the study might be of practical use in tobacco seed conditioning and storage design