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Sweet buttermilk, a by-product of butter production, remains highly underutilized despite containing some relevant components (i.e., phospholipids) that may have a high biological value and may exert some positive technological functions. The aim of this study was to investigate the possibility of using ultrafiltered (UF) sweet buttermilk at different volume reduction ratios (3 and 5) to replace emulsifiers and/or stabilizers in the production of a novel clean-label ice cream formulation made with sweet buttermilk-based mixtures. The functional, thermo-rheological, and sensory profile of four types of ice creams was investigated. Increasing the degree of sweet buttermilk concentration positively influenced the overrun values and at the same time improved the ice cream's resistance to melting. Also, the thermo-rheological profile during melting was influenced by the presence of UF buttermilk. These differences in techno-functional properties were probably partly caused by the different total phospholipids content caused by UF buttermilk. Some sensory properties (i.e., structure, consistency) were positively related to the utilization of UF buttermilk, while aroma and taste were negatively influenced. This study demonstrated that UF buttermilk can be used as an additive replacer in ice cream production because it enhances the structural and rheological properties of the final product. [ABSTRACT FROM AUTHOR]

Corrosion worldwide causes large losses of metal, which is why various ways are being sought to slow it down. The aim of this study was to investigate the inhibitory effect of fennel fruit essential oil (Foeniculum vulgare Mill.) and its main component anethole. The inhibitory effect of three different concentrations of the fennel essential oil and anethole (1.0 mL/L, 1.5 mL/L, and 2.5 mL/L) in a solution of 1 M HCl at 298 K for 6 h on a sheet of low-carbon steel was investigated. The inhibitory effect was established using gravimetric methods evaluating weight loss, corrosion rate, and inhibition efficiency, as well as electrochemical methods. In gravimetric studies, the inhibition effect of the inhibitors fennel essential oil and isolate anethole at a concentration of 2.0 mL/L was 70.85% and 45.86%, respectively. The anodic polarization curve data at 298 K demonstrate that the anethole and fennel essential oil adsorption on the metal surface creates a barrier that hinders hydrogen ions' access and prevents them from being reduced on the steel surface's cathode sites. Fennel essential oil acting as a mixed type-inhibitor can replace synthetic organic substances and could become an alternative to be used as environmental corrosion inhibitors. [ABSTRACT FROM AUTHOR]

This research was undertaken to evaluate the influence of the extrusion process on the sorption behavior of deproteinized sunflower meal (DSM). A patterned food extrudate (PFE), prepared from a mixture of DSM and corn grits (1:1), was obtained, and the equilibrium isotherms of both products (DSM and PFE) were determined at three temperatures (20 °C, 30 °C, and 40 °C) by the static gravimetric method. The comparison of the sorption behavior of the products showed that extrusion decreased the equilibrium moisture content and the monolayer moisture, while the hysteresis effect was significantly raised in size and span. The experimental sorption isotherms were fitted by five modified models including the temperature effect: Chung–Pfost, Halsey, Oswin, Henderson, and GAB. The modified models of Oswin were established to be suitable to describe the equilibrium sorption isotherms in the temperature range from 20 °C to 40 °C. The net isosteric heat of sorption of DSM and PFE decreases consistently with the increase in moisture content. Extrusion reduces the bond energy between the solid matrix and the water molecules. The ranges of moisture content and relative humidities in the temperature interval studied, appropriate for long-term storage of DSM and PFE, were predicted. [ABSTRACT FROM AUTHOR]

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.

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.

The energy consumption increases continuously around the world. The development of energy-saving processes is essential in order to environmental protection and application of green technologies. The purpose of this work was to investigate the effect of the transmembrane pressure (0.2 MPa to 0.5 MPa), the feed flow rate (190 to 330 dm3/h) and the volume reduction ratio (2 to 4) on the permeate flux and energy demand during ultrafiltration of goat’s milk. A laboratory equipment with a replaceable plate and frame membrane module, fitted with UF25-PAN polyacrylonitrile membrane with 25 kDa molecular weight cut-off was used for membrane filtration. A full factorial experimental design and response surface methodology were used to show the effect of the factors on the permeate flux and energy demand. The results showed that the transmembrane pressure and the feed flow rate influenced positively on the permeate flux, while the effect of the volume reduction ratio was negative. The increase in the values of the factors led to an increase in the energy demand. We recommend dairy processors to work at a pressure of 0.2 MPa, a feed flow rate of 330 dm3/h and a volume reduction ratio of 2 because these operational conditions represented the best ratio between the permeate flux and energy demand. [ABSTRACT FROM AUTHOR]

In this experimental work, the microbiological, physicochemical, organoleptic, and rheological properties of yoghurts produced by ultrafiltered goat's milk using two volume-reduction ratios and three probiotic starters were studied. It was established that the dry matter, fats, proteins, count of lactic acid bacteria, titratable acidity, and dynamic viscosity increased and the pH decreased with the rise of the volume-reduction ratio during ultrafiltration. All yoghurts exhibited Bingham plastic flow behaviour. We recommend using a volume-reduction ratio of 3 and MZ2f + Bifidobacterium bifidum BB-87 to produce probiotic Bulgarian yoghurts with the highest dry matter contents (23.02%), protein contents (10.20%), fat contents (9.80%), number of viable lactic acid cells (9.34 logN), viscosity (4.99 Pa·s at shear rate of 1.22 s−1), and organoleptic properties and the highest score (15) in the range of this experiment. [ABSTRACT FROM AUTHOR]

The present study examined the impact of refrigerated curd (1 °C, 2 months), so called "Cagliata" on Kashkaval cheese chemical characteristics. Changes of cheese components during ripening as well as proteolysis, biogenic amines formation, fatty acid profile, lipolysis and oxidation of milk fat were investigated. Kashkaval cheese samples were characterized by similar dry matters and protein contents but the results obtained for the components such as milk fat, minerals, salt and active acidity were significantly different (P<0.05). A more pronounced proteolysis was found in the cheese produced from refrigerated curd but no accumulation of biogenic amines in both analyzed samples was established. A greater lipolysis and oxidation of milk fat was observed in the cheese obtained from fresh milk. Cheese produced from refrigerated curd could be successfully used as a cheaper alternative of traditional Kashkaval or when a fresh curd is not available without compromising on its quality. [ABSTRACT FROM AUTHOR]

Diafiltration of ultrafiltration retentate from whey was carried out with a UF10-PAN polyacrylnitrile membrane with 10 kDa molecular weight cut-off at different operating conditions (working pressure, volume reduction ratio and temperature). The multifactorial model created and the response surfaces for the effect of the three investigated factors show that the highest value of the flux is obtained at high level of working pressure and temperature and low level of volume reduction ratio. The selectivity and concentration factors of dry matter and protein increase when the volume reduction ratio increases, while the concentration factor of mineral substances decreases. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Moisture equilibrium data (adsorption and desorption) of rice flour were determined using the static gravimetric method of saturated salt solutions at three storage temperatures: 10, 20 and 30 degrees C. The range of water activities for each temperature was from 0.11 to 0.85. Equilibrium moisture content decreased with increase in storage temperature at any given water activity. The experimental data were fitted to four mathematical models (modified Oswin, modified Halsey, modified Chung-Pfost and modified Henderson). The monolayer moisture content was estimated from sorption data using the Brunauer-Emmett-Teller (BET) equation. The isosteric heats of sorption were evaluated using Clausius-Clapeyron equation.