Physical and Chemical Charateristics of Milk. Variation due to Microwave Radiation

The purpose of this paper was to see what effects microwaves have on the physical-chemical composition of the raw milk. The results showed that the averages of fat, protein, dry substance and lactose concentrations decreased during the microwave exposure while the density averages increased. This variation was characterized by the critical time moment of 31.71 s, corresponding to the moment when a milk sample exposed to the microwaves action undergoes the first more significant alteration of its physical- chemical composition. (doi: 10.5562/cca1785

Nano Food Packages: from Food Preservation Efficiency to Consumer Legal Protection

The paper explores some aspects related to the application of nanomaterials in food packaging. Therefore, the paper is structured into two sections. In the first section, aspects that could restrict/restrain the application of nanomaterials in food packaging industry in terms of environmental and human risks, the consumer`s rights to be informed regarding the utilization of nano-packages and regulation issues in the field of large scale application of food nano-packages are discussed. In the second section, the efficiency of a nano-package based on Ag/TiO2 to preserve for a longer time (6 days) the physical attributes of wheat bread (moisture, specific volume, porosity) by comparison with shorter ranges allowed by the common polyethylene bag (3 days) and non-packaging respectively (1 day) is demonstrated

Attempts to Obtain Material Based on Polyvinyl Alcohol with Barrier Properties against Water Vapor

The purpose of this study was to obtain a biodegradable film based on polyvinyl alcohol with reduced water vapor permeability. The hydrophobic character of the films was achieved by incorporating beeswax, vegetable bio-surfactant, citric acid as a cross-linking agent, and glycerol to provide elasticity, along with the application of thermal treatment. Water vapor permeability was determined gravimetrically. The results indicated that all films produced had lower water vapor permeability compared to unmodified or untreated polyvinyl alcohol films. The barrier to water vapor varied directly with the mass of beeswax used, and the homogeneous dispersion of beeswax in the polyvinyl alcohol matrix was essential for achieving an efficient hydrophobic film. The best performing-material exhibited a water vapor permeability 5.15 times lower than that of the neat polyvinyl alcohol and 15 times higher than that of polyethylene. Considering the fact that the water vapor barrier property of neat polyvinyl alcohol was 78 times lower than that of polyethylene, the combination of beeswax, citric acid, and vegetable bio-surfactant—along with thermal treatment—can be a viable solution to reduce the hygroscopicity of polyvinyl alcohol-based films

Mathematic modelling of the copper recovery process from wastewaters using a graphite volumic electrode Polarisation curves

В статье анализируются основные параметры, что характеризируют электролитический процесс с. порошковым катодом (зернистость частиц покрытия, форма текущего питателя и места, где он расположен) за формами кривых поляризации. Полученные экспериментальные данные показывают, что графитный порошок с зернистостью в диапазоне -0.2А÷0.125 см имеет более однородные кривые поляризацииThe paper analyses the influence of main parameters that characterized an electrolytic process with powder cathode (granularity of the bed's particles, the form of current feeder and the place where she is located and fluidization) on shapes of polarization curves. The obtained experimental data show that graphite powders with granularity in range -0.2+0.125 cm has the most uniform polarization curve