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Chromium (VI) coatings are highly toxic and carcinogenic; therefore, thea should be replaced by a new eco-friendly material that retains its effectiveness in terms of corrosion. Herein, thin silicon oxycarbide films as an eco-friendly anticorrosive coating were deposited on a low carbon steel substrate by a radio frequency capacitively coupled plasma technique using tetraethyl orthosilicate (TEOS) as a precursor. The corrosion performance of the coatings were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in dependence on the gap distance between the plasma electrodes and the pH values at room temperature. The chemical bonding and morphological features of the deposited films were investigated by Fourier Transformer Infrared Spectroscopy in Attenuated Total Reflectance (ATR-FTIR) mode, X-Ray Diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX) coupled with scanning electron microscopy (SEM). The Icorr values were significantly decreased by reducing the gap distance and reached a minimum at 1 cm gap distance. It was reduced from 12 µA/cm2 for the blank sample to 0.714 µA/cm2 in treated sample at gap distance 1 cm and protective efficiency reached ~ 94% in the neutral solution. Nevertheless, the best protective efficiency achieved more than 99% of the total protection in alkaline medium as measured at room temperature for treated sample at gap distance 1 cm.

Lactobacillus plantarum Bu-Eg5 and Lactobacillus rhamnosus Bu-Eg6 showed a potential probiotic role in vivo and in vitro in a preliminary unpublished work. This study demonstrated that Lactobacillus plantarum Bu-Eg5 and Lactobacillus rhamnosus Bu-Eg6 mediated modifications of the physicochemical properties of fermented skimmed cow’s milk. Skim milk was inoculated with 1% (w/v) of Lactobacillus plantarum Bu-Eg5 (T1), 1% (w/v) of Lactobacillus rhamnosus Bu-Eg6 (T2) and 1% (w/v) of 1:1 Lactobacillus plantarum Bu-Eg5 and Lactobacillus rhamnosus Bu-Eg6 (T3). After that, fresh skimmed milk control (C), T1, T2, and T3 were freeze-dried (Zirbus Technology model: VaCo 5-D, S/N: COM98754, Germany). The resulting freeze-dried fresh and fermented milks powders were evaluated for their solubility index, bulk density and water holding capacity (WHC). The amino acids compositions of the freeze-dried treatments were analyzed using High Performance Amino Acid Analyzer (Biochrom 30). The microbiological quality of freeze-dried fresh and fermented milks powders was measured by enumerating lactic acid bacteria, yeast & mould and coliform bacteria. The total protein content of fresh freeze-dried skimmed milk (38.69%) was higher than that of fermented freeze-dried skimmed milk powders. The bulk density was 16.67 g/mL for all treatments. The solubility of fresh freeze-dried skimmed milk was the highest (100%), followed by the other treatments (78.95%). The WHC of fresh freeze-dried skimmed milks (11.16%) was lower than the other samples. The highest total essential amino acids were observed in fresh freeze-dried skimmed milk sample (17.26%) followed by the freeze-dried skimmed milk fermented with Lactobacillus plantarum Bu-Eg5 (16.22%) while the lowest recorded in the freeze-dried skimmed milk sample fermented with 1:1 Lactobacillus plantarum Bu-Eg5 and Lactobacillus rhamnosus Bu-Eg6 (12.87%), there was a very low bacterial count in the control treatment (1.09 log CFU/ml). Yeast & mould and coliforms were not detected in all samples.