Revista de bioprocesamiento y biotecnologías

Fat uptake is considered the major nutritional critical point of deep frying because of the obesity and negative effect of excess oil consumption on human health. Hence, this study investigated the effect of pre-drying and hydrocolloids batter coating during heat and moisture transfer of coated fried potato chips. The potato slices were pre-dried coated and deep fried at 180°C for 5 min. Chemical composition, color profile; thermo-physical properties, dimensionless numbers associated with convective heat and mass transfer coefficient and sensory properties were evaluated. The result revealed that chemical composition and color profile were significantly (p ≤ 0.05) affected by pre-drying and hydrocolloids batter coating. The density, viscosity, thermal conductivity, specific heat capacity and thermal diffusivity ranged from 333.3-444.0 kg/m3, 0.5281-0.5377 pas, 22.686-31.403 W/m °C, 198.686-258.383 KJ/kgK and 2.730 × 10-4-3.826 × 10-4 m2/s, respectively. The estimated Grashof, Prandtl, Schmidt, Nusselt and Sherwood numbers ranged between 0.024-0.032, 4.14-4.71, 2.053 × 10-5 and 2.739 × 10-5, 0.0167-0.0209, 9.70 × 10-8 and 1.02 × 10-7, respectively. The heat and mass transfer coefficient values ranged from 25.26 to 42.98 W/m2 °C and 3.80 × 10-12 to 4.01 × 10-12 m/s, respectively. Hydrocolloid type distinctly dictated considerable quality attributes and apparently potato chips pre-dried, coated with egg albumin and carboxyl methylcellulose were gum tragacanth demonstrates great reduction in the fat content of the chips which will in turn decline the tendency of obesity and equally reduce cholesterol level.

Hg (II) has been as one of the most toxic metals on health hazards. The biosorption of toxic metals from aqueous solution by biomass is effective as an alternative method in recent years. Therefore, the biosorption of Hg(II) was examined in view of solution pH, initial concentration of Hg(II), contact time and reaction temperature by using Bacillus subtilis ATCC 6051(B1). Concentration of Hg (II) was measured by ICP-MS. FT-IR was employed for the characterization of bacterial surface. pH of 4.5 was found as the best acidity of aqueous samples. The results from kinetic studies suggested that Hg(II) bio adsorption was best represented by the pseudo second order equation. Results from equilibrium data fitted to Langmuir isotherm model. While ΔH° and ΔS° was obtained as 76.01 kJ/mol and 239, 11 kJ/mol respectively, ΔG° had a low value (4.76 kJ/mol). This study demonstrated that Bacillus subtilis having low cost can be used as an effective biosorbent for Hg(II) removal from aqueous solutions.