Thermo-mechanical and micro-structural properties of xylanase containing whole wheat bread

Xylanase is a hemicellulase that can hydrolyses the complex polysaccharides.Hemicelluloses are main components of cell walls of cereal grains.Moreover,hemicelluloses are considered as potential sources of mono-and oligosaccharides.In this study,influence of xylanase on the physicochemical properties and sensory qualities of the whole wheat bread during storage was investigated.Studies of whole wheat bread on microstructure,texture,thermotics,Scanning Electron Microscopic(SEM),X-Ray Diffraction(XRD)were conducted at ambient temperature of 25 and 4◦C respectively.During storage at different temperatures,bread containing xylanase exhibited less firmness but larger volume with whiter crumb color and longer shelf life as compared to control bread.Results of firmness,enthalpy,Fourier Transformation Infra Red(FTIR)and X-Ray Diffraction(XRD)studies suggested a lower staling rate of bread containing xylanase as compared to control one.Bread containing xylanase showed a smoother surface and more uniform pore size than the control.Significant differences in microstructure of control and bread containing xylanase were observed which might be attributed due to the change in water starch gluten interaction.These differences were also found to be interrelated to the textural properties of bread.Better sensory features were achieved in bread containing xylanase.

Kinetics of Extraction of <i>β</i>-Carotene from Tray Dried Carrots by Using Supercritical Fluid Extraction Technique

β-carotene acts as an antioxidant and is receiving growing interest due to its ability as protecting agent against heart diseases, cancer and strengthening effect on red blood cells. The main aim of this work was to study the kinetics of the supercritical fluid extraction of β-carotene from tray dried carrots at 40℃, 50℃ and 55℃ and 30, 35 and 40 MPa at SC-CO2 flow rate of 2.0 L/min for extraction time of up to 6 h. It was observed that the concentration of β-carotene in the extract increased with pressure, temperature and extraction time. The results indicated that yield was found to be maximum at 45℃ and 35 MPa at 2 L/min SC-CO2 flow rate. Concentration of β-carotene in the extract increased with SC-CO2 flow rate. Weibull distribution model described adequately the kinetics of extraction of β-carotene from carrots.

Instability of binary nanofluids with magnetic field

The present paper investigates the effects of a vertical magnetic field on the double diffusive nanofluid convection, The effects of the Brownian motion and ther- mophoresis due to the presence of nanoparticles and the effects of the Dufour and Sorer parameters due to the presence of solute are included in the investigated model. The normal mode technique is used to solve the conservation equations. For the analytical study, valid approximations are made in the complex expression for the Rayleigh number to get useful and interesting results. The bottom heavy binary nanofluids are more stable than the regular binary fluids, while the top heavy binary nanofluids are less stable than the regular binary fluids. The critical wave number and the critical Rayleigh number in- crease whereas the frequency of oscillation （for the bottom heavy configuration） decreases when the Chandrasekhar number increases. The numerical results for the alumina-water nanofiuid are studied by use of the MATHEMATICA software.