Physicochemical,Morphological, Pasting,and Rheological Properties of Tamarind (Tamarindus indica L.) Kernel Starch

Starch was isolated from tamarind kernels, which are at present considered as waste. It was compared with corn and mung bean starch for its physicochemical, rheological, and morphological properties. Tamarind kernel starch showed significantly lower amylose content, light transmittance, solubility, and higher swelling power in comparison to corn and mung bean starch. The micrographs of tamarind kernel starch revealed its small oval shape granules with smooth surfaces. X-ray diffraction pattern of tamarind kernel starch was similar to corn starch with strong diffraction peaks at 15, 17, and 23° (2θ). Changes in storage modulus (G?), loss modulus (G??), and loss tangent (tan δ) during heating of starches showed the lowest peak G? for tamarind kernel starch, whereas the highest was observed for corn starch. Changes in G? and G?? during cooling, holding and subsequently heating were also studied. The frequency dependence of G? and G?? of starches measured at 25 and 95°C revealed their weak gel behavior. During cooling tamarind kernel starch showed lower increase in G? in comparison to other starches. Tamarind kernel starch was different from corn and mung bean starch in exhibiting highest peak, breakdown, and lowest setback viscosity. Tamarind seeds have potential as a relatively new, cheap, and underutilized source of starch in food applications.     

Role of an Isolator in Optimization of Forward Conversion Efficiency in an Er-Doped SFS Source at 1.55 μm

By incorporating an isolator at an appropriate location, it is shown that it is possible to realize an efficient single-pass superfluorescent-doped fiber source with a major fraction of its emitted power in the forward direction. A theoretical model to estimate the performance of such a superfluorescent source (SFS) has been suggested and verified with experiments performed on an erbium-doped fiber in a novel pump bypass SFS configuration. Results on design issues such as optimum location of the isolator, pump power requirements, and spectral characteristics are also presented.     

Tracking of deliberately inoculated Leuconostoc mesenteroides and Lactobacillus brevis in kimchi

Food Science and Biotechnology - The objective of this study was to track intentionally inoculated Leuconostoc mesenteroides (11251) and Lactobacillus brevis (B151) strains in kimchi using random...     

Lewis Acid‐Catalyzed Sequential Transformations: Straightforward Preparation of Functional Dihydropyridines

Lewis acids catalyze the addition of β‐enaminoacrylates or β‐enaminones to α,β‐unsaturated aldehydes leading to substituted dihydropyridines in high yields under mild reaction conditions.     

Antimutagenicity of curcumin and related compounds against genotoxic heterocyclic amines from cooked food: The structural requirement

Curcumin (a major constituent of widely-used spice and colouring agent, turmeric) was found to be very effective in antagonising the S9-mediated mutagenicity of several food-derived heterocyclic amines. In order to understand the chemical basis of antimutagenic properties of curcumin against these mutagens, we have studied the structure–activity relationship between curcumin and its naturally-occurring derivatives, namely demethoxycurcumin and bisdemethoxycurcumin, and other structurally-related natural and synthetic analogues of curcumin, namely tetrahydrocurcumin, dibenzoylmethane, dibenzoylpropane, vanillin, ferulic acid, isoferulic acid and caffeic acid, using Ames Salmonella/reversion assay, against different classes of cooked food mutagens. We conclude that unsaturation in the side chain, a methoxy group on the benzene ring and a central β-diketone moiety in the curcumin molecule are the important structural requirements responsible for high antimutagenic potential of curcumin against cooked food heterocyclic amines.     

Substrate dependent structural and magnetic properties of pulsed laser deposited Fe3O4 thin films

Nanocrystalline iron oxide thin films have been deposited on various substrates such as quartz, MgO(100), and Si(100) by pulsed laser deposition technique using excimer KrF laser (248 nm). The orientations, crystallite size and lattice parameters were studied using X-ray diffraction. The XRD results show that the films deposited on MgO and Si substrates are highly oriented and show only (400) and (311) reflections respectively. On the other hand, the orientation of the films deposited on quarts substrate changed from (311) to (400) with an increase in the substrate temperature from 400 degrees C to 600 degrees C, indicating thereby that the film growth direction is highly affected with nature of substrate and substrate temperature. The surface morphology of the deposited films was studied using Atomic Force Microscopy (AFM) and spherical ball like regular features of nanometer size grains were obtained. The magnetic properties were studied by Superconducting Quantum Interference Device (SQUID) magnetometer in the magnetic field +/- 6 Tesla. The magnetic field dependent magnetization (M-H) curves of all the Fe3O4 thin films measured at 5 K and 300 K show the ferrimagnetic nature. The electrochemical sensing of dopamine studied for these films shows that the film deposited on MgO substrate can be used as a sensing electrode.