Stabilization of Paste Viscosity of Cassava Starch by Heat Moisture Treatment

Cassava starch has poor paste stability during prolonged cooking. The starch was modified by heat moisture treatment. A premoistured starch (18–24% moisture) was subjected to heat treatment for 3–16h to bring about paste stability. Different types of heat treatments like moist pressure heating, dry heating and microwave heating was tried. The optimum heat treatment to bring about the paste stability was found to be 18–21% premoistured starch, which was heated at 110°C per 16h. The modified starch granules were intact and had comparatively increased sedimentation volume, oil binding capacity, amylase susceptibility, and decreaced crystallinity, water binding capacity, solubility and paste translucency. The freeze - thaw stability was excellent with modified cassava starch. “Pie filling and Halwa” (an Indian sweetmeat) made from modified cassava starch had good organoleptic properites.     

Photochemie von Acylaziden. VIII [1]. Reagieren Acylnitrene wie 1,3-Dipole??

Photochemistry of Acylazides. VIII. Do Acylnitrenes React like 1,3-Dipoles? The formation of three- ore five-membered heterocyclic rings by the reaction of acylnitrenes with olefins depends on the electron density at the double bond. The generally expected formation of aziridines by a cheletropic reaction was observed by photolysis of aroylazides 1 in the presence of 2,5-dihydrofuran 2 . But with enolethers 3 and 4 oxazolines were directly formed. This [3 + 2] cycloaddition is regiospecific. The cycloaddition is modestly stereoselective by steric hindrance within the cyclic enolether 3b . Very small de-values were found with chiral substituents in the acylazide 13 . The azide decomposition was also achieved by photoinduced electron transfer. The same cycloaddition products as obtained by direct photolysis of the azides were obtained via radical anions of the acylazide. Using Michler's ketone as electron donor in the triplet state the formation of isocyanate which diminishes the yield of cycloadducts can be avoided.     

Transport and solvent sensing characteristics of styrene butadiene rubber nanocomposites containing imidazolium ionic liquid modified carbon nanotubes

Obtaining strong interfacial interaction between filler and polymer matrix is very crucial for the fabrication of polymer nanocomposites with superior performance. Present study is aimed to fabricate high performance styrene butadiene rubber (SBR) nanocomposites with imidazolium type ionic liquid modified multiwalled carbon nanotube (MWCNT). Ionic liquid facilitates the dispersion of MWCNT in rubber matrix and it is obvious from transmission electron microscopy images. Diffusion of toluene through SBR nanocomposite membranes has been investigated as a function of surface modified MWCNT (f-MWCNT) content to analyze the chain dynamics and filler-polymer interactions. O₂ gas barrier effect of nanocomposites with special reference to the filler loading is explored. The substantial improvement in the barrier effect in presence of filler interpreted on the grounds of a theoretical model describing permeability of heterogeneous systems. Finally solvent sensing characteristics of prepared nanocomposites are also analyzed and it is observed that prepared nanocomposites can be used as a flexible solvent sensor.     

Dietary alteration of fatty acid composition of lipid classes in mouse mammary adenocarcinoma

The composition of total fatty acids in serially transplanted mammary adenocarcinomas of C3H mice which were fed a fat free diet or a stock diet containing 4% fat for 8 weeks were significantly different, although fatty acid amounts were similar. The difference in composition was manifested in the triglyceride, phosphatidyl choline, and phosphatidyl enthanolamine fractions. Tumors of mice fed fat free diet has appreciable amounts of eicosatrienoic acid, whereas neoplasms of stock diet fed animals had none. In addition, higher levels of oleic acid and lower contents of linoleic acid were found in tumors from mice fed fat free diet than in those from mice fed the stock diet. Thus, mechanisms which maintained the triglyceride fatty acid composition in some tumors, such as 7288CTC hepatoma, were not observed in mouse mammary adenocarcinomas, and, therefore, were not a general phenomena associated with carcinogenesis.     

Yield and Quality Characteristics of Rendered Chicken Oil for Biodiesel Production

Whole dead poultry birds obtained from commercial layer farms were assessed for fat in the whole carcass and then dry rendered in three different rendering regimens T₁, T₂ and T₃ (temperature = 120, 130 and 140 °C and shell pressure = 1, 2 and 3 kg/cm² respectively) and the effect on the yield and quality of the rendered chicken oil were studied. The overall fat percentage of the whole dead poultry carcass was 14.55 ± 0.17 % and the fat content of ‘greaves’ was 14.49 ± 0.38 %. In the dry batch rendering trials, the mean overall fat recovery was 24.46 ± 1.19, 26.78 ± 3.14 and 22.42 ± 2.32 % and the overall fat yield was 3.52 ± 1.72, 3.84 ± 0.44 and 3.22 ± 0.33 % of the carcass weight in T₁, T₂ and T₃ respectively. Solvent extraction of fat could recover 96.10 ± 0.14 % of fat from ‘greaves’ which was significantly higher than the mechanical centrifugation method. Among the quality characteristics of the rendered chicken oil (RCO), moisture content ranged from 0.61 % (T₂) to 1.09 % (T₁) and the mean specific gravity was 0.91 at 30 °C. The FFA values of RCO obtained from the T₃ rendering regimen were significantly (p < 0.05) higher than the FFA values of T₂ and T₁. The mean acid value, iodine number, peroxide value, saponification value and unsaponifiable matter present in RCO showed no significant difference. The fatty acid profile and calorific values were studied. The RCO was converted to biodiesel by transesterification and the physico-chemical properties of the biodiesel were studied and compared with the Indian biodiesel specification.     

Polyaniline / carbon nanotube composites: starting with phenylamino functionalized carbon nanotubes

Summary Composites of carbon a nanotube with polymers are a developing and interesting area of research. The dispersion of the nanotube in polymer matrices is an important factor while making its nanocomposites. Even though in-situ polymerization approach offers a better approach for synthesizing homogeneous polymer nanotube composites, the dispersion of the nanotubes in the monomer solution is a problem. In this article we report a new chemical method for dispersing nanotubes in monomer and the preparation of uniform tubular composite of polyaniline (PANI) and multiwalled carbon nanotube (MWNT). For this the oxidized multiwalled nanotube (o-MWNT) was functionalized with p-phenylenediamine, which gave phenylamine functional groups on the surface. This functionalization helped to disperse the nanotubes in acidic solution. The in-situ polymerization of aniline in the presence of these well dispersed nanotubes gave a new tubular composite of carbon nanotube having an ordered uniform encapsulation of doped polyaniline. The phenylamine functional groups on the surface were grown into polyaniline chain so that the composite contains polyaniline functionalized CNT and they were no more an impurity in the final nanocomposite. The microscopic and structural properties of this composite were compared with that of a composite prepared under identical condition using o-MWNT.     

rGO Sheets/ZnFe2O4 Nanocomposities as an Efficient Electro Catalyst Material for I3−/I− Reaction for High Performance DSSCs

In this paper, Reduced Graphene Oxide (rGO)/ZnFe₂O₄ (rZnF) nanocomposite is synthesized by a simple hydrothermal method and employed as a counter electrode (CE) material for tri-iodide redox reactions in Dye sensitized solar cells (DSSC) to replace the traditional high cost platinum (Pt) CE. X-ray diffraction analysis and High resolution Transmission electron microscopy, clearly indicated the formation of rZnF nanocomposite and also amorphous rGO sheets were smoothly distributed on the surface of ZnFe₂O₄ (ZnF) nanostructure. The rZnF-50 CE shows excellent electro catalytic activity toward I₃^? reduction, which has simultaneously been confirmed by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel polarization measurements. A DSSC developed by rZnF-50 CE (η?=?8.71%) obtained quite higher than the Pt (η?=?8.53%) based CE under the same condition. The superior performances of rZnF-50 CE due to addition of graphene in to Spinel (ZnF) nanostructure results in creation of highly active electrochemical sites, fast electron transport linkage between CE and electrolyte. Thus it’s a promising low cost CE material for DSSCs.

     

Application of β-Sitosterol + γ-Oryzanol-Structured Organogel as Migration Barrier in Filled Chocolate Products

Oil migration in filled pralines is a phenomenon that is highly correlated with the occurrence of chocolate bloom. In this study the potential to suppress or prevent oil migration by incorporation of sterol/sterolster-structured organogels was evaluated. Different quantities, 2.5 or 14% (w/w), of gel with structurant levels of either 10 or 25% (w/w) were studied in a layered model system. The gel was either a part of the nougat or of the chocolate phase, or as a separate layer. Samples were monitored regularly for a period of 24 weeks at storage temperatures of 10, 18 and 28 °C. The amount of migrated oil was determined via DSC analysis of a surface sample. The results indicate that, despite the additional oil brought into the system via the oleogel, the level of oil found in the chocolate layer is reduced through the presence of the gel. In particular, the three-layer system and gelled chocolate appear to be promising routes to either suppress oil migration or improve nutritional profiles by incorporation of liquid oils.     

Ku-band antenna array feed distribution network with ferroelectric phase shifters on silicon

This paper presents the design, fabrication, and experimental results of a 1 : 4 monolithic power distribution network for Ku-band array antenna applications. The network integrated on a high-resistivity silicon (HRS) substrate surface stabilized by polysilicon consists of three Wilkinson power dividers, four dc blocking filters, and four coplanar waveguide (CPW)-to-microstrip (MS) transitions. Each output ports are fed with a barium-strontium-titanate phase shifter. It is found that the introduction of the polysilicon layer between the oxide and HRS reduces RF losses significantly, which will enable the monolithic integration of high-power controller modules onto silicon because of the existence of the oxide layer, preventing any degradation of RF performances. The individual components show insertion losses ranging from 0.4 to 2.6 dB at 15 GHz, and the interconnecting CPW lines result in a loss of 0.064 dB/mm. This network was successfully integrated with MS patch antennas monolithically, showing good performance of 32-dB return loss at 14.85 GHz, and 10/spl deg/ beam-steering capability.