Effect of blending and lipase catalyzed interesterification reaction on the cholesterol lowering properties of palm oil with rice bran oil in rats

The effect of feeding blended and interesterified oils containing palm oil (PO) and rice bran oil (RBO) on serum and liver lipids was evaluated in rats. The PO and RBO were blended to contain saturated, monounsaturated and polyunsaturated fatty acids in the proportion of 1:1.5:1. The blended oil was subjected to transesterification reaction using immobilized lipase, lipozyme IM‐RM. Rats were fed a diet containing blended or interesterified oils for 8 weeks. Rats fed PO showed significantly higher levels of cholesterol in serum and liver as compared to those given RBO, blended oil of PO with RBO or interesterified oil. Rats fed blended oils showed a significant decrease in serum cholesterol by 51% compared to rats fed PO. Feeding interesterified oil to rats resulted in decrease in serum cholesterol by 56% compared to rats fed PO, which was 10% lower compared to that observed in rats given blended oil. The present study indicated that a combination of PO with RBO can significantly lower serum lipids in rats as compared to those given diet containing PO alone.     

Uptake of α-Linolenic Acid and Its Conversion to Long Chain Omega-3 Fatty Acids in Rats Fed Microemulsions of Linseed Oil

The present work was designed to prepare linseed oil (LSO) microemulsion and explore the possibility of enhancing the uptake and utilization of α-linolenic acid (ALA) present in LSO. The bioavailability of encapsulated LSO as against native oil was monitored in rats by measuring the uptake in vitro using the intestinal everted sac model and in-vivo administration of microemulsions of LSO to rats for a period of 30?days. Microemulsions were prepared by using different binding materials such as gum acacia, whey protein and lipoid. When LSO was encapsulated with gum acacia, whey protein and lipoid, the levels of ALA uptake into intestinal sacs was increased by 6, 17 and 28?% as compared to oil given without encapsulation. EPA and DHA were not observed in the oil absorbed by intestinal everted sacs when given as emulsions with gum acacia or whey protein. When LSO was given as microemulsions with lipoid, EPA?+?DHA was observed in oil absorbed by intestinal sacs. Similarly when LSO was given as a lipoid emulsion by intubation to rats, the EPA and DHA in serum lipids were found to be 41 and 34?μg/ml, respectively while rats given LSO without encapsulation contained EPA and DHA at 9.1 and 8.8?μg/ml, respectively. Similar changes in omega-3 fatty acid content in liver lipids were observed when LSO was given as a microemulsion with lipoid. This study indicated that ALA was taken up and metabolized to long chain omega-3 PUFA when given as microemulsion with lipoid.     

Performance of Reduced State S–T Trellis Coded MC-CDMA Systems

In this paper, performance of reduced state space-time trellis coded multi carrier code division multiple access (STTC-MC-CDMA) system is evaluated and compared with the performance of original state STTC-MC-CDMA system. The optimum decoding scheme, i.e., maximum likelihood sequence estimation is employed which uses Viterbi algorithm for decoding STTC code. To simplify the implementation of the STTC decoder, the number of states is reduced by reducing the constraint length of the STTC encoder using generating function technique. In this technique, the generator matrix of STTC code is minimized to reduce the number of states of S–T trellis decoder. It is observed that the performance loss in terms of frame error rate of the reduced state STTC-MC-CDMA system is negligible compared to the original state STTC-MC-CDMA system. It is also noted that by using the reduced state technique the STTC decoder can be made faster since it is having lower computational complexity.     

Microbial inactivation by high pressure processing: principle,mechanism and factors responsible

Food Science and Biotechnology - High-pressure processing (HPP) is a novel technology for the production of minimally processed food products with better retention of the natural aroma, fresh-like...     

Simulation of steam reforming of biogas in an industrial reformer for hydrogen production

The paper aims to investigate the steam reforming of biogas in an industrial-scale reformer for hydrogen production. A non-isothermal one dimensional reactor model has been constituted by using mass, momentum and energy balances. The model equations have been solved using MATLAB software. The developed model has been validated with the available modeling studies on industrial steam reforming of methane as well as with the those on lab-scale steam reforming of biogas. It demonstrates excellent agreement with them. Effect of change in biogas compositions on the performance of industrial steam reformer has been investigated in terms of methane conversion, yields of hydrogen and carbon monoxide, product gas compositions, reactor temperature and total pressure. For this, compositions of biogas (CH₄/CO₂ = 40/60 to 80/20), S/C ratio, reformer feed temperature and heat flux have been varied. Preferable feed conditions to the reformer are total molar feed rate of 21 kmol/h, steam to methane ratio of 4.0, temperature of 973 K and pressure of 25 bar. Under these conditions, industrial reformer fed with biogas, provides methane conversion (93.08–85.65%) and hydrogen yield (1.02–2.28), that are close to thermodynamic equilibrium condition.     

Study the effect of dip in reaction temperature on thermal and electrical properties of ZnO nanoparticles

The present study reports thermal and electrical properties of Zinc oxide (ZnO) nanoparticles prepared using co-precipitation route. Sudden dip in reaction temperature observed during the synthesis process created defects in the crystal lattice of ZnO which leads to reduction in crystallite size from 33?nm to 28?nm with increase in reaction temperature. This is confirmed by the X-ray diffraction studies. Thermal analysis of the samples shows better thermal stability for smaller nanoparticles. Temperature-dependent current-voltage characteristics of the ZnO samples show reduction in the conductivity and increase in dielectric constant with respect to rise in reaction temperature. Increase in dielectric constant with decrease in size of nanoparticles may be useful in the field of nanoelectronics like memory-storage devices, etc.     

N-nitrosamines formation from secondary amines by nitrogen fixation on the surface of activated carbon

Our previous study demonstrated that many commercial activated carbon (AC) particles may catalyze transformation of secondary amines to yield trace levels of N-nitrosamines under ambient aerobic conditions. Because of the widespread usage of AC materials in numerous analytical and environmental applications, it is imperative to understand the reaction mechanism responsible for formation of nitrosamine on the surface of ACs to minimize their occurrence in water treatment systems and during analytical methods employing ACs. The study results show that the AC-catalyzed nitrosamine formation requires both atmospheric oxygen and nitrogen. AC's surface reactive sites react with molecular oxygen to form reactive oxygen species (ROS), which facilitate fixation of molecular nitrogen on the carbon surfaces to generate reactive nitrogen species (RNS) likely nitrous oxide and hydroxylamine that can react with adsorbed amines to form nitrosamines. AC's properties play a crucial role as more nitrosamine formation is associated with carbon surfaces with higher surface area, more surface defects, reduced surface properties, higher O(2) uptake capacity, and higher carbonyl group content. This study is a first of its kind on the nitrosamine formation mechanism involving nitrogen fixation on AC surfaces, and the information will be useful for minimization of nitrosamines in AC-based processes.     

Performance of STTC-MC-CDMA Systems with Imperfect Channel Estimation

Since, in a practical system perfect channel state information (CSI) is not possible due to presence of noise. This paper deals with the performance of space-time trellis code (STTC) in multi-carrier code-division multiple-access systems in presence of channel estimation (CE) error and results are compared with perfect CSI at the receiver. The pilot symbol assisted (PSA) technique is used for CE employing minimum mean-square error method. The symbol error rate (SER) performance is observed by employing Viterbi decoding algorithm to decode STTC code at the receiver in multi-path fading channel. The simulated SER performances in presence of CE error and with perfect CSI are compared with the theoretical performances to validate the theoretical analysis.     

Clinical and angiographic features of patients with an occluded versus a patent infarct vessel after intravenous streptokinase for acute myocardial infarction

Despite early treatment with thrombolytic agents for acute myocardial infarction, a significant portion of patients fail to achieve a patent infarct artery. To study the various factors related to achieving patency in the infarct vessel, 201 patients who received streptokinase within six hours of symptoms were studied. All patients underwent cardiac catheterization during the same hospitalization at 5.40 +/- 3.26 days after admission. Forty-five (22.4%) patients were found to have an occluded infarct artery (group 1) and 156 (77.6%) had a patent infarct vessel (group 2). There was no difference in the time from onset of symptoms to receiving streptokinase between the two groups. The two groups were similar to each other with regard to age, gender, history of myocardial infarction or angina, and major risk factors for coronary disease. Coagulation parameters before and after streptokinase therapy, reflecting the lytic state, were similar in both groups. The left ventricular end diastolic pressure was significantly higher and the left ventricular ejection fraction was significantly lower in group 1 than in group 2. These observations suggest that despite early initiation of thrombolytic therapy in patients with acute myocardial infarction, a significant portion of patients fail to achieve a patent infarct artery. This failure cannot be explained by the observed clinical parameters or the lytic state after streptokinase.