High pressure processing of garlic paste: effect on the quality attributes

The effect of high pressure treatment and conventional thermal processing on the various quality attributes of garlic paste was evaluated in terms of physicochemical, enzymatic, sensory and microbiological parameters. Thermal treatment inactivated the polyphenol oxidase and peroxidase enzymes, whereas an enhanced activity was noted at 200 MPa which reduced significantly (P < 0.05) when treated with 400 and 600 MPa. Total phenolics, flavonoids and antioxidant activities showed an increasing trend with increase in pressure, whereas thermal processing was found to significantly (P < 0.05) decrease these phytocompounds. The CIE (L*, a*, b*) values were found to be better retained in high pressure‐processed pastes compared with thermally treated one. The microbial counts in terms of total plate count, yeast and mould count as well as total coliform counts were reduced significantly (P < 0.05) in both the treatments. Sensory attributes were found to be better in the case of high pressure‐processed samples as compared to the thermally treated one.     

Comparison of the yield and quality of cheese made with calf-rennet and treated enzyme preparations of Rhizopus oligosporus as coagulants

The curd working properties and chemical compositions of Cheddar cheese prepared with different enzyme preparations of Rhizopus oligosporus No. 1104 were compared with calf-rennet cheese. Three coagulants derived from R. oligosporus exoenzyme: heat treated (HT), aluminium trioxide adsorbed (ATA) and heated and aluminium trioxide adsorbed (HATA), having considerably less proteolytic activity were used along with crude enzyme (RO) for cheese making. These enzyme preparations did not affect significantly the renneting time, acidity development, fat loss in whey and the yields of green cheese as compared to calf-rennet, but they did show higher proteolysis and lipolysis. Cheese made with these enzymes graded slightly inferior in the organoleptic qualities to calf-rennet cheese. However, in the early stages of ripening these cheese exhibited body and flavour closer to calf-rennet cheese.     

Emotion recognition from speech: a review

Emotion recognition from speech has emerged as an important research area in the recent past. In this regard, review of existing work on emotional speech processing is useful for carrying out further research. In this paper, the recent literature on speech emotion recognition has been presented considering the issues related to emotional speech corpora, different types of speech features and models used for recognition of emotions from speech. Thirty two representative speech databases are reviewed in this work from point of view of their language, number of speakers, number of emotions, and purpose of collection. The issues related to emotional speech databases used in emotional speech recognition are also briefly discussed. Literature on different features used in the task of emotion recognition from speech is presented. The importance of choosing different classification models has been discussed along with the review. The important issues to be considered for further emotion recognition research in general and in specific to the Indian context have been highlighted where ever necessary.     

Language identification using phase information

The present work investigates the importance of phase in language identification (LID). We have proposed three phase based features for the language recognition task. In this work, auto-regressive model with scale factor error augmentation have been used for better representation of phase based features. We have developed three group delay based systems, namely, normal group delay based system, auto-regressive model group delay based system and auto-regressive group delay with scale factor augmentation based system. As mel-frequency cepstral coefficients (MFCCs) are extracted from the magnitude of the Fourier transform, we have combined this MFCC-based system with our phase-based systems to exploit the complete information contained in a speech signal. In this work, we have used IITKGP-MLILSC speech database and OGI Multi-language Telephone Speech (OGI-MLTS) corpus for our experiments. We have used Gaussian mixture models for building the language models. From the experimental results it is observed that the LID accuracy obtained from our proposed phase based features is comparable with MFCC features. We have also observed some performance improvement in the LID accuracy on combining the proposed phase-based systems with the state of the art MFCC-based system.     

Application of prosody models for developing speech systems in Indian languages

In this paper we demonstrate the use of prosody models for developing speech systems in Indian languages. Duration and intonation models developed using feedforward neural networks are considered as prosody models. Labelled broadcast news data in the languages Hindi, Telugu, Tamil and Kannada is used for developing the neural network models for predicting the duration and intonation. The features representing the positional, contextual and phonological constraints are used for developing the prosody models. In this paper, the use of prosody models is illustrated using speech recognition, speech synthesis, speaker recognition and language identification applications. Autoassociative neural networks and support vector machines are used as classification models for developing the speech systems. The performance of the speech systems has shown to be improved by combining the prosodic features along with one popular spectral feature set consisting of Weighted Linear Prediction Cepstral Coefficients (WLPCCs).     

Structure analysis on the Ba3Mg(Ta1−xNbx)2O9 ceramics: Coexistence of order and disorder

The Ba₃ZnTa₂O₉ (BZT) and Ba₃MgTa₂O₉ (BMT) ceramics, a family of A₃B²⁺B⁵⁺₂O₉ complex perovskites, are extensively utilized in mobile based technologies due to their intrinsic high unloaded quality factor, high dielectric constant and a low (near-zero) resonant frequency temperature coefficient at microwave frequencies. The preparation conditions as well as size and nature of B cations have a profound effect on the final dielectric properties. In this article, we report the effect of Nb⁵⁺ at the Ta⁵⁺ site on the BMT structure prepared at four synthesis temperatures (1300, 1400, 1500 and 1600 °C). The analysis has been carried out using the Rietveld technique on the X-ray powder diffraction data. Results suggest that both the preparation temperatures and Nb⁵⁺ content have significant effect on the ordering of B cations in the Ba₃Mg(Ta_1−xNb_x)₂O₉ solid solution. A disordered (cubic) structure is preferred by the 1300 °C compounds. The weight percentage of the ordered (trigonal) phase escalates, for a given composition, with increasing calcination temperature. A fully ordered trigonal arrangement exists only for x = 0.0 and 0.2 compounds calcined at 1600 °C, and the rest are biphasic (cubic and trigonal). The increase in the cubic fraction upon Nb⁵⁺ augmentation suggests that the solid solution leans more toward the disordered structural arrangement of B²⁺ and B⁵⁺ cations.     

Silica Gel Anchored Chiral Mn(III)Salen Complexes for Enantioselective Epoxidation of Unfunctionalised Olefins

Heterogeneous Mn(III) chiral salen complexes are prepared through covalent attachment of salen ligand on silica gel via chloropropyl spacer and subsequent complexation with manganese. The complexes are well characterized by IR, UV/VIS, TGA and elemental analysis. Epoxidation of unfunctionalised prochiral olefins by Mn(III) chiral salen complexes using iodosobenzene and m-CPBA as the terminal oxidants and NMO as a co-oxidant was achieved with good yields albeit low enantiomeric excess.     

Evaluation of the Central Effects of Systemic Lentiviral-Mediated Leptin Delivery in Streptozotocin-Induced Diabetic Rats

Type 1 diabetes (T1D) is characterized by hyperphagia, hyperglycemia and activation of the hypothalamic–pituitary–adrenal (HPA) axis. We have reported previously that daily leptin injections help to alleviate these symptoms. Therefore, we hypothesized that leptin gene therapy could help to normalize the neuroendocrine dysfunction seen in T1D. Adult male Sprague Dawley rats were injected i.v. with a lentiviral vector containing the leptin gene or green fluorescent protein. Ten days later, they were injected with the vehicle or streptozotocin (STZ). HPA function was assessed by measuring norepinephrine (NE) levels in the paraventricular nucleus (PVN) and serum corticosterone (CS). Treatment with the leptin lentiviral vector (Lepvv) increased leptin and insulin levels in non-diabetic rats, but not in diabetic animals. There was a significant reduction in blood glucose levels in diabetic rats due to Lepvv treatment. Both NE levels in the PVN and serum CS were reduced in diabetic rats treated with Lepvv. Results from this study provide evidence that leptin gene therapy in STZ-induced diabetic rats was able to partially normalize some of the neuroendocrine abnormalities, but studies with higher doses of the Lepvv are needed to develop this into a viable option for treating T1D.     

Effect of chopped/continuous fiber,coupling agent and fiber ratio on the mechanical properties of injection-molded jute/polypropylene composites

This paper presents the development of jute/polypropylene (PP) composites by twin-screw extrusion and injection molding. Jute/PP was compounded using twin-screw extruder and injection molded. The effects of chopped/continuous fibers, coupling agent and fiber ratio on mechanical properties were investigated. Tensile and flexural moduli of continuous jute/PP were greater than those of chopped fiber/PP. Tensile, flexural and impact strengths were greater in chopped fiber/PP along with elongation at break. Coupling agent improved the tensile and flexural strengths, and these increased with fiber content, whereas impact strength and elongation at break decreased with fiber loading. The results were analyzed using ANOVA and regression analyses.     

Fabrication of bimetallic PtPd alloy nanospheres supported on rGO sheets for superior methanol electro-oxidation

Bimetallic PtPd nanospheres strongly fabricated on reduced graphene oxide (rGO) sheets (rGO-PtPd) by simple one pot wet reflux method for superior methanol electro-oxidation. There is no any other polymer or seed involved for preparation of nanocomposite. The as-synthesized materials structure and morphology was calibrated by Powdered X-ray diffraction (P-XRD), Raman, X-ray photo electron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The PtPd nanoparticles supported rGO sheets displays superior electro-catalytic activity and stability towards methanol electro-oxidation (MOR) because of their large electrochemical surface area (ECSA, which is 1.68 times greater than that of commercial Pt/C black) and synergistic effect of the bimetallic alloy. The rGO-PtPd showed enhanced electro-catalytic performances towards MOR in acidic media due to particle size and uniform distribution of particles, which rGO-Pt1Pd1 (Pt/Pd molar ratio 1/1) showed the more specific activity, mass activity and stability for MOR. Thus, as-synthesized rGO-PtPd catalyst could apply potential applications in direct methanol fuel cells (DMFCs) to lower their cost and advance their cycle ability, which make it promising for practical catalysis in energy conversion and storage.