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  • Author or Editor: V. K. Joshi x
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The naturally fermented alcoholic (NFA) beverages collected from tribal areas contained higher quantity of methanol, with wide variations in ethanol, pH and volatile acidity. The NFA beverages were also found to be contaminated with Brettanomyces spp. and coliform bacteria indicating a potential danger of their consumption. The examination of natural sources of fermentation (NSF), frequently used in such fermentations, revealed the presence of fungi viz., Aspergillus flavus, Aspergillus oryzae, Mucor spp., Rhizopus spp.: the yeast included Saccharomyces spp., Scytalidium thermophilus (Torula) and Rhodotorula and bacteria viz., Pediococcus, Leuconostoc and Pseudomonas. Except for a few, the general ethanol productivity of the isolates from NSF was low. Saccharomyces spp. had higher population and was predominant among the yeasts isolated from NSF. The abnormal characteristics of the NFA beverages could be correlated with the raw materials, source and method of fermentation and distillation. Use of pure yeast and proper distillation method could improve the quality of such beverages.

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Strawberry fruits of three cultivars viz. Camarosa, Chandler and Doughlas were used to prepare wine by four different methods (control, thermovinification, fermented on the skin and carbonic maceration). Physico-chemical characteristics of the cultivar Camarosa were rated superior to Chandler and Doughlas. The must from the fruits fermented on the skin gave the highest rate of fermentation and ethanol content. The application of various treatments improved the fermentation behaviour of treated strawberry musts compared to the control as revealed by their physico-chemical characteristics. Thermovinified wines had many desirable characteristics such as more total phenols, esters and colour with comparable amount of higher alcohols, volatile acids, ethyl alcohol, sugars and anthocyanin. The carbonic maceration resulted in wines with more alcohol, higher pH, lower acidity, lesser higher alcohol and volatile acids than other wines. Fermented on the skin treated wines were typical for higher amount of anthocyanin, lower reducing sugar and total sugar than the control wines. Thermovinified wines, irrespective of cultivars, scored the highest with respect to most of the sensory quality characteristics. Wines from Camarosa cultivar registered many desirable characteristics such as esters, optimum acidity, more red colour units with comparable contents of alcohol and total phenols, while Chandler cultivar had higher amount of ethyl alcohol, more phenols, anthocyanin than other cultivars. Some of these differences are correlated with their initial characteristics, while others have been influenced by method of vinification. Based on the physico-chemical and sensory qualities, the wines from cv. Camarosa was rated the best, though the wines of all the cultivars were acceptable.

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Abstract  

Thorium along with its daughter products present in the soil is one of the major contributors to the external gamma dose in the environment. To establish the dose levels, quantification of thorium contents in soil samples is very important. As a part of pre-operational environmental radiological surveillance, a total of 23 soil and six sand samples were collected from different locations around the proposed nuclear power plant site of Jaitapur, Maharashtra. Thorium concentrations in these samples were determined by instrumental neutron activation analysis (INAA). Samples were irradiated with neutrons in Apsara reactor at a neutron flux of ~5 × 1011 cm−2 s−1 and radioactive assay was carried out using high resolution gamma ray spectrometry. Relative method of INAA was used for quantification of thorium utilizing 311.9 keV gamma ray of 233Pa, the daughter product of 233Th. The concentrations of thorium in the soil and sand samples were in the ranges of 4.0–18.8 and 1.2–6.2 mg kg−1 respectively.

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Flavour profiling by descriptive analysis of apple wines fermented with different Saccharomyces cerevisiae strains and natural sources of fermentation with or without nitrogen source addition was carried out. Out of 45 attributes used, 38 were found significant and were employed for further evaluation. Generally, the intensities of many of the descriptors in the apple wines were low. Both the natural sources of fermentation (NSF) imparted different flavours notes like lactic, sharp, acetic and fruity to the wine. “W” strain of Saccharomyces cerevisiae gave wines with higher astringency and phenolic flavours, ethyl acetate like, acetaldehyde like flavour, UCD 505 and UCD 522 fermentated wines were peculiar for more ethanolic, sweety and bitter taste, whereas UCD 595 imparted more phenolic, astringent, sour, and ethanolic flavour notes to the wines. The addition of nitrogen source (irrespective of source of fermentation) reduced the development of some flavours considered undesirable (acetic, amyl alcoholic, fusel alcoholic, vegetative). Addition of nitrogen source enhanced the intensity of some other flavour attributes like ethanolic and phenolic in the wines. Due to the same vinification practices (except for the source of fermentation) some modifications in the flavour attributes of apple wines fermented by natural source of fermentation were recorded. The flavour profile of wines fermented by different sources of fermentation, was also reflected in the chemical characteristics examined. Besides higher fermentability, the addition of nitrogen source also affected the physico-chemical characteristics of the wines and consequently, their flavour profile. Application of Principal Component Analysis (PCA) to the means of flavour scores generated from flavour profiling, weakly separated and characterized the wines fermented by different sources of fermentation but did not differentiate the wines fermented with or without nitrogen source. It is concluded that the descriptors described here can characterize apple wine of different quality attributes. The list of descriptors, concentration of standards and details of the technique have also been described.

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Summary

A simple, rapid, precise, and accurate, stability-indicating reversed phase high performance liquid chromatographic method was developed and validated for simultaneous determination of metformin HCl and repaglinide. The chromatographic separation was achieved on YMC Pack AM ODS (5 μm, 250 mm length × 4.6 mm i.d.) column at a detector wavelength of 210 nm, using an isocratic mobile phase consisting of methanol and 10 mM potassium dihydrogen phosphate buffer (pH 2.5) in a ratio of 70:30 v/v at a flow rate of 1 mL min−1. The retention times for metformin and repaglinide were found to be 2.6 and 11.3 min, respectively. The drugs were exposed to thermal, photolytic, hydrolytic, and oxidative stress conditions, and the stressed samples were analyzed by the proposed method. Validation of the method was carried out as per International Conference on Harmonization (ICH) guidelines. Linearity was established for metformin and repaglinide in the range of 5–200 μg mL−1 and 1–200 μg mL−1, respectively. The limits of detection were 0.3 μg mL−1 and 0.13 μg mL−1 for metformin and repaglinide, respectively. The method was found to be specific and stability-indicating as no interfering peaks of degradants and excipients were observed. The proposed method is hence suitable for application in quality-control laboratories for quantitative analysis of both the drugs individually and in combination, since it is simple and rapid with good accuracy and precision.

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