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Publications (8)9.04 Total impact

  • Bijay Krishna De · Jignesh Dahyabhai Patel
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    ABSTRACT: The applicability of calcium hydroxide (lime) in the neutralization of rice bran oil (RBO) was investigated. Crude RBO samples of three different free fatty acids (FFAs) (3.5–8.4 wt%) were degummed, dewaxed, bleached, and neutralized with lime and deodorized. The oils obtained thus were characterized by determining the color, peroxide value (PV), content of unsaponifiable matter (UM), and FFA. Conventionally practiced caustic soda neutralization (at 80–90°C) of FFA has in the present investigation been replaced by a high temperature (150–210°C) low pressure (2–4 mm Hg) reaction with lime. It was observed that neutralization with Ca(OH)2 at high temperature (210°C) and under low pressure (2–4 mm Hg pressure) may substantially reduce the FFA content (0.8 wt%, after 2 h). The deodorized oil was found to be of acceptable color, PV, and content of UM and FFA. Neutralization of oil was also carried out by using NaHCO3 and Na2CO3, nonconventional alkalies for neutralization, and the results were compared with NaOH and Ca(OH)2. Overall recovery of oil in Ca(OH)2 refining process (88.5 ± 0.6 wt%, for Sample 1 containing 8.4%-wt FFA) was found to be more than other competitive processes studied.
    No preview · Article · Sep 2011 · European Journal of Lipid Science and Technology
  • Bijay Krishna De · Shikha Verma
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    ABSTRACT: The fungus Cladosporium sp. was explored for its potential ability to produce lipids, fatty acids and protein. The lipids were characterized by the quantification of acylglycerols and fatty acids. Alterations in lipid and protein accumulation were observed by changing the growth medium, carbon source type (glucose and dextrose) and content, growth period and by developing salt stress through the incorporation of NaCl in the formulation of the medium. Lipid content was found to vary from 6.8 ± 0.3 to 27.3 ± 2.8%, w/w. The major fatty acids accumulated were palmitic, oleic and linoleic. The lipid fraction obtained from a Potato- dextrose medium (containing 2% dextrose and 4% NaCl) accumulated 73.7 ± 3.7%, w/w, oleic acid. Some lipid fractions were found to have fatty acid ratios like saturated, monounsaturated, and polyunsaturated close to 1:1:1 w/w/w. Triacylglycerol was obtained as the major constituent of lipid fractions.El hongo Cladosporium sp. fue estudiado por a su potencial para producir lípidos, ácidos grasos y proteínas. Los lípidos fueron caracterizados por la cuantificación de acilgliceroles y ácidos grasos. Alteraciones en la acumulación de proteínas y lípidos fue observada por cambios en el medio de crecimiento, el tipo y contenido de la fuente de carbono (glucosa o dextrosa), el período de crecimiento y por desarrollo de estrés salino a través de la incorporación de NaCl en el medio de formulación. El contenido lipídico vario desde 6.8% ± 0.3 hasta 27.3% ± 2.8 %, w/w. Los principales ácidos grasos acumulados fueron ácido palmítico, oleico y linoleico. La fracción lipídica obtenida con el medio de patatadextrosa (conteniendo 2% dextrosa y 4% NaCl) acumulo un 73.7% ± 3.7 w/w de ácido oleico. Algunas fracciones lipídicas encontradas tuvieron una proporción saturado: monoinsaturado: poliinsaturado cercana a 1:1:1 w/w/w. Los triglicérido fueron los principales constituyentes de la fracción lipídica.
    No preview · Article · Jun 2011 · Grasas y Aceites
  • Bijay Krishna De · Jignesh Dahyabhai Patel
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    ABSTRACT: In a unique attempt modification of only palm oil has been investigated. Triacylglycerols of palm oil has been randomized by chemical and biochemical means. Chemical randomization was carried out using sodium methoxide (NaOMe: 0.4 to 0.6 %, w/w) whereas the biochemical modifications were performed using five different commercial lipases from Amano Enzymes. It was observed that after chemical randomization (for 15 minutes at 90 degrees C) using sodium methoxide (0.5 %, w/w) catalyst the melting point of refined palm oil has risen from 32.0 degrees C to 40.1 degrees C. Chemical treatments for 15 minutes at 60 degrees C in miscella phase (60 %, w/v oil in hexane) using 0.5 %, w/v sodium methoxide resulted increase in melting point from 32.0 degrees C to 42.0 degrees C. After enzymatic treatment using lipases it was observed that the melting point may rise from 32.0 degrees C to 38.5 degrees C (in 15 minutes at 45.0 degrees C). All the five enzymes were found to be active in respect of randomization capacity and active at very low concentration 0.004 to 0.010 % (w/w).
    No preview · Article · Jun 2010 · Journal of oleo science
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    Shikha Verma · Aurobindo Kumar Ray · Bijay Krishna De
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    ABSTRACT: Saccharomyces cerevisiae is widely known for its catalytic activity on substrates such as aldehyde and ketone. Interestingly, the activity of S. cerevisiae on heptanal (C(6)H(13)CHO), in spite of its being a very common aldehyde, has not been explored. The main objective of this study was therefore to investigate the bioconversion of heptanal, using a strain of the yeast S. cerevisiae. Bioconversion parameters such as incubation period, pH, concentration of substrate, yeast and maltose were also optimized. The study revealed heptanol as the major product. The optimum conditions for biotransformation were found to be: 3 days incubation; pH 7.0; heptanal concentration 0.15 ml/100 ml medium; and S. cerevisiae concentration of 0.15 g/100 ml medium. Reduction in maltose content (to 0.3 g maltose/100 ml medium) showed increased conversion of heptanal. Heptanoic acid and 2-hydroxyheptanoic acid were obtained as two minor co-products. The overall study showed that S. cerevisiae converted heptanal to heptanol by a yield of 68.9 +/- 1.1% w/w under optimum conditions.
    Preview · Article · May 2010 · Yeast
  • Bijay Krishna De · J.D. Patel
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    ABSTRACT: The present investigation aimed at finding out the effect of different degumming processes and on the use of some nontraditional alkaline material for refining of rice bran oil. Attempt was made to treat crude rice bran oil with H(2)O, and H(3)PO(4) for degumming followed by with alum or H(2)O for dewaxing. After removal of the gums and waxes the oil was neutralized with commonly used NaOH, and some nontraditional neutralizing agents like Na(2)CO(3) and NaHCO(3). Finally the oil was bleached traditionally using earth and charcoal and deodorized. The RBD oil was characterized by determining their color, peroxide value, content of unsaponifiable matter, and free fatty acids. Among the different processes tried degumming with 0.2 %, w/w, H(3)PO(4) followed by dewaxing with 2.0 %, w/w, H(2)O; bleaching with tonsil earth (1.5 %, w/w) and charcoal (0.5 %, w/w) and finally deodorization at 220 degrees C temperature and 2-4 mm Hg pressure resulted best quality oil in terms of the measured parameters. The characteristics of refined rice bran oil could be as content of FFA and UM 0.2 (%, w/w), 2.6 (%, w/w) respectively; color 10.9Y, 2.0R (in 2.54 cm Lovibond Tintometer cell); PV 3.3 (meq/kg). The oil yield is 78-85 % (by weight).
    No preview · Article · Mar 2010 · Journal of oleo science
  • Shikha Verma · Bijay Krishna De
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    ABSTRACT: The soil-derived fungus Emericella sp. was explored for its potential to produce lipid. Lipid profile, fatty acid composition, production of proteins and carbohydrates from lipid-extracted biomass were determined. The effects of variations in the contents of carbon sources (glucose, dextrose), the salt content (NaCl) and the growth period were studied. A study on the effect of different growing media on the above-mentioned parameters was also carried out. Although the maximum amount of lipid (6.14 ± 0.42 g/L) and protein (5.99 ± 0.47 g/L) was produced after 13 days in medium A containing 10% wt/vol glucose, the optimum lipid (2.90 ± 0.21 g/L) and protein (3.23 ± 0.28 g/L) production was observed in 2% wt/vol glucose medium considering the glucose content in the medium. The principal fatty acids found were 16:0 (14.4 ± 1.0 to 24.5 ± 2.4 wt-%), 18:0 (12.1 ± 0.4 to 27.7 ± 2.7 wt-%), 18:1 (13.5 ± 2.1 to 25.2 ± 2.8wt-%) and 18:2 (30.9 ± 2.0 to 47.0 ± 2.8 wt-%). Some of the lipids, especially those grown for 7 days in less glucose-containing (1 and 2% wt/vol) medium were found to contain nearly 9.0 wt-% of long-chain PUFA 18:4, 20:4, 20:5, 22:4, and 22:5).
    No preview · Article · Mar 2010 · European Journal of Lipid Science and Technology
  • B.K. De · J.D. Patel
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    ABSTRACT: An improved detoxification method using liquid-liquid extraction of karanja {Pongamia glabra) oil is developed. Only 2 stage extractions [using oil and HC1 (1:0.35 w/v)] followed by 3 extractions [using oil and alkaline MeOH (1:2 w/ v)] can completely detoxify oil. After HC1 extraction, if alkaline isopropanol (IPA), dimethylformamide (DMF) and acetonitrile are used for extraction, total HC1 and corresponding solvent requirement would be (w/v) 1:1.0, 1:6.0; 1:0.2, 1:1.2; and 1:0.4, 1:1.6 respectively. When only acetonitrile is used, 5 stage extraction using oil: acetonitrile (1:0.5, w/v) per batch makes total acetonitrile requirement 2.5 times (v/w) of oil for complete detoxification. Physicochemical characteristics of refined oils are acceptable. Overall oil yield (75-80% w/w) is obtained when alkaline MeOH, IPA and DMF are used, but higher yield (85-88%, w/w) is obtained when acetonitrile is used.
    No preview · Article · Apr 2009
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    ABSTRACT: An attempt was made to study the bleaching ability of some alternative adsorbents like rice husk ash (HC), acid activated rice husk ash (AC), rice husk silica (S), and Al(OH)(3) gel to replace commercial Acid Activated Clay (AAC, like Tonsil Earth: TE) for bleaching of mustard oil. Quantities of AAC used were varied from 0.5 to 2.0 % (w/w). It was used as such and along with commercial activated carbon (0.25-0.75 %, w/w), and laboratory prepared Al(OH)(3) gel, rice husk ash and silica isolated from husk. The results show that quantity of AAC to be used can be reduced to 1.00 to 1.25% (w/w) by using a combination of AAC along with rice husk ash; Al(OH)(3) gel; rice husk silica either by wet bleaching or by conventional bleaching method.
    No preview · Article · Feb 2009 · Journal of oleo science