Showing papers by "Sudip Kumar Rakshit published in 2000"
TL;DR: In this paper, the cumulative interactive effect of substrate, water concentration and time was studied in optimizing the hydrolysis of methyloleate using lipase from Chromobacterium viscosum immobilized on IRC-50.
Abstract: Hydrolysis of methyloleate was optimized using lipase from Chromobacterium viscosum immobilized on IRC-50. The optimization was studied by a statistical methodology using response surface methodology (RSM). The cumulative interactive effect of substrate, water concentration and time was studied in optimizing the hydrolysis of methyloleate. The interactive effect of substrate-time was found to be significant compared to substrate-water and time-water interactions. A well correlation was observed between the optimum values obtained from the response surface contour plots and from the quadratic regression model equation. The optimal values obtained for substrate, water and time were found to be in the experimental range chosen.
105 citations
TL;DR: Product analysis of transferase enzymes obtained from the broth of Aspergillus foetidus revealed that the four forms of enzymes are distinct, producing oligosaccharides like panose, kestose and nystose or acting as hydrolytic enzymes depending on the conditions.
27 citations
TL;DR: Esterification of FFA extracted from the completely hydrolyzed mixture of tuna oil was found to be better with long chain fatty alcohol like octanol which lead to good enrichment and recovery of DHA and EPA in the glyceride mixture.
Abstract: Immobilized Pseudomonas fluorescens lipase enzyme was used to enrich the important polyunsaturated fatty acid (PUFA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) from tuna oil. Hydrolysis, esterification, and transesterification reactions were studied in detail to find out the fractionation pattern of DHA and EPA during these processes due to preferential selectivity for or against these PUFA. Hydrolysis with P. fluorescens biotype I lipase with stoichiometric amount of water content gave more than 80% of DHA and EPA in the free fatty acid (FFA) form after around 60% of hydrolysis. After some preferential specificity during the early stages of hydrolysis, P. fluorescens lipase exhibits nonselective characteristics on extended hydrolysis. Esterification of FFA extracted from the completely hydrolyzed mixture of tuna oil was found to be better with long chain fatty alcohol like octanol which lead to good enrichment (44.5% for DHA and 11.3% for EPA) and yields of the PUFA in the FFA form. Transesterification (ethanolysis) with immobilized P. fluorescens lipase enzyme resulted in good enrichment and recovery of DHA and EPA in the glyceride mixture. After around 60% of ester synthesis, 74% of (DHA + EPA) enrichment was achieved with yields of more than 90% in the glyceride mixture.
13 citations