The protein content, solubility and functional properties of a total protein concentrate prepared from the seeds of
Roxb. were determined. The effects of pH and/or NaCl concentration on some of these functional properties were also investigated. The protein content of the seed protein concentrate was found to be 65.88%. The minimal protein solubility was observed at pH 4 and the maximum was at pH 12. Water- and oil-holding capacities of the seed protein concentrate were 2.77 g g
and 5.79 g g
, respectively. The emulsifying activity and emulsion stability, as well as foaming capacity and foam stability, were greatly affected by pH levels and salt concentrations. Lower values were observed at slightly acidic pH (pH 4.0) and high salt concentration. Total protein concentrate was highly viscous which depends on concentration and pH levels. The lowest gelation concentration of seed protein concentrate was found to be 14% and 8% when the proteins were dissolved in distilled water and 0.5 M or 1 M NaCl solution, respectively.
Studies on functional propertiesof a protein concentrate produced from the seeds of bakul (Mimusops elengiL.; Sapotaceae) have been carried out. Solubility of the protein was minimum at pH 4.0. Water and oil holding capacities of the seed protein concentrate were 1.70 g g-1and 3.23 g g-1, respectively. Minimum foaming capacity, minimum emulsifying activity, minimum emulsion stability and maximum foam stability were found at pH 4.0. Moreover, emulsion stability of the protein concentrate was high (above 88.3%) over the pH range of 2-10.
Authors:T. Datta Samanta, S. Laskar, D. Nayak, and S. Lahiri
Binding ability of mercury, thallium, lead and bismuth with Erythrina variegata seed protein have been investigated using tracer packet technique. Due to the lack of standard methods, inter-comparisons
have been made among three different approaches, like trichloroacetic acid (TCA) precipitation, isoelectric precipitation
and dialysis of protein after incubation with the metals. Good agreement was observed for all the cases except that of lead.
Authors:D. Nayak, T. DattaSamanta, S. Laskar, and S. Lahiri
The tracer packet technique is an efficient tool to evaluate simultaneously the behavior of some closely associated elements.
The present study has been performed to determine the binding affinity of various toxic heavy and micronutrient elements with
the proteins extracted from Erythrina variegata Linn. (Family: Leguminosae) seed by means of ‘tracer packet’ technique. Effects of buffer and pH dependence on the binding
affinity of the elements of interest have also been examined.
Authors:D. Nayak, K. Hazra, S. Laskar, and S. Lahiri
The present study has been performed to preconcentrate gold using the proteins extracted from Mimusops elengi Linn. (Family: Sapotaceae) seed by radiometric technique using 198Au. Effects of buffer and pH dependence on the binding affinity of the gold have also been examined. It has been found that
the binding of gold with M. elengi protein neither depends on the addition of buffer nor the composition (phosphate/citrate) of buffer. The adsorption of gold
is also independent of pH of the solution. To verify the gold-protein interaction, inter-comparisons have been made between
four different approaches, (1) notably extraction with anion-exchange resin Amberlite IRA 400, (2) trichloroacetic acid (TCA)
precipitation, (3) isoelectric precipitation and (4) dialysis of protein after incubation with gold. Good agreement has been
observed for all the cases. Binding of gold have been studied with three different concentrations of gold, 1, 10 and 50 ppm
spiked with 198Au.
Authors:B. Mukhopadhyay, M. Nag, S. Laskar, and S. Lahiri
Pleurotus citrinopileatus, a species of edible mushrooms, is widely accepted food component, especially in Indian subcontinent. The accumulating susceptibility
of this edible mushroom species towards long-lived radioisotopes of cesium was studied in controlled laboratory condition
using the 134Cs (T1/2 = 2.06 y) radioisotope. It was observed that the experimental mushroom species accumulated 134Cs and maximum accumulation took place in the cap portion. The pileus (cap)/stipes (stem) ratio of each 134Cs accumulated mushroom sample was determined and found 2.22±0.74. The protein and fat fractions of the experimental mushroom
species were extracted separately after accumulation of radiocesium and it was found that most of the radiocesium accumulation
occurred in the protein fraction of the mushroom. The mushroom Pleurotus citrinopileatus which is white in color, turned completely black after radiocesium accumulation. The black mushroom so obtained was produced
upto fourth generation by tissue culture method without using any radiocesium further. All the successors were found to be
black indicating a permanent mutation of the mushroom species.
Authors:D. Nayak, M. Nag, S. Banerjee, R. Pal, S. Laskar, and S. Lahiri
bioaccumulation of 198Au radionuclide, by Rhizocloniumriparium
a member of Chlorophyceae has been studied. It has been observed that
accumulation of gold on Rhizoclonium is almost pH independent and
slightly higher at basic pH. Accumulation of gold was studied with 198Au
radiotracer, 0.1, 1 and 5 ppm concentrations of gold. It has been concluded
from the biochemical analysis that the gold accumulation is due to adsorption
in the cellulose and not in protein, fat and carbohydrate. Accumulated gold was
recovered when washed with conc. HNO3.