Sudip Kumar Rakshit

Bio: Sudip Kumar Rakshit is an academic researcher from Lakehead University. The author has contributed to research in topics: Starch & Fermentation. The author has an hindex of 31, co-authored 108 publications receiving 4860 citations. Previous affiliations of Sudip Kumar Rakshit include Asian Institute of Technology & Indian Institutes of Technology.

Enhancing antimicrobial activity of chitosan films by incorporating garlic oil, potassium sorbate and nisin

Abstract: Antimicrobial effect of chitosan edible film incorporating garlic oil (GO) was compared with conventional food preservative potassium sorbate (PS) and bacteriocin nisin (N) at various concentrations. This activity was tested against food pathogenic bacteria namely Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Listeria monocytogenes and Bacillus cereus. Mechanical and physical properties were characterized and Fourier Transform Infrared (FTIR) was also performed to determine functional groups interactions between the matrix and added agent. Incorporation of GO up to levels at least 100 μl/g, PS at 100 mg/g or N at 51,000 IU/g of chitosan were found to have antimicrobial activity against S. aureus, L. monocytogenes, and B. cereus. At these levels, the films were physically acceptable in term of appearance, mechanical and physical properties. GO components did not affect the physical and mechanical properties of chitosan films as it did not have any interaction with the functional groups of chitosan as measured by FTIR.

Physico-chemical Properties, Pasting Behavior and Functional Characteristics of Flours and Starches from Improved Bean (Phaseolus vulgaris L.) Varieties Grown in East Africa

Abstract: Haricot bean (Phaseolus vulgaris L.) starch from improved varieties was isolated by wet milling process and physico-chemical properties, pasting behavior and functional characteristics of bean flours and starches were analyzed. The functional and physical properties of the starches and flours including, swelling power and solubility pattern, color, pH, water and oil absorption capacity of bean starch-water suspension were examined. A rapid visco-analyzer and color flex spectrocolorimeter were used for evaluation of the pasting properties and color of the flours and starch extracts from beans respectively. Chemical composition of whole bean seed flours and starch isolates such as moisture, crude protein, crude fat, total ash, crude fiber, crude lipid, total carbohydrates, starch, phosphorus and amylose content were assessed. Results of analyses for pasting behavior, functional and physico-chemical properties indicated that significance differences (P < 0.05) among bean varieties existed. The factors which influence the pasting characteristics resulting to decrease in peak viscosity (PV), trough (MV) and final viscosity (FV) of starch compared to bean flour are attributed to the interaction of starch with the protein, fat, etc. which in their turn are dependent on the variety. These factors play an important role in governing the pasting properties of starch. The swelling power of the bean flour and starch isolates put them in the category of highly restricted-swelling starch. This characteristic is desirable for the manufacture of value-added products such as noodles and composite blends with cereals. The uses of starch from improved bean varieties to impart viscosity to local processed foods have remarkable potential in the context of East and Great Lakes Regions of Africa where bean consumption of such products are increasing.