Camel Lagnika

Separation and characterization of dextran extracted from deteriorated sugarcane

In this research work, dextran was extracted from deteriorated sugarcane by alcohol precipitation and purified by gel filtration chromatography. Total acid hydrolysis and enzymatic degradation were utilized to confirm the purity of separated polysaccharide. Using the more recently available techniques such as ((1)H,(13)C) and two-dimensional (COSY and HMQC) NMR spectral analysis, methylation GC-MS and MALDI-TOF mass spectrometry, the structure of sugarcane dextran (SC-Dex) was investigated. On the basis of all spectra, SC-Dex showed a branched polysaccharide that contained only d-glucose residues in consecutive α-(1-6) linkages in the main chain with α-(1-3) branches. Methylation analysis showed that, the degree of α-(1-3) branching levels was 4.37%. Several structural fragments were identified from MALDI-TOF spectrum with peak-to-peak mass difference of 162gmol(-1), which confirmed that the repeat unit in SC-Dex was d-glucose. The surface morphology of SC-Dex, revealed the spherically shaped and porous structure. Using HPSEC-MALLS-RI system, the average molecular weight of SC-Dex was estimated to be 1.753×10(6)gmol(-1) with an index of polydispersity value of 1.069.

Extension of mushroom shelf-life by ultrasound treatment combined with high pressure argon

Abstract Effects of ultrasound, high pressure argon, and treatments comprising their combinations on physicochemical and microbiological characteristics of white mushrooms were studied during 9 days of storage at 4°C. High pressure argon treatments were relatively effective in retaining firmness and were found to maintain the cell integrity. White mushrooms firmness after 9 days of storage was increased from 2.79 N for untreated mushrooms up to 3.01, 3.24, 3.58 N for ultrasound, treatments comprising ultrasound and high pressure argon, high pressure argon, respectively. Similarly, the loss of water, ascorbic acid and total soluble solid in fresh mushroom was also greatly reduced by the high pressure argon treatment. The ultrasound treatment followed by treatments comprising ultrasound and high pressure argon and high pressure argon, respectively exhibited a pronounced effect on retarding browning and in delaying mesophilic and psychrotrophic bacteria, yeasts and moulds growth in white mushroom, compared to the control during 9 days of cold storage. Treatments comprising ultrasound and high pressure argon treatment delayed pseudomonas growth, implying that it could extend shelf life of white mushrooms to 9 days at 4°C.