Study on the Effect of Different Woven Structures on Physical Properties of Cotton Muslin Fabric

In this paper studies were undertaken to observe the effect of fiber and yarn properties on the properties of cotton Muslin fabric made in Khadi sector. Fine cotton muslin fabrics, which are being produced from Suvin variety of cotton in various parts of the country were analyzed in terms of realization of fiber strength in yarn and yarn strength in fabric. Fine cotton bleached fabrics of three types of weaves namely plain, 1/3 twill and 4 end irregular sateen are prepared out of 2.7 tex unsized yarn and tested with respect to all relevant physical properties.     

Occurrence of inhibitory compounds in spent growth media that interfere with acid-tolerance mechanisms of enteric pathogens

Understanding the acid-tolerance ability of enteric human pathogens is critical in determining microbial food safety and the associated risk. We have discovered naturally occurring compounds in the spent growth media, which inhibit the acid-tolerance ability of several enteric human pathogens when challenged at pH 3.0 for 2 h at 37 degrees C. The compounds were detected in the spent growth media obtained from Escherichia coli O157:H7, Salmonella spp., and Vibrio cholera, but not from Shigella flexneri. The compounds were effective in reducing pathogen survival by 5-logs during acid-challenge assay. The low molecular weight (<300 Da) and heat resistant nature (121 degrees C, 15 min, at 15 psi) of the compounds make them excellent candidates to explore their suitability as food additives that would increase microbial food safety.     

Sequential microbial activities mediated bioelectricity production from distillery wastewater using bio-electrochemical system with simultaneous waste remediation

A two-chambered microbial fuel cell (MFC), which can function on the self-driven bio-electrogenic activity operated on anaerobically digested distillery waste (ADDW) i.e. wastewater post anaerobic digestion was designed and fabricated in the laboratory. MFC was evaluated for production of bioelectricity with a simultaneous reduction in the carbon content. Using a surface response methodology with a Box-Behnken design (BBD), operating conditions such as the concentration of antifoam, pH, and resistance were optimized and it was found that the pH and resistance were optimum at 8.3 and 1000 Ω, respectively with no antifoam in the system. Under optimum conditions, 31.49 Wm^?3 was generated, and 60.78 ± 0.95% total organic carbon was degraded. We revealed that the fermentative bacteria generated organic acids mainly acetate from dextrose present in ADDW and electrogenic bacteria oxidized acetate in a successive manner to generate electrons, which was confirmed by gas chromatography. The development of biofilm analyzed by scanning electron microscope (SEM) was found to be crucial in the transfer of electrons directly to the anode and was confirmed by cyclic voltammetry experiments. Identification of bacteria from biofilm by both culture and denaturing gradient gel electrophoresis methods found bacteria belonging to phylum Firmicutes and γ-proteobacteria. The study of successive nature of bacterial metabolism to generate electricity could play an important role in the production of electricity in a continuous mode of operation using MFCs fed with ADDW for further reduction of carbon content post anaerobic digestion for the benefit for the environment. Thus MFC can be used as a complementary technology to anaerobic digestion.     

A Rapid and Simple DNA Extraction Procedure to Detect Salmonella spp. and Listeria monocytogenes from Fresh Produce Using Real-time PCR

DNA isolation procedures significantly influence the outcome of PCR-based detection of human pathogens. Unlike clinical samples, DNA isolation from food samples, particularly from fresh and fresh-cut produce has remained a formidable task and has hampered the sensitivity and accuracy of molecular methods. We utilized a commercially available filter-based DNA isolation method (FTA) in conjunction with real-time PCR-based detection of Salmonella spp. and Listeria monocytogenes. The protocol uses filter paper discs impregnated with a patented chemical formulation that lyses cells, immobilizes DNA, and protects it from degradation. Use of the FTA method in conjunction with real-time PCR for the detection of Salmonella spp. and L. monocytogenes was compared with two commercially available DNA isolation procedures that are commonly used for high throughput real-time PCR pathogen detection systems. Both pathogens were successfully detected from artificially inoculated fresh and fresh-cut produce such as alfalfa sprouts, cilantro, green onion, broccoli, prepacked mixed salad, and spinach at low cell numbers (four to seven colony forming units per 25 g initial inoculum level before enrichment). The FTA protocol had distinct advantages of simplicity, biosafety, and compatibility for high throughput screening. This DNA preparation protocol was rapid, sensitive, required minimal handling, and reduced interference from produce-associated inhibitors of real-time PCR. Mention of brand names does not constitute an endorsement by the U.S. Department of Agriculture above others of a similar nature not mentioned.     

Enhancement of soluble dietary fibre, polyphenols and antioxidant properties of chapatis prepared from whole wheat flour dough treated with amylases and xylanase

BACKGROUND: Chapati preparation involves various processing steps such as mixing the flour into dough, sheeting and baking. During these processing steps, flour components are likely to undergo changes in their nutrient and polyphenol composition and their antioxidant properties due to phenol‐mediated crosslinking of proteins and carbohydrates. Therefore, in the present study, changes in nutritional, nutraceutical and antioxidant properties of chapatis prepared from doughs treated with amylases and xylanase were determined. RESULTS: An increase in insoluble dietary fibre content and a decrease in soluble polyphenol content were observed during preparation of control chapatis from whole wheat flours. However, significant increases in soluble dietary fibre and soluble polyphenol contents were observed in chapatis prepared from amylase‐treated doughs compared with control chapatis. Extracts of chapatis prepared from amylase‐ and xylanase‐treated doughs showed better antioxidant properties than extracts of control chapatis. Among these enzyme treatments, chapatis prepared from amylase‐treated doughs showed better antioxidant properties than chapatis prepared from xylanase‐treated doughs. High‐performance liquid chromatography analysis of extracts of chapatis prepared from doughs treated with amylases showed the presence of potential antioxidant phenolic acids such as caffeic, gentisic and syringic acids in addition to the phenolic acids present in control chapatis. CONCLUSION: Treatment of doughs with amylases increased the contents of soluble dietary fibre and soluble polyphenols as well as improving the antioxidant properties of chapatis. Copyright © 2011 Society of Chemical Industry     

The role of niobium carbide in radiation induced segregation behaviour of type 347 austenitic stainless steel

The effect of niobium carbide precipitates on radiation induced segregation (RIS) behaviour in type 347 stainless steel was investigated. The material in the as-received condition was irradiated using double-loop 4.8 MeV protons at 300 °C for 0.43 dpa (displacement per atom). The RIS in the proton irradiated specimen was characterized using double-loop electrochemical potentiokinetic reactivation (DL-EPR) test followed by atomic force microscopic examination. The nature of variation of DL-EPR values with the depth matched with the variation of the calculated irradiation damage (dpa) with the depth. The attack on grain boundaries during EPR tests was negligible indicating absence of chromium depletion zones. The interface between niobium carbide and the matrix acts as a sink for point defects generated during irradiation and this had reduced point defect flux toward grain boundaries. The attack was noticed at a few large cluster of niobium carbide after the DL-EPR test at the depth of maximum attack for the irradiated specimen. Pit-like features were not observed within the matrix indicating the absence of chromium depletion regions within the matrix.     

Simultaneous detection of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella strains by real-time PCR

A protocol enabling simultaneous detection of Escherichia coli O157:H7, Listeria monocytogenes and Salmonella strains was devised and evaluated using artificially contaminated fresh produce. Association of Official Analytical Chemists (AOAC)-approved polymerase chain reaction (PCR) detection methods for three human pathogens were modified to enable simultaneous and real-time detection with high throughput capability. The method includes a melting-curve analysis of PCR products, which serves as confirmatory test. The modified protocol successfully detected all three pathogens when fresh produce was washed with artificially contaminated water containing E. coli O157:H7 and S. typhimurium down to the predicted level of 1 to 10 cells/ml and L. monocytogenes at 1000 cells/ml. The ability to monitor several pathogens simultaneously will save time and increase our ability to assure food safety.     

Studies on pentosans in Indian wheat (Triticum aestivum) varieties in relation to chapati making quality

Different wheat varieties were screened for chapati making characteristics, of which DWR-162 and GW-322 showed good and MACS-2496 and HD-2189 exhibited poor chapati making quality. Various polysaccharide fractions such as water-soluble, barium hydroxide-soluble and alkali-soluble polysaccharides (viz., hemicelluloses A and B) were isolated from these wheat varieties and their carbohydrate composition was analysed by gas liquid chromatography. Glucose was the major sugar, along with small amounts of arabinose and xylose in water-soluble fractions. Barium hydroxide extract mainly consisted of arabinose and xylose, along with small amounts of glucose. Hemicellulose A fractions contained mainly xylose. Arabinose, xylose and glucose were the major sugars observed in hemicellulose B fractions. Hence, hemicellulose A may be more xylan type, while, hemicellulose B appears to be of complex hemicellulosic nature. Alkali-insoluble residue was basically cellulosic in nature and was strongly associated with arabinoxylans. The studies indicated that arabinose to xylose (A/X) ratio was higher in varieties having good chapati making quality compared to poor varieties in the flour and barium hydroxide extract, which are rich in arabinoxylan type polysaccharides. The ratio of xylose to glucose (X/G) was higher in good chapati making varieties compared to poor varieties.