Staphylococcus aureus and Candida albicans infection (animal experiments)

During a certain period of the course of infection in white mice inoculated intraperitoneally with the pure culture of a proteolysing strain of Candida albicans, Staphylococcus aureus and C. albicans both, were isolated simultaneously from the peritoneal abscesses, especially those adhering to the stomach, duodenum, pancreas and the upper part of small intestine. This concommitant occurrence of the two pathogens was further corroborated by histopathological examination which revealed large number of staphylococci present in the close neighbourhood of Candida cells, usually in the center of the granulomata caused by the fungus. In view of the facts that the proteolytic end-products of C. albicans can offer a good substratum for the growth of S. aureus and the latter may be isolated from the intestinal tract of apparently healthy mice, possibly as a constituent of the transient microflora, the co-existence of these two important aetiologic agents of endogenous infections as encountered during this study appears to be of great clinical interest. Furthermore, these observations also demonstrate the importance of controlling the bacterial flora of mice for pure mycological studies.     

Electron Microscopy of Annealed (Ni,Zn,Co)Fe2O4

( Ni,Zn)Fe₂O₄ samples containing small amounts of Co were characterized in a transmission electron microscope to ascertain the micro structural changes accompanying low-temperature oxidation of the samples. Although no new features resulting from oxidation were observed, prominent surjace reduction occurred in the thin foil specimens. Formation and growth of Ni particles on the ferrite surface are explained using the heats of formation of the oxides.²     

Photopolymerization of methyl methacrylate with the triethylamine-bromine charge transfer complex as photoinitiator

The triethylamine-bromine (TEA-Br₂) charge transfer complex was employed as photoinitiator in the photopolymerization of methyl methacrylate under light of 440 nm. The initial rate of conversion was 0.418%/min with an induction period of 56 min. The initiator and monomer exponents were 0.5 and 1.0, respectively. The polymerization was inhibited in the presence of hydroquinone but oxygen had a very little inhibitory effect. The value of k/k_t was 5.13 · 10^?2 l/mol · s and the activation energy was 19.18 kJ/mol. The rate constant for the decomposition of the charge transfer complex (k_ε) was 4.61 · 10^?6 1/s. Kinetic data and other evidence indicate that the overall polymerization takes place by a radical mechanism.     

Effects of simulated digestion in vitro on cell wall polysaccharides from kiwifruit (Actinidia spp.)

Cell wall polysaccharides are resistant to digestion and absorption in the human small intestine and are considered to be delivered to the colon in a chemically unaltered state. In this paper, pulp from green and gold kiwifruit was subjected to in vitro upper-intestinal tract digestion and the chemical and physical changes to cell wall polysaccharides (dietary fibre) were investigated. Yields of insoluble fibre decreased slightly with simulated digestion while soluble fibre yields increased. Constituent sugar and glycosyl linkage analysis of the soluble and insoluble fibre fractions revealed that the chemical composition and structure of the non-starch polysaccharides remained largely unchanged. However, the degree of methylesterification of galacturonic acid residues present in the pectin-rich soluble fibre fractions of both fruit decreased with treatment; size-exclusion chromatography detected changes in the molecular weight profiles of these fractions. These changes may affect the physicochemical properties and fermentability of kiwifruit dietary fibre in the large intestine.     

Kiwifruit remnants from digestion in vitro have functional attributes of potential importance to health

The physicochemical properties of plant cell walls in the gut are important in modulating processes that influence health. We investigated the physicochemical properties of kiwifruit cell walls digested under gastric and gastroileal conditions in vitro. Soluble and insoluble undigested polymer fractions were measured, the hydration properties of the digested pulp, and the capacity to retard diffusion and mixing in a simulated small intestinal segment. Undigested polymer (dietary fibre) fractions differed little between “Hayward’ (‘Hayward’) and ‘Hort16A’ (gold) kiwifruit cultivars in their relative proportions, although total dietary fibre was greater in ‘Hayward’ than in the ‘Hort16A’. The polysaccharide composition of seed-free digestion-resistant polymer was similar in both cultivars and not affected by in vitro digestion. Indigestible remnants from kiwifruit had strong water retention and swelling capacities, also little affected by digesting, and retarded both glucose diffusion and mixing significantly, especially in the presence of low background viscosity. We conclude that the particulate cell wall remnants of digested kiwifruit retain substantial potential to influence the properties of gut contents.     

Preparation of rice analogues using extrusion technology

Rice is considered as staple food in many parts of the world. An issue of concern is the breakage of rice kernels in milling processes, and these broken kernels are not generally accepted by consumers. These broken kernels can be mixed with some desired additives to improve their quality and extruded for the preparation of reconstituted rice kernels or rice analogues. Various studies have been conducted for the preparation of the rice analogues in the past few decades, and recently attempts have been made to fortify these analogues with protein, certain vitamins and minerals. The main features such as colour, shape, size, texture, and cooking characteristics and cooking time of these rice‐like grains can be tailored to the requirements of specific applications by modification of the extrusion parameters. Various organisations, such as Wuxi NutriRice Co. (DSM/Buhler) and China National Cereals, Oils and Foodstuffs Corporate (COFCO), Superlative Snacks Inc., Vigui and PATH, have utilised this technique to prepare fortified and reconstituted rice. Studies have shown that it is possible to improve the nutritional quality of rice by fortified rice analogues. This article reviews research results of the many approaches to the formation of fortified rice analogues by extrusion‐based technologies.     

Effect of TiO2 nanoparticles on basalt/polysiloxane composites: mechanical and thermal characterization

In the present investigation, a novel technique has been developed to fabricate composite materials containing TiO₂ nanoparticles, polysiloxane resin, and basalt fabric. A high-intensity ultrasonic probe was used to obtain a homogenous molecular mixture of TiO₂ nanoparticles and polysiloxane resin, thus the nanoparticles were infused into the resin through sonic cavitation. The loading effect of TiO₂ nanoparticles on the thermal and mechanical properties of basalt fabric reinforced polysiloxane composite materials has been investigated. Composite samples were prepared, each using two layers of basalt fabric with TiO₂ nanoparticles loading from 0.5, 1, 1.5, 2, 2.5, and 3% by weight. Size distribution of nanoparticles was observed by particle size analyzer and the prepared fabric nanocomposites were characterized by scanning electron microscopy, dynamic mechanical analysis (DMA), thermo gravimetric analysis (TGA), and differential scanning calorimetry (DSC). Tensile testing was performed as per American standard for testing of materials (ASTM) standards. The dependence of dynamic mechanical parameters E′, E′′, tan (delta), T _g, and heat distortion temperature (HDT) are associated with the filler content and can be controlled by the curing conditions. Tensile results show that 1.5 wt.% loading of TiO₂ nanoparticles in the nanocomposites resulted in highest improvement in tensile modulus compared to the neat system. DMA studies also revealed that 1.5 wt.% doped system exhibits highest storage modulus as compared to the neat and other loading percentages. DSC and TGA studies show that T _g and HDT of the composite increases with the increase in wt.% of nanofillers in the composite. Based on these results, it is clear that miscibility of nanoparticles in the resin is of prime importance with regard to performance.     

Effect of heating and acidic pH on characteristics of wheat gluten suspension

The effects of different pH treatments with and without heating on the characteristics of wheat gluten suspension was investigated. At pH 1, maximum changes in colour were observed with a concurrent 65% decrease in protein free-thiol content compared to the control gluten. The SDS-Extractability of protein (SDS-EP) chromatogram eluted at lower retention time and the presence of bands at the top lane even during reducing conditions in SDS-PAGE gel suggested complex formation involving bonds other than disulphides. An increase in the free-amino group content and the presence of an additional peak at a higher retention time in the SDS-EP chromatogram was suggestive of hydrolysis. At pH 2 and 3, similar decreases in SDS-EPs and free-thiol content indicated formation of complexes. When heated, the free-thiol content of the dispersions increased compared to the non-heated dispersions indicating disruption of disulphide bonds with changes in gluten structure and size distribution.     

Microbial Decontamination of Tea (Camellia sinensis) by Gamma Radiation

ABSTRACT:  Processed dry tea leaves are prone to microbial contamination during post-processing handling and storage. The dry tea leaves may thus carry bacteria and fungi of potential health risk to consumers. Also, during storage under high humidity, absorption of moisture may encourage fungal growth and result in caking of the product. Gamma radiation processing was tried as a method for microbial decontamination. A radiation dose of 5 kGy was found to be effective for this purpose. No significant effect was observed on total phenolics in radiation-processed tea leaves. The antioxidant and biological properties of tea such as free radical scavenging activity, inhibition of xanthine oxidase and lipid peroxidation, and superoxide and nitrite scavenging activities were not affected due to radiation treatment within a dose of 10 kGy. The antimicrobial and sensory properties were also unaffected by the radiation treatment.