Complexation of methyl salicylate with β-cyclodextrin and its release characteristics for active food packaging

Food Science and Biotechnology - A series of methyl salicylate (MeSA)/β-cyclodextrin (β-CD) inclusion complexes (ICs) were prepared at different MeSA concentrations by the...     

Preparation and characterization of porous polyester fibres by salt leaching method

Porous polyester fibres with cotton-like dull characteristics were produced by salt leaching method. Polyester was synthesized in the presence of common salt. Fibres containing submicron size salt particles (0.5–1%) were prepared by melt spinning. The fibres were washed in hot water to remove the salt particles creating small craters of size 50–1000?nm. Partially oriented yarn (POY) and fully drawn yarn (FDY) were produced. POY samples were textured to produce polyester textured yarn containing salt particles. The influence of salt particles on polymer crystallization was investigated and found that the presence of salt significantly influences the rate of crystallization. The gloss values of porous FDYs were compared with standard semi-dull polyester yarns of same denier. The light scattering behaviour of the yarn has been enhanced due to porosity. This resulted in a fibre with better dullness characteristics. The light reflectance of porous yarn is lower in the 400–700?nm region compared to control FDY samples. The dyeability of the porous fibre was better than non-porous counterpart.     

Evaluation of functional,antinutritional, pasting and microstructural properties of Millet flours

In the present study finger and pearl millet grains were milled and sieved to obtain flour. The flours were evaluated for chemical composition, nutritional, antinutritional, pasting and micro structural properties. Significant difference (p < 0.05) in nutrient and antinutrient contents was found among the millet flours. Protein, ash and fiber content of millet flours vary from 7.3 to 8.0 g/100 g, 2.73 to 5.16 g/100 g and 3.03 to 3.05 g/100 g. Results obtained for antinutrient factors in finger and pearl millet flours were (3.5 mg/g) and (2.2 mg/g) for tannic acid and (6.1 mg/g) and (9.2 mg/g) for phytic acid respectively. Mineral availability of pearl and finger millet flour (mg/100 g) was (109.2–139.2), (0.73–4.2), (1.18–8.7.0), (15.03–17.36) and (67.53–30.03) for calcium, zinc, iron, sodium and potassium respectively. Finger millet flour showed higher peak viscosity, breakdown, final and set back value compared to pearl millet flour. Findings from the scanning electron microscopy analysis showed microstructural differences in both millet flours. FTIR analysis showed that both finger and pearl millet flours possessed O–H and C–H compounds.     

Oil composition,mineral nutrient and fatty acid distribution in the lipid classes of underutilized oils of Trilepisium madagascariense and Antiaris africana from Nigeria

Trilepisium madagascariense (TM) and Antiaris africana (AA) are two underutilized plants from Nigeria. They have been subjected to standard analytical techniques in order to evaluate the proximate composition, physico-chemical properties, mineral nutrient, fatty acid composition and distribution in the lipid classes of the seeds and seed oils. The carbohydrate composition of these seeds are high; TM is 62.73 ± 0.30% and AA is 53.97 ± 0.50%. Iodine value of TM was found to be 46.10 ± 0.70 mg iodine/g while that of AA was 88.24 ± 0.50 mg iodine/g. The mineral composition of the seeds and the oils varied with K having the highest concentration in the seed and Na the highest concentration in the oils. Linoleic acid is the dominant fatty acid in the oil of AA with the highest composition in the neutral lipids while palmitic acid is the dominant fatty acid in oil of TM. Vitamin E, Gamma-Sitosterol, α and β-Amyrin, Lupeol, Stigmast-4-en-3-one, and hydrocarbons were isolated from these oils. The results of the proximate, mineral nutrient compositions, chemical characterization and fatty acid distribution of these seeds and seed oils shows their possibility as potential resources.     

Viscosity variation considering cavitation in a journal bearing lubricant containing additives

The variation in viscosity with temperature is important in lubrication: this was studied by using a viscosity—film thickness relation. This is justified since it has been verified experimentally that the highest temperature occurs in zones where the film thickness is lowest. The use of additives was considered by using a micropolar fluid model. The geometry considered was that of an infinitely long journal bearing considering cavitation. There is an increase in the load capacity when additives are used. It was established theoretically that the use of additives increases the operating temperature range in bearings.     

Non-newtonian power law fluid lubrication of lightly loaded cylinders with normal and rolling motion

The lubrication of lightly loaded cylinders with rotating and normal motion was investigated using a non-newtonian power law fluid under cavitation boundary conditions. The load capacity and frictional drag increase as the squeeze velocity increases. This increase is enhanced by an increase in the flow behaviour index of the lubricant. However, when the two surfaces move apart these results are reversed. The effect of the flow behaviour index on the location of the point of cavitation does not seem to be very significant.     

Allergenic responses of red kidney bean (Phaseolus vulgaris cv chitra) polypeptides in BALB/c mice recognized by bronchial asthma and allergic rhinitis patients

Allergenicity potential of red kidney beans (Phaseolus vulgaris cv chitra) was assessed and attempts were made to identify the responsible proteins by pepsin digestibility assay and IgE immunoblotting. To evaluate allergenic potential, BALB/c mice were sensitized with red kidney bean proteins and levels of specific immunoglobulin, histamine, mast cell protease-1, cytokines and CCL-2 were measured. To confirm our findings in BALB/c, the studies were also extended to human subjects. Human sera collected from control subjects and allergic patients after skin prick test were used for IgE immunoblotting, measuring the levels of total and specific IgE and determining cross reactivity of red kidney bean with other legumes. Red kidney bean allergenic potential was evident by significant increase in specific IgE, IgG1, histamine, mast cell protease-1 and Th2 cytokine levels in comparison to control. Enhanced level of eosinophils in jejunum, prominent anaphylactic symptoms, and eruptive histopathological changes give indication towards red kidney beans allergenicity. IgE immunoblotting detected five protein components with molecular weights of approximately 170, 100, 43, 34 and 20 kDa. Red kidney bean proteins showed cross reactivity with peanut, soybean, chickpea and black gram. Finally, this work demonstrated that red kidney beans may induce allergic response in mice similar to human subjects, with identification of five clinically relevant allergenic protein components.     

Effects of high pressure extraction on the extraction yield,total phenolic content and antioxidant activity of longan fruit pericarp

High pressure extraction (HPE) was carried out to extract phenolic compounds from longan fruit pericarp. The influence of different solvents, solvent concentration (25?100%, v/v), solid to liquid ratio (1:25?1:100, w/v) were individually determined using these optimum extraction conditions. HPE was carried out at various pressures (200?500 MPa), durations (2.5?30 min) and temperatures (30?70 °C). The extraction yield, total phenolic contents and scavenging activities of superoxide anion radical and 1,1-dipheny l-2-picrylhydrazyl (DPPH) radical of HPE extract were examined and then compared with those of the conventional extraction (CE). The application of HPE obtained a higher extraction yield and required a less extraction time when compared to CE. Furthermore, the total phenolic contents and the antioxidant activities of HPE extract were higher than CE extract. This study indicated that this new technology can benefit the food and pharmaceutical industries.Industrial relevanceThis study focused on the evaluations of the extraction yield, total phenolic content and antioxidant activity of longan fruit pericarp by high pressure treatment. The high pressure extraction technology provided a better way of utilizing longan fruit pericarp as a readily accessible source of natural antioxidants in food and pharmaceutical industries.     

Effect of support modification on the chlorobenzene hydrodechlorination activity on Pt/Al2O3 catalysts

Al₂O₃ was modified with TiO₂ and ZrO₂ using organometallic precursors and is used in the preparation of supported platinum catalysts. The catalysts have been characterised by nitrogen adsorption, hydrogen chemisorption and X-ray diffraction and were tested for their activity in the hydrodechlorination of chlorobenzene. The investigations show that support modification controls the catalyst deactivation remarkably and the catalysts were found to be highly active and selective. This revised version was published online in July 2006 with corrections to the Cover Date.     

FILM CONDENSATION ON A HORIZONTAL ISOTHERMAL SURFACE

This paper concerns an analytical study of laminar film condensation on horizontal isothermal surfaces. The flow that arises on a surface of finite length is studied to determine the temperature field and the local heat transfer to the surface. The study considers both transient and steady laminar flow. The governing nonlinear equations are also considered for the circumstance when the surface tension effects are included. The profiles in the condensate film, for steady laminar flow, are found to be strongly dependent on the edge conditions and on the length of the horizontal condensing surface. The dependence on vapor properties and on the surface temperature is also determined. The surface tension effects are found to be negligible, even for quite small values of the Bond number, for a surface terminated by a round fall. The results for transient, laminar, flow show that the transient effects are large for highly viscous condensing fluids and for low gravity fields. An expression for the local Nusselt number is also obtained.