Effect of domestic processing on flatus producing factors in ricebean (Vigna umbellata)

The effect of various processing treatments viz., soaking, pressure cooking, open pan cooking, germination followed by pressure cooking and roasting of whole ricebean and pressure cooking, open pan cooking and fermentation and frying of fermented batter of dehulled ricebean flour was assessed for total sugars and oligosaccharide contents. Dehulling caused a significant reduction in the raffinose and stachyose contents. Pre-soaking of ricebean caused appreciable losses in the oligosaccharide content. Germination (48 h) followed by pressure cooking and fermentation (18 h) followed by frying caused the maximum losses in the raffinose and stachyose contents.     

Effect of Transglutaminase Enzyme on Physico-mechanical Properties of Rambouillet Wool Fiber

ABSTRACT

Rambouillet wool fiber was scoured and treated with transglutaminase (TG) enzyme for different concentrations and duration at neutral pH at 45°C. The physical, mechanical, dyeing, and antimicrobial properties of the wool fiber before and after enzymatic treatment were evaluated as per standard methods. Results inferred that TG enzyme-treated wool fiber sample showed improvement in softness, luster, and tensile strength in comparison with scoured wool fiber. It is found that 0.5% TG enzyme treatment at 45°C for 60 min at pH 7 was an optimum condition. Scanning electron microscope images also confirmed the flattened and smooth scales of wool fiber after enzymatic treatment.     

Graft copolymerization of 4-vinyl pyridine onto isotactic polypropylene hydroperoxide by mutual irradiation method

An attempt has been made to graft copolymerize 4-vinyl pyridine onto isotactic polypropylene hydroperoxide by mutual irradiation method in an aqueous medium. Polypropylene hydroperoxide has been prepared by irradiating recrystallized polypropylene beads from a Co⁶⁰ source in the presence of air. The resulting polypropylene hydroperoxide beads have been used as the backbone polymer and grafting of 4-vinyl pyridine has been studied as a function of various reaction parameters. Optimum conditions for maximum percentage of grafting have been evaluated. Rate of grafting (R_g) has been determined as a function of preirradiation dose and initial monomer concentration. Water has been found to affect percentage of grafting. The graft copolymers have been characterized by spectroscopic method and isolation of the grafted poly(4-VP) from the graft copolymer. A plausible mechanism is proposed to explain the mutual grafting of 4-vinyl pyridine onto polypropylene hydroperoxide. © 1993 John Wiley & Sons, Inc.     

Graft copolymerization of acrylonitrile and methacrylonitrile onto gelatin by mutual irradiation method

In order to improve upon certain properties of gelatin graft copolymerization of acrylonitrile (AN) and methacrylonitrile (MAN) onto gelatin has been studied in aqueous medium using γ rays as a source of initiation. Optimum conditions for affording maximum percentage of grafting have been evaluated as a function of various reaction parameters. The grafted polyacrylonitrile (PAN) was isolated from the graft copolymer by acid hydrolysis, and the average molecular weight (M_v) of the isolated polymer has been determined viscometrically. The graft copolymers were characterized by IR spectroscopic methods and thermogravimetric analysis (TGA). Acrylonitrile was found to be more reactive than methacrylonitrile toward graft copolymerization. © 1994 John Wiley & Sons, Inc.     

Aza-Michael Addition of <Emphasis Type="Italic">γ</Emphasis>-Aminopropylsilatranes to Substituted N-Phenylmaleimides: Design and Synthesis of a Heterocyclic Amine Receptor and Their Preliminary Antimicrobial Studies

An efficient method for C-N bond formation via aza-Michael addition of γ-aminopropylsilatranes to substituted N-phenylmaleimides under mild conditions is described. The five receptors enclosing the maleimide moiety have been synthesized by the aza-Michael addition to strong nucleophile γ-aminopropylsilatrane producing silatranes possessing substituted N-phenylsuccinimide at the axial position without any catalyst. All the compounds have been characterized by elemental analysis, spectroscopic techniques and thermo-gravimetric analysis. The synthesized compounds have been screened for possible antimicrobial properties and results have shown modest activity.     

Moisture Adsorption Isotherms of Watermelon Seed and Kernels

The moisture adsorption isotherms of watermelon seeds and kernels from Citrullus lanatus Cv Mateera and Citrullus vulgaris Cv Sugar baby were obtained using standard static method with saturated salt solutions over a range of water activities from 0.113 to 0.92 at 20–60°C. The adsorption capacity of seeds decreased with the increase in temperature at constant water activity. Sorption models were used to explain the adsorption behavior involving water activity and moisture content (Type I) and also temperature (Type II). Oswin's models gave best fit among Type I with coefficient of determination of 0.953–0.995, standard error of 0.031–0.0571, mean relative error of 0.071–0.152, and scattered residual plots. Modified Oswin was the best fit model among Type II for the seeds and kernels of both the cultivars with coefficient of determination of 0.997–0.999, standard error of 0.151–0.255, mean relative error of 0.018–0.244, and scattered residual plots. The net isoelectric heat of adsorption, estimated from Clausius-Clapeyron decreased from about 27.0 to 0.5 kJ/mol in kernels and 18.0 to 0.5 kJ/mol in seeds of both the cultivars as the moisture content increased from 5 to 25% (dry basis).     

Particle size reduction of RDX by sequential application of solvent–antisolvent recrystallization and mechanical methods

ABSTRACT

Solvent–antisolvent recrystallization produced ~8 µm average size RDX particles (UF-RDX) that were subsequently subjected to mechanical methods of ultrasonication and ball-milling to find further achievable reduction in particle size. Long duration ultrasonication for 20 h and 300 rpm ball milling for 4 h of UF-RDX decreased its average particle size to ~2 µm. RDX produced by all the three processes (solvent–antisolvent recrystallization, ultrasonication and ball-milling) was similar to coarser RDX in structure and thermal decomposition behavior. However, UF-RDX produced by solvent–antisolvent recrystallization was significantly less impact sensitive than that produced by ball-milling and ultrasonication. The issues of residual solvent and the metal contamination during RDX processing were addressed by process parameter optimization. Solvent–antisolvent recrystallization and mechanical methods even when used sequentially could not bring average particle size of RDX to nano-scale.     

Viscometric studies of starch-g-polyacrylamide composites

Composites of starch-g-polyacrylamide, starch, and polyacrylamide have been prepared by gamma radiation-initiated polymerization of acrylamide in the presence of starch in aqueous medium. The polymerization was studied as a function of the (i) amount of water (ii) monomer concentration, and (iii) total dose. The optimum conditions for maximum conversion of the monomer to homopolymer and graft copolymer have been evaluated. Percentage of grafting of polyacrylamide could not be determined precisely as both the homopolymer and the graft are soluble in common solvents and all attempts to separate the graft from the homopolymer were unsuccessful. However, the formation of the starch-g-polyacrylamide copolymer was confirmed by the turbidimetric studies using acetone as a nonsolvent. The products of polymerization of acrylamide in the presence of starch consisted of unreacted starch, starch-g-polyacrylamide, and polyacrylamide and is referred to as the composite. Acrylamide was also polymerized in the absence of starch using γ-rays as means of initiation and the optimum conditions for maximum conversion of acrylamide to polyacrylamide have been evaluated. Viscosity behavior of the composite and polyacrylamide was studied in aqueous medium at 30±0.04°C. The reduced specific viscosity of the aqueous solution of acrylamide and the composite as well was found to increase with increasing dilution, the effect being more pronounced in the composite. This tends to indicate that both the homopolymer and the composite behave as polyelectrolytes. An attempt has been made to explain the polyelectrolytic behavior of the homopolymer and the composite. © 1993 John Wiley & Sons, Inc.     

In vitro digestibility,structural and functional properties of starch from pigeon pea (Cajanus cajan) cultivars grown in India

Starches isolated from two pigeon pea cultivars (AL-15 and AL-201) were evaluated for their in vitro digestibility, structural and functional properties. Both the cultivars exhibited a characteristic C-type diffraction pattern with relative crystallinity values of 31.9% and 34.2%, for AL-15 and AL-201, respectively. The structural characterization obtained using high performance size exclusion column chromatography revealed that molecular weight of amylopectin and amylose was higher for AL-201 (396 and 3.92 × 10⁶ g/mol, respectively) in comparison to AL-15 starch (354 and 3.31 × 10⁶ g/mol, respectively). AL-201 exhibited higher values for transition temperatures, enthalpy of gelatinization, pasting temperature and percentage retrogradation in comparison to AL-15 starch. Slowly digestible starch, readily digestible starch and resistant starch contents of AL-15 and AL-201 cultivars were observed to be 31.0, 8.1 and 60.9% and 29.6, 5.2 and 65.2%, respectively. The hydrolysis index and RS values indicated that pigeon pea starches were highly resistant to digestion.