Initial Water Absorption Rate Research Articles

Effect of a saponin-based surfactant on water absorption, processing characteristics and in vitro ruminal fermentation of barley grain

The effects of a saponin-based surfactant on tempered barley grain were studied in three in vitro experiments. In Experiment 1, barley kernels were tempered at 220 or 246 g/kg moisture with surfactant included at 0, 60 or 120 μl/kg dry matter (DM). Surfactant increased ( P < 0.05) the rate of water uptake during the initial 2 h of tempering, but not if tempering was extended beyond 4 h. Experiment 2 evaluated effects of surfactant on barley grain processing characteristics. Surfactant was included at 0, 60, 120, or 240 μl/kg DM during tempering of barley (190 g/kg moisture; 2 or 4 h), then the barley was processed with rollers set 2.032, 2.223 or 2.413 mm apart. Surfactant did not affect ( P > 0.05) the processing index (PI) of the barley or the particle size distribution. Increasing the roller distance from 2.032 to 2.413 mm increased ( P < 0.05) the PI and the proportion of particles with 3.35–4.75 mm diameter, and reduced ( P < 0.05) the proportions of particles larger than 4.75 mm or smaller than 2.36 mm. No surfactant × roller distance interactive effects on processing characteristics were observed. In Experiment 3, barley was tempered (190 g/kg moisture; 2 h) with surfactant at 0 or 120 μl/kg DM and processed with rollers at 2.032 or 2.413 mm, then incubated in batch culture with surfactant supplemented at 0 or 360 μl/kg DM. Apparent in vitro dry matter digestibility (IVDMD) and gas production were higher ( P < 0.01) with rollers at 2.032 mm than at 2.413 mm. Irrespective of substrate particle size, applying surfactant during tempering and/or prior to incubation reduced ( P < 0.05) the 4 h IVDMD, accumulation of volatile fatty acids (VFA) and reducing sugars, and molar percentage of acetic acid in the VFA, but it increased ( P < 0.05) the molar percentage of butyric acid. The acetate:propionate ratio at 4 h was reduced ( P < 0.05) by surfactant applied during (120 μl/kg DM) and/or after (360 μl/kg DM) tempering if the barley had been rolled at 2.032 mm, but at 2.413 mm roller spacing this effect on acetate:propionate was observed only with the maximum application of surfactant (120 + 360 μl/kg DM). Despite enhancing the initial rate of water absorption by barley kernels, surfactant applied during tempering did not affect the processing characteristics of barley. Added during or after tempering, surfactant reduced the extent of IVDMD measured at 4 h, but not at 24 h.

Interlayer toughened unidirectional carbon prepreg systems: effect of preformed particle morphology

Abstract A new production process was used to change the surface morphology and reduce the water sensitivity of a commercial preformed rubber particle used for interlayer composite toughening. These particles were incorporated in a model epoxy resin and impregnated into unidirectional carbon fibers. The mode II fracture toughness of a laminate made with experimental particles was 250% higher than the control system and 100% higher than a laminate made with the commercial preformed rubber particles. The new particles were also found to reduce the damage area resulting from impact; however, the ultimate laminate compression strength after impact was lower for the experimental particle modified composite than the commercial particle modified laminate. The composites were also subjected to hot–wet conditions and the initial water absorption rate was less for the experimental particle modified laminates than the laminate containing the commercial material. Yet, after 6400 h, the laminates made with experimental particles were found to absorb more water than the other materials.

Wet-milling Factors of Sorghum and Relationship to Grain Quality

Relationships of grain sorghum quality factors (proximate composition and physical properties) to laboratory wet-milling attributes (fraction yields, protein content of fractions and recovery values) of 24 grain sorghum commercial hybrids were determined. Initial water absorption rate was positively correlated with both starch and gluten recoveries (r>0·45), thus showing the greatest significance among all quality factors. The need to understand fully protein matrix breakdown relative to obtaining optimum separation of components was indicated. Positive correlations of residual protein in starch with density and percent abraded (r>0·45) were observed. Laboratory wet-milling attributes also were correlated among themselves. The highest positive correlations were observed among yield and recovery of starch and gluten (r>0·6). These four parameters had strong negative correlations with fiber/germ yield (r<−0·6). Principal component factor analysis identified five factors (named as matrix-breakdown effect, solids-leaching effect, protein-dispersion effect, protein content of gluten effect, and washing-solids effect) that explained 91% of the total variation among wet-milling attributes.

Relationships Among Grain Sorghum Quality Factors

ABSTRACTCorrelations among grain sorghum quality factors (proximate composition, physical properties, and water absorption properties) were evaluated. Samples of 46 commercial hybrids (24 and 22 from crop years 1993 and 1994) were analyzed for starch, protein, crude free fat, test weight, absolute density, 1,000 kernel weight, percent kernel abraded, water absorption index, initial water absorption rate, and moisture saturation point. Test weight, absolute density, and percent kernel abraded were positively correlated among themselves (r &gt; 0.5). Protein was negatively correlated with both test weight and absolute density (r &lt; ‐0.5), while moisture saturation point showed negative correlations with test weight, absolute density, 1,000 kernel weight, and percent kernel abraded (r &lt; ‐0.4). Principal component factor analysis through the covariance matrix explained 95% of the total variation of quality factors among hybrids (two factors), and, through the correlation matrix, 85% of the total variation (five factors). Water absorption rate decreased with increasing starch content of grain sorghum kernels as water absorption rate increased and amount of water for saturation decreased with softening of kernels.

Effects of the Pressure and Finishing Agents on the Water Absorption of Cotton Fabric.

The relation between the pressure-dependence of water absorption and the compression characteristics of cotton fabrics, and the changes in the water absorption of the fabrics by the treatment of a softener, thickener, or a mixture of them were investigated. The initial water absorption rate of the cotton fabric increased with the pressure, and was equilibrated at 626 Pa or above. The compression ratio also increased with the pressure, reached about 25% at the pressure of 626 Pa, where the initial water absorption rate was eqilibrated, and continued to increase after this point. The time needed for the saturation of water was shortened with the increase in the pressure, showing the peaks of the saturation of water at the pressure of 210 Pa and 349 Pa. No changes were observed in the compression-characteristics of the fabrics with the treatment of the finishing agents (softener, thickener or the mixture of them) or with the treating times. However, the amount of absorbed water at 626 Pa showed the most decrease in the fabric treated with a softening agent of the all finishing agents examined. The amount of absorbed water was increased in the fabric treated with a thickening agent compared with the untreated fabric when the treating time was 2 minutes or longer. Changes in the amount of absorbed water with the treating time was smallest in the fabric treated with a mixture of the softener and the thickener.

Some Functional Characteristics of Cowpea (Vigna unguiculata), Bambara Beans (Voandzeia subterranea) and their Products

Cowpeas (Vigna unguiculata) and bambara beans (Voandzeia subterranea) are important legumes in the diets of Ghanaians. The characteristics of the seed, flour and protein isolates were studied. The initial rate of water absorption was significantly lower in the varieties with thicker seed coats. In general, the protein isolates were found to possess better foaming and fat absorption properties than the flours. Cowpea products were found to possess better functionality than the bambara beans.