T. B. Bailey

Preparation of clear noodles with mixtures of tapioca and high-amylose starches

Abstract Ways to simulate the making of clear noodles from mung bran starch were investigated by studying the molecular structures of mung bean and tapioca starches. Scanning electron micrographs showed that tapioca starch granules were smaller than those of mung bean starch. X-ray diffraction patterns of mung bean and tapioca starch were A- and C A -patterns, respectively. Iodine affinity studies indicated that mung bean starch contained 37% of apparent amylose and tapioca starch contained 24%. Gel permeation chromatograms showed that mung bean amylopectin had longer peak chain-length of long-branch chains (DP 40) than that of tapioca starch (DP 35) but shorter peak chain-length of short-branch chains (DP 16) than that of tapioca starch (DP 21). P-31 n.m.r. spectroscopy showed that both starches contained phosphate monoesters, but only mung bean starch contained phospholipids. Physical properties, including pasting viscosity, gel strength, and thermal properties (gelatinization), were determined. The results of the molecular structure study and physical properties were used to develop acceptable products using mixtures of cross-linked tapioca and high-amylose maize starches. Tapioca starch was cross-linked by sodium trimetaphosphate (STMP) with various reaction times, pH values, and temperatures. The correlation between those parameters and the pasting viscosity were studied using a visco/amylograph. Starches, cross-linked with 0.1% STMP, pH 11.0, 3.5xa0h reaction time at 25, 35, and 45°C (reaction temperature), were used for making noodles. High-amylose maize starch (70% amylose) was mixed at varying ratios (9, 13, 17, 28, 37, and 44%) with the cross-linked tapioca starches. Analysis of the noodles included: tensile strength, water absorption, and soluble loss. Noodle sensory properties were evaluated using trained panelists. Noodles made from a mixture of cross-linked tapioca starch and 17% of a high-amylose starch were comparable to the clear noodles made from mung bean starch.

CROPPING SYSTEM EFFECTS ON NO3–N LOSS WITH SUBSURFACE DRAINAGE WATER

An appropriate combination of tillage and nitrogen management practices will be necessary to develop nsustainable farming practices. A six–year (1993–1998) field study was conducted on subsurface–drained nClyde–Kenyon–Floyd soils to quantify the impact of two tillage systems (chisel plow vs. no tillage) and two N fertilizer nmanagement practices (preplant single application vs. late–spring soil test based application) on nitrate–nitrogen (NO3–N) nleaching loss with subsurface drain discharge from corn (Zea mays L.) soybean (Glycine max L.) rotation plots. Preplant ninjected urea ammonium nitrate solution (UAN) fertilizer was applied at the rate of 110 kg ha–1 to chisel plow and no–till ncorn plots, while the late–spring N application rate averaged 179 and 156 kg ha–1 for the no–till and chisel plow corn plots, nrespectively. Data on subsurface drainage flow volume, NO3–N concentrations in subsurface drainage water, NO3–N loss nwith subsurface drainage flow, and crop yield were collected and analyzed using a randomized complete block design. nDifferences in subsurface drainage flow volume due to annual variations in rainfall significantly (P = 0.05) affected the nNO3–N loss with subsurface drainage flows. High correlation (R2 = 0.89) between annual subsurface drainage flow volume nand the annual NO3–N leaching loss with subsurface drainage water was observed. The flow–weighted average annual nNO3–N concentrations varied from a low of 6.8 mg L–1 in 1994 to a high of 13.9 mg L–1 in 1996. Results of this study indicated nthat NO3–N losses from the chisel plow plots were 16% (16 vs. 19 kg–N ha–1) lower in comparison with no–till plots, while ncorn grain yield was 11% higher in the chisel plow plots (8.3 vs. 7.5 Mg ha–1). Late–spring N application applied as a sidedress nresulted in 25% lower NO3–N leaching losses with subsurface drainage water in comparison with preplant single N napplication and also significantly (P = 0.5) higher corn grain yield by 13% (8.4 vs. 7.4 Mg ha–1). These results clearly ndemonstrate that chisel plow tillage with late–spring soil test based N application for corn after soybean can be a sustainable nfarming practice for the northeast part of Iowa.

Phagosomal maturation and intracellular survival of Mycobacterium avium subspecies paratuberculosis in J774 cells.

The mechanisms by which Mycobacterium avium subspecies paratuberculosis (M. a. ptb) survives within macrophages are not well characterized. One strategy for intracellular survival developed by Mycobacterium tuberculosis is inhibition of phagosomal maturation. In this study it was hypothesized that M. a. ptb is capable of survival within macrophages by residing within a phagosomal compartment that does not mature into a functional phagolysosome. To test this hypothesis the following objectives were determined. Phagosomal maturation was evaluated by comparison of stage specific markers on the membranes of phagosomes containing live M. a. ptb with those containing killed M. a. ptb, Mycobacterium smegmatis, and zymosan A using immunofluorescent labeling and confocal microscopy. Intracellular survival of live M. a. ptb within J774 macrophages was compared to that of M. smegmatis by direct determination of bacterial viability by differential live/dead staining. The results of this study show that the phagosomes containing live M. a. ptb had increased levels of an early marker (transferrin receptor [TFR]) and decreased levels of a late maturation marker (lysosome associated membrane protein one [Lamp-1]), relative to those containing killed M. a. ptb, M. smegmatis, and zymosan A. Additionally, compared to M. smegmatis, M. a. ptb has enhanced ability to survive within cultured macrophages. These data indicate that M. a. ptb resists intracellular killing by residing within a phagosomal compartment that retains the characteristics of early phagosomes and resists maturation into functional phagolysosome.

Corn-Soybean and Alternative Cropping Systems Effects on NO 3 -N Leaching Losses in Subsurface Drainage Water

Alternative cropping systems can improve resource use efficiency, increase corn grain yield, and help in reducing nnegative impacts on the environment. A 6-yr (1993 to 1998) field study was conducted at the Iowa State University’s nNortheastern Research Center near Nashua, Iowa, to evaluate the effects of non-traditional cropping systems [strip inter ncropping (STR)-corn (Zea mays L.)/soybean (Glycine max L.)/oats (Avina sativa L.)]; alfalfa rotation (ROT)-3-yr (1993 to n1995) alfalfa (Medicago sativa L.) followed by corn in 1996, soybean in 1997, and oats in 1998), and traditional cropping nsystem (corn after soybean (CS) and soybean after corn (SC) on the flow weighted average nitrate-nitrogen (NO3-N) nconcentrations and NO3-N leaching losses with subsurface drainage water. The soils at the research site are loamy with 3% nto 4% organic matter and are underlain by subsurface drainage system. The data collected from four experimental treatments nwere analyzed as an unbalanced incomplete block design using F-test and T-test among treatments and within treatments, nrespectively. When averaged across 6-yr, non-traditional cropping systems reduced flow weighted average NO3-N nconcentrations in subsurface drain water with highly significantly effect (P < 0.01) in comparison with traditional cropping nsystem (6.5 vs. 11.2 mg L-1). Similarly, the strip inter cropping system increased corn grain yields by 5% (9.03 vs. 8.6 Mg ha-1) nand reduced NO3-N leaching losses by 6% (12.6 vs. 13.5 kg-N ha-1) and showed no difference in soybean yields when ncompared with traditional cropping system. Results of the study indicate that strip inter cropping and alfalfa rotation systems nhave the potential to reduce NO3-N leaching into the shallow groundwater system and possibly can become one of the better nsustainable farming systems in Midwestern agriculture.

Inhibitory Effects of Organic Acid Salts for Control of Listeria monocytogenes on Frankfurters

Sodium diacetate (SD), sodium diacetate plus potassium benzoate (SD-PB), and sodium lactate plus sodium diacetate plus potassium benzoate (SL-SD-PB) were selected for initial effectiveness against Listeria monocytogenes on frankfurters. Treatments were evaluated at -2.2, 1.1, 4.4, 10.0, and 12.8 degrees C for up to 90 days. The compounds were applied as 3 or 6% (total concentration) dipping solutions for surface treatment of the frankfurters. The treated frankfurters were inoculated with a five-strain cocktail of L. monocytogenes (Scott A 4b, H7764 1/2a, H7962 4b, H7762 4b, and H7969 4b) using 1 ml of 10(4) cells for each 90.8-g package of two frankfurters. The maximum population of L. monocytogenes was decreased and generation time and lag phase were increased after surface treatments with 6% SD, 6% SL-SD-PB, 3% SD-PB, and 6% SD-PB solutions at 1.1 degrees C. Surface treatment of frankfurters with SD at 6% was more effective for inhibiting L. monocytogenes growth than were the other treatments. Under the conditions of this study, L. monocytogenes survived in refrigerated storage even in the presence of the additives tested.

Comparison of laboratory and pilot-plant corn wet-milling procedures

ABSTRACT One waxy and three regular yellow dent corn hybrids were wet milled by using two scales of laboratory procedures (modified 100-g and 1-kg) and a pilot-plant procedure (10-kg). The modified 100-g and 1-kg laboratory procedures gave similar yields of wet-milling fractions. Starch yields and recoveries were significantly lower for the pilot-plant procedure, whereas gluten and fiber yields were greater because of their high contents of unrecovered starch. Protein contents of the starches obtained by all three procedures were within commercially acceptable limits (<0.50% db for normal dent corn and <0.30% for waxy corn). Rankings for starch yields and starch recoveries for the four hybrids, having very different physical and compositional properties, were the same for all three procedures. The harder the grain, the lower the yield and recovery of starch. Least significant differences (P < 0.05) for starch yield were 0.8% for the modified 100-g procedure, 1.2% for the 1-kg procedure, and 2.0% for the p...

Assessing phenotypic, biochemical, and molecular diversity in coriander (Coriandrum sativum L.) germplasm

Our goals for this research were to elucidate phenotypic and biochemical diversity in coriander (Coriandrum sativum L.) populations maintained at the North Central Regional Plant Introduction Station in Ames, IA, and examine relationships between amplified fragment length polymorphism (AFLP) markers and patterns of phenotypic and biochemical diversity. Phenotypic and biochemical traits were evaluated, and analyses of variance and mean comparisons were performed on the resulting data sets. Euclidean distances from phenotypic (PD) and biochemical (BD) data were estimated, and modified Rogers’ distances (RD) were estimated for 80 polymorphic AFLP markers. These data were subjected to cluster analyses (CA) and principal components analyses (PCA), to reveal patterns among populations, and to analyses of molecular variance (AMOVA) for grouping patterns from PD and BD by using the 80 polymorphic AFLP markers. Resulting phenotypic, biochemical, and molecular distance matrices were also compared by applying Mantel tests. Our results describe significant differences among populations for all the phenotypic traits, and dendrograms obtained from PD and BD revealed complex phenetic patterns, as did groups from PCA. The primary seed essential oils and nearly all fatty-acid components were identified and their abundance measured; the primary chemical constituents of corresponding PCA groups are described herein. Molecular evidence supported phenotypic and biochemical subgroups. However, variation attributed among subgroups and groups was very low (∼4–6%), while variation among populations within groups was intermediate (∼24–26%), and that within populations was large (∼69–70%), reflecting weak differentiation among subgroups and groups, which was confirmed by values for fixation indices. Phenotypic subgroups described in this study differed somewhat from previous infraspecific classifications. Weak correlations were found between the phenotypic and biochemical matrices and between the biochemical and AFLP matrices. No correlation was found between the phenotypic and AFLP matrices. These results may be related to coriander’s phenotypic plasticity, its wide range in lifecycle duration, its predominantly allogamous reproductive biology, a human-selection process focused on special traits that may be controlled by few genes, and the widespread trade of coriander seeds as a spice, which may result in dynamic, poorly differentiated molecular variation, even when phenotypic and biochemical differentiation is easily documented.

TILLAGE AND NITROGEN MANAGEMENT EFFECTS ON CROP YIELD AND RESIDUAL SOIL NITRATE

Tillage and N management can have great impact on crop yield and off-site transport of nitrate-nitrogen n(NO 3 -N). This six-year field study on tile-drained Clyde-Kenyon-Floyd soils in northeast Iowa was conducted to quantify ncorn (Zea mays L.) and soybean (Glycine max (L.) Merr.) yield and residual soil NO 3 -N. Eight treatments (chisel plow vs nno-tillage by preplant versus late-spring N-management for both corn and soybean phases of a rotation) were evaluated nusing a randomized complete block design. Preplant N was applied by injecting liquid urea-ammonium nitrate solution n(UAN) at a rate of 110 kg N ha –1 . Late-spring soil-test based N-rates averaged 179 and 156 kg N ha –1 for no-till and nchisel treatments, respectively. No additional N was applied to soybean. Average corn yield on chisel plots was nsignificantly (P = 0.05) higher than with no-tillage for both preplant (7.9 vs 6.9 Mg ha –1 ) and late-spring (8.6 vs 8.1 Mg nha –1 ) N-management. Average soybean yield where corn had received preplant N (3.6 Mg ha –1 ) was significantly (P = n0.05) greater than where late-spring N-management (3.4 Mg ha –1 ) was used. Residual tillage effects did not significantly n(P = 0.05) affect soybean yield. The average residual soil NO 3 -N to a depth of 1.2 m following corn was significantly n(P = 0.05) lower for preplant (21 kg N ha –1 ) than late spring (29 kg N ha –1 ) N-management under no-till system, npresumably reflecting differences in N application rates. Residual soil NO 3 -N following soybean was significantly n(P = 0.05) lower in no-till (28 kg N ha –1 ) than chisel (37 kg N ha –1 ) plots. Average over-winter changes in residual soil nNO 3 -N were greatest in corn plots previously fertilized with a single preplant application (+13 to 18 kg N ha –1 ) and most nvariable following soybean in plots where corn was fertilized based on late-spring nitrate test (LSNT) values (-8.5 to n+6.3 kg N ha –1 ). Therefore development of efficient N-management strategies may require complete understanding of nN-cycling processes taking place in the soil profile over winter months. The results of the study demonstrate that chisel nplow increased corn yield with late-spring N-management and with preplant N when compared to no-till system.

A Mitochondria-Targeted Vitamin E Derivative Decreases Hepatic Oxidative Stress and Inhibits Fat Deposition in Mice

Our objective in this study was to determine whether a mitochondria-targeted vitamin E derivative (MitoVit E) would decrease oxidative stress and associated obesity by preventing a previously proposed aconitase inhibition cascade. Sixty-four mice were fed a high-fat (HF) diet for 5 wk. They were then switched to either a low-fat (LF) or a medium-fat (MF) diet and gavaged with MitoVit E (40 mg MitoVit E x kg body weight(-1)) or drug vehicle (10% ethanol in 0.9% NaCl solution) every other day for 5 wk. Epididymal fat weight, as well as liver lipid and remaining carcass lipid, were significantly lower in the MF group receiving MitoVit E (MF-E) than in the MF group receiving vehicle only (MF-C). Liver mitochondrial H(2)O(2) production and the protein carbonyl level were also significantly lower in MF-E than in MF-C mice. In contrast, none of the biochemical variables (aconitase activity, ATP and H(2)O(2) production, and protein carbonyl level) in the muscle mitochondria were modified by MitoVit E in either MF or LF groups. Expression of acetyl-CoA carboxylase and fatty acid synthase in both liver and adipose tissue of MF groups was not affected by MitoVit E. However, expression of carnitine palmitoyltransferase 1a in the liver and uncoupling protein 2 in adipose tissue were significantly enhanced by MitoVit E in both LF and MF groups. In conclusion, MitoVit E attenuates hepatic oxidative stress and inhibits fat deposition in mice but not through alleviation of the aconitase inhibition cascade.

Extrusion of Cross-Linked Hydroxypropylated Corn Starches I. Pasting Properties1

ABSTRACT A series of cross-linked (0, 0.014, 0.018, 0.024, and 0.028% POCl3, dry starch basis) hydroxypropylated (8%) corn starches were extruded using a Leistritz micro-18 co-rotating extruder. Process variables included moisture, barrel temperature, and screw design. Differential scanning calorimetry and X-ray diffraction studies showed the level of starch crystallinity decreased with increasing severity of extrusion conditions. Pasting properties of the extruded starches were examined using a Rapid Visco Analyser. Pasting profiles of starches extruded at different conditions displayed different hot paste viscosity and final viscosity. Increasing starch moisture content during extrusion and level of cross-linking increased starch viscosity (P < 0.0001), whereas increasing extrusion temperature and shear decreased starch viscosity (P < 0.0001). Interactions were found between level of cross-linking and screw design and between extrusion temperature and starch moisture content (P < 0.0001).