Environment and Hybrid Influences on Rapid-Visco-Analysis Flour Properties of Food-Grade Grain Sorghum
Grain processors would benefi t from informa- tion about the production environment and the infl uences of the sorghum (Sorghum bicolor (L.) Moench) hybrid on food-grade fl our proper- ties. The objective of this study was to deter- mine the effects of environment and hybrid on rapid-visco-analysis (RVA) fl our properties of commercially available food-grade sorghum. A randomized complete block experiment was planted in 12 environments, which included the 2004 and 2005 growing seasons and irrigated and dryland water regimes in eastern, central, and west central Nebraska, and a dryland, low-N environment in eastern Nebraska. The environment accounted for 71-85% of the total variation in RVA parameters, while the hybrid accounted for 11-23% and the environment- by-hybrid interaction, 1-3%. Unfortunately, the results of this experiment suggest that it is dif- fi cult to predict the effect that environment will have on resulting sorghum-fl our parameters. Although of secondary importance in terms of total variation in sorghum-fl our RVA properties, the choice of hybrid predictably and signifi - cantly contributes to sorghum-starch viscosity properties. Food-grade hybrids were grouped based on viscosity properties into those best suited for dry-mill and alkaline-cooked prod- ucts (Asgrow Orbit; Sorghum Partners NK1486) and those best suited for porridge, consumable alcohol, and ethanol production (Kelly Green Seeds KG6902; NC+ Hybrids 7W92; Asgrow Eclipse; and Fontanelle W-1000). These results were consistent with those previously reported for grain density.
Impact of Environment and Genotype-by-Environment Interaction on Functional Properties of Amylose-Free and Wildtype Cassava Starches
Ten and thirty cassava genotypes producing wildtype and amylose‐free (waxy) respectively, were grown at low (LA) and intermediate (IA) altitudes (< 213 and < 900 meters above sea level‐m.a.s.l., respectively). The functional properties of the starch from these materials were analyzed. The relative importance of environment, clones (within starch type) and genotype‐by‐environment interaction (GxE) was assessed through an analysis of variance. GxE effects were non‐significant, whereas environment and clones (within starch type), were highly significant in most of the cases (particularly for waxy starches). Results confirm that waxy cassava starches consistently show higher peak viscosity (PV) compared with wildtypes. Peak viscosity was statistically higher in plants grown in IA compared with those from the same genotypes grown in LA, both for waxy and wildtype genotypes. In a second experiment, a single waxy genotype was grown in five locations ranging from 934 to 1485 m.a.s.l. PV was highest in the location with higher altitude. The second highest PV was measured in starches from the second highest location at 1071 m. Both experiments clearly indicate that PV is positively correlated with altitude above sea level where cassava was grown. Altitude above sea level influenced starch granule size: the higher the altitude the larger the average granule size. Waxy starch granules tended to be larger than those from wildtype genotypes.
Enumeration of total coliforms, fecal coliforms, and Escherichia coli in foods by hydrophobic grid membrane filter: supplementary report.
Raw, comminuted poultry meat was used to determine the specificity of the media and incubation conditions used in the hydrophobic grid membrane filter method. Confirmation rates for target colonies were 100% for total coliforms, 98% for fecal coliforms, and 97-99% for Escherichia coli. The results of total coliform enumeration in 30 pasteurized milk samples by both the hydrophobic grid membrane filter method and AOAC method 46.013-46.016 are also reported.