Lester A. Wilson

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.

Chapter 22 – Soy Foods

Publisher Summary Soybeans have been highly prized as a nutritional food source due to their ease of production, long-term storage characteristics, and exceptional protein content. Soybeans are traditionally consumed in non-fermented and fermented forms. The non-fermented forms include soymilk, yuba, tofu, and toasted soy protein powders. The fermented forms include miso, natto, soy sauce, and tempeh. Soybeans are a rich source of protein and oil. In spite of the fact that soybeans are excellent nutritional staples, they are not consumed raw, because of their hard texture and undesirable flavor. Undaunted by these attributes, the people of Japan and other Asian countries have developed a variety of sophisticated processed soy foods. These products and their culinary presentation have done a great deal to enhance the table aesthetics, palatability, and nutritive value of soy protein. Traditional soybean foods are classified into two groups: non-fermented foods, including regular, deep-fried, frozen-dried, roasted tofu, soybean protein film (yuba), and soybean sprouts; and fermented soybean foods, such as miso, soy sauce (shoyu), and fermented whole soybeans (natto).

Effect of Organic Pest Management Practices on Apple Productivity and Apple Food Safety

ABSTRACT Research was conducted in a certified organic apple (Malus x domestica Borkh.) orchard in 2000 to determine the effect of organic pest management techniques on pest control, apple yields and microbial populations on harvested apples. In Experiment 1, apple colouring bags, sticky red spheres, kaolin particle film, kaolin particle film plus sticky red spheres, or colouring bags plus sticky red spheres were applied to Redfree, Jonafree and Liberty apple trees in a split-plot design. Insects and diseases were sampled in the control and kaolin particle film treatments. Apple yields and insect damage ratings at harvest were determined for all treatments. There was a significant treatment x cultivar interaction related to insect damage on apples. Insect and disease damage ratings throughout the growing season and at harvest were lowest in Jonafree trees treated with kaolin particle film or colouring bags. There was no effect of treatment on beneficial insects during the growing season. Marketability was greatest in the Jonafree apples treated with colouring bags or kaolin particle film. In Experiment II, the effect of the organic management practices in Experiment I on the food safety of harvested organic apples was examined. Microbial populations on untreated apples and apples treated with kaolin particle film or colouring bags were enumerated post-harvest. No E. coli populations were observed on any apples. Low populations (225.0 ± 95.0 colony-forming units [CFU] apple−1) of coliform bacteria were observed on unwashed control apples. Postharvest yeast and mould populations were greatest on unwashed apples treated with kaolin particle film and lowest on apples protected by colouring bags. When kaolin particle film-treated apples were washed prior to analysis, yeast and mould populations were reduced by 50%.

Inheritance studies of aromatic compounds in Agastache foeniculum (Pursh) Kuntze.

Abstract Genetic control of volatile oil production in Agastache foeniculum and, more specifically, of the production of myrcene, limonene, and methyl chavicol, three major components of its essential oils, was elucidated. Controlled crosses were made between individuals with different chemotypes, and F2 populations were analyzed for their composition of volatiles by using headspace gas chromatography. Total aromatic volatile emittance was found to be under polygenic control with additive gene effects for four of eight families studied, and each of the three major components was controlled by one to a few genes with recessive to additive effects. Evidence is also presented suggesting that population PI 561057 transmits a genetic factor or factors that suppress the overall production of the major volatile oil components.

A round robin evaluation of differential scanning calorimetry to measure transition enthalpy and temperatures

Twelve laboratories participated in a thermal analysis study to determine onset and peak transition temperatures and enthalpy, for both starch gelatinization and tristearin melting and crystallization. The reproducibility of these results was compared for three types of Differential Scanning Calorimeters (DSC). The transition temperatures and enthalpy results for starch were similar between labs, as were the melting and crystallization temperatures for tristearin. Enthalpy values for tristearin were consistent among most labs, however significant differences existed between DSC types. From this data it appears that some differences between laboratories do exist, but reliable comparisons can usually be made when the DSC is used to evaluate the thermal properties of foods.

Effectiveness of Broad-Spectrum Chemical Produce Sanitizers against Foodborne Pathogens as In Vitro Planktonic Cells and on the Surface of Whole Cantaloupes and Watermelons.

Over the past few years, foodborne disease outbreaks linked to enteric pathogens present on cantaloupe and watermelon surfaces have raised concerns in the melon industry. This research evaluated the effectiveness of commercially available produce sanitizers against selected foodborne pathogens, both in cell suspensions and on the outer rind surface of melons. The sanitizers (65 and 200 ppm of chlorine, 5 and 35% hydrogen peroxide, 5 and 50 ppm of liquid chlorine dioxide, various hydrogen peroxide-acid combinations, 0.78 and 2.5% organic acids, and 300 ppm of quaternary ammonium) were tested against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella, and non-O157 Shiga toxin-producing E. coli (O26, O45, O103, O111, O121, and O145). The cell suspension study revealed the ability of all tested sanitizers to reduce all selected pathogens by 0.6 to 9.6 log CFU/ml in vitro. In the melon study, significant differences in pathogen reduction were observed between sanitizers but not between melon types. The most effective sanitizers were quaternary ammonium and hydrogen peroxide-acid combinations, with 1.0- to 2.2-log CFU/g and 1.3- to 2.8-log CFU/g reductions, respectively, for all pathogens. The other sanitizers were less effective in killing the pathogens, with reductions ranging from 0.0 to 2.8 log CFU/g depending on pathogen and sanitizer. This study provides guidance to the melon industry on the best produce sanitizers for use in implementing a broad-spectrum pathogen intervention strategy.