Factors contributing to the utility as food of five grades of Michigan potatoes

American Journal of Potato Research -     

Improvement of Sorghum-Wheat Composite Dough Rheological Properties and Breadmaking Quality Through Zein Addition

Addition of sorghum flour to wheat flour produces marked negative effects on rheological properties of dough and loaf volume. Although there are notable differences in the chemical composition of sorghum proteins (kafirins) compared with wheat gluten that might imply poor functionality in breadmaking systems, a larger constraint may be the unavailability of kafirins due to encapsulation in protein bodies. In this study, zein, the analogous maize prolamin to kafirin, was used to determine the potential effects of protein-body-free prolamins on dough rheology and baking quality of wheat-sorghum composite flour. Mixograms run at 35°C (above the glass transition temperature of zein) were significantly (P < 0.01) improved with addition of zein. Mixogram peak heights increased while mixing time decreased uniformly with addition of zein. Dough extensibility studies showed an increase in maximum tensile stress, while baking studies showed an increase in loaf volume with increasing amounts of added zein. These data are supported by a previous study showing that, in a model system, zein mixed with starch can form viscoelastic networks, and suggest that kafirin, if made available, could contribute to dough formation.     

Fatty acid and carotenoid composition of gac (Momordica cochinchinensis Spreng) fruit

In this study, we analyzed fatty acid and carotenoid composition of fruit tissues, including seed (which are surrounded by a bright red, oily aril) of Momordica cochinchinensis Spreng, known as gac in Vietnam. Carotenoid content was analyzed by reversed-phase HPLC, using a C(30) column and a method separating cis- and trans-isomers of the major carotenoids in this fruit. Mean values obtained in aril tissues were 1342 microg trans-, 204 microg cis-, and 2227 microg total lycopene; 597 microg trans-, 39 microg cis-, and 718 microg total beta-carotene; and 107 microg alpha-carotene/g FW. Mesocarp contained 11 microg trans-, 5 microg cis-beta-carotene/g FW, trace amounts of alpha-carotene, and no lycopene. Gac aril contained 22% fatty acids by weight, composed of 32% oleic, 29% palmitic, and 28% linoleic acids. Seeds contained primarily stearic acid (60.5%), smaller amounts of linoleic (20%), oleic (9%), and palmitic (5-6%) acids, and trace amounts of arachidic, cis-vaccenic, linolenic, and palmitoleic, eicosa-11-enoic acids, and eicosa-13-enoic (in one fruit only) acids.     

Effects of Two Triazole Seed Treatments,Triticonazole and Triadimenol,on Growth and Development of Wheat

The triazole fungicides, triadimenol and triticonazole, applied as seed treatments at various rates on spring wheat, affected plant growth, shoot development, and root axis production. The main growth regulatory effects were reductions in lengths of the coleoptile, the first leaf and the subcrown internode. A marked effect on tiller appearance occurred with high rates of triadimenol. Modification of root-system development included a reduction in the number of seminal roots, increased outgrowth of roots associated with the coleoptilar node, and a reduction of roots at the first foliar node (correlated with reduced production of Tiller 1). Seed treatment effects on both shoot and root development illustrated the close relationship between these plant structures. Both fungicides induced both beneficial and deleterious effects on wheat growth and development, but the magnitude of deleterious effects was less with triticonazole than with triadimenol.     

Epigenetic tailoring for the production of anti-infective cytosporones from the marine fungus Leucostoma persoonii

Recent genomic studies have demonstrated that fungi can possess gene clusters encoding for the production of previously unobserved secondary metabolites. Activation of these attenuated or silenced genes to obtain either improved titers of known compounds or new ones altogether has been a subject of considerable interest. In our efforts to discover new chemotypes that are effective against infectious diseases, including malaria and methicillin-resistant Staphylococcus aureus (MRSA), we have isolated a strain of marine fungus, Leucostoma persoonii, that produces bioactive cytosporones. Epigenetic modifiers employed to activate secondary metabolite genes resulted in enhanced production of known cytosporones B (1, 360%), C (2, 580%) and E (3, 890%), as well as the production of the previously undescribed cytosporone R (4). Cytosporone E was the most bioactive, displaying an IC(90) of 13 μM toward Plasmodium falciparum, with A549 cytotoxicity IC(90) of 437 μM, representing a 90% inhibition therapeutic index (TI(90) = IC(90) A459/IC(90)P. falciparum) of 33. In addition, cytosporone E was active against MRSA with a minimal inhibitory concentration (MIC) of 72 μM and inhibition of MRSA biofilm at roughly half that value (minimum biofilm eradication counts, MBEC90, was found to be 39 μM).     

Broad spectrum insect resistance and metabolites in close relatives of the cultivated tomato

Wild relatives of tomato possess effective means to deal with several pests, among which are a variety of insects. Here we studied the presence of resistance components against Trialeurodes vaporariorum, Myzus persicae, Frankliniella occidentalis, and Spodoptera exigua in the Lycopersicon group of Solanum section Lycopersicon by means of bioassays and comprehensive metabolite profiling. Broad spectrum resistance was found in Solanum galapagense and a few accessions of S. pimpinellifolium. Resistance to the sap sucking insects may be based on the same mechanism, but different from the caterpillar resistance. Large and highly significant differences in the leaf metabolomes were found between S. galapagense, containing type IV trichomes, and its closest relative S. cheesmaniae, which lacks type IV trichomes. The most evident differences were the relatively high levels of different methylated forms of the flavonoid myricetin and many acyl sucrose structures in S. galapagense. Possible candidate genes regulating the production of these compounds were identified in the Wf-1 QTL region of S. galapagense, which was previously shown to confer resistance to the whitefly B. tabaci. The broad spectrum insect resistance identified in S. galapagense will be very useful to increase resistance in cultivated tomato.     

Variability of neutrophil and pulmonary alveolar macrophage function in swine

Neutrophils and alveolar macrophages are essential defence mechanisms against bacterial infection of the lung. The purpose of this study was to evaluate the variability of a panel of neutrophil and alveolar macrophage function assays in swine, and to determine if the function of these leukocytes differed at various stages of production. Measured neutrophil functions included chemotaxis, phagocytosis, oxidative burst, and degranulation. Phagocytosis and oxidative burst were measured in alveolar macrophages isolated from bronchoalveolar lavage fluid (BALF). Both neutrophil and alveolar macrophage functions were highly variable from day-to-day and between pigs. Individual pigs did not have consistently high or low neutrophil and macrophage responses over time when compared to their cohorts. Older grower-finisher pigs had significantly greater neutrophil oxidative burst responses than younger suckling and weaner pigs (P < 0.001). Similarly, alveolar macrophages from suckling and early weaner pigs less than 40 days of age had significantly lower oxidative burst responses than those from older pigs (P = 0.02). Age-related variation in phagocytosis, chemotaxis, or granule secretion were not detected. These results establish baseline data for individual and age-related variation in swine leukocyte function, and form a basis for further evaluation of the contribution of non-infectious factors to development of the porcine respiratory disease complex.     

Gender and resource management: Community supported agriculture as caring-practice

Interviews with Community Supported Agriculture (CSA) growers in Iowa, a majority of whom are women, shed light on the relationship between gender and CSA as a system of resource management. Growers, male and female alike, are differentiated by care and caring-practices. Care-practices, historically associated with women, place priority on local context and relationships. The concern of these growers for community, nature, land, water, soil, and other resources is manifest in care-motives and care-practices. Their specific mix of motives differs: providing safe and nutritious food, educating self and others, and building relationships with other growers, shareholder-members, and the land. Care-practices include reducing or eliminating chemical usage, encouraging or accepting beneficial insects and wildlife, building soil, and creating resource management partnerships with shareholder members. CSA, viewed through a lens of care, may offer a means of transcending gender stereotypes. This revised version was published online in June 2006 with corrections to the Cover Date.     

Altered capsaicin levels in domesticated chili pepper varieties affect the interaction between a generalist herbivore and its ectoparasitoid

Journal of Pest Science - Plant domestication has commonly reduced levels of secondary metabolites known to confer resistance against insects. Chili pepper is a special case because the fruits of...