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No description available.

Call number: LD2668 .T4 1986 V56 / Master of Science / Grain Science and Industry

Thesis (Ph. D.)--Pennsylvania State University, 1968. / Includes bibliographical references.

Thesis (Ph. D.)--Pennsylvania State University, 1971. / Includes bibliographical references.

Experiments were performed to determine the nature of maize influence on bean disease in additive-type intercrops. Overall effects of intercrops on angular leaf spot (caused by Phaeoisariopsis griseola) in Kenya indicated >23% reductions (P<0.05) in area under the disease progress curve (AUDPC) in two of three season-site combinations. Fertilization tended to increase disease (135-205%, P<0.10), but changes in bean density or planting pattern had no effect. Intercrops reduced temperature and wind velocity, but increased relative humidity. A 27% AUDPC reduction (P=0.07) in bean rust (caused by Uromyces appendiculatus) due to intercropping was observed in Oregon in 1989 and 1990 in two of three locations. Mechanisms of maize influence on rust were also assessed in Oregon. Intercropping, and competition of maize with beans alone, consistently steepened dispersal gradients (P<0.10). Interference of maize with dispersal alone tended to flatten gradients. Spore retention in plots was increased in mid-season, then decreased late in the season, due to competition in both years (P<0.05). Intercropping reduced infection by 96% late in 1989 (P<0.05), probably due to microclimatic influence of maize. The data from these experiments were used as inputs for computer simulation to evaluate effects of specific mechanisms on disease dynamics. Combination of all mechanisms (= intercrop) reduced AUDPC to 32% of monocrop, using 1989 data. Infection efficiency reductions, and to a lesser extent dispersal effects, were responsible for these changes. Intercrop effects declined as pathogen multiplication rate (DMFR) increased. No intercrop effect occurred at any DMFR using 1990 data, although interference and competition effects of maize alone both increased AUDPC at low DMFR. Partitioning dispersal effects into those due to gradient slope changes and spore retention indicate that the latter accounts almost entirely for disease alteration. / Graduation date: 1992

Thesis (M. S.)--Pennsylvania State University, 1976. / Includes bibliographical references.

Thesis (Ph.D.). / Written for the Dept. of Bioresource Engineering. Title from title page of PDF (viewed 2008/02/12). Includes bibliographical references.

Please read the abstract in the section 00front of this document / Dissertation (MSc Agric (Agronomy))--University of Pretoria, 2005. / Plant Production and Soil Science / unrestricted

Dry bean utilization by the food industry can be increased by developing value-added processing applications. The goals of this research were to evaluate (1) the effect of milling method on the physical, chemical and functional properties of whole black bean flour and its fractions and (2) the effect of removing soluble phenolic compounds on the functional and rheological properties of black bean protein isolates. Black bean was milled with five laboratory mills [cyclone mill, hammer mill, stone mill (fine, medium, coarse), disc mill (fine, coarse), and centrifugal mill (10,000 or 12,000 rpm and 250, 500, 1000 μm aperture screen)] and the resulting flours were evaluated for their physical, chemical and flow properties of bulk samples and particle size fractions. Whole black bean flour and cotyledon flour were subjected to phenolic extraction and protein isolation, resulting in protein isolates with and without soluble phenolics. Solubility, wettability, dispersibility, water binding capacity, foam capacity and stability, emulsification capacity, and gelation properties of protein isolates were evaluated. Variation in milling method produced flours with significantly different flour characteristics. Geometric mean size of whole bean flour was negatively correlated with starch damage (r = -0.92), L* (r = -0.94), angle of repose (r = -0.94), and angle of slide (r = -0.80 to -0.90) and positively correlated with moisture (r = 0.72), and loose bulk density (r = 0.72). Milling method and particle size interaction was significant on characteristics of black bean flour fractions. Particle circularity of flour fractions had a negative correlation of r = -0.93, r = -0.81, r ≈ -0.95, and r = -0.94 with L*, angle of repose, angle of slide and compact density, respectively. Particle circularity had a positive correlation of r = 0.93 and r = 0.89 with average minimum particle size and loose bulk density, respectively. The removal of soluble phenolic compounds improved the brightness, solubility, wettability, dispersibility, foaming capacity, foaming stability, emulsion capacity, emulsion stability and gelling properties of protein isolates. These findings will help food manufacturers to process black bean ingredients using different mill settings to achieve different functionalities depending on the consumer requirements.