Antidiabetic Potential of Protein Hydrolysates and Peptide Fractions from Lima Bean (Phaseolus lunatus L): An In Vitro Study

International Journal of Peptide Research and Therapeutics - Characterized by uncontrolled, long-term high blood sugar levels, diabetes mellitus affects ever increasing numbers of people worldwide....     

Effect of nixtamalization on the modification of the crystalline structure of maize starch

Endosperm of nixtamalized corn was analyzed using X-ray diffraction. Relative crystallinity changed with lime concentration and steeping. Diffractograms showed peaks corresponding to V-type crystalline structures, indicating formation of complexes during cooking and steeping. Diffraction patterns of the soluble fraction showed that complexed amylose can be leached out during solubilization. While diffraction patterns of the insoluble fraction suggested that some of the formed complexes remain in this fraction. During alkali steeping, release of amylose is strongly inhibited as indicated by the pronounced decrease in the starch–I₂ absorbance of the lime treated samples compared to the lime-free treated sample. This decrease is interpreted as evidence of starch cross-linking during the nixtamalization process. Differences in starch–I₂ absorbance and in X-ray diffraction patterns of the soluble fractions suggested that lime treatment could also modified formation of amylose complexes with lipids.     

Mechanisms and traits associated with compensation for defoliation in <Emphasis Type="Italic">Ruellia nudiflora</Emphasis>

A full understanding of the ecology and evolution of plant tolerance to damage requires the measurement of a diversity of traits (including multiple fitness-correlates) and underlying mechanisms. Here, we address the compensatory response to defoliation in the perennial herb Ruellia nudiflora, measure biomass allocation patterns and relate them to compensation, and address multiple mechanisms and traits that determine compensatory ability. We used maternal full-sib lines of R. nudiflora and conducted a defoliation experiment in which half the plants of each line were subjected to removal of 40% of leaf area (the other half remained undamaged). Fitness-correlated traits, physiological traits, and leaf longevity were measured during a 2-month period after defoliation. Using another set of plants, we conducted a second defoliation experiment and measured the concentration of non-structural carbohydrates to test for root-to-shoot carbon mobilization as a compensatory mechanism. R. nudiflora showed full compensation in terms of fruit output, and compensatory ability was positively correlated with investment in root biomass in the absence of damage. In addition, defoliated plants produced shorter-lived leaves and had a greater concentration of starch in roots, suggesting that reduced leaf longevity and accumulation of below-ground carbon reserves act as compensatory mechanisms. By measuring multiple fitness-correlates and induced traits, we provide a comprehensive evaluation of R. nudiflora compensatory responses to herbivory.