Delivery of Functionality in Complex Food Systems: Physically Inspired Approaches from Nanoscale to Microscale,Wageningen 18–21 October 2009

The Wageningen Delivery of Functionality symposium covered all aspects involved with food structural design to arrive at high-quality foods which meet demanding customer expectations and regulatory requirements. The symposium integrated aspects from the structural organization of foods at molecular and supramolecular scales to dedicated techniques required to describe and visualize such structures, the gastro-intestinal events and how to model these in a laboratory setting, and finally the impact those food structures and ingredients have on the consumer’s physiology and on the human perception. As an interdisciplinary platform, bringing together more than 160 researchers from academia and industry, the symposium meanwhile fulfills an important role in the food science community.     

A new species of Oryctina (Loranthaceae) from Guyana

A new species ofOryctina (Loranthaceae) from Guyana,O. atrolineata Kuijt is described and illustrated. It possesses one-flowered inflorescences, the flowers being hexamerous and each subtended by a bract and two minute bracteoles. A peculiarity of the style is a distinctive fusiform, subterminal swelling.Oryctina atrolineata is closely related, and similar to,O. myrsinites (Eichler) Kuijt.     

Influence of various soil factors on the effects of ferulic acid on leaf expansion of cucumber seedlings

Summary Cucumber seedlings were grown in a Portsmouth soil-sand system to study how varying soil clay and organic matter content might modify cucumber seedling response to ferulic acid, a reported allelopathic agent. Leaf area expansion of cucumber seedlings, soil respiration, and soil solution concentrations of ferulic acid were monitored. Leaf area, mean absolute rates of leaf expansion, and shoot dry weight of cucumber seedlings were significantly reduced by ferulic acid concentrations ranging from 10 to 70 μg/g dry soil. Ferulic acid was applied every other day, since it rapidly disappeared from soil solution as a result of retention by soil particles, utilization by microbes and/or uptake by roots. The amount of ferulic acid retained (i.e., adsorbed, polymerized,etc.) by soil particles appeared to be secondary to microbial utilization and/or uptake by roots. Varying clay (5.3 to 9.8 g/cup) and organic matter (2.0 to 0.04g/cup) contents of the soil appeared to have little impact on the disappearance of ferulic acid from soil solution under “ideal” growth conditions for cucumber seedlings unless larger amounts of ferulic acid were added to the soil; in this case 200 μg/g. The addition of ferulic acid to the soil materials substantially increased the activity of the soil microbes. This latter conclusion is based on recovery of ferulic acid from soil solution and soil respiration measurements. Paper No. 10347 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, N C 27695-7601. The use of trade names in this publication does not imply endorsement by the North Carolina Agricultural Research Service of the product named, nor criticism of similar ones not mentioned.     

Field inversion gel electrophoretic separation of Cryptosporidium spp. chromosome-sized DNA

Chromosomal DNA from 5 isolates of Cryptosporidium parvum and 1 of C. baileyi were compared by field-inversion gel electrophoresis (FIGE). FIGE analyses of parasite DNA prepared from purified sporozoites versus intact oocysts showed no observable differences. Chromosomal DNA migration patterns of the 5 C. parvum isolates were indistinguishable, whereas similar but distinct differences were evident between C. baileyi and the isolates of C. parvum. Oocyst-reactive monoclonal antibodies differentiated oocysts of C. parvum from those of C. baileyi but were unable to distinguish oocysts of 1 isolate of C. parvum from another.     

Sliding of STOP proteins on microtubules

Microtubules are stabilized against cold temperature disassembly by 145-kilodalton proteins [stable tubule only polypeptides (STOPs)] that block the end-wise dissociation of subunits from the polymers. We describe here several kinetic parameters of the interaction of STOPs with microtubules. STOPs will bind to microtubules either during assembly of the polymer or at steady state. The addition appears random on the polymers and does not require the mediation of tubulin subunits. Tubulin subunits compete with microtubules for STOP binding, but binding to the polymers is apparently irreversible. We demonstrate that STOPs do not exchange measurably between polymers at steady state. Nonetheless, a displacement of STOPs within a single polymer is readily demonstrable. We have determined that the displacement is apparently due to a surface translocation, or "sliding", of STOPs on microtubules.     

Aspects of the neuroendocrine control of ovulation and broodiness in the domestic hen

The neuroendocrine control of ovulation and broodiness in the domestic hen involves complex interactions between hypothalamic neuropeptides, neurotransmitters, and ovarian steroids which regulate the secretion of luteinizing hormone (LH) and prolactin. Nuclear progesterone receptor is localized in many neurons throughout the hypothalamus but is absent from LHRH neurons. Hence, the positive feedback action of progesterone on LH release is not mediated by a genomic mechanism within the LHRH neuron. Precursors of 5-hydroxytryptamine (5HT) and dopamine (DA) inhibit the preovulatory release of LH, while the turnover rates of these neurotransmitters in the anterior hypothalamus decrease when preovulatory levels of LH are at their highest. Further, a population of receptors for 5HT which occurs in the anterior hypothalamus in laying birds is absent in nonlaying, incubating hens. Taken together, these observations suggest that the preovulatory surge of LH is mediated by a transitory decrease in the inhibitory action of 5HT and possibly DA, on the secretion of LHRH. Neurons containing 5HT may play a role in the regulation of prolactin release and, more specifically, in the control of broodiness. Drugs which enhance the function of 5HT neurons stimulate prolactin release while increased prolactin secretion in incubating hens is associated with an increase in the turnover of 5HT in the anterior hypothalamus. No receptors for 5HT were demonstrable in the anterior pituitary gland, showing that the prolactin-releasing activity of 5HT must be mediated by a prolactin-releasing factor (PRF). A candidate for a physiological PRF is vasoactive intestinal polypeptide (VIP).(ABSTRACT TRUNCATED AT 250 WORDS)