Assimilate partitioning in leaves of the raffinose-storing herb Lamium album L.: the effects of altering source-sink balance

In Lamium album, sucrose and raffinose-family oligosaccharides are the major products of photosynthesis that are stored in leaves. Using gas analysis and 14CO2 feeding, we compared photosynthesis and the partitioning of recently-fixed carbon in plants where sink activity was lowered by excision of flowers and chilling of roots with those where sink activity was not modified. Reduction in sink activity led to a reduction in the maximum rate of photosynthesis, to retention of fixed carbon in source leaves and to the progressive accumulation of raffinose-family oligosaccharides. This ultimately affected the extractable activities of invertase and sucrose phosphate synthase. At the end of the light period, invertase activity was significantly higher in treated plants. By contrast sucrose phosphate synthase activity was significantly lower in treated plants. We propose that reducing sink activity in L. album is associated with a shift in metabolism away from starch and sucrose synthesis and towards sucrose catabolism, galactinol utilisation and the synthesis of raffinose-family oligosaccharides.

Diallel cross analysis for young plants of brachytic maize (Zea mays L.) varieties

Six brachytic maize varieties were crossed in a diallel mating scheme. Both varieties and crosses were grown hydroponically in a greenhouse, in randomized complete blocks with three replications in two seasons. Four brachytic double cross hybrids were used as checks. Twenty-eight days after planting, data for eight traits were taken for weights of the total plant (TPW), top plant (TOW), total roots (TRW), seminal roots (SRW), and nodal roots (NRW) and number of total roots (TRN), seminal roots (SRN), and nodal roots (NRN). Ten plants were measured in each plot and all the analyses were accomplished with plot means. In the diallel cross the top plant contributed 57.6% of the total plant weight, for seminal roots 15.4%, and for nodal roots 27.0%. Root number distribution was 36.7% seminal roots and 63.3% nodal roots. Approximately the same ratios were observed in the checks. The average heterosis effects were nonsignificant for all traits; the other components of heterosis (variety and specific heterosis) also were not important sources of variation in young plants. The overall results suggest that nonadditive gene action is not an important source of variation for the plant and root system of young plants. The positive correlation coefficients for combinations of traits indicated that they are under the control of a polygenic system

Computerized analysis of isometric tension studies provides important additional information about vasomotor activity

Concentration-response curves of isometric tension studies on isolated blood vessels are obtained traditionally. Although parameters such as Imax, EC50 and pA2 may be readily calculated, this method does not provide information on the temporal profile of the responses or the actual nature of the reaction curves. Computerized data acquisition systems can be used to obtain average data that represent a new source of otherwise inaccessible information, since early and late responses may be observed separately in detail

In silico analysis identifies a C3HC4-RING finger domain of a putative E3 ubiquitin-protein ligase located at the C-terminus of a polyglutamine-containing protein

Almost identical polyglutamine-containing proteins with unknown structures have been found in human, mouse and rat genomes (GenBank AJ277365, AF525300, AY879229). We infer that an identical new gene (RING) finger domain of real interest is located in each C-terminal segment. A three-dimensional (3-D) model was generated by remote homology modeling and the functional implications are discussed. The model consists of 65 residues from terminal position 707 to 772 of the human protein with a total length of 796 residues. The 3-D model predicts a ubiquitin-protein ligase (E3) as a binding site for ubiquitin-conjugating enzyme (E2). Both enzymes are part of the ubiquitin pathway to label unwanted proteins for subsequent enzymatic degradation. The molecular contact specificities are suggested for both the substrate recognition and the residues at the possible E2-binding surface. The predicted structure, of a ubiquitin-protein ligase (E3, enzyme class number 6.3.2.19, CATH code 3.30.40.10.4) may contribute to explain the process of ubiquitination. The 3-D model supports the idea of a C3HC4-RING finger with a partially new pattern. The putative E2-binding site is formed by a shallow hydrophobic groove on the surface adjacent to the helix and one zinc finger (L722, C739, P740, P741, R744). Solvent-exposed hydrophobic amino acids lie around both zinc fingers (I717, L722, F738, or P765, L766, V767, V733, P734). The 3-D structure was deposited in the protein databank theoretical model repository (2B9G, RCSB Protein Data Bank, NJ).

Analysis of acylcarnitine profiles in umbilical cord blood and during the early neonatal period by electrospray ionization tandem mass spectrometry

Acylcarnitine profiling by electrospray ionization tandem mass spectrometry (ESI-MS/MS) is a potent tool for the diagnosis and screening of fatty acid oxidation and organic acid disorders. Few studies have analyzed free carnitine and acylcarnitines in dried blood spots (DBS) of umbilical cord blood (CB) and the postnatal changes in the concentrations of these analytes. We have investigated these metabolites in healthy exclusively breastfed neonates and examined possible effects of birth weight and gestational age. DBS of CB were collected from 162 adequate for gestational age neonates. Paired DBS of heel-prick blood were collected 4-8 days after birth from 106 of these neonates, the majority exclusively breastfed. Methanol extracts of DBS with deuterium-labeled internal standards were derivatized before analysis by ESI-MS/MS. Most of the analytes were measured using a full-scan method. The levels of the major long-chain acylcarnitines, palmitoylcarnitine, stearoylcarnitine, and oleoylcarnitine, increased by 27, 12, and 109%, respectively, in the first week of life. Free carnitine and acetylcarnitine had a modest increase: 8 and 11%, respectively. Propionylcarnitine presented a different behavior, decreasing 9% during the period. The correlations between birth weight or gestational age and the concentrations of the analytes in DBS were weak (r £ 0.20) or nonsignificant. Adaptation to breast milk as the sole source of nutrients can explain the increase of these metabolites along the early neonatal period. Acylcarnitine profiling in CB should have a role in the early detection of metabolic disorders in high-risk neonates.

Oat hulls treated with alkaline hydrogen peroxide associated with extrusion as fiber source in cookies

Cookies were prepared with the replacement of 20% of wheat flour by chemically (alkaline hydrogen peroxide) and physically (extrusion) treated oat hulls, with the objective to investigate the possibility of use of this modified material. Cookies elaborated with the untreated hulls were used as control. Cookies were evaluated for their physical (spread ratio, specific volume and color) and sensory characteristics, and no difference was detected (p<0.05) among the cookies in relation to the physical properties. Triangule test, used to verify difference (p<0.05) among treated and untreated cookies, confirmed the efficiency of the treatment in sensory level. The acceptance level of cookies with treated fiber was evaluated by potential consumers of the product, obtaining 91% acceptance. The cookies presented 10.6 g of dietary fiber per 100 g of product.

Isotope analysis (δ13C) of pulpy whole apple juice

The objectives of this study were to develop the method of isotope analysis to quantify the carbon of C3 photosynthetic cycle in pulpy whole apple juice and to measure the legal limits based on Brazilian legislation in order to identify the beverages that do not conform to the Ministry of Agriculture, Livestock and Food Supply (MAPA). This beverage was produced in a laboratory according to the Brazilian law. Pulpy juices adulterated by the addition of sugarcane were also produced. The isotope analyses measured the relative isotope enrichment of the juices, their pulpy fractions (internal standard) and purified sugar. From those results, the quantity of C3 source was estimated by means of the isotope dilution equation. To determine the existence of adulteration in commercial juices, it was necessary to create a legal limit according to the Brazilian law. Three brands of commercial juices were analyzed. One was classified as adulterated. The legal limit enabled to clearly identify the juice that was not in conformity with the Brazilian law. The methodology developed proved efficient for quantifying the carbon of C3 origin in commercial pulpy apple juices.

Revalorization of cactus pear (Opuntia spp.) wastes as a source of antioxidants

Recently, an increased interest in antioxidant activity and health-improving capacity of cactus pear has been registered. The antioxidant capacity of the pulp of cactus-pear fruits has been previously assessed. In this work, total phenolics, flavonoids and tannins of peel and seeds of four cactus pear cultivars were examined as well as their antioxidant capacity. Tannins were the major phenolics in cactus pear seeds accounting for almost fifty percent for all cultivars. Analysis of variance revealed that ripeness, cultivar, and its interaction had highly significant effect on the total phenolics, tannin, and flavonoid contents of cactus pear peel. With regard to the seeds, only the stage of ripeness and interaction (ripeness stage x cultivar) were significant on total phenolics and tannins contents. The flavonoid content in seeds was not affected by any of the factors or their interactions. The antioxidant capacity was higher in the peel than in the seeds. Generally, fruits with light-green or yellow-brown peel have higher antiradical activity and Trolox equivalent antioxidant capacity (TEAC) values compared with those with red-purple peel. Cactus pear by-products can indeed be exploited as a good and cheap source of natural antioxidants.

Carbon isotope analysis in apple nectar beverages

The aims of this study were to use the isotope analysis method to quantify the carbon of C3 photosynthetic cycle in commercial apple nectars and to determine the legal limit to identify the beverages that do not conform to the safety standards established by the Brazilian Ministry of Agriculture, Livestock and Food Supply. These beverages (apple nectars) were produced in the laboratory according to the Brazilian legislation. Adulterated nectars were also produced with an amount of pulp juice below the permitted threshold limit value. The δ13C values of the apple nectars and their fractions (pulp and purified sugar) were measured to quantify the C3 source percentage. In order to demonstrate the existence of adulteration, the values found were compared to the limit values established by the Brazilian Law. All commercial apple nectars analyzed were within the legal limits, which enabled to identify the nectars that were in conformity with the Brazilian Law. The isotopic methodology developed proved efficient to quantify the carbon of C3 origin in commercial apple nectars.

Okara, a soymilk industry by-product, as a non-meat protein source in reduced fat beef burgers

Okara is a by-product generated during the manufacture of soymilk and tofu. Wet okara was added to beef burgers at 0%, 20%, and 25%. The effects of okara on certain physicochemical, textural, and sensory properties of reduced fat beef burgers were investigated. The beef burgers formulated with okara (104.0-106.0 kcal/100 g) had 60% less calories than commercial beef burgers (268.8 kcal/100 g). The texture profile analysis showed that the addition of wet okara led to a significant increase in hardness (p < 0.05) and a concomitant reduction in the values of chewiness, springiness, and cohesiveness. Lower sensory scores (p < 0.05) of flavour were observed in the beef burgers containing 25% wet okara. However, the sensory evaluation results showed that juiciness, appearance, tenderness, and overall acceptability of beef burgers formulated with okara did not differ statistically from that of the control (0% okara). Wet okara (20%) can be used as a non-meat protein source in the production of reduced-fat beef burgers without changing their sensory quality.

Automated static image analysis as a novel tool in describing the physical properties of dietary fiber

Abstract The growing interest in the usage of dietary fiber in food has caused the need to provide precise tools for describing its physical properties. This research examined two dietary fibers from oats and beets, respectively, in variable particle sizes. The application of automated static image analysis for describing the hydration properties and particle size distribution of dietary fiber was analyzed. Conventional tests for water holding capacity (WHC) were conducted. The particles were measured at two points: dry and after water soaking. The most significant water holding capacity (7.00 g water/g solid) was achieved by the smaller sized oat fiber. Conversely, the water holding capacity was highest (4.20 g water/g solid) in larger sized beet fiber. There was evidence for water absorption increasing with a decrease in particle size in regards to the same fiber source. Very strong correlations were drawn between particle shape parameters, such as fiber length, straightness, width and hydration properties measured conventionally. The regression analysis provided the opportunity to estimate whether the automated static image analysis method could be an efficient tool in describing the hydration properties of dietary fiber. The application of the method was validated using mathematical model which was verified in comparison to conventional WHC measurement results.