Suchergebnisse

Nowadays, new strategies and alternatives are being implemented to improve the protein quality of foods containing essential amino acids, like quality protein maize (QPM). The techno-functional properties of protein concentrate from QPM maize: Sac Beh (SB), Chichen Itza (ChI), and Blanco Uxmal (BU); non-nixtamalized (NN) and nixtamalized (N), were evaluated in the present work. The non-nixtamalized varieties showed higher amounts of protein in the QPM ChI (86.81%) and nitrogen solubility of 64.94% as the pH increased to 9. The emulsifying capacity was higher at pH 5 (60.74%). The non-nixtamalized SB samples showed higher foaming stability (1.82%) at pH 7, and the non-nixtamalized BU samples had higher foaming capacity at pH 5 (60.74%). Water holding capacities ranging from 1.2 to 3.13 g/g were achieved. The non-nixtamalized QPM concentrates had higher water and oil holding capacities. There was a predominance of elastic character over viscous character (G' > G'') in all treatments behaving as weak gels, which were affected in alkaline conditions by decreasing the modulus value. The techno-functional properties were affected by the processing method. These results could be beneficial for providing a better understanding of the properties of QPM proteins, allowing innovative ways of utilising these proteins as an ingredient in food systems.

The assignment of functions to genes in the carotenoid biosynthesis pathway is necessary to understand how the pathway is regulated and to obtain the basic information required for metabolic engineering. Few carotenoid ε-hydroxylases have been functionally characterized in plants although this would provide insight into the hydroxylation steps in the pathway. We therefore isolated mRNA from the endosperm of maize (Zea mays L., inbred line B73) and cloned a full-length cDNA encoding CYP97C19, a putative heme-containing carotenoid ε hydroxylase and member of the cytochrome P450 family. The corresponding CYP97C19 genomic locus on chromosome 1 was found to comprise a single-copy gene with nine introns. We expressed CYP97C19 cDNA under the control of the constitutive CaMV 35S promoter in the Arabidopsis thaliana lut1 knockout mutant, which lacks a functional CYP97C1 (LUT1) gene. The analysis of carotenoid levels and composition showed that lutein accumulated to high levels in the rosette leaves of the transgenic lines but not in the untransformed lut1 mutants. These results allowed the unambiguous functional annotation of maize CYP97C19 as an enzyme with strong zeinoxanthin ε-ring hydroxylation activity. ; This work was supported by the National Natural Science Foundation of China (31470394; 31070269); MICINN, Spain (BIO2011-23324; BIO2011-22525; PIM2010PKB-00746); European Union Framework 7 European Research Council IDEAS Advanced Grant (to PC) Program-BIOFORCE; and ERC Proof of Concept Grant (to PC).

The objective of this study was to evaluate the effects of diets supplemented with 0.0, 8.0, 16.0, and 24.0% distiller's dried grain solubles (DDGS) on nitrogen (N) intake, fecal and urinary N excretion, and N absorption and retention (N balance, NB) by feeding sheep. Four sheep of unidentified race were used, with an average body weight of 23.5 ± 1.5 kg, and housed in metabolism cages. We used a 4 × 4 Latin square design for the experimental design, and each experimental period lasted for 20 days. Data on N intake (NI), fecal N, urinary N, absorbed N, and NB were expressed in g day-1; percentage of NI and grams per kilogram of metabolic weight g (kg0.75)-1 were subjected to analysis of variance (ANOVA) and regression analysis at 5% probability. Inclusion of the different concentrations of DDGS in sheep diets had no effect on NI (mean of 15.11 g animal-1 day-1), nor on fecal and urinary N excretion (mean of 5.16 and 0.16 g animal-1 day-1, respectively). Moreover, DDGS supplementation did not alter NB or N absorption (mean of 9.79 and 9.95 g animal-1 day-1, respectively). Thus, it can be concluded that inclusion of up to 24% of DDGS in feed does not affect NI, fecal and urinary N excretion, and NB in sheep.

Maize is one of the most commonly cultivated crops in southwestern Nigeria, but its production is constrained by virus diseases. Information on viruses infecting maize within the region is still limited. Therefore, a survey was conducted to identify the viruses infecting maize on randomly selected farmers' cultivated maize fields in 16 local government areas in Ekiti State, southwestern Nigeria using molecular detection tools. Four cultivated maize fields were randomly surveyed in each local government area with an average size of 50 m x 50 m. The sampling was done on fifty randomly selected plants per field. Viral diseases were confirmed on maize plants through visual symptoms observations and serological diagnosis, although severity and incidence varied per location. Visible symptoms observed include chlorotic patches, severe streaking, red pigments and venation along mid rib and vein with stunted growth. Although only Maize streak virus (MSV) and Maize chlorotic mottle virus (MCMV) were targeted, serological assay indicated the occurrence of only MSV. Polymerase chain reaction (PCR) confirmed the presence of MSV while MCMV was negative. This provides additional information to the prevalence of MSV as an ongoing threat to maize production in southwest Nigeria.Keywords: Maize streak virus, Maize chlorotic mottle virus, ELISA, Polymerase chain reaction, Symptoms