A study on relationships between durum wheat semolina properties, technological mixing parameters and the properties of dough after mixing

Partial least square regression analysis was used to study the correlation between X variables (semolina quality, hydration level and mixing time) and Y variables, which were, in a first model, dough consistency during mixing, and, in a second model, dough properties after mixing (strength, elasticity, density) and leavening (maximum volume). The first model showed a predictive residual sum of squares (PRESS) of 2.98 and a predictive R2 (Q2) of 0.92, and highlighted the key role of hydration and mixing time ondough consistency. The second model had the best PRESS (8.25) and Q2 (0.94) values for dough volume and indicated that the volume increased with increasing mixing time until the dough consistency decreased of 20–30%. Dough volume was primarily affected by hydration. The model indicated that maximum volume after leavening, corresponding to optimum mixing time, was obtained with a soft and elastic dough, with a low-density valu

Listeria monocytogenes in Five Sardinian Swine Slaughterhouses: Prevalence, Serotype, and Genotype Characterization

In a 3-year study (2008 to 2011) to estimate the prevalence and the contamination sources of Listeria monocytogenes in pork meat in Sardinia, Italy, 211 samples were collected from five Sardinian swine slaughterhouses: 171 samples from slaughtered pigs and 40 from the slaughterhouse environment. Fifty L. monocytogenes isolates were characterized by PCR-based serotyping, presence of virulence-associated genes, and pulsed-field gel electrophoresis restriction analysis. The overall prevalence of L. monocytogenes was 33% in swine carcasses, 7% in cecal material, 23% on meat contact surfaces, and 25% on noncontact surfaces. Only two serotypes were detected: 1/2c (78%) and 1/2a (22%). In all, based on the presence of virulence-associated genes, eight pathogenic profiles were detected. Only 42% of all isolates carried the full complement of virulence-associated genes and were allotted to profile 1. Six pulsed-field gel electrophoresis profiles persisted in the slaughterhouses; restriction profiles appeared to be specific to each plant

Notulae to the Italian alien vascular flora: 14

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as Suppl. materia

Notulae to the Italian alien vascular flora: 14

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates, published elsewhere, and corrections are provided as Suppl. material

Notulae to the Italian alien vascular flora: 11

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1

In Vivo and In Vitro Starch Digestibility of Fresh Pasta Produced Using Semolina-Based or Wholemeal Semolina-Based Liquid Sourdough

The use of wholemeal flour and sourdough fermentation in different food matrices has received considerable attention in recent years due to its resulting health benefits. In this study, a semolina-based and a wholemeal semolina-based sourdough were prepared and added to the formulation of gnocchetti-type fresh pasta. Four types of gnocchetti were made, using semolina plus semolina-based sourdough (SS), semolina plus wholemeal semolina-based sourdough (SWS), semolina alone (S), and semolina plus wholemeal semolina (WS). The latter two were used as controls. The digestibility of starch was studied both in vitro and in vivo, and the glycemic response (GR) and glycemic load (GL) were determined. Starch digestibility, both in vivo and in vitro, was higher in wholemeal semolina than semolina pasta and the resulting GR values (mg dL−1 min−1) were also higher (2209 and 2277 for WS and SWS; 1584 and 1553 for S and SS, respectively). The use of sourdough significantly reduced the rapidly digestible starch (RDS) content and increased the inaccessible digestible starch (IDS) content. The addition of sourdough to the formulation had no effect on the GR values, but led to a reduction of the GL of the pasta. These are the first data on the GR and GL of fresh pasta made with sourdough

The Effect of nitrogenous fertiliser application on leaf traits in durum wheat in relation to grain yield and development

Nitrogen (N) fertilisation boosts the grain yield of wheat through its influence on yield components, phenology and leaf traits. Both crop growth and senescence are dependent on N supply, as are the number of kernels set per unit area and per ear, and the mean kernel size. A two-season trial of four semi-dwarf durum wheat cultivars, grown at two levels of N, was used to illustrate the effects of N on canopy temperature, leaf resistance and flag leaf senescence pattern under irrigated conditions in a Mediterranean climate, and to explore the consequences of these effects on the crop phenology, its yield and its yield components. The well-fertilised crop developed a larger leaf area index at anthesis and a lower leaf resistance, thus generating a lower canopy temperature and delayed anthesis. Its grain fill duration was shorter, in spite of its lower canopy temperature, presumably because the increased N availability resulted in the development of a stronger sink (more kernels per unit area and per ear), which was associated with earlier senescence, thereby shortening the duration of grain fill, and led to reduced kernel weight

Relationship between grain yield and quality of durum wheats from different eras of breeding

High protein content and a ‘strong’ gluten are required in durum wheat (Triticum turgidum L. var. durum) to process semolina into a suitable final pasta product. The variation in grain protein content and quality realized through breeding and the concomitant variation in biomass production and partitioning have been analyzed by comparing in a 2-year field trial, four groups of cultivars released in different eras and areas of breeding. Three groups of cultivars represented the evolution of the Italian germplasm from the first landraces and genealogical selections (Group 1) to the cultivars constituted by crossing Mediterranean types with Syriacum types (Group 2), and the modern dwarf and semi-dwarf cultivars (Group 3). Group 4 was an ICARDA collection of breeding lines bred for adaptation to high altitudes. The measured traits included both biomass production and its partitioning to the grain, and total nitrogen uptake and its partitioning to the grain. Grain protein percentage, gluten content and gluten index were utilized as quality traits. Breeding resulted in an increased earliness, reduced height without significant decreases in total biomass, and improved partitioning. The concomitant total nitrogen uptake did not change, whereas the changed biomass partitioning caused a parallel change in nitrogen partitioning, with an increase in nitrogen harvest index from 0.41 to 0.59. The lower protein percentage in the grains of modern cultivars was therefore not due to a reduced nitrogen uptake, nor to a lower NHI or to less milligram of nitrogen per grain, but to the dilution effect caused by the heavier grains of modern cultivars. A notable increase in gluten index was observed in the modern cultivars, reflecting an improvement in the pasta-making quality of grain proteins

Protein content and gluten quality of durum wheat (<i>Triticum turgidum</i> subsp. <i>durum</i>) as affected by sowing date

The end use quality of durum wheat is sensitive to the environmental conditions pertaining before and during grain filling, and can therefore be modified by manipulation of cultivar and sowing date. A field trial was carried out to study the effect on protein content and gluten quality of varying both sowing date (October, December and March) and cultivar (Simeto, Colosseo and Creso). A delay in sowing date was associated with a decrease in mean grain weight, but not in grain nitrogen content, thus leading to an overall increase from 10.7 to 14.7% in grain protein percentage. Independent of sowing date, over 78% of the grain nitrogen was derived from re-translocation from vegetative tissue. The similar amounts of nitrogen accumulated in each grain at maturity were set by the similarity in the amount of nitrogen available at anthesis. The observed increase in protein percentage partly explained the greater dough strength (alveographic W) observed in material harvested from the latest sowing. The gluten index, on the other hand, decreased as sowing was delayed. Given the parallel increase in glutenin percentage, we propose that temperatures above 30 ◦C at the end of the grain filling period have a negative effect on the gluten polymerisation process