Exploitation of an olive oil industry by-product: olive pomace as a source of food aroma compounds

Italy is the second largest producer in the world of olive oil, preceded only by Spain. Although olive oil can be considered as a “green gold” all over the world, the treatment of its by-products is a critical aspect to cope with. Indeed, the polluting character of such by-product together with its high costs for an effective disposal strongly penalize the olive oil industry. In particular, 50 % of oil production costs depend on its waste disposal. In this context, the aim of this work was to evaluate a potential exploitation of olive pomace as a feedstock for the production of flavours of interest for the food industry

How Listeria monocytogenes Shapes Its Proteome in Response to Natural Antimicrobial Compounds

The goal of this study was to investigate the adaptation of L. monocytogenes Scott A cells to treatments with sublethal doses of antimicrobials (ethanol, citral, carvacrol, E-2-hexenal and thyme essential oil). The survival of L. monocytogenes cells was not affected by the antimicrobials at the concentrations assayed, with the exception of ethanol (1% v/v) and thyme essential oil (100 mg/L), which decreased cell viability from 8.53 \ub1 0.36 to 7.20 \ub1 0.22 log CFU/mL (P = 0.04). We subsequently evaluated how L. monocytogenes regulates and shapes its proteome in response to antimicrobial compounds. Compared to the control cells grown under optimal conditions, L. monocytogenes treated for 1 h with the antimicrobial compounds showed increased or decreased ( 65 or 642-fold, respectively, P < 0.05) levels of protein synthesis for 223 protein spots. As shown multivariate clustering analysis, the proteome profiles differed between treatments. Adaptation and shaping of proteomes mainly concerned cell cycle control, cell division, chromosome, motility and regulatory related proteins, carbohydrate, pyruvate, nucleotide and nitrogen metabolism, cofactors and vitamins and stress response with contrasting responses for different stresses. Ethanol, citral (85 mg/l) or (E)-2-hexenal (150 mg/L) adapted cells increased survival during acid stress imposed under model (BHI) and food-like systems

Lactobacillus paracasei A13 and high-pressure homogenization stress response

Sub-lethal high-pressure homogenization treatments applied to Lactobacillus paracasei A13 demonstrated to be a useful strategy to enhance technological and functional properties without detrimental effects on the viability of this strain. Modification of membrane fatty acid composition is reported to be the main regulatory mechanisms adopted by probiotic lactobacilli to counteract high-pressure stress. This work is aimed to clarify and understand the relationship between the modification of membrane fatty acid composition and the expression of genes involved in fatty acid biosynthesis in Lactobacillus paracasei A13, before and after the application of different sub-lethal hyperbaric treatments. Our results showed that Lactobacillus paracasei A13 activated a series of reactions aimed to control and stabilize membrane fluidity in response to high-pressure homogenization treatments. In fact, the production of cyclic fatty acids was counterbalanced by the unsaturation and elongation of fatty acids. The gene expression data indicate an up-regulation of the genes accA, accC, fabD, fabH and fabZ after high-pressure homogenization treatment at 150 and 200 MPa, and of fabK and fabZ after a treatment at 200 MPa suggesting this regulation of the genes involved in fatty acids biosynthesis as an immediate response mechanism adopted by Lactobacillus paracasei A13 to high-pressure homogenization treatments to balance the membrane fluidity. Although further studies should be performed to clarify the modulation of phospholipids and glycoproteins biosynthesis since they play a crucial role in the functional properties of the probiotic strains, this study represents an important step towards understanding the response mechanisms of Lactobacillus paracasei A13 to sub-lethal high-pressure homogenization treatments

Suitability of the nisin Z-producer lactococcus lactis subsp. lactis CBM 21 to be used as an adjunct culture for squacquerone cheese production

This research investigated the technological and safety effects of the nisin Z producer Lactococcus lactis subsp. lactis CBM 21, tested as an adjunct culture for the making of Squacquerone cheese in a pilot-scale plant. The biocontrol agent remained at a high level throughout the cheese refrigerated storage, without having a negative influence on the viability of the conventional Streptococcus thermophilus starter. The inclusion of CBM 21 in Squacquerone cheesemaking proved to be more effective compared to the traditional one, to reduce total coliforms and Pseudomonas spp. Moreover, the novel/innovative adjunct culture tested did not negatively modify the proteolytic patterns of Squacquerone cheese, but it gave rise to products with specific volatile and texture profiles. The cheese produced with CBM 21 was more appreciated by the panelists with respect to the traditional one

Evaluation of Common Bean Varieties for Yield and Yield Component in Segen Area Peoples Zone SNNPRS, Ethiopia

Studies on the evaluation of variety performance provide opportunities to increase productivity of common bean. Therefore, the current study evaluates the performance of varieties on yield and yield components of common bean during the main cropping season of 2015 and 2016 at four locations in Segen Zone,Konso woreda (Southwestern Ethiopia) with the objectives of  selecting high yielding common bean varieties those are adapted to the study area. Fifteen released common bean varieties and one local cultivar were planted in randomized complete block design with three replications. The analysis revealed that significant variation for all traits except maturity date. Highest yield obtained from Nasir(2136 kgha-1) and Hawassa dume (1948 kgha-1) followed by Sari (1751 kgha-1) were as at Addis Gebere, high grain yield was obtained from Sari (2227 kgha-1), Hawassa dume (2111 kgha-1) and Dimtu (2073 kgha-1). For average mean yield from overall location, high yield obtained from Hawassa dume (2129 kgha-1) and Nasir (2002 kgha-1) followed by Sari (1989 kgha-1). Results revealed that Hawassa dume, Nasir and Sari were best performed and better adapted varieties than the others respectively. Therefore, the above mentioned varieties are promising varieties for the production area and recommendable for area with similar agro-ecologies. Keywords: Phaseolus Vulagris L, Evaluation, Grain yield,Varieties

Immunoreactivity of gluten-sensitized sera toward wheat, rice, corn, and Amaranth flour proteins treated with microbial transglutaminase

The aim of this study was to analyze the effects of microbial transglutaminase (mTG) on the immunoreactivity of wheat and gluten-free cereals flours to the sera of patients with celiac disease (CD) and non-celiac gluten sensitivity (NCGS). Both doughs and sourdoughs, the latter prepared by a two-step fermentation with Lactobacillus sanfranciscensis and Candida milleri, were studied. In order to evaluate the IgG-binding capacity toward the proteins of the studied flours, total protein as well as protein fractions enriched in albumins/globulins, prolamins and glutelins, were analyzed by SDS-PAGE and enzyme-linked immunosorbent assay (ELISA). Results showed that while mTG modified both gluten and gluten-free flour by increasing the amount of cross-linked proteins, it did not affect the serum's immune-recognition. In fact, no significant differences were observed in the immunoreactivity of sera from CD and NCGS patients toward wheat and gluten-free protein extracts after enzyme treatment, nor did this biotechnological treatment affect the immunoreactivity of control samples or the sera of healthy patients. These results suggest that mTG may be used as a tool to create innovative gluten and gluten-free products with improved structural properties, without increasing the immune-reactivity toward proteins present either in doughs or in sourdoughs

Alloying effects on the critical layer thickness in InxGa1−xAs/InP heterostructures analyzed by Raman scattering

International audienceRaman scattering has been used to estimate the critical layer thickness and to analyze the alloying effect on strain relaxation in InxGa1−xAs layers grown by molecular beam epitaxy on InP [001]-oriented substrate, for x ranging from 0.0 to 1.0. Measurements of longitudinal optical GaAs-like phonon frequency and Raman linewidth showed that the indium/gallium ratio contents greatly influences the strain relaxation. A comparison between Raman and x-ray diffraction measurements of relaxation ratios as a function of layer thickness is presented. The results can be explained in terms of the combined effect of strain and chemical and structural disorder

Comparative West Nile virus detection in organs of naturally infected American Crows (Corvus brachyrhynchos).

Widespread deaths of American Crows (Corvus brachyrhynchos)were associated with the 1999 outbreak of West Nile (WN) virus in the New York City region. We compared six organs from 20 crow carcasses as targets for WN virus detection. Half the carcasses had at least one positive test result for WN virus infection. The brain was the most sensitive test organ; it was the only positive organ for three of the positive crows. The sensitivity of crow organs as targets for WN virus detection makes crow death useful for WN virus surveillance