Antagonistic effect of Pseudomonas graminis CPA-7 against foodborne pathogens in fresh-cut apples under simulated commercial conditions

Recently, we reported that the application of the strain CPA-7 of Pseudomonas graminis, previously isolated from apple, could reduce the population of foodborne pathogens on minimally processed (MP) apples and peaches under laboratory conditions. Therefore, the objective of the present work was to find an antioxidant treatment and a packaging atmosphere condition to improve CPA-7 efficacy in reducing a cocktail of four Salmonella and five Listeria monocytogenes strains on MP apples under simulated commercial processing. The effect of CPA-7 application on apple quality and its survival to simulated gastric stress were also evaluated. Ascorbic acid (2%, w/v) and N-acetyl-l-cysteine (1%, w/v) as antioxidant treatments reduced Salmonella, L. monocytogenes and CPA-7 recovery, meanwhile no reduction was observed with NatureSeal^® AS1 (NS, 6%, w/v). The antagonistic strain was effective on NS-treated apple wedges stored at 10 °C with or without modified atmosphere packaging (MAP). Then, in a semi-commercial assay, efficacy of CPA-7 inoculated at 10⁵ and 10⁷ cfu mL⁻¹ against Salmonella and L. monocytogenes strains on MP apples with NS and MAP and stored at 5 and 10 °C was evaluated. Although high CPA-7 concentrations/populations avoided Salmonella growth at 10 °C and lowered L. monocytogenes population increases were observed at both temperatures, the effect was not instantaneous. No effect on apple quality was detected and CPA-7 did not survived to simulated gastric stress throughout storage. Therefore, CPA-7 could avoid pathogens growth on MP apples during storage when use as part of a hurdle technology in combination with disinfection techniques, low storage temperature and MAP.     

Application of an HPLC–MS/MS method for mycotoxin analysis in commercial baby foods

This article describes the validation of an analytical method for the detection of 21 mycotoxins in baby food. The analytical method is based on the simultaneous extraction of selected mycotoxins by matrix solid-phase dispersion (MSPD) followed by liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) using a hybrid triple quadrupole-linear ion trap mass spectrometer (QTRAP®). Information Dependent Acquisition (IDA), an extra confirmation tool for samples that contain the selected mycotoxins, was used. The matrix effects were evaluated, and the corrections for the matrix effects were performed using two calibration approaches: external matrix-matched calibration and internal standard calibration. Matrix-matched calibration was ultimately used for accurate quantification, and the recoveries obtained were generally higher than 70%. The analytical method was applied to the analysis of 35 samples of commercial baby foods. No sample exceeded the maximum limit (ML) fixed by the European Union for these mycotoxins in baby food. However, this survey highlighted the occurrence of mycotoxins in cereal-based infant foods.     

Control of post‐harvest brown rot on nectarine by Epicoccum nigrum and physico‐chemical treatments

Post-harvest physico-chemical treatments—water at 40 °C or 60 °C (HW), and sodium bicarbonate at 1 or 2.5% (SBC) at 20, 40 and 60 °C—were tested on peaches and nectarines in order to control brown rot caused by Monilinia spp. and to select the best physico-chemical treatment to be used in combination with pre-harvest applications of the biological control agent Epicoccum nigrum (ATCC number 96794). Experiments were carried out in France, Italy and Spain in order to test different experimental conditions. Monilinia rot was reduced in peach and nectarine treated with HW (40 °C for 2 min) in all three countries, the percentage of rot reduction was similar for France, Italy and Spain (over 40%). A synergistic effect between HW at 40 °C during 150 s or at 60 °C during 20 s and SBC was observed in all three countries. After preliminary experiments post-harvest treatment of HW (60 °C) + SBC (1%) during 20 s was selected to combine it with field treatments. Pre-harvest treatments with fungicide or E. nigrum did not reduce brown rot in any country. However, pre-harvest treatments with E. nigrum, chemical fungicide, and their integration followed by post-harvest physico-chemical treatment significantly reduced Monilinia rot compared to pre-harvest untreated fruits followed by post-harvest physico-chemical treatment in Italy (over 70%). Post-harvest treatments with E. nigrum were also tested in Italy on natural and artificial infections in nectarine over 3 years. E. nigrum, as fresh or formulated cells, at a concentration of 10⁸ conidia mL⁻¹ were effective, significantly reducing the incidence of brown rot compared to control, both under artificial and natural infection, from 43 to 100%. Copyright © 2007 Society of Chemical Industry     

Physico-chemical properties,composition and pollen spectrum of french lavender (Lavandula stoechas L.) honey produced in Spain

The palynological and physico-chemical properties of 26 samples of French lavender (Lavandula stoechas) honey commercially produced in Spain have been defined. Each sample was examined to determine the total pollen content, percentage ofL. stoechas pollen and pollen spectrum. On the basis of the honey pollen analysis, 14 samples were excluded as they were of different botanical origin (Echium spp.). In total 67 different pollen types were identified. The sugar spectrum showed low percentages of trisaccharides and sucrose. The enzymatic activity was lower than that found in other unifloral Spanish honeys. A minimum of 10%L. stoechas pollen and maximum of 30%Echium sp. pollen are the suggested requirements to characterize this honey.     

Effect of heavy metals and water content on the strength of magnesium phosphate cements

In this paper the mechanical properties of magnesium potassium phosphate cements used for the Stabilization/Solidification (S/S) of galvanic wastes were investigated. Surrogate wastes (metal nitrate dissolutions) were employed containing Cd, Cr(III), Cu, Ni, Pb or Zn at a concentration of 25 g dm⁻³ and different water-to-solid (W/S) ratios (0.3, 0.4, 0.5 and 0.6 dm³ kg⁻¹) have been employed. Cements were prepared by mixing hard burned magnesia of about 70% purity with potassium dihydrogen phosphate. Compressive strength and tensile strength of specimens were determined. In addition the volume of permeable voids was measured. It was found that when comparing pastes that the volume of permeable voids increases and mechanical strength decreases with the increase of water-to-solid ratio (W/S). Nevertheless pastes with the same material proportions containing different metals show different mechanical strength values. The hydration products were analyzed by XRD. With the increase of water content not previously reported hydration compound was detected: bobierrite.     

Anionic copolymerization of diglycidyl ether of bisphenol A with Meldrum's acid derivatives initiated by 4‐(N,N‐dimethylamino) pyridine

The anionic copolymerization of diglycidyl ether of bisphenol A with 2,2,5,5‐tetramethyl‐4,6‐dioxo‐1,3‐dioxane or 6,6‐dimethyl‐(4,8‐dioxaspiro[2.5]octane‐5,7‐dione) with 4‐(N,N‐dimethylamino) pyridine as an initiator to form thermosets was studied with differential scanning calorimetry, and the kinetics were evaluated with isoconversional procedures. The evolution during the curing process of the epoxide, lactone, and linear ester bands was evaluated with Fourier transform infrared spectroscopy in the attenuated total reflection mode to clarify the reactions taking place. The shrinkage during curing, thermomechanical properties, and thermal degradability of the materials obtained by copolymerization with the different derivatives of Meldrum's acid were evaluated and related to the chemical structure of the final network. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Sustainability based on LCM of residential dwellings: A case study in Catalonia,Spain

Life cycle management (LCM) can be applied to the whole construction process, thus making it possible to improve sustainability indicators and also minimize the environmental loads of the full building life cycle. To illustrate this, a case study has been carried out based on the application of the LCM approach to a typical Spanish Mediterranean house located in Barcelona with a total area of 160 m² and a projected 50-year life span, which has been modeled according to the Spanish building technical code (CTE). The aim of this research is to use sustainability indicators in the pre-construction and operation (use and maintenance) phases and also to promote and support the adoption of the LCM within the construction industry. This paper concludes that regarding the significant environmental issue of climate change, there was a total emission of 2.34E03 kg CO₂-Eq/m² per 50 years, of which about 90.5% was during the operation phase (use 88.9% and maintenance 1.7%) and the pre-construction phase account for a total of 9.5%. In terms of this dwelling's environmental loads, the operation phase is the most critical because of the high environmental loads from energy consumption for heating, ventilation and air conditioning (HVAC), lighting, electrical appliances and cooking.