Investigation of Bioactive Complexes of Chitosan and Green Coffee Bean or Artichoke Extracts

The formation of water-insoluble complexes between chitosan (ChS) and caffeoylquinic acid (CQ) derivatives present in artichoke (AE) and green coffee bean (GCBE) extracts was investigated by the equilibrium adsorption method. The UPLC/HPLC analysis revealed that the phenolic compounds accounted for 8.1% and 74.6% of AE and GCBE respectively, and CQ derivatives were the predominant compounds. According to the applied Langmuir adsorption model, anionic compounds present in natural extracts were adsorbed onto the active centers of ChS, i.e., primary amino groups. The driving forces of adsorption were electrostatic interactions between cationic groups of ChS and anionic compounds of natural extracts. Chromatographic analysis revealed that not only CQ derivatives, but also other phenolic compounds of natural extracts were attached to ChS. The release of adsorbed compounds into different media as well as the bioactive properties of complexes were also studied. With the immobilization of bioactives onto ChS, increased and prolonged ABTS^•+ radical scavenging activity and decreased antifungal activity against Fusarium graminearum and Botrytis cinerea were observed compared to those of ChS. The findings of the current study highlight that the adsorption approach could be used to successfully prepare water-insoluble complexes of ChS and components of natural extracts with prolonged antioxidant activity.

Synthesis of N-alkyl-beta-D-glucosylamines and their antimicrobial activity against Fusarium proliferatum, Salmonella typhimurium, and Listeria innocua

In this study, different N-alkyl-beta-D-glucosylamines were evaluated for both antifungal and antibacterial activity against Fusarium proliferatum (INRA, MUCL 1807.7), Listeria innocua (ISTAB, Université Bordeaux 1), and Salmonella typhimurium (Institut Pasteur 5858). The tested glucosylamines were beta-D-glucosylamine (GPA), N-ethyl-beta-D-glucosylamine (EtGPA), N-butyl-beta-D-glucosylamine (BuGPA), N-hexyl-beta-D-glucosylamine (HeGPA), N-octyl-beta-D-glucosylamine (OcGPA), N-dodecyl-beta-D-glucosylamine (DoGPA), N-(2-hydroxyethyl)-beta-D-glucosylamine (HEtGPA), N,N-di(2-hydroxyethyl)-beta-D-glucosylamine (DHEtGPA) and N,N-diethyl-beta-D-glucosylamine (DEtGPA). The effectiveness of N-alkyl length, N-substitution, and N-hydroxyalkyl groups on both antibacterial and antifungal activity were evaluated. Results indicated that these compounds exhibited different biological activities and their effectiveness was highly increased from short to long N-alkyl chains. DoGPA exhibited more potent biological activity against all target strains than other N-alkyl glucosylamines tested. Using a radial growth method, we demonstrated that this compound completely inhibited fungal growth at 0.5 x 10(-4) mol mL(-1), while OcGPA and HeGPA lead to 71% and 43% fungal inhibition, respectively. Using the coating method, we demonstrated that DoGPA completely inhibited bacterial growth at 0.025 x 10(-4) and 0.05 x 10(-4) mol mL(-1) for L. innocua and S. typhimurium, respectively, while at the same concentrations, OcGPA exhibited weaker antibacterial activity of 12% and 27%, respectively, for L. innocua and S. typhimurium. The hole plate method enabled us to estimate the minimum inhibitory concentration (MIC) of DoGPA found to be 0.02 x 10(-4) and 0.025 x 10(-4) mol mL(-1) for L. innocua and S. typhimurium, respectively. Glucosylamines with N-hydroxyalkyl and short N-alkyl chains varying from C-2 to C-4 exhibited weaker antimicrobial activity.

Water and moisture susceptibility of chitosan and paper-based materials: structure-property relationships

Environmentally friendly and potentially bioactive food packaging based on chitosan-coated papers were elaborated. The morphology and the microstructure of these new materials were characterized by infrared spectroscopy and scanning electron microscopy. These observations suggested that the chitosan penetrated deeply into the paper, embedding the cellulose fibers, instead of forming a layer as expected. Through the barrier properties against moisture, the liquid water sensitivity, and NMR-relaxometry measurements, the water interactions were evaluated on the chitosan films and the chitosan-coated papers. They revealed that the coating by a chitosan film forming solution improved the paper moisture barrier properties but the surface hydrophilicity remained high. Relaxometry studies showed that, due to its hydrophilic character, chitosan controlled the interaction with water, despite the very low amount of deposit. On the other hand, the mechanical properties of papers were unmodified by the chitosan coating, which did not fundamentally affect the solid structure of the papers.

Effects of ultraviolet light (315 nm), temperature and relative humidity on the degradation of polylactic acid plastic films

The influence of temperature (30, 45 and 60 degrees C) and relative humidity (RH) (30%, 50% and 100%) on the degradation of poly(l-lactic acid) (PLA) films were studied. In addition, the effects of ultraviolet (UV) light (315 nm) on the degradation of PLA films were also analyzed. Various analytical techniques were applied to observe changes in the properties of PLA polymer films. FTIR spectroscopy was used as semi-quantitative method to get information about the chemistry of the degradative process. The degradation rate of PLA was enhanced by increasing temperature and RH, factors responsible for a faster reduction of the weight-average molecular weight (M(W)), of the glass transition temperature (Tg) and of the percentage of elongation at break. Moreover, UV treatment accelerated these phenomena.

Antimicrobial edible packaging based on cellulosic ethers, fatty acids, and nisin incorporation to inhibit Listeria innocua and Staphylococcus aureus

Edible cellulosic films made with hydroxypropylmethylcellulose (HPMC) have proven to be inadequate moisture barriers. To improve its water vapor barrier properties, different hydrophobic compounds were incorporated into the HPMC matrix. Some fatty acids and derivatives were included into the film-forming solution prior to film formation. Stearic acid was chosen because of its high capacity to reduce significantly the water vapor transmission rate. Antimicrobial activity of edible HPMC film was obtained by the incorporation of nisin into the film-forming solution. Nisin is an antimicrobial peptide effective against gram-positive bacteria. The inhibitory activity of this bacteriocin was tested for inhibition of Listeria innocua and Staphylococcus aureus. The use of stearic acid was observed to reduce the inhibitory activity of active HPMC film against both selected strains. This phenomenon may be explained by electrostatic interactions between the cationic nisin and the anionic stearic acid. Further studies showed that antimicrobial activity of film varied with the nature of the hydrophobic compound incorporated, in decreasing order: film without lipid, methylstearate film, and stearic acid film. This corroborated the idea of electrostatic interactions.

[A multicenter study on the quality of use of long-term medication card]

OBJECTIVE

To evaluate and improve the use of Long-term Medication Cards (LMC) at three Primary Care Centres and to obtain information about the impact of ongoing education on quality guarantee methodology.

DESIGN

A before and after study.

SETTING

The Caldes de Montbui, Rubi-1 and Concordia (Sabadell) Primary Care Centres.

PARTICIPANTS

LMC samples from these three centres: 462 and 333 LMC for the first and second evaluations, respectively.

INTERVENTIONS

The professionals involved were fed back the results of the evaluations carried out. Modifications in the system of control and organisation of the LMC were introduced. These included keeping the information contained on the LMC in the centres and changes in their cancellation and renewal norms.

MEASUREMENTS AND MAIN RESULTS

The results showed intracenter increases on all except one of fifteen measurements, presenting the following extreme values in the two evaluations performed at the three centres: record on the LMC of the length of treatment (from 63 to 98%); non-inclusion of treatments with authorization of less than three months (58 to 100%); non-inclusion of authorization above a year (83 to 100%); recording of the guidelines (61 to 87%); non-inclusion of antibiotic treatments on the LMC (94 to 100%).

CONCLUSIONS

As for training, experience showed that its is feasible and profitable to follow up ongoing training, both to evaluate the impact of this training and to use the application of the quality guarantee cycle in the introduction and setting-up of internal QEI activities.