Traditional packaging concepts are reaching their limits in enhancing food safety, quality and shelf life. Active, antimicrobial sachets containing different concentrations of oregano essential oil (OEO) were developed, and their antimicrobial efficiency was evaluated on agar medium -against Escherichia coli, Salmonella Enteritidis and Penicillium sp. -and on sliced bread -against yeasts and molds. Residual OEO on treated bread was quantified by gas chromatography-mass spectrometry. Bread slices were also evaluated as to texture and sensory properties. Sachets containing OEO showed in vitro antimicrobial effect against the tested microorganisms, as well as reduced the growth rates of yeasts and molds on sliced bread. Compared with untreated samples, γ-terpinene and ρ-cymene contents on treated bread increased throughout storage, whereas their acceptance was reduced. Our findings indicate the potential application of antimicrobial sachets as an antimicrobial packaging system for sliced bread preservation.

Fluoride toothpastes containing trimetaphosphate possess good anticaries potential required to reduce the prevalence of dental caries in high-risk patients.

Objective: To evaluate the remineralizing potential of a conventional toothpaste (1,100 ppm F) supplemented with nano-sized sodium hexametaphosphate (HMPnano) in artificial caries lesions in situ. Design: This double-blinded crossed study was performed in 4 phases of 3 days each. Twelve subjects used palatal appliances containing 4 bovine enamel blocks with artificial caries lesions. Volunteers were randomly assigned into the following treatment groups: no F/HMP/HMPnano (Placebo); 1,100 ppm F (1100F); 1100F plus 0.5% micrometric HMP (1100F/HMP) and 1100F plus 0.5% nano-sized HMP (1100F/HMPnano). Volunteers were instructed to brush their natural teeth with the palatal appliances in the mouth for 1 min (3 times/day), so that blocks were treated with natural slurries of toothpastes. After each phase, surface hardness post-remineralization (SH2), integrated recovery of subsurface hardness (ΔIHR), integrated mineral recovery (ΔIMR) and enamel F concentration were determined. Data were submitted to analysis of variance and Student-Newman-Keuls’ test (p < 0.001). Results: Enamel surface became 42% harder when treated with 1100F/HMPnano in comparison with 1100F (p < 0.001). Treatment with 1100F/HMP and 1100F/HMPnano promoted an increase of ∼23 and ∼87%, respectively, in ΔIHR when compared to 1100F (p < 0.001). In addition, ΔIMR for the 1100F/HMPnano was ∼75 and ∼33% higher when compared to 1100F and 1100F/HMP respectively (p < 0.001). Enamel F uptake was similar among all groups except for the placebo (p < 0.001). Conclusion: The addition of 0.5% HMPnano to a conventional fluoride toothpaste was able to promote an additional remineralizing effect of artificial caries lesions.

The recombinant xylanases showed potential for application in bakery processing and can improve techno-functional properties in sponges. © 2018 Society of Chemical Industry.

Endo-β-1,4-xylanases (EC 3.2.1.8) are able to hydrolyse xylan, the second most abundant polysaccharide in plant cell walls. In this work, two recombinant xylanases derived from Orpinomyces xynA gene were studied: one with mutations A226T and V135A (XM) and the other without mutations (XNM). They have been cloned in E. coli/pET24b, using IPTG as inducer and purified using ion exchange chromatography (Q-Sepharose). After purification, only one band of 25 kDa, corresponding to xylanases, was visualized on SDS-PAGE. Specific activities and Km against arabinoxylan were 12.844 U.mg -1 and 0.0021 mg.mL -1 for XNM and 10.794 U.mg -1 and 0.0014 mg.mL -1 for XM. The mutations improve thermo stability. The half-life of XNM was 220 min and 31 min at 50 °C and 60 °C, while for XM the values were 440 and 71 min at 50 o C and 60 o C, respectively. The clarification assays were conducted at 60 o C, 100 rpm for 60 min, using 50U xylanase/mL apple juice. The parameters available was pH, A660 (clarity), L* (luminosity), C (chroma) and h* (hue). All the juices tended to orange while only enzymatically treated with XM had an increase in color intensity (chroma / C) and higher content of soluble solids (sst) of 4,7 o brix. The results indicate that the processing of apple juice with xylanases can promote clarification and improvement of its properties.

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