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Little information is available regarding the incorporation of dietary fiber into edible films and coatings. In this work, apple fiber and inulin were incorporated into polysaccharide-based (alginate, pectine and gellan gum) edible coating formulations and their effects on the quality attributes of fresh-cut apples were evaluated. Antioxidant properties, color, firmness, sensory quality and microbial growth of fresh-cut apple were studied during 16 days of storage at 4°C. Results show that dietary fiber extracts incorporated to gellan gum, pectin and alginate-based coatings together with calcium chloride and ascorbic acid successfully maintained the firmness and color of coated fresh-cut apples in comparison with uncoated control samples, which presented severe texture softening and browning. T h e f i r m n e s s o f a p p l e p i e c e s c o a t e d w i t h polysaccharide-based coating formulations incorporating apple fiber doubled, and sometimes tripled, that of uncoated samples. Any of the assayed coatings exhibited a positive effect on the sensory properties of fresh-cut apples. The incorporation of apple fiber, together with the use of ascorbic acid, contributed to keep the antioxidant potential of the fruit at least during the first week of storage. Furthermore, gellan gum coatings had a marked effect in reducing mesophilic and psychrophilic counts on fresh-cut apples throughout storage regardless the addition of dietary fibers. The results achieved demonstrate the feasibility of the addition of dietary fiber to edible coating formulations for increasing the nutritional value of fresh-cut apples without compromising their fresh-like quality attributes.

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Quorum sensing (QS) is a bacterial communication mechanism that depends on population density. QS inhibitory activity of four bioactive agents and two essential oils was evaluated using the bacteria model Chromobacterium violaceum. On the other hand, antimicrobial activity was tested using two foodborne pathogens, Listeria monocytogenes and Escherichia coli. Agents were able to inhibit the violacein production, being tea tree and rosemary more effective than propolis and pollen, and resveratrol more effective than pomegranate. Tea tree and rosemary essential oils, applied at 0.5 mL/mL, reduced violacein production by more than 80%. In order to evaluate whether the inhibition of violacein production owed to the microbial growth reduction or acylated homoserine lactone inhibition, the antimicrobial activity was analyzed using C. violaceum as indicator. None of the tested agents showed antimicrobial activity at the minimal QS inhibitory concentration. Agents showed varying degrees of antibacterial activity against pathogens. Tea tree and rosemary resulted more effective than the others. These essential oils showed bacteriostatic effect on pathogen counts at low concentrations (0.5-1 mL/ mL). When they were applied at concentrations higher than 2 mL/mL, bactericidal effect was observed against E. coli and L. monocytogenes. These findings strongly suggest that these agents have potential to be good preservatives because of anti-QS capacity and antimicrobial properties. PRACTICAL APPLICATIONSFood spoilage is a complex process, and excessive amounts of foods are lost due to microbial spoilage even with modern day preservation techniques. Another problem related to public health is the contamination of foods with human pathogen microorganisms. Quorum sensing (QS) is a cell-to-cell communication mechanism by which bacterial population measures its cell density. Because many important animal and plant pathogens use QS to regulate virulence, the interruption of bacteria QS have broad applicability for biological control of diseasecausing organisms. It is considered a good strategy to reduce or prevent spoilage reaction in foods. In this work, we investigated antimicrobial activity against foodborne pathogens and anti-QS activity (using Chromobacterium violaceum) of some bioactive extracts and essential oils. The results obtained from this study indicate that agents tested could potentially be used as natural preservatives to prolong shelf life and ensure safety of foods. bs_bs_banner Journal of Food Safety

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The effectiveness of essential oil application in foods is the result of factor associations such as composition and storage temperatures. The aim was to evaluate the effectiveness of clove and tea tree essential oils to control Escherichia coli O157:H7 on blanched spinach and minced cooked beef exposed at 8 and 20C For both essential oils, the highest concentrations (three and four times minimal inhibitory concentrations) were needed to restrict O157:H7 populations in blanched spinach and minced cooked beef, respectively. The antimicrobial action of these essential oils was dependent on the oil concentration, the food composition and the storage temperature. The inhibition of pathogen and native microorganisms was more important at high temperatures than at low temperatures. Preliminary findings in actual foods suggest that clove and tea tree oils could be used as potential biopreservatives capable of controlling foodborne pathogens when foods are exposed to abusive temperatures.

19Pulsed light (PL) has received considerable attention during the last years as a non-20 thermal method for the superficial decontamination of fresh foods. The aim of the 21 present study was to evaluate the quality attributes of fresh-cut 'Golden Delicious' 22 apples as affected by the combined application of a pulsed light treatment (12 J/ cm 2 ) 23 and a gellan-gum based (0.5% w/v) edible coating enriched with apple fiber. Changes 24 in color, firmness, antioxidant capacity, microbial growth and sensory attributes were 25 determined during 14 days of storage at 4 °C. The combined application of coating 26 and PL treatment retarded the microbiological deterioration of fresh-cut apples and 27 maintained the sensory attribute scores above the rejection limits after prolonged 28 storage. Incorporation of fiber in the coating formulation did not curb the sensory 29 acceptability of apple cubes. Results show that the use of a gellan-gum based coating 30 incorporating apple fiber followed by the application of a PL treatment significantly 31 reduced softening and browning of apple pieces through storage. 32Our results reveal that PL treatments applied to gellan-coated fresh-cut apples can be 33 used to decontaminate the cut fruit surface without dramatically affecting its fresh-34 like quality attributes, thus conferring prebiotic potential and contributing to their 35 shelf-life extension.36 37