The aim of this study was to evaluate the effect of γ-radiations on the heat shock proteins (Hsps) content of strains of Enterobacteriacea and Pantoea agglomerans. Radiation treatments (1 and 3.5 kGy) were performed to highlight the radiotolerance. Total proteins were extracted after irradiation treatments and heat shock proteins (Hsp) of interest (GroEL, GroES and DnaK) were visualized and quantified using Western blot analysis. It was found that GroEL synthesis was increased significantly (P ≤ 0.05) for both strains while the DnaK seemed to be down regulated for the strain from ATCC 49174. Basal level of GroEL proteins was much higher in the strain isolated from carrots. The obtained results indicated the modification effects of γradiations on the Hsps at cellular level.

Cancer chemopreventive properties were evaluated in HPLC fractions of different polarity obtained from two cranberry juices and three extracts isolated from frozen cranberries and pomace containing anthocyanins, water-soluble and apolar phenolic compounds, respectively. Compounds with close polarities were collected in order to obtain between three and four fractions from each juice or extract. Cranberry fractions were screened for their ability to induce the phase II xenobiotic detoxification enzyme quinone reductase (QR). The results showed that there was no cytotoxicity against the cells used in the test. All samples stimulated the quinone reductase activity except the highest concentrations of the less polar fraction of anthocyanin-rich extract from pomace, which inhibited the QR activity. The QR induction for all samples varied with the concentration and there was an optimal concentration for which the QR induction was maximal. The technological process to manufacture cranberry juice had little influence on the overall QR inducer potencies of cranberry fractions, whereas the ability of phenols in fractions to stimulate the QR activity has been reduced significantly (P≤0.05) during the technological process. Among all samples, phenolic compounds of eight fractions presented a maximum QR induction greater than 100 II(QR)/mg phenol. The phenolic compounds of the most polar fraction (rich in phenolic acids) and those of the less polar fraction (rich in proanthocyanidins) showed stronger induction than those observed with phenols from intermediate fractions.

The effects of the industrial juice process on the antioxidant capacities of cranberry samples and of three phenolic extracts (polar phenolics (E1), apolar phenolics (E2) and anthocyanins (E3)) adjusted at pH 2.5 and 7.0 were investigated. The free radical-scavenging (FRS) and the lipid peroxidation inhibition (LPI) activities of each sample and extract, were studied using a N,N-diethyl-p-phenylenediamine discoloration test and the thiobarbituric acid reactive substances assay, respectively. The FRS and the LPI results, expressed in mM Trolox® equivalent (TE)/mg phenol and mg TE/mL/mg phenol, respectively, showed a negative effect of the juice process steps on E1. The E2 and E3 extracts were also affected by the process but not as much. The milling step increased the FRS capacity of E2 and E3 extracts, but decreased their LPI capacity. The evaporation of the juice did not have a significant effect on the FRS capacity, but lowered the LPI capacity. Before and after each step of the juice process, the FRS capacity of the cranberry extracts was greater than the LPI capacity. The results were consistent in classifying the FRS capacity of the extracts in the following order of polarity: E1>E3>E2; and their total phenolic (TP) content in the following order: E3>E2>E1. In general, the neutralization of the pH of the extracts did not significantly influence the changes observed during the juice process in the FRS and LPI capacity, except for E3 for which a decrease in the LPI capacity was observed.

The antimicrobial effect of cranberry juice and of three cranberry extracts (water-soluble (El) and apolar phenolic compounds (E2), and anthocyanins (E3)) was investigated against seven bacterial strains (Enterococcus faecium resistant to vancomycin (ERV), Escherichia coli O157:H7 EDL 933, Escherichia coli ATCC 25922, Listeria monocytogenes HPB 2812, Pseudomonas aeruginosa ATCC 15442, Salmonella Typhimurium SL1344, and Staphylococcus aureus ATCC 29213). Each cranberry sample was analyzed to determine the minimum inhibitory concentration (MIC) and the maximal tolerated concentration (MTC) at neutral pH. The results, reported in mu g phenol/mL, indicated that all the bacterial strains, both Gram-positive and Gram-negative, were selectively inhibited by the cranberry phenolic compounds. The extract rich in water-soluble phenolic compounds caused the most important growth inhibitions. The bacteria ERV, and to a lesser degree, P. aeruginosa, S. aureus and E. coli ATCC 25922, were the most sensitive to the antimicrobial activity of extract El. The growth of P. aeruginosa and E. coli ATCC was also affected by the presence of the anthocyanin-rich cranberry extract E3, although the observed antibacterial effect was not as important as with extract El. In general, L. monocytogenes, E. coli O157:H7 and S. Typhimurium were the most resistant to the antibacterial activity of the cranberry extracts. Within 30 min of exposure with pure neutralized cranberry juice, L monocytogenes and ERV were completely inactivated. (C) 2011 Elsevier Ltd. All rights reserved.

The antioxidant capacities of cranberry juice and three extracts isolated from frozen cranberries containing anthocyanins, water-soluble and apolar phenolic compounds, were evaluated at pH 2.5 and 7, respectively. The free radical-scavenging (FRS) and the lipid peroxidation inhibition (LPI) activities of each samples, and extracts, were studied using the N,N-diethyl-p-phenylenediamine (DPD) decoloration test and the thiobarbituric acid reactive substances (TBARS) assay, respectively. The cranberry phenols displayed good free radical-scavenging properties, but were less efficient at inhibiting the peroxidation of lipids. Of all the samples tested, the water-soluble phenolic compounds showed the greatest free radical-scavenging (68.2mmol TE/mg phenol) and antioxidant (13.4mmol TE phenol) activities. The polarity of the phenols, the pH of the medium and the juice process had a great influence on the antioxidant activities. The phenols isolated from cranberries with an aqueous solvent have greater antioxidant properties than those extracted with an organic solvent mixture. The antioxidant activity of the cranberry samples adjusted at pH 2.5 was greater than those adjusted at pH 7. Compared to the cranberry extracts, the juice exhibited a much lower antioxidant activity, especially when compared with the extract containing water-soluble compounds which the extraction conditions were similar to those used to obtain the juice.

Cancer chemopreventive properties were evaluated in cranberries and cranberry products (mash, depectinized mash, pomace, raw juice, clarified juice and juice concentrate). Three extracts isolated from frozen cranberries and cranberry solids (mash, depectinized mash and pomace) containing anthocyanins, water-soluble and apolar phenolic compounds were tested. Cranberry juices and extracts were screened for their ability to induce the phase II xenobiotic detoxification enzyme quinone reductase (QR). The results showed that there was no cytotoxicity against the cells used in the test. All samples stimulated quinone reductase activity except the highest concentrations of the anthocyanin-rich extract of pomace, which inhibited QR activity. Also, the results showed that the QR induction for all samples varied with concentration and that there was an optimal concentration for which the QR induction was maximal. Although the three cranberry extracts were good QR inducers, our results indicated that the phenols present in aqueous extract showed QR inductions which were more important than those obtained with phenols present in solvent extracts. Also, the ability of phenols to stimulate the QR activity has been reduced continuously and significantly (P≤0.05) during the technological process. Especially, it appears that conditions of the evaporation to obtain a juice concentrate exerted a significant effect (P≤0.05) on inducer potencies of bioactive molecules.

The effects of the industrial juice process on the ability of neutralized cranberry samples and extracts (polar, apolar and anthocyanins) to inhibit the growth of Enterococcus faecium resistant to vancomycin (ERV), Escherichia coli O157:H7 EDL 933, E. coli ATCC 25922, Listeria monocytogenes HPB2812, Pseudomonas aeruginosa ATCC 15442, Salmonella Typhimurium SL1344 and Staphylococcus aureus ATCC 29213 were investigated. The juice process appeared to have a general enhancing effect on the antibacterial properties of cranberry polar and anthocyanin extracts. The lowest minimum inhibitory concentrations (MICs) (1.80–7.0μg phenol/well) were obtained when S. aureus, S. Typhimurium, and ERV were exposed to the juice concentrate. The growth of P. aeruginosa, L. monocytogenes, E. coli ATCC, and E. coli O157:H7 was not inhibited by the juice concentrate, but did show sensitivity (maximal tolerated concentrations of 0.007–0.4μg phenol/well). The lowest MICs (22.6–90.5μg phenol/well) for P. aeruginosa, S. aureus, S. Typhimurium, and ERV were observed when they were exposed to the cranberry anthocyanin extract obtained from cranberry pomace. The results also showed a negative effect of the juice process on the antibacterial properties of the cranberry apolar extracts: the one obtained from frozen cranberries was most efficient against P. aeruginosa, S. aureus, L. monocytogenes and S. Typhimirium (MIC of 45.50μg phenol/well). The tested bacteria showed the greatest resistance toward the cranberry extracts obtained from the mash and the macerated and depectinized mash.

There is a growing public interest for the North American cranberry (Vaccinium macrocarpon) as a functional food because of the potential health benefits linked to phytochemical compounds present in the fruit--the anthocyanin pigments, responsible for its brilliant red color, and other secondary plant metabolites (flavonols, flavan-3-ols, proanthocyanidins, and phenolic acid derivatives). Isolation of these phenolic compounds and flavonoids from a sample matrix is a prerequisite to any comprehensive analysis scheme. By far the most widely employed analytical technique for the characterization of these compounds has been high-performance liquid chromatography(HPLC) coupled with ultraviolet-visible(UV/Vis) and mass spectrometer(MS) detection. This review covers the cranberry major bioactive compounds, the extraction and purification methods, and the analytical conditions for HPLC used to characterize them. Extraction, chromatographic separation and detection strategies, analyte determinations, and applications in HPLC are discussed and the information regarding methods of specific cranberry analyte analyses has been summarized in tabular form to provide a means of rapid access to information pertinent to the reader.

Cranberries are healthy fruit that contribute color, flavor, nutritional value, and functionality. They are one of only three fruits native to America. Over the past decade, public interest for the North American cranberry (Vaccinium macrocarpon) has been rising with reports of their potential health benefits linked to the numerous phytochemicals present in the fruitthe anthocyanins, the flavonols, the flavan-3-ols, the proanthocyanidins, and the phenolic acid derivatives. The presence of these phytochemicals appears to be responsible for the cranberry property of preventing many diseases and infections, including cardiovascular diseases, various cancers, and infections involving the urinary tract, dental health, and Helicobacter pylori-induced stomach ulcers and cancers. Recent years have seen important breakthroughs in our understanding of the mechanisms through which these compounds exert their beneficial biological effects, yet these remain to be scientifically substantiated. In this paper these characteristics, as well as the antioxidant, radical scavenging, antibacterial, antimutagen, and anticarcinogen properties of cranberry major bioactive compounds are explained.

Cranberries are healthy fruit that contribute color, flavor, nutritional value, and functionality. They are one of only three fruits native to America. Over the past decade, public interest for the North American cranberry (Vaccinium macrocarpon) has been rising with reports of their potential health benefits linked to the numerous phytochemicals present in the fruit—the anthocyanins, the flavonols, the flavan-3-ols, the proanthocyanidins, and the phenolic acid derivatives. The presence of these phytochemicals appears to be responsible for the cranberry property of preventing many diseases and infections, including cardiovascular diseases, various cancers, and infections involving the urinary tract, dental health, and Helicobacter pylori-induced stomach ulcers and cancers. Recent years have seen important breakthroughs in our understanding of the mechanisms through which these compounds exert their beneficial biological effects, yet these remain to be scientifically substantiated. In this paper these characteristics, as well as the antioxidant, radical scavenging, antibacterial, antimutagen, and anticarcinogen properties of cranberry major bioactive compounds are explained.

Spice extracts under the form of essential oils (Eos) were tested for their efficiency to increase the relative bacterial radiosensitivity (RBR) of Listeria monocytogenes, Escherichia coli and Salmonella typhi in culture media under different atmospheric conditions. The selected Eos were tested for their ability to reduce the dose necessary to eliminate E. coli and S. typhi in medium fat ground beef (23% fat) and Listeria in ready-to-eat carrots when packed under air or under atmosphere rich in oxygen (MAP). Results have demonstrated that depending of the compound added and the combined treatment used, the RBR increased from 2 to 4 times. In order to evaluate the industrial feasibility, EOs were added in ground beef at a concentration which does not affect the taste and treated at a dose of 1.5 kGy. The content of total mesophilic aerobic, E. coli, Salmonella, total coliform, lactic acid bacteria, and Pseudomonas was determined during 28 days. The results showed that the combined treatment (radiation and EOs) can eliminate Salmonella and E. coli when done under air. When done under MAP, Pseudomonas could be eliminated and a shelf life of more than 28 days was observed. An active edible coating containing EOs was also developed and sprayed on ready-to-eat carrots before radiation treatment and Listeria was evaluated. A complete inhibition of Listeria was obtained at a dose of 0.5 kGy when applied under MAP. Our results have shown that the combination of an edible coating, MAP, and radiation can be used to maintain the safety of meat and vegetables.

The aim of this study was to evaluate the effect of gamma-irradiation on the fatty acids (FA) and muropeptides content of two strains of an Enterobacteriacea: Pantoea agglomerans.Pantoea agglomerans strains ATCC 49174 and RL1 isolated from irradiated carrots were used for this study. Radiation treatments (1 and 3.5 kGy) were performed to study the radiotolerance. Total lipids were obtained by multiple extractions using methanol/chloroform (2 : 1) and were quantified by GC. Muropeptides were purified by successive enzymatic digestions and analysed using a reverse phase C-18 column in high performance liquid chromatography. A significant (P <= 0.05) modification of the bacterial wall was noticed for the membrane FA composition and the muropeptides.Effects of irradiation on the bacterial membrane are noticeable and could play an important role on the cellular response and ability to survive this harsh environment.To our knowledge, it is the first study to demonstrate the effects of ionizing irradiation on the modification of the FA and one of the few to confirm its effects on the muropeptides of the peptidoglycan.

AIMS:The effects of gamma radiation on three heat shock proteins (Hsps) (GroEL, DnaK and GroES) synthesis in two Gram-negative (Escherichia coli and Salmonella serotype Typhimurium) and two Gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria were investigated.METHODS AND RESULTS:The bacterial strains were treated with three radiation doses to induce cell damage, to obtain a viable but nonculturable state, and to cause cell death. Western blot analysis and quantification of Hsps in bacteria were performed immediately after irradiation treatment. In the four foodborne pathogens, GroEL was strongly induced by gamma rays in a dose-dependent manner, confirming the involvement of this protein in the cellular response to the stress generated by ionizing radiation. In addition, it was found that E. coli exposed to gamma radiation showed a significantly induction of DnaK and GroES proteins when compared with nonirradiated bacteria, whereas a GroES slight induction and a DnaK inhibition were observed in Salm. Typhimurium.CONCLUSIONS:The gamma rays influence the synthesis of Hsps in foodborne pathogen in a way that critically depends on the radiation dose.SIGNIFICANCE AND IMPACT OF THE STUDY:The study of stress response to several radiation doses was undertaken to elucidate how bacteria can survive in harsh conditions and cope with gamma radiation used to control foodborne pathogens and to characterize their adaptative response to this treatment.

Aim:  The aim of this study was to evaluate the effect of γ radiation on the carotenoid content of two strains of the Enterobacteriaceae: Pantoea agglomerans.

Aims: To evaluate the efficacy of a biodegradable silage coating for the ability to protect timothy (Phleum pratensa) type silage against spoilage and its quality under natural conditions.Methods and Results: Triplicate mini-silos of silage were prepared for three treatments (1: uncoated; 2: coated with biodegradable coating and 3: sealed with plastic), two types of storage (unprotected or protected from rain) and 10 sampling times (0, 7, 14, 21, 28, 35, 42, 56, 63 and 70 days postensiling). Triplicate mini-silos were opened at each sampling time for microbiological (total aerobic bacteria, lactic acid bacteria, moulds and yeasts) and biochemical analyses [pH, dry matter (DM), water-soluble sugars (WSC), lactic (LA), acetic, propionic and butyric acids content]. The study showed that at day 70, counts of moulds and yeasts in silages protected against rain and coated with biodegradable coating were 5-98 log CFU g(-1) when compared with 5-92 and 3-62 log CFU g-1 in samples from plastic-sealed silage and uncoated silage, respectively. The pH was low and stable pH (4-34) when compared with uncoated (7.17) and plastic sealed (8-34) silages (P <= 0.05). A DM, WSC and LA content of 421.7, 13.4 and 20.9 g kg(-1) was, respectively, observed. For silage stored outdoors, a level of moulds and yeasts of 3.77 log CFU g(-1) of silage was also observed in silages coated with biodegradable coating after 28 days of storage. A stable pH showing a mean value of 4 was also observed. The pH, DM, WSC and LA content were, respectively, 4.18, 341.1, 13.34 and 31.8 g kg(-1) in these samples. After 70 days of storage, the level of moulds and yeasts on silage sealed with biodegradable coating was 7-73 log CFU g(-1). A DM, WSC and LA content of 291.9, 5.56 and 10.0 g kg-(1) was, respectively, observed.Conclusions: When compared with uncoated silage, the application of biodegradable coating can preserve the quality of silage for up to a month when exposed to rain and up to 70 days when protected from rain.Significance and Impact of the Study: Results emphasize the possibility of the use of a biodegradable coating as an alternative to plastic film for sealing horizontal bunker silos.

The mechanism of the antimicrobial action of Spanish oregano (Corydothymus capitatus), Chinese cinnamon (Cinnamomum cassia), and savory (Satureja montana) essential oils against cell membranes and walls of bacteria was studied by the measurement of the intracellular pH and ATP concentration, the release of cell constituents, and the electronic microscopy observations of the cells when these essential oils at their MICs were in contact with Escherichia coli O157:H7 and Listeria monocytogenes. E. coli O157:H7 and L. monocytogenes, two pathogenic foodborne bacteria, were used as gram-negative and gram-positive bacterial models, respectively. Treatment with these essential oils at their MICs affected the membrane integrity of bacteria and induced depletion of the intracellular ATP concentration. Spanish oregano and savory essential oils, however, induced more depletion than Chinese cinnamon oil. An increase of the extracellular ATP concentration was observed only when Spanish oregano and savory oils were in contact with E. coli O157:H7 and L. monocytogenes. Also, a significantly higher (P < or = 0.05) cell constituent release was observed in the supernatant when E. coli O157:H7 and L. monocytogenes cells were treated with Chinese cinnamon and Spanish oregano oils. Chinese cinnamon oil was more effective to reduce significantly the intracellular pH of E. coli O157:H7, whereas Chinese cinnamon and Spanish oregano decreased more significantly the intracellular pH of L. monocytogenes. Electronic microscopy observations revealed that the cell membrane of both treated bacteria was significantly damaged. These results suggest that the cytoplasmic membrane is involved in the toxic action of essential oils.

Three commercial extracts of grape phenols (seeds, skin, whole) were used in this study. Each extract was divided by HPLC into five fractions of different polarities, and their free radical-scavenging activities were measured using the DPD (N,N-diethyl-p-phenylenediamine) colorimetric method. Total phenol contents were determined using the Folin-Ciocalteu method to assess their contribution to the antiradical activity. The results showed that there was good correlation between total phenolic compound contents and free radical-scavenging activities of the different grape extracts. Moreover, the seed extract presented the most important free radical-scavenging properties (138USP/mg extract), whereas the whole extract presented the lowest free radical-scavenging capacity (80.5USP/mg extract). However, the free radical-scavenging properties, reported on the basis of content of phenolic compounds in each extract, showed that the free radical-scavenging activities of seed and whole extracts were not significantly different (171 versus 162USP/mg phenol). In addition, free radical-scavenging activities of fractions from seed and skin extracts decreased as their polarities decreased.

The inhibitory effect of 60 different essential oils was evaluated on a Pseudomonas putida strain of meat origin, associated with meat spoilage. Essential oils were tested at concentrations from 0.003 to 0.8% (wt/vol) to determine minimum inhibitory and maximal tolerated concentrations (MIC and MTC, respectively) using an agar medium culture. Of the 60 samples tested, Corydothymus capitatus essential oil was the most active showing a MIC of 0.025% and a MTC of 0.06%. Seven essential oils (Cinnamomum cassia, Origanum compactum, Origanum heracleoticum, Satureja hortensis, Satureja montana, Thymus vulgaris carvacroliferum, Thymus vulgaris thymoliferum) have shown a strong antimicrobial activity against P. putida with a MIC of 0.05% and a MTC ranging from 0.013% to 0.025%. Ten other oils (Cinnamomum verum (leaf and bark), Eugenia caryophyllus, Cymbopogon martinii var. motia, Cymbopogon nardus, Melaleuca linariifolia, Origanum majorana, Pimenta dioica, Thymus satureoides, Thymus serpyllum) showed a high antimicrobial activity showing a MIC ranging from 0.1% to 0.4%, while the remaining were less active showing a MIC ⩾ 0.8%.

Radiosensitization of Listeria monocytogenes was determined in the presence of trans-cinnamaldehyde, Spanish oregano, winter savory, and Chinese cinnamon on peeled minicarrots packed under air or under a modified atmosphere (60% O2, 30% CO2, and 10% N2). Samples were inoculated with L. monocytogenes HPB 2812 serovar 1/2a (106 CFU/g) and were coated separately with each active compound (0.5%, wt/wt) before being packaged under air or the modified atmosphere and irradiated at doses from 0.07 to 2.4 kGy. Results indicated that the bacterium was more resistant to irradiation under air in the absence of active compound. The dose required to reduce L. monocytogenes population by 1 log CFU (D10) was 0.36 kGy for samples packed under air and 0.17 kGy for those packed under the modified atmosphere. The active compounds evaluated in this study had an effect on the radiation sensitivity of L. monocytogenes on carrots. The most efficient compound was trans-cinnamaldehyde, where a mean 3.8-fold increase in relative radiation sensitivity was observed for both atmospheres compared with the control. The addition of winter savory and Chinese cinnamon produced a similar increase in relative radiation sensitivity but only when samples where packed under modified atmosphere conditions.