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This article belongs to the Special Issue Antioxidant and Biological Properties of Plant Extracts., Helicobacter pylori (H. pylori) is a pathogenic bacteria identified as a potential risk factor for gastritis, gastric ulcers and gastric cancer. During the stomach colonization, H. pylori triggers a strong inflammatory response and subsequent oxidative stress, which are associated with tissue damage. For this reason, it is of particular interest to develop alternative natural tools that enable modulation of the associated damaging immune response. With this purpose, we obtained grape seed extract (GSE) from sweet (not fermented) food grade seeds. The aim of our study was to investigate the effect of GSE and its two enriched procyanidins fractions (OPC and PPC) on the inflammatory process and oxidative stress produced by different H. pylori strains in human gastric epithelial cells (AGS). Anti-inflammatory activity was evaluated by measuring the level of interleukin-8 (IL-8) secretion. IL-8 production was significantly reduced in H. pylori-infected human gastric epithelial cells pre-treated with GSE or its enriched fractions when compared with non-pre-treated infected cells (from 21.6% to 87.8%). Pre-treatment with GSE or its fractions significantly decreased intracellular reactive oxygen species (ROS) production in AGS cells after infection, depending on the H. pylori strain. Our results also showed that GSE and its fractions demonstrate antibacterial activity against all strains of H. pylori used in the study. This work demonstrates the effectiveness of GSE enriched in procyanidins against the main events associated with H. pylori infection., This research was funded by AGL2017-89566-R project from the Consejo Superior de Investigaciones Científicas (Spain).

H. pylori is one of the major human pathogens infecting approximately 50% of the world's population. Its treatment is based on the combined use of different antibiotics. In recent years, the number of antibiotic resistant strains have been increased. Therefore, new alternative therapies are required for H. pylori treatment. The aim of the present work was to evaluate the antibacterial, anti-inflammatory and antioxidant effect of olive leaf extracts against antibiotics resistant H. pylori strains. Two olive leaf extracts were used: E1, enriched in hydroxytyrosol (10%); and E2, enriched in oleuropein (20%). E1 extract showed a bactericidal effect for all evaluated H. pylori strains (7/7), while the E2 extract was bactericidal for three of the studied strains (3/7) and caused a decrease of around 1 log in colony forming units (CFU) for the rest of the strains. About antioxidant activity, both extracts reduced up to 33% the production of intracellular reactive oxygen species in human gastric AGS cells infected by H. pylori, being the antioxidant activity of the E2 extract higher than E1. Finally, E1 and E2 extracts showed anti-inflammatory activity, reducing IL-8 pro-inflammatory factor secretion by infected-AGS cells in a range of 20-74% and 71-93%, respectively. Therefore, the olive leaf extracts could be consider as a potential new candidate for H. pylori treatment, providing an alternative for the 20% of infected people with symptoms for whom antibiotic treatments are not effective. Furthermore, the recycling of olive industry by-products could also contribute to its revalorization, reducing also the environmental impact.

This article belongs to the Special Issue Integrated Membrane Systems and Processes., The effectiveness of a preparative integrated ultrafiltration/solid-phase extraction (UF/SPE) process for purification of oligomeric procyanidins (OPCs) from a crude grape seed extract (GSE) was studied for the first time. The separation of OPCs from polymeric procyanidins (PPCs) by UF was very efficient. The membrane showed an acceptable filtration flux of 6 to 3.5 L/h·m2 at 0.5 bar of transmembrane pressure and 95% recovery of its water flux after chemical cleaning. The process was scalable to a pilot scale. The separation of very polar and ionic species from OPCs by SPE (XAD7HP and XAD16 resins) was also very good, but both adsorbents lost their retention capacities quickly, due probably to irreversible retention of OPCs/PPCs. Even though the global purification of OPCs by the integrated UF/SPE process allowed the recovery of 24.2 g of highly purified OPCs (83% purity) from 14.4 L of crude grape seed extract, the use of these adsorbents for further purification of the OPCs was very limited., This research was funded by MINECO (Spain), Project HELIFOOD (AGL2017-89566-R).

This article belongs to the Special Issue Natural Alternatives against Bacterial Foodborne Pathogen., In recent years, increased resistance to antibiotics and disinfectants from foodborne bacterial pathogens has become a relevant consumer health issue and a growing concern for food safety authorities [...]

This article belongs to the Special Issue Natural Alternatives against Bacterial Foodborne Pathogens., The consumption of plums in a fresh form is seasonal, therefore the transformation of plum juice extracts into powdered form is a good alternative for its longer availability throughout the year. The drying process can moderate the physical and chemical properties of the plum extracts, thus, this study examined the changes in biological activity, i.e., antibacterial, antioxidant, and anti-inflammatory properties moderated by freeze, vacuum, and spray drying. It was suggested that the drying processes and the applied parameters might moderate the content of polyphenolic compounds in the powders, which influence the different levels of growth inhibition against the foodborne pathogens (17% to 58% of inhibition), demonstrating a strain-dependent effect. These powders could also induce cellular protection against oxidative stress by preventing intracellular reactive oxygen species (ROS) accumulation (23% to 37% of reduction), but the level of antioxidant capacity may be determined by the conditions applied during the drying process. Moreover, plum extract powders exhibited a greater anti-inflammatory capacity (24% to 39% of inhibition), which would be influenced both, by the type of treatment used and by the temperature used in each treatment. The results demonstrate that the selection of the drying method can be an effective tool for modulating the composition, physical, and bioactive properties of plum extracts powders., This research was funded by AGL2017-89566-R project from the Consejo Superior de Investigaciones Científicas (Spain).

Phenolics and secoiridoids from crude olive mill wastewater (OMW) were purified using a preparative hybrid separation process: pressure-driven cross-flow membrane micro-(MF) and ultrafiltration (UF) and solid phase extraction (SPE). Five fractions with different contents of these compounds were obtained and their antibacterial activity against several strains of Campylobacter was evaluated. The results showed that the fraction with the highest content of phenolic and secoiridoid compounds had a relevant antibacterial activity against all tested strains with a strain-dependent character. Pre-treatment of LPS-stimulated cells with this fraction decreased the production of nitric oxide (NO), showing its potential as anti-inflammatory agent. Finally, the effect of the same fraction on the viability of human intestinal epithelial cell lines was evaluated. In conclusion, OMW could be useful as a potential source of bioactive compounds against Campylobacter, increasing the valorisation of olive oil by-products., This work was founded through Project AGL2013-47694-R from the Consejo Superior de Investigaciones Científicas (Spain).

This review describes the role of different food by-products as alternative tool to the use of antibiotics and disinfectants in the control of Campylobacter, the main bacterial foodborne pathogen associated to human gastroenteritis. These by-products are a source of bioactive compounds potentially applicable at all stages of the food chain where Campylobacter is present. Therefore, the use of industrial food by-products in the mitigation of Campylobacter contamination may contribute to its revalorization and the sustainability of different production processes, which is a cause of global concern nowadays.

Strains of Helicobacter pylori (H. pylori) resistant to various antibiotics have increased in recent years. In this context, the search for new therapeutic approaches is crucial. The aim of the present study was to demonstrate the antibacterial activity of a procyanidin-rich extract obtained from food-grade winery grape seeds against 14 H. pylori strains and elucidate its phenolic composition. Ten strains (71.4%) showed resistance to at least some of the tested antibiotics, while four isolates (28.6%) were susceptible to all antibiotics. Resistance to more than one class of antibiotics was observed in six strains (42.9%). The extract was able to inhibit the growth of all H. pylori strains in a range of a minimum inhibitory concentration (MIC) from 0.015 mg/mL to 0.125 mg/mL, confirming also the existence of a strain-dependent effect. The phenolic composition determined by reverse phase high pressure liquid chromatography, photodiode array, and mass spectrometry detection (RP-HPLC-PAD-MS) analysis revealed the presence of 43 individual compounds and allowed the quantification of 41 of them, including seven procyanidin tetramers, seven procyanidin pentamers, and six galloylated procyanidin dimers, trimers, and tetramers. The extract was composed mainly by catechin and procyanidin oligomers with a total amount of 5801 mg/100 g, which represent 92% of the total individual phenolic content. Among them, the most abundant were catechins (2047 mg/100 g), followed by procyanidin dimers (1550 mg/100 g), trimers (1176 mg/100 g), tetramers (436 mg/100 g), and pentamers (296 mg/100 g) that represent 35, 27, 20, 8, and 5%, respectively of the total flavanol constituents. The composition profile information may help to improve the production process of useful antibacterial extracts against H. pylori., This research was funded by MINECO (Spain), Project HELIFOOD (AGL2017-89566-R). Alba Gutiérrez and Silvia Moreno thank to Consejería de Educación e Investigación from the Madrid’s Community for the financial support of contracts PEJ-2018-AI/BIO-11720 and PEJD-2018-POST/BIO-8797, respectively.

Campylobacter is the leading cause of bacterial diarrheal disease worldwide. Although most episodes of campylobacteriosis are self-limiting, antibiotic treatment is usually needed in patients with serious enteritis, and especially in childrens or the elderly. In the last years, antibiotic resistance in Campylobacter has become a major public health concern and a great interest exists in developing new antimicrobial strategies for reducing the impact of this food-borne pathogen on human health. Among them, the use of silver nanoparticles as antibacterial agents has taken on increased importance in the field of medicine. The aim of the present study was to evaluate the antimicrobial effectiveness of glutathione-stabilized silver nanoparticles (GSH-Ag NPs) against multidrug resistant (MDR) Campylobacter strains isolated from the chicken food chain (FC) and clinical patients (C). The results obtained showed that GSH-Ag NPs were highly effective against all MDR Campylobacter strains tested. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were in a range from 4.92 to 39.4 μg/mL and 9.85 to 39.4 μg/mL, respectively. Cytotoxicity assays were also assessed using human intestinal HT-29, Caco-2, and CCD-18 epithelial cells. Exposure of GSH-Ag NPs to intestinal cells showed a dose-dependent cytotoxic effect in all cell lines between 9.85 and 39.4 μg/mL. More than 60% of the tested Campylobacter strains were susceptible to GSH-Ag NPs concentrations ≤ 9.85 μg/mL, suggesting that practical inhibitory levels could be reached at low GSH-Ag NPs concentrations. Further works are needed with the purpose to evaluate the practical implications of the toxicity studies and to know more about other attributes linked to the biological compatibility. This behavior makes GSH-Ag NPs as a promising tool for the design of novel antibacterial agents for controlling Campylobacter., This work was founded through Project AGL2013-47694-R and AGL2015-64522-C2-R from the Consejo Superior de Investigaciones Científicas (Spain).

This work was funded through Projects Bodega Terras Gauda LTD-Xunta de Galicia (PGIDIT04TAL035E), 2004-7-OE-242, AGL2006-02558, and A36108900.

The main aim of this study was to investigate the effect of Grape seed extract (GSE) on Campylobacter induced-cytokine production by human intestinal cell lines. With this purpose, Caco-2 and HT-29 cells were challenged with culture supernatants from several strains of C. jejuni and levels of secreted IL-6, IL-8, and MCP-1 were measured. Cytokine production was higher in HT-29 than in Caco-2 cells, showing different levels of secretion depending of the epithelial cells origin. Also, infective isolates coming from campylobacteriosis patients rendered higher levels of pro-inflammatory cytokines. Co-treatment and pre-treatment of HT-29 cells with GSE and C. jejuni significantly reduced cytokines production in a dose-dependent manner. These results make this natural product a putative nutritional tool for use in the treatment of campylobacteriosis, which could contribute to improve disease prevention or reduce disease severity., This work was founded through Projects AGL [2009-07894 and AGL 2013-47694-R] from the Consejo Superior de Investigaciones Científicas, and CSD2007-00063FUN-C-FOOD [CONSOLIDER INGENIO 2010]. J. M. Silvan wishes to thank Ministry of Science and Innovation and CSIC, for a JAE post-doctoral contract [JAEDoc_2010_087].

In this study, a recombinant Saccharomyces cerevisiae strain EKD13 overproducing mannoproteins has been used to obtain Albariño white wines. The inoculated strain prevailed and produced complete fermentation of the must, as also occurred in the case of spontaneous (non-inoculated) fermentation and in the must inoculated with the S. cerevisiae EC1118 strain. The analytical study of the wines obtained showed that the most important chemical differences among the wines produced with EKD-13, corresponded to the high concentration of mannoproteins, 2-phenyl ethanol and tyrosol. These differences were attributed to the expression, during must fermentation, of genes modified in the recombinant EKD-13 strain. The results obtained imply that this strain could be potentially useful to produce wines rich in mannoproteins that have distinctive characteristics compared to other similar wines, modifying the sensorial and technological parameters of the wines obtained. © 2013 Elsevier Ltd. All rights reserved., This work was funded through Projects Bodega Terras Gauda LTD. Xunta de Galicia (PGIDIT04TAL035E), 2004-7-OE-242, AGL2006-02558, A36108900, ALIBIRD-CM-S-0505/AGR-0153, and CONSOLIDER INGENIO 2010 (CSD2007-00063FUN-C-FOOD).

In this work, a grape phenolic extract obtained by methanol extraction has been demonstrated to be effective in inhibiting the growth of different strains and species of Campylobacter, one of the most important bacterial foodborne pathogens causing gastroenteritis worldwide. Noteworthily, it was particularly effective against several strains presenting multiple antibiotic resistances. In all cases, the minimum inhibitory concentration (MIC) was lower than 300 mg GAE/L, being of 60 mg GAE/L for one of the most resistant strains (C. coli LP2), while the others were between 120 mg GAE/L and 180 mg GAE/L. The analytical study of the main phenolic compounds in the grape extract revealed that it was mainly constituted by catechins (85.7%) and phenolic acids (13.7%). However, experiments developed using pure standards demonstrate that phenolic acids (such as gallic, p-hidroxibenzoic, vanillic, and homovanillic acids) were the most active, provoking a Campylobacter growth decrease between 6.7 and 7.6 log, while epicatechin was the only catechin with activity as pure compound (1 log of growth decrease).

[Aim]: This study was aimed to investigate the influence of malolactic fermentation (MLF) on sensory profile and organoleptic characteristics of Albariño and Caiño white wines. [Methods and Results]: Autochthonous bacteria were isolated from wines after alcoholic fermentation (AF) and further identified as Pediococcus damnosus by 16S rRNA gene sequence analysis. When a commercial Oenococcus oeni starter was inoculated into Albariño and Caiño white wines to perform MLF, which was checked by HPLC quantification of malic and lactic acids, it was shown that autochthonous Ped. damnosus strains were able to predominate over the commercial O. oeni starter and perform MLF in Caiño wine. By contrast, neither commercial strain nor indigenous Pediococcus carried out MLF in Albariño wine. However, MLF was achieved when autochthonous strains that predominated in Caiño were inoculated into Albariño. Sensory analysis showed that after the MLF Albariño increased its body and softness, while Caiño result a more mature wine. [Conclusions]: MLF can positively affect Albariño and Caiño wines giving them new attributes. Pediococci isolated and characterized in this work can successfully perform MLF without negative effects on the wine, because no production of biogenic amines or exopolysaccharides by the selected pediococcus strains was detected. [Significance and Impact of the Study]: The effect of MLF in the sensory profile of Albariño and Caiño wines has never been studied before. Results obtained in this work showed that Ped. damnosus strains can be considered as a new topic of investigation on malolactic starter. © 2013 The Society for Applied Microbiology., Funded by: Bodega Terras Gauda LTD; Xunta de Galicia. Grant Numbers: PGIDIT04TAL035E, 2004-7-OE-242, AGL2006-02558, A36108900, ALIBIRD-CM-S-0505/AGR-0153; CONSOLIDER INGENIO 2010. Grant Number: CSD2007-00063FUN-C-FOOD and BIODATI. Grant Number: DM 16101/7301/08.

In this study, the antibacterial activity of a grape seed extract (GSE) was examined against different Campylobacter strains. Growth inhibition was in the range from 5.08 to 6.97 log CFU/ml, demonstrating the strong capacity of the GSE to inhibit Campylobacter growth. Further dilution of the extract showed a minimal inhibitory concentration (MIC) of 20 mg/l and a minimal bactericidal concentration (MBC) of 60 mg/l against Campylobacter jejuni. GSE was fractioned by RP-HPLC and phenolic composition was determined by HPLC-DAD and HPLC-MS. The phenolic profile of GSE mainly consisted on flavonols, phenolic acids, catechins and proanthocyanidins, and anthocyanins. Among them, catechins and proanthocyanidins were the major compounds, representing 77.6% of total phenolic compounds determined. The analysis of the antibacterial activity against C. jejuni of the collected fractions showed that phenolic acids, catechins and proanthocyanidins were the main responsible of the behavior observed. These results showed that identification and quantification of the individual phenolic compounds of GSE could be feasible to standardize the production process to obtain an enriched extract potentially useful to control Campylobacter in the food chain. © 2012 Elsevier Ltd., This work was founded through Projects AGL 2009-07894 from the CSIC, ALIBIRD-CM-P 2009/AGR-1469 (Comunidad de Madrid) and CSD2007-00063FUN-C-FOOD (CONSOLIDER INGENIO 2010).

The feasibility of winemaking waste (WW) as source of active phenolic compounds against Campylobacter was evaluated using a mixture of ethanol-water (50% v/v) as extraction solvent. The winemaking waste extract (WWE) was active against all the strains tested, and most of them were inhibited at WWE concentrations between 40 and 100 mg GAE/L. However, different lactic acid bacteria (LAB) strains were practically unaffected by WWE, suggesting a selective antibacterial effect of WWE against Campylobacter. The fractioning and phenolic characterization of WWE using HPLC-MS showed that catechins and proanthocyanidins were the main compounds involved in the antibacterial effect. Among them, the structural verification using pure phenolic standards showed that epicatechin gallate and resveratrol were the most active compounds against Campylobacter. We conclude that the study of the main mechanisms involved in the antibacterial activity against Campylobacter of epicatechin gallate, resveratrol, and other related compounds presenting gallate side-chain, can contribute for future design of useful antibacterials against this pathogen., This work was founded through Projects AGL 2009-07894 and AGL 2013-47694-R from the CSIC, and CSD2007-00063FUN-C-FOOD (CONSOLIDER INGENIO 2010).

In the present work, 3 different yeast strains (1, 2, and 3) were used to elaborate white wines using Albariño must. The concentration of polymeric mannose was determined using a method based on the mannoprotein precipitation, hydrolysis and analysis of sylylated mannose derivatives by gas chromatography. Wines elaborated with the strain 1 (W1) presented a higher mannoprotein concentration than the other wines. The analysis of the volatile composition of wines showed significant differences (P < 0.05) among them, being W1 which presented the highest concentration of aroma compounds, mainly terpens and norisoprenoids. The sensorial analysis of wines also showed that W1 had the best quality. The results obtained from this work demonstrate that mannoproteins could be involved in the behavior observed. Some evidences were obtained using a model wine, where 2 major terpens in W1 were preferentially retained by the colloids rich in mannoproteins released by strain 1. Practical Application: White wines elaborated with yeast strains overproducing mannoproteins could have better quality than others. Mannoproteins could contribute to aroma enhancement of Albariño white wines. © 2012 Institute of Food Technologists ®., This work was funded through Projects Bodega Terras Gauda LTD. Xunta de Galicia (PGIDIT04TAL035E), 2004–7-OE-242, AGL2006–02558, A36108900, ALIBIRD-CM-S- 0505/AGR-0153, and CONSOLIDER INGENIO 2010 (CSD2007–00063FUN-C-FOOD)., S0505/AGR-0153/ALIBIRD

This work was partially funded through the project AGL 2009-07894 from the CSIC. Dr Ganan is the recipient of a postdoctoral contract from the Campus de Excelencia, Universidad Complutense de Madrid.

et al., Chitosan has several biological properties useful for the food industry, but the most attractive is its potential use as a food preservative of natural origin due to its antimicrobial activityagainst a wide range of food-borne microorganisms. Among food-borne pathogens, Campylobacterjejuni and related species are recognised as the most common causes of bacterial food-borne diarrhoeal disease throughout the world. Recently, it has been demonstrated that campylobacters are highly sensitive to chitosan. Even though chitosan is known to have important functional activities, poor solubility makes them difficult to use in food and biomedical applications. Unlike chitosan, the low viscosity and good solubility of chitosan oligosaccharides (COS) make them especially attractive in an important number of useful applications. In the present work, the effect of different COS on C. jejuni was investigated. Variables such as the physicochemical characteristics of chitosan and the enzyme used in COS preparation were studied. The COS had been fractioned using ultrafiltration membranes and each fraction was characterized regarding its FA and molecular weight distribution. It has been demonstrated that the biological properties of COS on Campylobacter depend on the composition of the fraction analysed. COS prepared by enzymatic hydrolysis with chitosanase were more active againstCampylobacter that lysozyme-derived COS, and this behaviour seems to be related with the acetylation of the chains. On the other hand, the 10–30 kDa fraction was the most active COS fraction, independently of the enzyme used for the hydrolysis. These results have shown that COS could be useful as antimicrobial in the control of C. jejuni., This work was partially funded through Projects MAT2007- 63753 of the Spanish Ministry of Education and CCG07-CSIC/AGR- 2255 and AGL2009-07894 of the CSIC. BM thanks the Deutscher Akademischer Austauschdienst (DAAD) for a research scholarship at the University of Potsdam.

The ability of pectic oligosaccharides (POS) to inhibit adherence to and invasion of undifferentiated (UC) and differentiated (DC) Caco-2 cells by Campylobacter jejuni (C. jejuni) was investigated. It was observed that both adherence and invasion were significantly higher in UC than in DC. POS (2.5 mg/ml) had no significant effect on the number of bacteria which can adhere to cells, but they significantly inhibited cell invasion. The extent of the anti-invasive effect of POS was dependent on the concentration, although the entire range tested (from 2.5 mg/ml to 0.05 mg/ml) was capable of inhibiting the invasion of Caco-2 cells by Campylobacter to some degree. The pre-incubation or not of C jejuni with POS did not influence the behaviour observed. The results obtained in this work suggest that POS could be potentially useful as alternatives to antibiotics in the control of C. jejuni. © 2009 Elsevier B.V. All rights reserved.

Campylobacter jejuni is a food pathogen which causes gastrointestinal conditions with an ever-increasing incidence at a global level. The antimicrobial power of wine and its components has been studied. Wines having 11.5% ethanol significantly reduced the viability of C. jejuni when they were diluted to 25% in water. The microbicidal power of red wine was higher than that of white wine. While pH does not seem to affect the viability of this pathogen, different phenolic compounds have an effect on it when tested at concentrations from 0 to 1000 mg/L. Gallic acid and p-hydroxybenzoic acid reduced the viability of C. jejuni at concentrations as low as 1 mg/L, but quercetin and catechin did not even affect it at concentrations of 1000 mg/L. Methyl gallate, epicatechin, synaptic acid, vanillic acid, and caffeic acid were microbicidal at concentrations starting at 10 mg/L. Tryptophol, ferulic acid, and cumaric acid were effective starting at 100 mg/L. According to this, wine constitutes an adverse environment for the survival of this pathogen. Furthermore, it would be interesting to study the possible use of phenolic compounds in wine as an alternative to the use of antimicrobial growth promoters against these bacteria in broilers.

Sparkling wines produced by the traditional method owe their peculiar characteristics to a double process of fermentation and to the ageing with yeast that takes place in the same bottle that reaches the consumer. Special winemaking practices result in wines with distinct and unique characteristics, in which their study from a scientific, technological and economical point of view are very interesting. Over recent years, considerable progress has been made in understanding the biochemistry behind their production technology and their relationship with sensory characteristics. New scientific approaches based on modifications of yeast responsible for the second fermentation are being introduced, showing the interest for improvements in this traditional winemaking technology. The aim of this paper is to provide in a single review, an overall view of the current situation of knowledge of the chemical and biochemical aspects involved in this particular winemaking technology giving reference to interesting advances as well as future trends.

In this work, an effort is made to elucidate the main hazard of microbial origin in winemaking, the presence of ochratoxin A (OTA), which has not yet been considered from an HACCP (Hazard Analysis and Critical Control Points) point of view, and for which a limit of

The influence of some variables on the manufacturing process for sparkling and red wines on the angiotensin I-converting enzyme inhibitory (ACEI) activity has been studied. Ageing on lees significantly influenced the angiotensin I-converting enzyme inhibitor activity in sparkling wines. It reached maximum values at 9 months, decreasing afterwards. In red wines, the ACEI activity also increased in the wines aged on lees. In both wines, hydrophobic peptides were responsible for the ACEI activity. These peptides would make a much greater contribution to the total activity if present in higher proportions. It would therefore be advantageous to increase their concentrations in wines, either by using starting materials with high initial peptide contents or by using a highly autolytic yeast, giving a greater degree of hydrolysis of wine proteins, and higher concentrations of peptides with ACEI activity.

Lactic acid bacteria are important in enology since they undergo the malolactic fermentation, a process which main effect is the reduction of wine acidity and is almost indispensable in red wine-making. However, if this process is not well controlled during the elaboration of wine, alterations in wine quality due to bacteria metabolic activity can happen. Polyphenols are wine natural components in must and wine that can potentially affect the growth of lactic acid bacteria and the malolactic fermentation. In this paper, after describing the main features of the malolactic fermentation in wine, we review the use of different chemical substances to control growth of lactic acid bacteria in enology. Special attention is given to phenolic compounds, being revised the recent studies about the effect of polyphenols on the growth and metabolism of lactic acid bacteria in wine in order to establish the extent to which these compounds are involved in malolactic fermentation during wine-making. Finally, the potential use of phenolic extracts as new antimicrobial agents during wine-making, as a total or partial alternative to traditional treatments mainly using sulphur dioxide (SO 2 ) is discussed.

The ACE inhibitory activity (IACE) and the oxygen radical absorbance capacity (ORAC-FL) values of yeast peptides isolated from a model wine during accelerated autolysis of Saccharomyces cerevisiae have been studied. Samples were taken at 6, 24, 48, 121, and 144 h of autolysis. Peptide concentration increased throughout autolysis process. Peptides were fractionated into 2 fractions: F1, constituted by hydrophilic peptides, and F2, containing hydrophobic peptides. Both IACE activity and ORAC-FL values increased during 121 h of autolysis, then decreased afterward. Peptide fraction F2 was the main fraction involved in IACE activity and ORAC-FL.

Reaction mixtures containing β-lactoglobulin and chitosan (1:4 weight ratio) were dry-heated at 40 °C and 79% relative humidity for 2 weeks. Absorbance measurements and SDS-PAGE analysis indicated the occurrence of the Maillard reaction and conjugate formation, respectively. Some β-lactoglobulin and chitosan properties were modified. For example, the emulsifying capacity at pH 4 and bactericidal activity against Escherichia coli of the Maillard reaction products (MRPs) increased with incubation period up to 2 days, after which these properties deteriorated. The latter was explained by MRPs degradation, which was confirmed by the increased appearance of degradation products in electrophoresis gels at longer incubation times. Data show that the Maillard reaction, under the studied conditions, can be successfully employed to generate MRPs from β-lactoglobulin and chitosan, which exhibit improved properties with respect to β–lactoglobulin alone.

The potential of several alternative genetic engineering based strategies in order to accelerate Saccharomyces cerevisiae autolysis for wine production has been studied. Both constitutively autophagic and defective in autophagy strains have been studied. Although both alternatives lead to impaired survival under starvation conditions, only constitutively autophagic strains, carrying a multicopy plasmid with the csc1-1 allele under the control of the TDH3 promoter, undergo accelerated autolysis in the experimental conditions tested. Fermentation performance is impaired in the autolytic strains, but industrial strains carrying the above-mentioned construction are still able to complete second fermentation of a model base wine. We suggest the construction of industrial yeasts showing a constitutive autophagic phenotype as a way to obtain second fermentation yeast strains undergoing accelerated autolysis.

The sensory and analytical characteristics of five rose sparkling wines manufactured by the traditional method have been determined. Moreover, the changes that take place in the nitrogen and volatile fraction of the wines during the second fermentation and the aging with the yeasts have been studied. Each of these wines was made from a single industrial rose base wine of the Garnacha Tinta variety, with five selected yeasts strains. The base wine had a low content in free amino acids, 16 mg/L, and the yeast consumed more peptides than free amino acids during second fermentation. From the application of the two-way analysis of variance, yeast strain, and aging time factors to the data of volatile compounds, it has been found that most of the differences between these sparkling wines are due to the aging time. It has been verified that these rose sparkling wines have foam of good quality and that the grape variety Garnacha Tinta is suitable for the production of rose sparkling wines.

During the stationary phase of Campylobacter jejuni NCTC 11351 viable numbers fluctuate in a characteristic fashion. After reaching the maximum cell count (ca. 2 x 10(9) CFU/ml) in early stationary phase (denoted phase 1), viable numbers subsequently decrease to about 10(6) CFU/ml after 48 h and then increase again to about 10(8) CFU/ml (denoted phase 2) before decreasing once more to a value intermediate between the previous maximum and minimum values. To investigate whether the increase in viable numbers following the initial decline was due to the emergence of a new strain with a growth advantage in stationary phase analogous to the 'GASP' phenotype described in Escherichia coli [Science 259 (1993) 1757], we conducted mixed culture experiments with cells from the original culture and antibiotic-resistant marked organisms isolated from the re-growth phase. In many experiments of this type, strains isolated from phase 2 failed to out-compete the original strain and we have thus been unable to demonstrate a convincing GASP phenotype. However, strains isolated from phase 2 showed a much lower rate of viability loss in early stationary phase and a small increase in resistance to aeration, peroxide challenge and heat, indicating that the emergent strain was different from the parent. These results support the view that dynamic population changes occur during the stationary phase of C. jejuni that may play a role in the survival of this organism.

When Campylobacter jejuni cultures that had been grown in broth at 39°C were subcultured into fresh medium at 30°C, there was a transient period of growth followed by a decline in viable-cell numbers before growth resumed once more. We propose that this complex behavior is the net effect of the growth of inoculum cells followed by a loss of viability due to oxidative stress and the subsequent emergence of a spontaneously arising mutant population that takes over the culture.

A selection method, based on a temperature-sensitive autolytic phenotype, has been used to genetically improve a second fermentation Saccharomyces cerevisiae yeast strain by UV mutagenesis. The mutations carried by the resulting strains affected cell morphology, growth kinetics, sporulation and the release of nitrogenous compounds in an accelerated autolysis experimental model. Their fermentation power was not severely impaired., This work was supported by the Spanish Ministerio de Ciencia y Tecnologı́a (AGL2000-1569 and ALI99-1224

When producing sparkling wines by the traditional method, a small amount of bentonite is added to the tirage solution to help with the flocculation of the yeast. This work studies the effect of this addition on the nitrogen composition and sensory quality of the sparkling wines. Two batches of sparkling wines were industrially produced, one with addition of bentonite to the tirage solution and the other without bentonite addition. Samples were taken at 20, 40, 90, 180, 270 and 365 days of aging with yeast. Total, free amino-, protein- and peptide-nitrogen concentrations were determined and foam properties and sensory quality were evaluated. It was observed that the bentonite retained part of the peptides and proteins and had an adverse effect on the sensory quality of the wine.

The influence of five yeast strains on the nitrogen fractions, amino acids, peptides and proteins, during 12 months of aging of sparkling wines produced by the traditional or Champenoise method, was studied. High-performance liquid chromatography (HPLC) techniques were used for analysis of the amino acid and peptide fractions. Proteins plus polypeptides were determined by the colorimetric Bradford method. Four main stages were detected in the aging of wines with yeast. In the first stage, a second fermentation took place; amino acids and proteins plus polypeptides diminished, and peptides were liberated. In the second stage, there was a release of amino acids and proteins, and peptides were degraded. In the third stage, the release of proteins and peptides predominated. In the fourth stage, the amino acid concentration diminished. The yeast strain used influenced the content of free amino acids and peptides and the aging time in all the nitrogen fractions.

To detect differences among three strains of Saccharomyces cerevisiae used in the manufacture of sparkling wines and to study the changes in nitrogen compounds during autolysis, a model wine system was used. Significant differences were observed between the mean values of the autolytic capacity of the three strains. The amount of nitrogen (total, protein, peptide and amino) present in the autolysates and the concentration of most free amino acids was significantly affected by the strain. These findings suggest that the strain of yeast used in the manufacture of sparkling wines can play an important role in the aging process and can affect final composition.

This study proposes a selection methodology for secondary fermentation yeast strains for the production of sparkling wines. It began with 34 different yeast strains, mainly of the Saccharomyces cerevisiae species. The selection methodology was divided into four consecutive stages: (1) a study of the fermenting capacity of the strains under secondary fermentation conditions; (2) analysis of the most important enological characteristics of the strains; (3) a study of the autolytic capacity of the yeast; and (4) analysis of the foaming properties of the autolysates obtained. Following this methodology, three strains were selected, with which three sparkling wines were produced by the Champenoise method. Industrial sparkling wines were also produced with the commercial strain EC-1118, used as a control in this study, and with strain J, from the collection of the winery where the sparkling wines were prepared. The wines thus obtained were aged for 12 months in presence of the yeast. The findings of the sensory analysis indicated that all of the sparkling wines were good quality.

The nitrogen composition of wines aged with yeast for a long period of time, as in the case of sparkling wines, depends on the composition of the base wine and on the compounds released by the yeast. In this paper, the release of the different classes of nitrogen compounds during autolysis of one of the strains of yeast used in the manufacture of sparkling wines has been studied. The yeast, Saccharomyces bayanus, was suspended in a model wine buffer, pH 3.0 and 10% ethanol, and incubated at 30 degrees C. Samples of the autolysate were taken after 4, 24, 48, 72, 168, and 360 h of autolysis. An electrophoretic and chromatographic study was conducted of the proteins, peptides with molecular weights higher and lower than 700 Da, and amino acids released during the autolysis. Using SDS-PAGE, it was observed that it was predominantly polypeptides with molecular weights lower than 10 000 that were released. Through HPLC of the fraction lower than 10 000 Da, it was observed that it is polypeptides with molecular weights of between 10 000 and 700 Da that are released first and that these later break up to give rise to peptides with molecular weights lower than 700 Da, which in turn break down into amino acids. This indicates that the nature of the nitrogen compounds present in wines aged with yeast depends on the aging time, being less polymerized as the aging time increases.

The release of lipids during the aging of sparkling wines in contact with yeast can influence wine sensory attributes and, especially, foam characteristics. Model systems allow study of the autolysis process in a reasonable period of time compared to natural conditions, at which it can last several months. In this paper, the release of the different classes of lipids during the autolysis of three commercial yeast strains in a model wine medium has been monitored. Due to the absence of accurate quantitative methods, an HPLC method for separating and quantifying the different neutral and polar yeast lipid classes was developed. Lipids were eluted through a YMC PVA-Sil column with a complex solvent mixture. Detection was carried out with a light-scattering detector. The yeasts were suspended in the model wine buffer and incubated at 30 degrees C for up to 12 days. A release of triacylglycerols, 1,3-diacylglycerols, 2-monoacylglycerols, free fatty acids, sterol esters, and sterols was observed over the first 2 days, a period that corresponded to the maximum loss of yeast viability. A decrease in most of these lipids was observed from day 2, possibly indicative of the release of yeast hydrolytic enzymes due to the breakdown of the cell wall. Phospholipids were not detected in any of the autolysates. The mean lipid content in the autolysates as a percentage of the total lipid content in the yeasts was 8.6% for sterol esters, 3.8% for sterols, 2% for triacylglycerols, and2% for 1,3-diacylglycerols and free fatty acids.

Campylobacteriosis is considered the most frequent zoonosis in humans, and the handling and/or consumption of poultry meat is considered the main source for human infection. The reduction of the rates of infection in chickens should make an effective contribution to substantially controlling the illness in humans. However, the increase of the general concern about the spreading of antibiotic resistance in humans has determined the elimination of antibiotics as growth promoters in livestock. At this point, it is essential to search for new, natural and sustainable strategies to reduce the incidence of this bacterium in the food chain, especially in its main host. The objective of this review is to revise the different strategies, designed to reduce the presence or to eradicate Campylobacter from the human food chain. © 2011 Elsevier Ltd., This work was founded through Projects AGL 2009-07894 from the CSIC, ALIBIRD-CM-P 2009/AGR-1469 (Comunidad de Madrid) and CSD2007-00063FUN-C-FOOD (CONSOLIDER INGENIO 2010).

The use of selected yeast strains with improved or novel properties may promote wines with special and original quality attributes. In this paper, changes in the chemical composition (aroma compounds and polyphenols) and sensorial properties of Albariño white wines elaborated with the same must and selected yeast (named as 1, 2 and 3) have been studied in comparison with wines subjected to non-inoculated fermentation (control wine). The results indicated that yeast strain can significantly influence the aroma and polyphenol composition of the wines. Wines elaborated with strain 1 had a higher concentration of terpenes and norisoprenoids, which are compounds closely associated with the fruity and fresh character of Albariño white wines. These same wines had a lower concentration of flavan-3-ols, closely associated with the astringency and bitterness of the wine and the lowest browning potential. The formal sensory analysis conducted by 8 trained judges showed that wines elaborated with strain 1 were preferred by the tasting panel. Therefore, the selection of yeast strains could offer the possibility to modulate sensorial attributes related with the aroma and phenol composition in Albariño white wines. © 2011 Elsevier Ltd., This work was funded through Projects Bodega Terras Gauda LTD. Xunta de Galicia (PGIDIT04TAL035E), 2004-7-OE-242, AGL2006- 02558, A36108900, ALIBIRD-CM-S-0505/AGR-0153, and CONSOLIDER INGENIO 2010 (CSD2007-00063FUN-C-FOOD)., S0505/AGR-0153/ALIBIRD

Publisher Summary The hazard analysis and critical control point (HACCP) system, which emerged in the 1970s as a systematic way of ensuring food hygiene and protecting consumer health, is based on controlling microorganisms that constitute a hazard for consumers. This chapter focuses on the application of HACCP system to Ochratoxin A (OTA) in wine. Although the HACCP system was conceived to improve and ensure hygiene and sanitation in both the agricultural and food processing sectors, it has mainly been applied in the latter. One of the reasons is that, whereas a processing facility like a winery might have just one owner, the vineyards supplying the winery may have many owners. Hence, fully preventing or eliminating a food hazard or reducing it to an acceptable level is generally more difficult in the primary processing of plant-based foods. It is also more difficult to control parameters outdoors than in indoor production facilities. Nonetheless, since the application of the HACCP system to OTA in wine is closely associated with the grape growing phase, to all effects and purposes, this phase is considered to be an integral part of the winemaking process. Indeed, in the case of mycotoxins such as OTA, it is crucial to implement production controls aimed at protecting grape berries from fungal infection in the vineyards.

Publisher Summary Traditional-method sparkling wines, which are made using particular varieties of grape, contain carbon dioxide gas as a natural consequence of the process used in their production. This gas is a byproduct of the secondary fermentation of natural or added sugars in the base wine. The fermentation takes place in closed vessels and the resulting wine has a minimum pressure of 4 atm at 20oC. Depending on the winemaking method used, sparkling wines are classified as tank-fermented wines or bottle-fermented wines. In the tank-fermented method, secondary fermentation takes place under isobaric conditions in a sealed tank with a capacity of tens of hectoliters. These tanks are equipped with stirring mechanisms that mix the yeast uniformly into the base wine. In the transfer method, the sparkling wine is produced in bottles, which are generally magnums measuring 1.5 or 2 L to minimize storage space requirements. It is then left to age on lees for at least 2 months, after which it is transferred to a tank maintained under isobaric conditions with carbon dioxide or nitrogen to prevent loss of the gas. The wine is then cold processed at –5oC, filtered, and sometimes transferred to a second tank.

5 páginas, 3 figuras, 2 tablas., The effect of growth phase on the adherence to and invasion of Caco-2 epithelial cells by five strains of Campylobacter was studied. No significant differences were observed between the behaviors in the exponential or stationary phases for the most stationary-phase tolerant strains (C. jejuni 118 and C. coli LP2), while the strains that produced a greater reduction in the viability in the stationary phase (C. jejuni 11351, C. jejuni 11168 and C. jejuni LP1), also presented reduced adherence to and invasion of Caco-2 cells. In order to find a possible explanation for the observed differences, the presence of putative virulence factors was studied in the analyzed strains. In spite of the fact that C. jejuni 118 and C. jejuni 11168 strains showed a different adherence to and invasion of Caco-2 cells behavior, they posses identical alleles for ciaB, cadF, and pldA loci. From the virulence factors analyzed, only the flaA locus was different among both strains., This work was funded through Projects CCG07-CSIC/AGR-2255 and AGL 2009-07894 from the CSIC and 25506 FUN C FOOD (CONSOLIDER-INGENIO 281 2010).

The main objective of the present work was to study the influence of yeast-derived mannoproteins on the adherence to and invasion of Caco-2 cells by Campylobacter jejuni. Mannoprotein fractions were prepared by enzymatic and thermal extraction methods. The method used to prepare the mannoprotein extracts influenced their composition and determined the efficacy of the extract against C. jejuni adherence and/or invasion. The availability of mannose in the mannoprotein fraction seemed to be important for inhibiting effective adherence and invasion of Caco-2-cells by C. jejuni, although protein moieties also played a role in the process. The study of the mechanisms involved in the inhibition of C. jejuni adherence and invasion by mannoproteins may have further implications in the control of this foodborne pathogen. Copyright ©, International Association for Food Protection., This work was founded through projects MERG-CT-2004-513472 from the European Union and AGL2004-06933-C02-01 and CCG07- SIC/AGR-2255 from the Consejo Superior de Investigaciones Científicas (CSIC). M.