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The aim of this work was to determine the antimicrobial activity of the essential oils of six plants widely distributed in the Dehesa of Extremadura, such as Calendula officinalis, Cistus ladanifer, Cistus salviifolius, Cistus multiflorus, Lavandula stoechas, and Rosmarinus officinalis. The content of total phenolic compounds (TPC) and the antimicrobial activity of the essential oils against pathogenic and spoilage bacteria and yeasts as well as aflatoxin-producing molds were determined. A great variability was observed in the composition of the essential oils obtained from the six aromatic plants. The Cistus ladanifer essential oil had the highest content of total phenols (287.32 ppm), followed by the Cistus salviifolius essential oil; and the Rosmarinus officinalis essential oil showed the lowest amount of these compounds. The essential oils showed inhibitory effects on the tested bacteria and also yeasts, showing a maximum inhibition diameter of 11.50 mm for Salmonella choleraesuis and Kregervanrija fluxuum in the case of Cistus ladanifer and a maximum diameter of 9 mm for Bacillus cereus and 9.50 mm for Priceomyces carsonii in the case of Cistus salviifolius. The results stated that antibacterial and antiyeast activity is influenced by the concentration and the plant material used for essential oil preparation. In molds, aflatoxin production was inhibited by all the essential oils, especially the essential oils of Cistus ladanifer and Cistus salviifolius. Therefore, it can be concluded that the essential oils of native plants have significant antimicrobial properties against pathogenic and spoilage microorganisms, so they could be studied for their use in the industry as they are cheap, available, and non-toxic plants that favor the sustainability of the environment of the Dehesa of Extremeña.

The expression of genes associated with aflatoxin biosynthesis by different Aspergillus flavus strains growing on a cheese model system has not been studied. To control aflatoxin biosynthesis, it would be useful to understand the changes in gene expression during cheesemaking and relate those changes to toxin production. The objective of this study was to evaluate the effects of pH, water activity, and temperature on the expression of 2 regulatory genes (aflR and aflS) and 1 structural gene (aflP) involved in aflatoxin biosynthesis, using 3 aflatoxigenic A. flavus strains growing on a cheese-based medium and reverse-transcription real-time PCR. The gene expression patterns were influenced by A. flavus strain and environmental conditions. The structural gene aflP and the regulatory genes aflR and aflS showed similar expression patterns in each A. flavus strain, but we also observed inter-strain differences. We observed the highest expression levels at 6 and 9 d of incubation by A. flavus strains CQ8 and CQ103, and saw a decrease in the days following. Strain CQ7 showed the lowest expression of these genes. We observed the highest expression levels of these genes at pH 5.5, water activity 0.95, and 20 to 25°C; strain CQ103 showed a different pattern for the aflS gene, with maximum expression at pH 6.0 on d 6 of incubation. For the 3 strains, we found a strong correlation between the relative expression of the aflR and aflS genes and the concentration of aflatoxins under conditions that simulated cheese ripening. Control strategies to avoid aflatoxin contamination during cheesemaking could use the detection of regulatory gene expression.

Nowadays, there is a growing interest in the extraction and identification of new high added-value compounds from the agro-food industry that will valorize the great amount of by-products generated. Many of these bioactive compounds have shown beneficial effects for humans in terms of disease prevention, but they are also of great interest in the food industry due to their effect of extending the shelf life of foods by their well-known antioxidant and antimicrobial activity. For this reason, an additional research objective is to establish the best conditions for obtaining these compounds from complex by-product structures without altering their activity or even increasing it. This review highlights recent work on the identification and characterization of bioactive compounds from vegetable by-products, their functional activity, new methodologies for the extraction of bioactive compounds from vegetables, possibly increasing their biological activity, and the future of the global functional food and nutraceuticals market.

Most of European Union goats are slaughtered with carcase weights between 5 kg and 11 kg. Some farmers rear kids with milk replacers to produce cheese with the dams’ milk. The aim of this experiment was to study the volatile compounds (VOCs) of meat of suckling light kids reared with natural milk or milk replacers and to study the influence of consumers’ psychographic characteristics on the sensory preference for meat. Gas chromatography-mass spectrometry was performed to identify the VOCs and consumers evaluated the flavour, juiciness and overall acceptability. Thirty-five VOCs were detected and 44.3%, 25.1%, 6.9% and 2.3%, were aldehydes, hydrocarbons, ketones and alcohols, respectively. The influence of the rearing system on VOCs clearly depended on the breed. The use of milk replacers did not affect the percentage of linear aldehydes compared to the use of natural milk. However, the major aldehyde, hexanal (34.8%), was related to the use of natural milk and correlated positively with both the flavour (r = 0.21) and overall acceptability (r = 0.24). On the other hand, hydrocarbons such as hexane were related to MR, and 2-methyl-pentane and 3-methyl pentane were correlated with the acceptability of flavour (r = −0.22 and −0.25, respectively) and with the overall acceptability (r = −0.21 and −0.24). The 2-penthyl furan and 2-ethyl-1-hexanol were correlated with the overall acceptability (r = −0.22 and −0.22, respectively). Therefore, the acceptability of meat from suckling kids fed natural milk was greater for older consumers and people with a moderate consumption of meat.HighlightsGoat farmers remove the kids from their dams at a very young age and rear them with milk replacers, but this practice may alter the flavour of meat.The major aldehyde, hexanal, was related to the use of natural milk and correlated positively with the flavour and overall acceptability.Acceptability of meat from suckling kids fed natural milk was greater for older consumers and people with a moderate consumption of meat. Published

BACKGROUND Traditionally, peppers (Capsicum annuum L.) of Jaranda variety used for the production of smoked paprika are harvested manually in the north of Extremadura (Spain). Mechanical harvesting is necessary to improve the profitability of this crop. The present study aimed to evaluate the effect of plant density (D1 = 36 765 and D2 = 73 530 plants ha-1 ) and harvesting type (manual or mechanical) on the yield and quality of fresh, dried and powdered peppers. RESULTS The increase in plant density increased marketable yield per hectare, although the yield per plant decreased. With mechanical harvesting, the optimal density was D2 (15 151 kg ha-1 ) over D1 (12 493 kg ha-1 ). After processing the fruits, the application of D2 and mechanical harvesting significantly improved quality parameters, such as a*, ASTA (American Spice Trade Association) units and carotenoide concentration, primarily capsanthin. CONCLUSION The cultural practices tested provided an adequate productivity of fresh pepper and a better quality of the final product. According to the results of the present study, the increase in plant density and the substitution of manual harvesting by mechanical harvesting could be profitable practices with respect to the Jaranda variety of pepper used for the manufacture of smoked paprika. These practices maintain the main quality parameters of dried peppers and paprika. © 2018 Society of Chemical Industry.

Traditional cheeses may be contaminated by mycotoxin-producing fungi, during ripening. This study aimed to evaluate the influence of water activity (aw), pH, and temperature, on the lag phases, growth, and cyclopiazonic acid (CPA) production of three Penicillium strains (P. commune CBS311 and CBS341, and P. camemberti CBS273), in a cheese-based medium. The behaviour of the Penicillium strains was influenced by the pH, aw, and temperature conditions. P. commune CBS311 and CBS341, showed the highest (P

Here we characterised the aroma of smoked, oven-dried, and sun-dried paprikas by sensorial evaluation and analysis of their volatile profiles. The sensorial panel defined smoked paprikas as having an intense, persistent, smoked odour and flavour and the highest acceptability. The oven-dried paprikas had a fruity odour and flavour related with aroma notes to fresh peppers. The sun-dried paprikas were associated with straw aromas and the worse valued. The chemical classes of volatile compounds also defined the paprika types. The smoked paprikas were richer in alcohols, phenols, pyrroles, and pyranones, whereas the oven-dried samples were characterised by their aldehydes and terpenes. The sun-dried paprikas had significantly lower amounts of odorant substances than the smoked and oven-dried paprikas. The intensity, persistence and smokiness descriptors (associated with smoked paprika) were positively associated with phenols and alcohols. Aldehydes were positively correlated with a fruity descriptor, which defined oven-dried paprikas, and negatively correlated with intensity, persistence, smokiness, toasted, and dried pepper descriptors. The descriptor straw, which defined sun-dried paprikas, was negatively correlated with alcohols, phenols, furans, and pyrroles.

Mild pressure (300 MPa, 5 min, 10 °C) was combined with lactic acid bacteria (Pediococcus acidilactici, HA-6111-2) and its bacteriocin (bacHA-6111-2) to treat traditional Portuguese ready-to-eat meat sausage (Chourico de carne) and the effect on the survival of Listeria innocua was evaluated. Five batches of sausage slices were prepared: i) non-inoculated; ii) inoculated with L. innocua; iii) inoculated with P. acidilactici; iv) inoculated with L. innocua and P. acidilactici; and v) inoculated with L. innocua and bacteriocin. Pressure had no impact on the growth of P. acidilactici cells. In non pressurized samples inoculated with L. innocua, cells were inactivated by the traditional hurdles (e.g., salt, spices), and the reduction was higher when pressure alone was applied. No significant differences (P > 0.05) were observed for L. innocua co-inoculated with P. acidilactici alone or in combination with pressure, but when inoculated with the bacteriocin, an immediate and further decrease was obtained by pressurization. During refrigerated storage, the highest inactivation rate was obtained for pressurized slices inoculated with L. innocua in the presence of bacteriocin. The use of bacteriocins can effectively contribute to food safety, especially when integrated into hurdle concepts. This treatment strengthens the traditional hurdles applied to slices of Chourico de Carne.

Rotting caused by grey mould (Botrytis cinerea) is a concerning disease for numerous crops both pre- and postharvest stages. Application of antagonistic yeasts is a promising strategy for controlling grey mould incidence which could mitigate undesirable consequences of using synthetic fungicides. In this work, a screening for detection of yeasts isolated from figs producers of antifungal volatile organic compounds (VOCs) were performed by confrontation in double dishes systems. Eleven out of 34 yeasts confronted reduced B. cinerea growth parameter in vitro. This reduction was correlated (p ≤ 0.050) with the production of 10 volatile compounds: two acids (acetic acid and octanoic acid), 7 esters (Ethyl propionate, n-Propyl acetate, Isobutyl acetate, 2-methylbutyl acetate, furfuryl acetate, phenylmethyl acetate, 2-phenylethyl acetate) and one ketone (Heptan-2-one). In bases on in vitro assay, Hanseniaspora uvarum 793 was applied to in vivo assays with strawberries and cherries. The reduction of incidence of B. cinerea in strawberries at 7 °C and 25 °C was 54.9 and 72.1% after 6 and 3 days, respectively. The reduction of incidence of B. cinerea in cherries at 7 °C and 25 °C was 48.9 and 45.6% after 5 and 4 days, respectively. These results showed that VOCs produced by Hanseniaspora uvarum 793 are effective in the control of incidence of Botrytis cinerea in fruits, being a potential alternative to chemical fungicide.

A genetic characterization of 13 species of cayenne provided by Spanish milling industries was performed, and their colour, pungency and antioxidant properties were evaluated. Colour parameters (carotenoids, reflected and extractable colour), capsaicinoids, total phenolic compounds and antioxidant activity by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging method and 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) were determined in the cayenne samples, and the stability of cayenne properties was determined after exposure to UV light. Genetic characterization using different barcode markers (26S large subunit of rDNA, internal transcribed spacer 2, rbcL gene and matK gene) revealed close relationships among samples. However, notable differences were found for most of the quality parameters studied. Specifically, colour parameters were the most important traits for the discrimination of different samples. Samples with high colour quality presented 989.9 μg of capsanthin/g of dry matter, 104.8 ASTA units and 26.6 units in the a* coordinate of the CIELAB space. In contrast, the lowest-quality sample presented 582.7 μg of capsanthin/g of dry matter, 21.1 ASTA units and 15.4 units in the a* coordinate. DPPH and ABTS values ranged from 73.8 to 161.8 and from 217.1 to 325.7 mg Trolox/100 g, respectively. Pungency was highly variable among samples, with values ranging between 68.2 and 751.9 μg of capsaicin/g and 38.7 and 273.5 μg of dihidrocapsaicin/g. Principal component analysis indicated that capsaicinoids and total phenolic compounds are the best indices to determine the antioxidant activity of cayenne, which is highly correlated with the stability of colour and pungency. According to these findings, the desirable technological qualities and the longest shelf-life of cayenne are associated with a high content of capsaicinoids and phenolic compounds, which guarantee good colour stability and pungency associated with high antioxidant activity.

This study aimed to evaluate the usefulness of bioactive extracts obtained from red wine by-products, such as grape skins and stems, for reducing or eliminating the use of SO2 in red wine production. Special attention was focused on guaranteeing the microbiological stability of the red wines and protecting them against oxidation. Therefore, the antioxidant and antimicrobial activities of the extracts and red wines were studied. Red grape stems and skins, by-products of the wine industry, from six types of monovarietal wines, were used. Extracts obtained from stems displayed higher concentrations of total phenolic compounds and higher in vitro antioxidant activity. Both stem and skin extracts demonstrated higher antimicrobial activity against pathogenic bacteria and lower activity against yeasts. In the wines produced, higher antimicrobial and antioxidant activities were observed, mainly in the skin extract batches. This study highlights that bioactive extracts obtained from by-products of wine making could be used to reduce or eliminate the use of SO2 in wine production. In this way, healthier red wines could be obtained while guaranteeing their microbiological stability and protecting them from oxidation. Furthermore, the use of these by-products is strongly associated with the circular economy, as they could help to reduce the environmental impact of the wine industry.

The prevalence and antibiotic resistance of Acinetobacter spp. from fifty samples of meat (chicken, turkey, beef and pork) were evaluated. Acinetobacter spp. was recovered from all samples and the clonal relatedness of 223 isolates identified to belong to the genus Acinetobacter was established by PFGE. A high genetic diversity was observed and 166 isolates from different samples, 141 representing different PFGE profiles, were further identified to the species level by rpoB gene sequencing. Thirteen distinct Acinetobacter species were identified among 156 isolates. The remaining ten isolates may represent three putatively novel species since rpoB sequence homologies with type strains of all available described Acinetobacter species, were < 95%. The most common species was Acinetobacter guillouiae with a prevalence of 34.9%. However 18.7% of the strains belong to the Acinetobacter baumannii group (n = 31) which include the species Acinetobacter baumannii (n = 7), Acinetobacter pittii (n = 12), Acinetobacter seifertii (n = 8) and Acinetobacter nosocomialis (n = 4) that are the species most frequently associated with nosocomial infections worldwide. In general, strains were resistant to some of the antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin-tazobactam (64.9% of strains resistant), ceftazidime (43.5%), ciprofloxacin (42.9%), as well as to colistin (41.7%) and polymyxin B (35.1%), the last-resort drugs to treat infections caused by multidrug-resistant Acinetobacter. The percentage of resistant strains to trimethoprim-sulfamethoxazole, tetracycline, aminoglycosides (amikacin and tobramycin) and ampicillin-sulbactam was > 10% (23.2%, 23.2%, 14.3%, 12.5%, 12.5%, respectively). However, resistances to meropenem, imipenem and minocycline were only sporadically observed (8.3%, 1.2% and 1.2%, respectively). Overall, 51.2% of the strains were considered as multidrug-resistant (MDR) and 9.6% as extensively drug-resistant (XDR). The prevalence of MDR strains within the A. baumannii group (38.7%) was lower than the prevalence within the others species identified (54.1%). Therefore, food of animal origin may be a vehicle of spread Acinetobacter strains resistant to several antibiotics in the community and in the hospital setting environment. This may led to nosocomial and community-acquired infections in susceptible individuals.

Fruit decay caused by pathogenic moulds is a major concern in the postharvest quality and shelf life of fruit. Blue mould decay is caused by Penicillium expansum (P. expansum) and is one of the most important postharvest diseases in cherries (Prunus avium L.). Synthetic fungicides are the main medium used to control pathogenic moulds. However, alternative approaches are available for developing safer technologies to control postharvest disease. An integrated approach that combines biological control, using antagonistic yeasts and modified atmosphere packaging (MAP) with cold storage is a promising alternative to synthetic fungicide treatment. In this work, two microperforated films (M10 and M50) and two antagonistic yeast strains (Hanseniaspora opuntiae L479 and Metschnikowia pulcherrima L672) were evaluated for their effectiveness to control the development of P. expansum in wounded cherries stored at 1 °C. Results showed that the microperforated films had fungistatic effects, particularly M50, due to the level of CO2 achieved (mean CO2 of 11.2 kPa at 35 days), and the decrease in disease severity. Antagonistic yeasts, particularly Metschnikowia pulcherrima L672, delayed the development of P. expansum and decreased disease incidence and severity. The combination of MAP and antagonistic yeasts was the most effective approach to control P. expansum, during cold storage.

Expression of genes associated with cyclopiazonic acid (CPA) biosynthesis by Penicillium strains in a cheese-based medium has not been previously studied. To control CPA biosynthesis, it would be useful to understand the changes in gene expression during cheese production and relate them to toxin production. The objective was to evaluate the influence of pH, aw, and temperature on expression of dmaT, which encodes the enzyme dimethylallyl tryptophan synthase involved in the biosynthesis of CPA. We assayed three Penicillium strains, Penicillium commune CBS311 and CBS341 and Penicillium camemberti CBS273, using reverse transcription real-time PCR. Our results showed that the expression patterns of the gene were influenced by strain and environmental conditions. The highest expression for the P. commune strains was observed at pH 6.0, 0.95 aw, at 25 or 30 °C, depending on the strain. In contrast, P. camemberti CBS273 showed a lower dmaT expression with a maximum at 25 °C, pH 5.0 and 0.95 aw. Correlation analysis indicated that the three toxigenic strains showed a strong correlation between the relative expression of the dmaT gene and concentration of CPA under conditions simulating cheese ripening. This method could be used to control CPA production in cheese by detection of dmaT expression.

The aim of this study was to evaluate the effect of two protective lactic acid bacteria cultures combined with modified atmosphere packaging on the survival/growth of Listeria innocua 2030c (as a surrogate for Listeria monocytogenes) and on sensory attributes of ready-to-eat ‘lombo’ over storage time. Sliced ‘lombo’, a traditional cured-smoked pork loin, was inoculated with L. innocua 2030c, Lactobacillus sakei ST153 (isolated from ‘salpicão’) and BLC35 culture (with Lactobacillus curvatus, Staphylococcus xylosus and Pediococcus acidilactici; CHR Hansen) as protective cultures. Samples were packed in two modified atmosphere packaging conditions (20% CO2/80% N2 and 40% CO2/60% N2) and stored at 5 ℃ for 124 days. Both cultures led to a reduction of 1–2 log CFU/g of L. innocua 2030c after 12 h; however, at the end of storage only Lb. sakei ST153 maintained this antilisterial effect, which was more evident at 40% CO2/60% N2. The influence of cultures addition and modified atmosphere packaging conditions on the sensory characteristics of the product were not significant. Thus, Lb. sakei ST153 combined with modified atmosphere packaging is a strong candidate to be used in a biopreservation strategy maintaining the traditional sensory quality of cured-smoked pork products and increasing their safety with respect to Listeria spp.

The purpose of this work was to investigate the influence of a starter culture on the generation of nitrogen compounds with antioxidant activity during the ripening of Iberian dry-fermented sausages. Starters P200S34 (P. acidilactici M200 and S. vitulus RS34) and P198S34 (P. acidilactici MS198 and S. vitulus RS34) were used to make the Iberian dry-fermented sausages 'salchichón' and chorizo; then, the physicochemical and microbial properties were determined during the ripening process. The oxygen radical absorbance capacity (ORAC) assay was employed to evaluate the antioxidant potential of the nitrogen extracts obtained during ripening of the sausages. This activity was correlated with the most relevant compounds detected by HPLC-ESI-MS in the final ripened extracts. Although a relevant part of the antioxidant activity was attributed to the predominant natural nitrogen fraction, the microbial population found in fermented sausages and the fermentation conditions significantly influenced the low molecular weight nitrogen profile and antioxidant activities. Inoculation with the starter culture P200S34 increased free amino acids and amines, such as methionine and tyramine, but other nitrogen compounds also increased the antioxidant activity of the low molecular weight nitrogen extracts. Thus, these starter cultures in Iberian sausages can contribute to delaying oxidative changes during storage., This work was supported by Proyect PRI08A093 from the Government of Extremadura (Spain) and FEDER. M. Fernandez is the beneficiary of a predoctoral grant from the Valhondo Calaff Foundation (Caceres, Spain).

This study aimed to assess the effect of high pressure at 300 and 500 MPa for 3 and 10 min on the phenolic compounds, antioxidant capacity and antimicrobial activity of citrus peel extracts. Total phenolic contents (TPC) and antioxidant properties of extracts were determined as free radical-scavenging ability of DPPH and using the ABTS radical cation decolorization assay. Additionally, extracts were tested for antimicrobial activity against twenty different strains of bacteria representing both Gram-positive and Gram-negative types. Citrus peel extracts demonstrated antimicrobial activity against a wide range of bacteria. The maximum level of TPC as well as antioxidant capacity were observed at 300 MPa for 3 min. Citrus peels extracts demonstrated antimicrobial activity against a wide range of microorganisms. The antimicrobial activity of orange peel extract was the highest among the four citrus peels studied. Generally, bacteria Acinetobacter and the strain Listeria innocua were more sensitive to the peel extracts.

Traditional cheeses may be contaminated by aflatoxin-producing Aspergillus flavus during the ripening process, which has not been sufficiently taken into account. The objectives of this study were to evaluate the influence of water activity (aw), pH, and temperature on the lag phases, growth, and aflatoxin production of 3 A. flavus strains (CQ7, CQ8, and CG103) on a cheese-based medium. The results showed that the behavior of A. flavus strains was influenced by pH, aw, and temperature conditions. The CQ7 strain showed the maximum growth at pH 5.5, 0.99 aw, and 25°C, whereas for CQ8 and CQ103 strains, no differences were obtained at pH 5.5 and 6.0. In general, low pH, aw, and temperature values increased the latency times and decreased the growth rate and colony diameter, although aw and temperature were the most limiting factors. Maximum aflatoxin production on the cheese-based medium occurred at pH 5.0, 0.95 aw, and 25 or 30°C, depending on the strain. This study shows the effect of pH, aw, and temperature factors on growth and aflatoxin production of 3 aflatoxigenic A. flavus strains on a cheese-based medium. The findings may help to design control strategies during the cheesemaking process and storage, to prevent and avoid aflatoxin contamination by aflatoxigenic molds.

This study evaluated the effect of high pressure processing on the recovery of high added value compounds from citrus peels. Overall, the total phenolic content in orange peel was significantly (P < .05) higher than that in lemon peel, except when pressure treated at 500 MPa. However, lemon peel demonstrated more antioxidant activity than orange peel. Pressure-treated samples (300 MPa, 10 min; 500 MPa, 3 min) demonstrated higher phenolic content and antioxidant activity comparatively to the control samples. For more severe treatments (500 MPa, 10 min), the phenolic content and antioxidant activity decreased in both lemon and orange peels.

The purpose of this work was to investigate the influence of technological properties of vegetable rennet (Cynara cardunculus) on the characteristics of ‘Torta del Casar’ cheese to establish the parameters that can be useful for quality control of this coagulant. The physicochemical, microbial, texture and sensory properties of the cheeses were evaluated and correlated to clotting and proteolytic activities of the vegetable rennets used for their manufacture. The level of in vitro degradation of α-casein and κ-casein/β-casein degradation ratio was found to be good tools to predict the effect of vegetable rennet on the rheological properties of these cheeses.

The objective of this work was to study the growth and development of fortuitous flora and food pathogens in the traditional Spanish cheese “Torta del Casar”. Sixteen batches of “Torta del Casar” were manufactured from the same unpasteurized Merino ewe's milk, using Cynara cardunculus L. rennets, corresponding to 16 plants, one for each batch. The cheeses were classified based on their texture spreadability analysis data (TSA) into four clusters, from very creamy to not creamy cheeses. Although there were no differences between the counts of different microbial groups in the different clusters of cheese, the microorganism isolated did differ between clusters, especially between the Group 1 cluster (less creamy cheese) and Group 4 (creamiest cheese), with the most notable isolates in the latter being a LAB Lactococcus lactis subsp. cremoris, and the enterobacteria Serratia proteamaculans and Enterococcus devriesei. Pathogen development was similar in all four groups of cheeses. Small differences were found for some pathogens (Listeria spp. and Salmonella spp.) which may have been due to interference with the different autochthonous microbiota. Indeed, the different autochthonous microbiota appears to influence the texture of the cheeses and the development of pathogens in them.

The effect of sequential treatments of pressure (50-150 MPa, 10 degrees C, 5 min) and temperature (57 degrees C, 15 min) on the survival and bacteriocin production of Pediococcus acidilactici HA-6111-2 cells in the exponential growth phase was assessed. The growth curves were fi tted with the modifi ed Gompertz model, and the estimated maximum specifi c growth rate was considered to be pressure dependent. A delay in the maximum value of bacteriocin production was registered for more severe pressure conditions, but it was found more notorious for pressure followed by temperature treatments. At lower pressure intensity treatment, regardless of the application order, there was an enhancement of bacteriocin production per cell when compared to the control while maintaining the maximum production value. Bacteriocin production after the treatments can be described by an exponential model.

Summary The effect of the addition of an autochthonous starter culture and commercial starter culture on the physico-chemical and sensory characteristics of the dry-fermented sausage ‘salchichon’ was investigated. Sausages were prepared with a mixture of Pediococcus acidilactici MC184 and Staphylococcus vitulus RS34 as the autochthonous starter culture (P184S34), ripened for 86 days, and compared with a commercial starter batch (CS1). Strains of acid lactic bacteria and Staphylococcus were identified in the samples along the ripening process which demonstrated that the inoculation of sausages assures their implantation during the ripening process. However, P184S34 starter culture showed a higher inhibitory effect on enterobacteria and coliform flora than the CS1 batches, guaranteeing a better quality hygienic sausages. Dry-fermented sausages ripened with P184S34 showed higher amounts of NPN and volatile compounds derived from amino acid catabolism than the CS1 batches. Especially important was the result found in biogenic amines, since the P184S34 reduced their accumulation compared to the commercial starter batch. The inoculation of a decarboxylase-negative autochthonous starter culture P184S34 reduced the biogenic amine accumulation guaranteeing safety and homogeneity of the products without producing a negative effect on the sensory characteristics of the traditional fermented sausages.

The objective of this study was to evaluate the effect of autochthonous selected starter cultures on the growth and development of fortuitous flora and food pathogens for the production of two traditional dry-fermented products, salchichon and chorizo, in two different ripening processes. Three strains of Pediococcus acidilactici (MC184, MS198 and MS200) and one of Staphylococcus vitulus (RS34) which possess desirable technological properties were associated to prepare three starter cultures: P184S34, P198S34 and P200S34. Then salchichon and chorizo were prepared following two different manufacturing procedures. The use of these starter cultures decreased the “spontaneous” flora growing in the traditional fermented products and constituted an additional improvement to the microbial safety by reducing Enterobacteriaceae proliferation at the beginning of the ripening process. An effect against food-borne pathogens was also observed. Hence the three inoculated autochthonous starter cultures can be used as protective agents.

The aim of the study was to determine how two different ripening processes affected the development of lactic acid bacteria (LAB) plus Staphylococcus autochthonous starter cultures, and the physico-chemical and sensory characteristics of the Iberian dry-fermented sausages (Salchichon). Each of two strains of Pediococcus acidilactici (MS198 and MS200) and one of Staphylococcus vitulus (RS34) were associated to prepare two starter cultures: P198S34 and P200S34. Then salchichon was prepared following two different manufacturing procedures. Both starter cultures were able to compete well and colonize the sausages, although P200S34 was better adapted to process 1 ripening conditions. There were evident differences shown by the texture analysis, with the control batches being tougher. Also, the highest biogenic amine levels were found in control batches. While the use of these starter cultures does not produce a negative effect on the sensory characteristics of these traditional fermented sausages, it can improve their homogeneity and healthiness but an appropriate combination of strains should be chosen for each process.

Summary The purpose of this study was to investigate pre-selected pediococci for potential probiotic use in Iberian dry-fermented sausages. A total of twelve strains isolated from Iberian dry-fermented sausages and pig faeces were evaluated according to safety and functional characteristics including biogenic amines and d-lactic acid production, antibiotic susceptibility, cell adhesion and antimicrobial activity against food-borne pathogens. The strain P. acidilactici SP979 was able to establish itself and compete with enteropathogens such as Salmonella choleraesuis on the intestinal epithelium and an inhibition of such pathogenic bacteria as Listeria monocytogenes and Staphylococcus aureus in vitro. This strain was also considered safe to be used with regard to its void aminogenic potential, low d-lactic acid production and antibiotic resistance pattern; being identified as a potential probiotic meat starter culture suitable for manufacture of dry-fermented Iberian sausages.

The purpose of this study was to investigate lactobacilli for potential probiotic use in Iberian dry-fermented sausages. A total of 18 strains, previously selected, isolated from different sources were evaluated according to safety and functional characteristics including biogenic amines and d-lactic acid production, antibiotic susceptibility, haemolysis, cell adhesion, and antimicrobial activity against food-borne pathogens. The strains Lactobacillus reuteri PL519, L. reuteri PL542, and Lactobacillus fermentum HL57 were able to establish their self on the intestinal epithelium, and an inhibition of such pathogenic bacteria as Listeria monocytogenesin vitro. These strains were also considered safe to be used with regard to their low aminogenic potential and d-lactic acid production, antibiotic resistance pattern and haemolytic activity. Thus, they were selected as a potential probiotic meat starter culture suitable for manufacture of dry-fermented Iberian sausages.

This study aimed to assess the efficacy of chitosan, Pediococcus acidilactici HA-6111-2 (bacteriocinogenic strain with antilisterial activity) and Pediococcus pentosaceus HA-3083-3 (a nonbacteriocinogenic strain), added individually or in combination, in the control of Listeria innocua, Staphylococcus aureus, Escherichia coli and Salmonella typhimurium during storage of Alheira paste at 4C. The behavior of pathogenic bacteria in the food matrix was significantly affected by the addition of chitosan. Chitosan at 0.3% reduced pathogenic bacteria counts in Alheira paste by 2–3 log cfu/g during the first 7 days of storage. This effect was increased when chitosan was used synergistically with lactic acid bacteria (LAB) (P

The purpose of this study was to investigate the impact on flavor quality of 2 autochthonous starter cultures in the manufacture of Iberian dry-fermented “salchichon.” A total of 2 strains of Pediococcus acidilactici (MS200 and MS198) were combined individually with a strain of Staphylococcus vitulus (RS34) to obtain 2 starter cultures: P200S34 and P198S34. The ability of both starter cultures to implant during 2 different manufacturing procedures of “salchichon” was evaluated by 16S rRNA gene sequence analysis. Changes due to starter culture inoculations on volatile compounds were determined by gas chromatography/mass spectrometry, and the impact on flavor quality evaluated by sensorial analysis. The implantation of starter cultures was adequate and did not significantly modify the flavor of the traditional Iberian dry-fermented “salchichon,” while modulating the volatile compound profile with respect to that found in sausages with wild microbial populations. The influence of the starter cultures studied was more evident in the shorter sausage processing time. P198S34 was related with the increase in some volatile compounds deriving from lipid degradation. P200S34 contributed to the formation of several volatile compounds arising from lipid degradation, amino acid catabolism, and microbial esterase activity. Practical Application: P200S34 and P198S34 are autochthonous starter cultures for specific use in the processing of Iberian dry-fermented sausages. The application of these starters allows obtaining Iberian dry-fermented sausages with sensorial characteristics standardized. It is greatly interesting for processing and marketing industry of these high-quality meat products.

The purpose of this study was to investigate the potential of incorporating the probiotic L. reuteri PL519 into the manufacturing of Iberian dry fermented sausages, and to observe its effect on the sensory properties of these meat products. Specific polymerase chain reaction (PCR) was carried out to detect the presence of probiotic strain at high counts in the inoculated sausages. Changes due to probiotic inoculation on physicochemical parameters were determined and the impact on sensory quality evaluated. Dry fermented sausages inoculated with L. reuteri PL519 may be considered as functional products according to the counts of this strain found at the end of processing. Inoculation with L. reuteri PL519 increased the amount of acetic acid, protein, and lipid degradation products in dry fermented sausages. The differences observed in the descriptive sensorial analysis corresponded, however, to a little impact on overall acceptability since no significant changes were found between the control and L. reuteri PL519 batch in the hedonic test. Practical Application: Processing and marketing of Iberian dry fermented sausages with functional characteristics.

The present study determined how the different ripening conditions affected the growth and development of 3 autochthonous starter cultures, and the physico–chemical and sensory characteristics of chorizo. Each of 3 strains of Pediococcus acidilactici (MC184, MS198, and MS200) and one of Staphylococcus vitulus (RS34) were associated to prepare the starter cultures, P184S34, P198S34, and P200S34. Then, chorizo was prepared following 2 manufacturing procedures. The autochthonous starter cultures were able to compete and colonize the sausages in both ripening procedures. The use of the starter cultures showed evident differences by the texture analysis, with the control batches being generally tougher than the starter culture batches. Also, the highest biogenic amine (BA) levels were found in control batches and the lowest in P200S34 batches. While the use of these starter cultures does not change the sensory characteristics of these traditional fermented sausages, it improves their homogeneity and safety, except for P184S34 batch in which more BAs are detected in industry 2. Practical Application: The 3 autochthonous starter cultures selected could be used in traditional industries because they are able to compete well and colonize the dry fermented sausages “chorizo.” The use of these starter cultures improves the texture and homogeneity of traditional fermented sausages. Biogenic amines decreased in the starter cultures batches improving the safety.

The effect of the addition of an autochthonous starter culture and the protease EPg222 on the physico-chemical and sensory characteristics of dry-fermented sausage ‘‘salchichon” was investigated. Sausages were prepared with purified EPg222 and Pediococcus acidilactici MS200 and Staphylococcus vitulus RS34 as starter culture (P200S34), separately and together, ripened for 90 days, and compared with a control batch. Dry-fermented sausages ripened with EPg222 and starter culture showed higher amounts of AN and volatile compounds derived from amino acid catabolism than the control, especially in samples in which was added the association of enzyme and starter culture (P200S34 + EPg222). There were clear differences shown by the texture analysis, with the P200S34 + EPg222 batch being less hard. Especially important was the result found in biogenic amines, since the association P200S34 + EPg222 reduced their accumulation compared to the EPg222 batch. The use of EPg222 may be of great interest to improve the sensory characteristics of dry-fermented sausages, but its association with the selected starter culture with low decarboxylase activity is necessary to guarantee healthiness and homogeneity.

The purpose of this study was to investigate enterococci for potential probiotic use in Iberian dry-fermented sausages. A total of 15 strains isolated from Iberian dry-fermented sausages, human feces, and pig feces were evaluated for their safety and functional characteristics including biogenic amine (BA) production, antibiotic susceptibility, hemolysis, virulence determinants, cell adhesion, and antimicrobial activity against foodborne pathogens. The strain Enterococcus faecium SE906 was able to establish itself on the intestinal epithelium, inhibiting such pathogenic bacteria as Listeria monocytogenes in vitro. This strain was also considered safe to be used for its low aminogenic potential, and its antibiotic resistance pattern and virulence determinants, being identified as a potential probiotic meat starter culture suitable for manufacture of dry-fermented Iberian sausages.