Staphylococcus aureus in the Processing Environment of Cured Meat Products.

The presence of Staphylococcus aureus in six dry-cured meat-processing facilities was investigated. S. aureus was detected in 3.8% of surfaces from five facilities. The occurrence was clearly higher during processing (4.8%) than after cleaning and disinfection (1.4%). Thirty-eight isolates were typified by PFGE and MLST. Eleven sequence types (STs) were defined by MLST. ST30 (32%) and ST12 (24%) were the most abundant. Enterotoxin genes were detected in 53% of isolates. The enterotoxin A gene (sea) was present in all ST30 isolates, seb in one ST1 isolate, and sec in two ST45 isolates. Sixteen isolates harbored the enterotoxin gene cluster (egc) with four variations in the sequence. The toxic shock syndrome toxin gene (tst) was detected in 82% of isolates. Regarding antimicrobial resistance, twelve strains were susceptible to all the antibiotics tested (31.6%). However, 15.8% were resistant to three or more antimicrobials and, therefore, multidrug-resistant. Our results showed that in general, efficient cleaning and disinfection procedures were applied. Nonetheless, the presence of S. aureus with virulence determinants and resistance to antimicrobials, particularly multidrug-resistant MRSA ST398 strains, might represent a potential health hazard for consumers.

Probiotic and Functional Properties of Limosilactobacillus reuteri INIA P572.

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.

Characterization of persistent Listeria monocytogenes strains from ten dry-cured ham processing facilities.

The majority of cases of listeriosis are associated with the consumption of contaminated food. Some strains of Listeria monocytogenes can persist over months or years in meat processing plants increasing the risk of product contamination. The presence of L. monocytogenes was examined in 10 dry-cured ham processing facilities. A total of 1801 samples were collected from environment and equipment, during processing (1095) and after cleaning and disinfection (706). These samples were taken from non-food contact (736) and food contact (1065) surfaces. In addition, 204 samples from ham surfaces were also analysed. Prevalence varied from 6% to 34% among facilities, and was higher during processing than after cleaning and disinfection (24.8% vs 11.0%) and from non-food than from food contact surfaces (22.6% vs 17.4%). L. monocytogenes serotype 1/2a was predominant (53.9%), followed by 1/2c (26.0%) and 1/2b (15.3%) and less frequently 4b (4.8%). A total of 142 different pulsotypes were registered. Potential persistent L.monocytogenes strains were isolated in 9 out the 10 facilities, with no more than 6 pulsotypes in a given plant. Two pulsotypes were common in different installations, detected before and after cleaning and disinfection, highlighting the importance of monitoring the presence of this pathogen in dry-cured ham processing environments.

In vitro anti-inflammatory activity of phenolic rich extracts from white and red common beans.

According to epidemiological evidence, diets rich in fruits and vegetables can reduce the incidence of several chronic diseases that share an inflammatory component. These protective effects are attributed, in part, to the occurrence of different antioxidant components, mainly phenolic compounds. Our aim was to characterise phenolic composition, and to determine antioxidant and anti-inflammatory activities of phenolic rich extracts obtained from two kinds of common beans, white kidney beans (WKB) and round purple beans (RPB). Phenolic acids were the predominant component in WKB extracts, whereas RPB extracts presented higher concentrations of phenolic compounds, mainly catechin derivatives, proanthocyanidins and catechin glucoside. In addition, RPB extracts showed higher antioxidant capacity and higher anti-inflammatory activity by the reduction of NO production and cytokine mRNA expression of LPS stimulated macrophages. These results suggest that common bean extracts may be used as a source of anti-inflammatory agents as well as a dietary complement for health promotion.

Storage temperature and UV-irradiation influence on the ergosterol content in edible mushrooms.

Ergosterol (5,7,22-ergostatrien-3ß-ol) and ergosteryl derivatives from different genera of edible mushrooms were separated and quantified by an isocratic reversed-phase high performance liquid chromatography (HPLC) method. The technique allowed a rapid separation of free ergosterol and two ergosteryl derivatives occurring in mushrooms. The ergosterol content varied considerably depending on the fungus. Thus, the species Agaricus bisporus and Hygrophorus marzuolus presented high quantities of ergosterol (6.4-6.8 mg/g, dry matter) followed by Pleurotus ostreatus, Calocybe gambosa, Lentinus edodes, and Boletus edulis (3.3-4.0mg/g). In contrast, other species, such as Cantharellus cibarius, Lactarius deliciosus and Craterellus cornucopioides, contained significantly lower ergosterol amounts (0.2-0.4 mg/g). Two ergosteryl derivatives were found in mushrooms and also the content depended on the fungus. The stability of ergosterol, in terms of the formation of ergosterol peroxide, was evaluated under different storage temperatures and UV radiation. The lower the temperature (-20°C) and the radiation time (10 min), the lower ergosterol oxidation was observed.

Novel isolation of water-soluble polysaccharides from the fruiting bodies of Pleurotus ostreatus mushrooms.

Novel water-soluble polysaccharides have been isolated from the fruiting bodies of the edible mushroom Pleurotus ostreatus. Three polysaccharide fractions were obtained by ethanol precipitation from cold water, hot water and hot aqueous NaOH extracts. The fractions were purified by size exclusion chromatography showing a unique carbohydrate occurring in each fraction: PC from the cold fraction, PH from the hot fraction and PB from the hot aqueous NaOH fraction. The analysis of the methylated alditol acetates and the NMR studies revealed that all the polysaccharides displayed a linear backbone. PC was formed by α-(1→3),(1→6)-linked galactopyranosyl residues whereas PH and PB consisted of glucose-linked units. PH was exclusively composed of glucopyranosyl units bound by α-(1→4) linkages whereas PB was a ß-linked glucan showing (1→3) and (1→6) glycosidic bonds. The analysis of molecular arrangement by complexation with Congo red showed that only the ß-linked polysaccharide (PB) displayed a triple helix conformation.

Strategies for the preparation and concentration of mushroom aromatic products.

Fungal aroma comprises at least seven chemical groups of volatile organic compounds, which are plain hydrocarbons, heterocycles, alcohols, phenols, acids and derivatives, carbonyls (aldehydes and ketones), and sulfur containing molecules. This aromatic blend provides the excellent sensory properties to produce and several strategies have been employed to create aromatic products having the aroma and taste of mushrooms and truffles. Nowadays, there are several procedures to obtain aroma concentrates. Among them, the simulation of mushroom aroma by the combination of the main substances responsible for the flavour could be an efficient strategy. Nevertheless, natural procedures are gaining more importance since the concentrate is not a synthetic product and the processes commonly involve the use of mushroom waste. In this field, the maceration with precursor molecules, such as linoleic acid, or different types of enzymes is commonly used in food industry. This article provides a wide view of the most common strategies to produce fungal aroma taking into account the main advantages and disadvantages they present. The article presents some promising patents on strategies for the preparation and concentration of mushroom aromatic products.

Use of modified atmosphere packaging to preserve mushroom quality during storage.

Mushrooms have attracted much attention due to their excellent nutritional and sensory properties. However, they are highly perishable and rapidly lose their organoleptic characteristics. Many methods have been employed for mushroom storage, such as packaging, blanching, canning, or freeze drying. Among them, modified atmosphere packaging (MAP) has been widely employed for preserving fresh mushrooms. MAP provides an affordable packaging system that partly avoids enzymatic browning, fermentation and other biochemical processes by maintaining a controlled gas atmosphere. Several factors, including optimum CO2 and O2 partial pressures, permeability, package material, thickness, or product weight, must be considered in order to design a suitable modified atmosphere package for mushrooms. Thus, different strategies are available to preserve mushroom quality after harvest. The article presents some promising patents on use of modified atmosphere packaging to preserve mushroom quality during storage.

Edible mushrooms: role in the prevention of cardiovascular diseases.

Edible mushrooms are a valuable source of nutrients and bioactive compounds in addition to a growing appeal for humans by their flavors and culinary features. Recently, they have become increasingly attractive as functional foods for their potential beneficial effects on human health. Hence, food industry is especially interested in cultivated and wild edible mushrooms. Cardiovascular diseases are one of the most prevalent causes of morbidity and mortality in the Western world. Several investigations have shown the influence of mushrooms intake on some metabolic markers (total, LDL, HDL cholesterol, fasting triacylglycerol, homocysteine, blood pressure, homeostatic function and oxidative and inflammatory damage), which potentially may reduce the risk of suffering cardiovascular diseases. Relevant nutritional aspects of mushrooms include a high fiber supply, a low fat content with low trans isomers of unsaturated fatty acids and a low concentration of sodium as well as the occurrence of components such as eritadenine, phenolic compounds, sterols (such as ergosterol), chitosan, triterpenes, etc., which are considered as important responsible agents for some hitherto healthy properties. The aims of this review are to report putative positive effects of mushrooms consumption on cardiovascular diseases risk markers and to identify some putative bioactive compounds involved in these effects.

Flavonoids as anti-inflammatory agents: implications in cancer and cardiovascular disease.

Chronic inflammation is being shown to be increasingly involved in the onset and development of several pathological disturbances such as arteriosclerosis, obesity, diabetes, neurodegenerative diseases and even cancer. Treatment for chronic inflammatory disorders has not been solved, and there is an urgent need to find new and safe anti-inflammatory compounds. Flavonoids belong to a group of natural substances occurring normally in the diet that exhibit a variety of beneficial effects on health. The anti-inflammatory properties of flavonoids have been studied recently, in order to establish and characterize their potential utility as therapeutic agents in the treatment of inflammatory diseases. Several mechanisms of action have been proposed to explain in vivo flavonoid anti-inflammatory actions, such as antioxidant activity, inhibition of eicosanoid generating enzymes or the modulation of the production of proinflammatory molecules. Recent studies have also shown that some flavonoids are modulators of proinflammatory gene expression, thus leading to the attenuation of the inflammatory response. However, much work remains to be done in order to achieve definitive conclusions about their potential usefulness. This review summarizes the known mechanisms involved in the anti-inflammatory activity of flavonoids and the implications of these effects on the protection against cancer and cardiovascular disease.

Fecal excretion of human deoxyribonucleic acid as an index of inflammatory activity in ulcerative colitis.

BACKGROUND & AIMS: Several indices evaluate disease activity in ulcerative colitis, but most have drawbacks to their application (invasiveness, complexity, or lack of specificity), and discrepancies between them are frequent. Assuming that desquamation of epithelial and inflammatory cells increases in damaged colonic mucosa, we hypothesized that fecal excretion of human DNA is an index of mucosal inflammation and damage. The aim of our study was to determine whether excretion of human DNA is useful in the evaluation of disease activity in ulcerative colitis. METHODS: Thirty-one controls and 36 ulcerative colitis patients were included. Ulcerative colitis patients and controls underwent colonoscopic examination after preparation by gut lavage with polyethylene-glycol electrolyte solution. In patients, disease activity was established using the clinical index of Rachmilewitz and an endoscopic score. Feces and gut lavage fluid were obtained and DNA levels were measured by quantitative polymerase chain reaction of the human beta-globin gene. RESULTS: Fecal DNA excretion correlated with the clinical index (r = 0.59, P < 0.05) and the endoscopic score (r = 0.76, P < 0.01). Gut lavage fluid DNA levels also correlated with clinical and endoscopic activity scores (r = 0.41 and 0.51, respectively, P < 0.05). Fecal DNA excretion was significantly higher in patients with endoscopically or clinically active disease than in controls or patients in remission. Fecal DNA excretion discriminates between endoscopically active disease and remission (sensitivity 0.67, specificity 1.00, P < 0.01). CONCLUSIONS: Excretion of human DNA in feces, as an expression of cellular desquamation, is a novel noninvasive technique to objectively assess disease activity in ulcerative colitis.