Bactericidal Efficacy of Hydrogen Peroxide-Based Disinfectants Against Gram-Positive and Gram-Negative Bacteria on Stainless Steel Surfaces.

In order to develop disinfectant formulations that leverage the effectiveness of hydrogen peroxide (H2 O2 ), this study evaluated the bactericidal efficacy of hydrogen peroxide-based disinfectants against Gram-positive and Gram-negative bacteria on stainless steel surfaces. Low concentration of hydrogen peroxide as 0.5% with a cationic polymer, ethoxylated fatty alcohol, and ethyl alcohol had bactericidal efficacy (reductions ≥ 4 log10 CFU/mL) against Escherichia coli, Staphylococcus aureus, Enterococcus hirae, and Pseudomonas aeruginosa. Hydrogen peroxide-based disinfectants were more effective against E. hirae and P. aeruginosa than to S. aureus. However, the efficacy of hydrogen peroxide against catalase positive bacteria such as S. aureus was increased when this compound was formulated with low concentrations of benzalkonium chloride or ethyl alcohol, lactic acid, sodium benzoate, cationic polymer, and salicylic acid. This study demonstrates that the use of hydrogen peroxide with other antimicrobial products, in adequate concentrations, had bactericidal efficacy in Gram-positive and Gram-negative bacteria on stainless steel surfaces, enabling to reduce the effective concentration of hydrogen peroxide. In the same way, the use of hydrogen peroxide-based disinfectants could reduce the concentrations of traditional disinfectants as quaternary ammonium compounds and therefore a reduction of their chemical residues in the environment after being used. PRACTICAL APPLICATION: The study of the bactericidal properties of environmentally nontoxic disinfectants such as hydrogen peroxide, sole or in formulations with other disinfectants against Gram-positive and Gram-negative bacteria can enhance the efficacy of various commonly used disinfectant formulations with the hygiene benefits that it entails. Also, the use of hydrogen peroxide formulations can reduce the concentration levels of products that generate environmental residues.

Biodisponibilidad de lactato ferroso adicionado a caramelos de goma / Bioavailability of ferrous lactate added to gum caramels

Fundamentos: El enriquecimiento de alimentos consulfato ferroso es la alternativa más usada para combatirla deficiencia de hierro, pero tecnológicamente es difícilde manejar, por lo que se propone en su lugar ellactato ferroso que imprime menos modificaciones.Objetivo: Evaluar la biodisponibilidad del lactato ferrosoadicionado a caramelos de goma, en cerdos en crecimiento.Métodos: La biodisponibilidad del hierro se evaluó enlechonas. Aleatoriamente se formaron 2 grupos que recibieron:alimento bajo en hierro, mas los caramelos adicionadoscon lactato ferroso y alimento normal.Quincenalmente se midieron peso y parámetroshematológicos. Se realizó análisis pareado y comparaciónde medias.Resultados: El producto tuvo características organolépticasaceptables, contenido de hierro de 2,4 mg porgramo. Las lechonas suplementadas con lactato ferrosopresentaron mayor ganancia de peso (15,7% más). Lamortalidad en el grupo de lactato fue del 20% y de 50%en el grupo control. El hierro detectado, fue mayor en elgrupo de lactato (2.987 mg) que en el control (2.792mg); en cambio, la cantidad de hierro consumido fuemayor en este último.Conclusiones: La suplementación con lactato ferrosodemostró ser mejor en el incremento de peso y en lamenor mortalidad de lechonas. La biodisponibilidad dellactato ferroso fue superior en un 30% a la del sulfatoferroso

Background: The enrichment of food with ferrous sulfateis the most frequently use alternative to combat irondeficiency, but it is technologically difficult to managewhich is why we propose ferrous lactate which providesthe benefit of fewer modifications.Objective: To evaluate the bioavailability of ferrous lactateadded to gum caramels to female growing pigs.Methods: The bioavailability of the iron was evaluated inpiglets. At random 2 groups were formed which received:Feed low in iron, plus caramels added with ferrous lactateand normal feed. Every 15 days were weight andhematological parameters were measured. Paired analysiswere made and comparison of measurements.Results: The product had acceptable characters, quantityof iron of 2,4 mg per gram. The female pigs supplementedwith ferrous lactate showed more aid on weight (15,7%more). The mortality in the group of lactate was 20% and50% in the control group. The iron detected, was higherin the group of lactate (2 987 mg) than in the controlgroup (2 792 mg); whereas, the quantity of iron consumedwas higher in the last group.Conclusions: The supplement with ferrous lactate provedto be the best in increasing weight and reduced the mortalityof female pigs. The bioavailability of ferrous lactate wassuperior by 30% compared with ferrous sulfate

Histidine Decarboxylase Activity of Enterobacter cloacae S15/19 during the Production of Ripened Sausages and Its Influence on the Formation of Cadaverine.

The histidine decarboxylase activity of Enterobacter cloacae S15/19 was studied during the production process of salchichón , a Spanish ripened sausage. Counts of fecal coliform and histidine decarboxylase bacteria decreased during the production process, showing a good correlation in both inoculated and control samples. In the samples inoculated with Enterobacter cloacae S15/19, fecal coliforms were undetectable the last day of the survey, while the population of histidine decarboxylase bacteria was over 2 log MPN/g. Despite the fact that inoculation with Enterobacter cloacae S15/19 increased histidine decarboxylase bacteria counts, no differences were observed in the histamine concentration reached, which was undetectable in most of the control and inoculated samples. In contrast, cadaverine concentration increased significantly (P < 0.01) in the inoculated samples, suggesting that cadaverine could be used as a hygienic-quality indicator of the raw materials employed in sausage processing.

Sensory Quality and Histamine Formation during Controlled Decomposition of Tuna ( Thunnus thynnus ).

Histamine production was studied during controlled tunafish decomposition at 0, 8, and 20°C. The influence of the location of the anatomic section on the amount of histamine formed and the incidence of histidine decarboxylating bacteria were also considered. By the time of sensory rejection, histamine levels in tunafish sections stored at 0 and 20°C were still below the hazard levels and the allowable levels established by both the U.S. Food and Drug Administration (FDA) and the European Union. Toxic amounts were only formed after the tunafish was considered organoleptically unsuitable for human consumption. However, at 8°C, levels of histamine between 100 and 200 mg/l00 g of fish were found before tuna reached the rejection point. Hence, physical appearance was not a good criterion for estimating the shelf life and especially the histamine-related health hazard when tuna was stored at 8°C, a common temperature in many home refrigerators.

Histidine Decarboxylase Activity of Bacteria Isolated from Raw and Ripened Salchichón , a Spanish Cured Sausage.

Twenty samples of raw sausages (before the ripening process) and 10 of ripened sausages of two different sizes of salchichón , one of the most-consumed ripened meat products in Spain, were microbiologically analyzed. Histidine decarboxylase activity of different isolates obtained from different culture media was evaluated by a decarboxylase agar medium and confirmed afterwards by an enzymatic method. Of the isolates obtained from raw sausages, 15.8% showed histamine-forming activity, most of them (78.1%) belonging to the Enterobacteriaceae family. Klebsiella oxytoca , Enterobacter aerogenes (one isolate), and Enterobacter cloacae (six isolates) showed a powerful histamine-forming activity, producing more than 3,000 µg/ml. In spite of histamine-forming activity being detected in eight of ten analyzed samples of ripened sausages, only one histamine-forming bacterium, identified as Lactobacillus curvatus , was isolated; it showed an ability to form 1,994 µg/ml of histamine in experimental conditions.

Bacteriological Quality of Tuna Fish ( Thunnus thynnus ) Destined for Canning: Effect of Tuna Handling on Presence of Histidine Decarboxylase Bacteria and Histamine Level.

The present paper analyzes the bacteriological quality and histamine content of tuna fish samples destined for canning. Raw material used in the canning process was of good quality. Histamine-producing bacteria counts were only found in three samples from the last step of the canning process before sterilization. Most of the bacteria identified as histamine formers were gram negative, and nearly all of which belonged to the Enterobacteriaceae family. Morganella morganii was the most frequent and active histamine former in tuna fish destined for canning. Other powerful histamine-producing bacteria isolated during the canning operation were Klebsiella oxytoca , Klebsiella pneumoniae and some strains of Enterobacter cloacae and Enterobacter aerogenes . They all were able to produce more than 500 ppm of histamine in experimental conditions. Most of these species might be expected to be found as a result of contamination of fish during capture and subsequent unhygienic handling in the canning plant. An increase in histamine content in tuna meat was not expected through the canning process. Histamine content always was acceptable in accordance with the maximum allowable levels of histamine fixed by both the European Economic Community and Food and Drug Administration.