Efeito alcalinizante de soluções eletrolíticas intravenosas com concentrações elevadas de lactato de sódio infundidas em bezerros sadios / Alkalinizing effect of intravenous electrolyte solutions with high sodium lactate concentrations infused in healthy calves

Com o objetivo de investigar o potencial alcalinizante de soluções eletrolíticas com concentrações elevadas de lactato de sódio em bezerros sadios, foram idealizadas seis soluções contendo 28, 56 e 84mEq/L de lactato (L28, L56 e L84) ou de bicarbonato (B28, B56 e B84), com concentrações de sódio, de potássio e de cálcio semelhantes às da solução de Ringer com lactato (SRL). As soluções contendo bicarbonato de sódio foram utilizadas como padrão para comparação. Seis bezerros receberam, por via intravenosa, todas as seis soluções, uma a cada vez, com intervalo de quatro a cinco dias entre as infusões, em volume correspondente a 10% do peso corporal, durante cinco horas (20mL/kg/h). Amostras de sangue venoso e de urina foram coletadas antes de iniciar a infusão, na metade do volume, ao término e duas horas e meia após o término da infusão. Determinaram-se concentração de proteína plasmática total, pH sanguíneo e urinário, pCO2, HCO3 -, BE, concentração plasmática e urinária de lactato L e concentrações séricas e urinárias de Na+, K+, Cl- e creatinina. A solução L28, idêntica à SRL, provocou discreto incremento da reserva alcalina e, consequentemente, produziu efeito alcalinizante insuficiente para a correção de estados de acidose metabólica. A solução L84, além de provar-se segura, provocou o maior aumento da reserva alcalina, equivalente à B84, e, assim, produziu efeito capaz de corrigir o grau moderado de acidose metabólica.

The alkalinizing effects of electrolyte solutions with high concentration of sodium lactate were evaluated in healthy calves. Six solutions were formulated containing 28, 56 and 84mEq/L of lactate (L28, L56 and L84) or bicarbonate (B28, B56 and B84), and sodium, potassium and calcium concentrations similar to the lactated Ringer's solution (LRS). The solutions containing sodium bicarbonate were used as a standard for comparison. Six calves received all six solutions intravenously, one at a time, with an interval of four to five days between the infusions, in a volume corresponding to 10% of body weight, during five hours (20mL/kg/h). Venous blood and urine samples were taken prior to the beginning of the infusion, at a half volume, at the end and two and a half hours after the end of the infusion. Total plasma protein concentration, urinary and blood pH, blood pCO2, HCO3 - and BE, plasma and urine L lactate concentration and serum and urine Na+, K+, Cl- and creatinine concentrations were measured. The L28 solution, equal to LRS, caused a slight increase in the alkaline reserve, producing an alkalinizing effect insufficient for correction of metabolic acidosis states. The L84 solution was safe and produced the greater increase in the alkaline reserve, equivalent to B84 solution, and suitable for correcting a moderate degree of metabolic acidosis.

Effects of NaCl substitution on the sensory properties of sausages: temporal aspects.

The aim of this study was to determine the effects of different salt substitutes on the sensory perception of sausages. TDS was used to explore the temporal perception of the samples and DA was used as a reference method. Grill-style sausages with different levels of salt reduction combined with different salt substitutes (KCl, Na-lactate, K-lactate/Na-diacetate and milk minerals) were tested. Results showed relatively few discriminating attributes from DA. However, results from TDS indicated differences in the dynamic perception of the sodium reduced sausages compared to the control sample, especially during the aftertaste.

Evaluation of metal impurities in foods preserved with sodium lactate.

The public is being bombarded by the media almost dailywith real and potential food health concerns leadingto a public sentiment that questions the vulnerability and quality of our food. Sodium lactate is a food-grade product that in recent years has been used in bioremediation to stimulate microbial growth and contaminant breakdown processes. In previous work, impurities including arsenic and chromium were discovered to be present in the sodium lactate concentrate. The study described in this article was performed to determine whether arsenic and chromium were at detectable levels, posing a potential concern in food products preserved with sodium lactate available to the general public. A pilot sampling of three sodium-lactate-preserved food products was obtained from a local market and used to determine the commercial laboratory's detection and reporting limits for arsenic and chromium for these food products. Once these limits were established, a random sampling and analyses of 17 food products was performed. Arsenic was not reported above the detection limits in either the pilot or subsequent study, but chromium was detected at concentrations up to 0.30 parts per million in a pilot test sample and lower concentrations in the subsequent study. This study suggests that the sodium lactate in the sampled products was diluted enough for the arsenic concentration to be below the laboratory detection limit. Chromium was detected and may be an unaccounted source of chromium in diets of vulnerable populations.

Efecto de distintos antimicrobianos sobre el crecimiento de Listeria monocytogenes / Effect of different antimicrobial agents on the growth of Listeria monocytogenes

En este estudio se ha evaluado la eficacia de dos ácidos orgánicos contemplados en la lista positiva de aditivos alimentarios, el lactato sódico (E-325) y el diacetato sódico (E-262), sobre el crecimiento de Listeria monocytogenes. Estos aditivos se adicionaron en diferentes concentraciones a un medio de cultivo líquido, determinando el incremento de densidad óptica del medio a 600 nm durante 24 horas a 37 ºC, con respecto al medio sin inocular que se tomó como blanco, realizando la medida cada hora. El incremento de absorbancia se midió con respecto al tiempo, evaluando el crecimiento de la bacteria a través de la interpretación de la tasa máxima de incremento de absorbancia (micro) y el tiempo mínimo requerido para detectar un incremento en la densidad óptica del medio (epsilon). Este último parámetro se puede equiparar al tiempo de latencia o tiempo de adaptación al medio. Así, para el lactato sódico, se observó que ejerce un efecto negativo dosis dependiente sobre el crecimiento de L. monocytogenes, prolongando el tiempo que necesitó la bacteria para adaptarse al medio de cultivo (epsilon), sin afectar a la tasa de crecimiento (micro) una vez que esta comenzó a crecer. El diacetato sódico mostró ser más efectivo que el lactato sódico frente al crecimiento de la bacteria, incrementando el tiempo de adaptación al medio, así como disminuyendo la tasa de crecimiento. Además, el diacetato sódico consiguió inhibir de forma completa el crecimiento de la bacteria a concentraciones iguales o superiores a 0.2%(AU)

The effectiveness of two organic acids included in the positive list for additives, sodium lactate (E-325) and sodium diacetate (E-262), was evaluated against Listeria monocytogenes growth. Different concentrations of these additives were added to the liquid culture medium. The optical density increments at 600 nm was measured for a 24 hours period under 37 0C, using non-inoculated medium as blank. The measurements were taken every hour in sterile 96 wells plates each. After this analysis, a graphical representation of absorbance increment against time was done, extrapolating the maximum absorbance increment rate (micro) and the minimum time required to detect an absorbance increment (epsilon) from the graphic. These two parameters made possible to evaluate the bacterial growth. After the analysis of epsilon and micro for lactate concentrations, a negative effect in bacterial growth was observed, extending epsilon value. Nevertheless, once the bacterial growth started, any effect on micro value was detected. A higher inhibitory effect was observed after the analysis of these parameters for diacetate concentrations, an extension on epsilon value as well as a micro value descent was found. In this way, a total inhibition of growth occurred when diacetate concentration was 0,2% or higher(AU)

Simultaneous determination of electroactive and non-electroactive food preservatives by novel capillary electrophoresis with amperometric detection.

A novel capillary electrophoresis and amperometric detection method was achieved by adding an electroactive additive (3,4-dihydroxybenzylamine, 3,4-DHBA) to the running buffer, so that both electroactive and non-electroactive food preservatives were simultaneously determined. Under the selected optimum conditions, four electroactive preservatives (methylparaben, ethylparaben, propylparaben and butylparaben) and two non-electroactive preservatives (potassium sorbate and sodium lactate) were well separated and sensitively detected with detection limits (S/N=3) ranging from 1.06×10(-8) to 2.73×10(-6) g mL(-1). This method has been successfully employed for the determination of both electroactive and non-electroactive preservatives in several food commodities.

Quantitative studies and taste re-engineering experiments toward the decoding of the nonvolatile sensometabolome of Gouda cheese.

The first comprehensive quantitative determination of 49 putative taste-active metabolites and mineral salts in 4- and 44-week-ripened Gouda cheese, respectively, has been performed; the ranking of these compounds in their sensory impact based on dose-over-threshold (DoT) factors, followed by the confirmation of their sensory relevance by taste reconstruction and omission experiments enabled the decoding of the nonvolatile sensometabolome of Gouda cheese. The bitterness of the cheese matured for 44 weeks was found to be induced by CaCl2 and MgCl2, as well as various bitter-tasting free amino acids, whereas bitter peptides were found to influence more the bitterness quality rather than the bitter intensity of the cheese. The DoT factors determined for the individual bitter peptides gave strong evidence that their sensory contribution is mainly due to the decapeptide YPFPGPIHNS and the nonapeptides YPFPGPIPN and YPFPGPIHN, assigned to the casein sequences beta-CN(60-69) and beta-CN(60-68), respectively, as well as the tetrapeptide LPQE released from alphas1-CN(11-14). Lactic acid and hydrogen phosphate were identified to play the key role for the sourness of Gouda cheese, whereas umami taste was found to be due to monosodium L-glutamate and sodium lactate. Moreover, saltiness was induced by sodium chloride and sodium phosphate and was demonstrated to be significantly enhanced by L-arginine.

The growth of Paracoccus halodenitrificans in a defined medium.

A synthetic medium, consisting of inorganic salts and any of a number of carbon sources, supported the aerobic growth of Paracoccus halodenitrificans when supplemented with thiamine. The same medium plus an appropriate nitrogenous oxide supported anaerobic growth when additionally supplemented with methionine. The observation that vitamin B12 or betaine replaced methionine suggested that P. halodenitrificans had a defect in the cobalamin-dependent pathway for methionine biosynthesis, as well as the inability to synthesize betaine when growing anaerobically.