Addition Of Caprylic Acid Research Articles

Development of poly(lactic acid)-based natural antimicrobial film incorporated with caprylic acid against Salmonella biofilm contamination in the meat industry

Using a solvent-casting method, a poly(lactic acid) (PLA) film incorporated with caprylic acid (CA) was developed as an active packaging against Salmonella enterica ser. Typhimurium and S. enteritidis to reduce the risk of microbial contamination during distribution and storage of meat. According to the minimum inhibitory concentration (MIC) test results of the natural antimicrobial, CA was introduced at 0.6, 1.2, 2.4, and 4.8 % (v/v) into neat PLA. The biofilm inhibitory effect and antimicrobial efficacy of CA-PLA film against both Salmonella strains, as well as the intermolecular interactions and barrier properties of CA-PLA film, were evaluated. Biofilm formation was reduced to below the detection limit (<1.0 log CFU/cm2) for both S. typhimurium and S. enteritidis when co-cultured overnight with 4.8 % CA-PLA film. The 4.8 % CA-PLA film achieved maximum log reductions of 2.58 and 1.65 CFU/g for S. typhimurium and 2.59 and 1.76 CFU/g for S. enteritidis on inoculated chicken breast and beef stored at 25 °C overnight, respectively, without any quality (color and texture) losses. CA maintained its typical chemical structure in the film, as confirmed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectra. Furthermore, film surface morphology observations by field emission scanning electron microscopy (FESEM) showed that CA-PLA film was smoother than neat PLA film. No significant (P > 0.05) changes were observed for water vapor permeability and oxygen permeability by the addition of CA into PLA film, suggesting that CA-PLA film is a promising strategy for active packaging to control Salmonella contamination in the meat industry.

A new approach of immunotherapy against Crotalus snakes envenoming: ostrich (Struthio camelus) egg yolk antibodies (IgY-technology)

Crotalid envenomation is a neglected collective health problem involving many countries in America, which need secure and inexpensive snake anti-venom treatments. Here, high antibody titers (IgY) were raised in the Ostrich (Struthio camelus) egg yolk by immunizing with the venom of Venezuelan venomous Crotalus snakes. Ostriches were immunized with a pool of venoms from common rattlesnake (Crotalus durissus cumanensis), Uracoan rattlesnake (Crotalus vegrandis), Guayana rattlesnake (Crotalus durissus ruruima) and black rattlesnake (Crotalus pifanorum). The anti-snake venom antibodies were prepared from egg yolk by the water dilution method, enriched by the addition of caprylic acid (CA) and precipitation with ammonium sulfate at 30% (W/V). The purity and molecular mass of the final product was satisfactory, yielding a single ∼ 175 kDa band in SDS-PAGE gels ran under non-reducing conditions. In the immunoblot analysis, specific binding of the antivenom was observed with most venom proteins. The LD50 was 16.5 g/mouse (825 µg/kg body weight). High titers of IgY against Crot/pool venom were shown by ELISA. The median effective dose (ED50) was 19.66 mg/2LD50. IgY antibodies neutralized efficiently the Crot/pool venom lethality. As far as we know, this is the first anti-snake venom produced in ostriches, which could make this technology an affordable alternative for low-income countries, since it is likely to produce about 2-4 g of IgY per ostrich egg. Hence, almost 400 g of IgY can be purified from only one ostrich during a year. In addition, there are enormous differences in the cost of investment in the maintenance of horses, from the points of view of infrastructure, feeding and veterinary care, in which the cost can reach USD 100 per animal per day, compared to a maintenance cost of USD 146 per month per producing bird. These results are encouraging and could easily be extrapolated to the manufacturing of other antivenoms and antitoxins as well, as they could be applied to the manufacturing of potential diagnostic tools.

Effects of free fatty acids on somatostatin secretion, content and mRNA levels in cortical and hypothalamic fetal rat neurones in monolayer culture.

The effects of free fatty acids on somatostatin secretion, content and mRNA levels in fetal rat hypothalamic and cortical cell cultures were investigated. Somatostatin secretion and content were quantified by radioimmunoassay. Somatostatin mRNA levels were measured by Northern blot hybridization using a cRNA probe. Treatment with either caprylic acid (5 x 10(-3) M) or oleic acid (5 x 10(-5) M) for 90 min inhibited basal somatostatin secretion in both hypothalamic and cortical cell cultures. In addition, the increase in somatostatin secretion induced by incubation with veratridine (10(-4) M) or carbachol (10(-4) M) for 90 min was significantly reduced by the addition of caprylic acid, but somatostatin release stimulated by 5.6 x 10(-2) M KCl was not affected. Furthermore, treatment with these free fatty acids for 90 min markedly decreased somatostatin mRNA levels in both types of neurone culture. These inhibitory effects were transient, being observed after 90 min, but not after 5 h. These results support the probability that there is a role for free fatty acids in the regulation of somatostatin mRNA levels and somatostatin secretion in both hypothalamic and cortical cell cultures.

Production and isolation of guinea pig IgE antibody

Immunoglobulins of the IgE and IgG classes have been causally associated with hypersensitivity reactions in man and in numerous animal species including mice, rats and guinea pigs. The use of the guinea pig as an animal model for both pulmonary and dermal hypersensitivity reactions, and the recent recognition of the importance of IgE antibodies in both early- and late-onset hypersensitivity responses, has heightened interest in production, separation, and isolation of this immunoglobulin class from the guinea pig. IgE antibodies were produced by treatment of strain 13 guinea pigs with cyclophosphamide followed by injection with S. aureus enterotoxin. Serum was obtained and the globulin fraction isolated by addition of caprylic acid then ammonium sulfate. Immunoglobulins were separated into classes using fast protein liquid chromatography (FPLC) employing a Mono Q column and a linear gradient of 0.01–0.3 M Na,K phosphate buffer, pH 7.5 (buffer B). IgG eluted in two major peaks. IgG2 was not retained on the column and emerged with the starting buffer; IgG1 was eluted with 15–20% buffer B. IgE, detected as heat labile homocytotropic antibody, was found in the fraction eluting with 30–35% buffer B. The elution profile of the guinea pig immunoglobulins was predicted from the pattern obtained with immunoglobulin classes from other species. This chromatographic procedure enabled rapid isolation of immunoglobulin classes from guinea pig sera and effectively separated IgG1 from IgE, the two classes associated with hypersensitivity reactions.

Corneal permeability to bunazosin in rabbits.

Topical and systemic absorption of bunazosin after topical instillation was investigated in rabbits. Corneal permeability of bunazosin in vivo was increased by the addition of caprylic acid in amounts equimolar to bunazosin. Aqueous humor levels of bunazosin were significantly elevated. These results correlated well with those obtained in vitro experiments. Contrarily, the levels of plasma were not significantly affected and only slightly lowered by caprylic acid.

Evaluation of Kidney Viability during Hypothermic Perfusion or Cold Storage

The effect of up to 6 days of hypothermic perfusion and up to 72 h of cold storage on tissue viability were studied from measurements of sodium potassium pump activity and adenosine nucleotide content. For the hypothermic perfusion two different albumin-based perfusates were used, one with, the other without addition of caprylic acid and amino acids. No difference could be found in the parameters studied between perfusion with these two perfusates. For both perfusates total adenine nucleotide content (TAN) decreased by approximately 60% during perfusion while energy charge potential (ECP) and the ATP/ADP ratio remained constant. During cold storage a decrease of both TAN and ECP and the ratio ATP/ADP was seen, the main decrease occurring within the 1st h. The transmembrane potassium influx as deduced from potassium content in incubated cortical slices during steady state conditions decreased during 6 days of hypothermic storage to 24.5 +/- 2.4 mumol/kg which was a significantly higher level than after 24 h of cold storage. Thus, addition of extra substrate to the perfusate does not seem to improve kidney cortex viability during hypothermic perfusion. Parenchymal viability is better preserved with continuous hypothermic perfusion, compared to simple cold storage in a solution of the same ionic composition as that used for perfusion.

酵素による澱粉のヨード反應反轉現象

A new method for the preparation of pure amylose fraction was proposed and it was named the “precipitant-enzyme method” by the present authors. By the addition of sufficient quantity of caprylic acid to about 2% starch paste, all the amylose component was precipitated as fine needle crystals, though the bulk of amorphous amylopectin was also precipitated with them. Taka-diastase or other α-amylase solution was added to the starch paste, and the paste was digested during 2_??_6 hours at room temperature. Dissolved and precipitated amorphous amylopectin fractions were hydrolyzed almost completely. However, the majority of amylose component was left intact, though unstable micells of shorter chain amylose component and the surroundings of the crystals might be digested to some extent. The enzymic action was stopped by rapid heating, and the digested solution was filtered with suction. Cooling the clear filterate, disk-shaped crystals of amylose-caprylic acid complex were separated out. The crystals were collected by centrifugation (3, 000 r. p. m.), and recrystallized by addition of caprylic acid or by the ordinary butanol method. The recrystallized complex was collected, washed, dried and weighed. The yield of pure amylose was 10_??_15% of the parent starch.