Maria Beatriz Abreu Glória

Determinação de carbamato de etila em aguardentes de cana por CG-EM.

A simple, specific and sensitive GC-MS procedure with ion m/z 62 was validated for the determination of ethyl carbamate (EC) in spirits. It exhibited linearity over the concentration of 30 to 600 μg/L with 30 μg/L limit of quantification. EC was detected in 70 of the 71 samples analyzed with levels from 33 to 2609 μg/L (mean level = 893 μg/L). 35% of the samples contained 500 to 1000 μg/L and 23% contained 150 to 500 and 1000 to 1500 μg/L. No significant correlation was found between EC and the levels of copper, pH and alcohol content of the samples.

Influence of post harvest processing conditions on yield and quality of ground turmeric (Curcuma longa L.)

Studies were carried out to evaluate the influence of post harvest processing conditions on yield and quality of ground turmeric. Rhizomes were peeled, cooked (autoclave or immersion) in water or alkaline media, sliced, dehydrated, ground, sieved, packaged in polyethylene bags and stored for 60 days at room temperature. Yields ranged from 9.84 to 14.51 g of powder/100 g of rhizome with moisture varying from 8.84 to 9.86 g/100 g. Peel removal caused 30% mass loss but the powder obtained had higher intensity of yellow and red. Cooking caused a reduction in dehydration time and provided a powder with lower moisture content, higher levels of curcuminoid pigments and higher Hunter CIE L*, a* and b* values. Cooking by immersion provided higher quality powder compared to autoclave. Use of alkaline media resulted in a product with lower curcuminoid content, and higher intensity of yellow. There was no change in pigment and colour characteristics during storage.

Bioactive amines in Brazilian wines: types, levels and correlation with physico-chemical parameters

ABSTRACT The levels of ten bioactive amines and the physico-chemical characteristics of Cabernet Sauvignon, Cabernet Francand Merlot wines from Bento Goncalves, RS, Brazil, vintage of 1999 were investigated. The physico-chemicalcharacteristics varied significantly: pH from 3.80 to 4.07, total acidity from 67.7 to 85.3 meq/L, alcohol contentfrom 11.45 to 12.46 mL/100 mL and total SO 2 from 9.6 to 102 mg/L. Six amines were detected in every sample -spermidine, putrescine, histamine, tyramine, serotonine and phenylethylamine. Total amine levels ranged from 2.03to 7.60 mg/L. Putrescine was the prevalent amine, contributing with 20 to 66% of total levels. The amine profileand total levels were affected to a greater extent by vinification practices compared to grape type. There wassignificant correlation between some amines and also between amines and the physico-chemical parameters.Histamine levels were well below limits recommended by several countries.Key words: Red wine; amines; histamine; tyramine

The Role of L-Arginine and Inducible Nitric Oxide Synthase in Intestinal Permeability and Bacterial Translocation

BACKGROUND Arginine has been shown to have several immunological and trophic properties in stressful diseases. Its metabolites, nitric oxide (NO) and polyamines, are related to arginines effects. Thus, the aim of this study was to determine the effects of the NO donor L-arginine and the role of inducible NO synthase (iNOS) on intestinal permeability and bacterial translocation in a model of intestinal obstruction (IO) induced by a simple knot in the terminal ileum. MATERIAL AND METHODS Male C57BL6/J wild-type (WT) and iNOS knockout (iNOS-/-) mice were randomized into 6 groups: Sham and Sham-/- (standard chow), IO and IO-/- (standard chow +IO), and Arg and Arg-/- (standard chow supplemented with arginine + IO). After 7 days of treatment with standard or supplemented chows, IO was induced and intestinal permeability and bacterial translocation were evaluated. The small intestine and its contents were harvested for histopathological and morphometric analysis and the determination of polyamine concentration. RESULTS Pretreatment with arginine maintained intestinal permeability (P > .05; Arg and Arg-/- groups vs Sham and Sham-/- groups), increased polyamine concentration in intestinal content (P < .05; Arg vs IO group), and decreased bacterial translocation in WT animals (Arg group vs IO and IO-/- groups). Absence of iNOS also presented a protective effect on permeability but not on bacterial translocation. CONCLUSION Arginine supplementation and synthesis of NO by iNOS are important factors in decreasing bacterial translocation. However, when intestinal permeability was considered, NO had a detrimental role.

Effect of water activity on the stability of bixin in an annatto extract-microcrystalline cellulose model system

Abstract The influence of water activity on the stability of bixin in an annatto extract-micro-crystalline cellulose model system during storage at 21 ± 1 °C in the presence or absence of light and/or air was investigated. The water adsorption characteristic of the model system was determined. The samples were stored in desiccators containing saturated salt solutions for water activities of 0.33 to 0.97 and after equilibrium was reached, the samples were stored in the presence or absence of air and/or light. The degradation of bixin in every condition tested followed a first-order reaction. By comparing half-lives, bixin was observed to be more stable at intermediate/higher water activities.

Effect of Aging on Bioactive Amines, Microbial Flora, Physico-Chemical Characteristics, and Tenderness of Broiler Breast Meat

The objective of this study was to investigate the influence of aging on the levels of bioactive amines, microbial flora, physico-chemical characteristics, and tenderness of broiler breast. Forty-five 1-d-old Cobb broilers were aged at temperatures from 1.0 to 5.7 degrees C for 8 h. Nonaged broiler breast contained spermine, spermidine, and low levels of putrescine. There was prevalence of aerobic mesophiles followed by Pseudomonas. Mean pH, nonprotein N, weight loss after roasting, and shear force were 5.92, 0.46 g of N/100 g, 19.4%, and 5.57 kg, respectively. During aging, there was a significant increase in Pseudomonas and on the levels of amines. Two different amines were detected - tyramine and histamine. Aging resulted in a significant increase in tenderness without affecting pH, non-protein N, and weight loss after roasting. There was significant correlation between aging temperature and total bioactive amine levels. Aging above 4.9 degrees C induced the formation of histamine; therefore, aging should be performed at temperatures < or = 4.9 degrees C to prevent the formation of this amine, which has been associated with human health hazards. During storage of aged broiler breast at -18 +/- 1 degrees C for 89 d, there was no significant difference on pH, nonprotein N, and weight loss after roasting; however, there was a significant decrease on spermine, spermidine, putrescine, and tyramine levels. On the 89th day of storage, histamine was detected, and the shear force was significantly lower when compared with the samples immediately after aging. Therefore, the storage time of aged breast should not exceed 64 d to prevent histamine formation and to avoid excessive softening of the meat. Histamine in aged broiler breast could be used as an index of aging temperatures above 4.9 degrees C and also of frozen storage for more than 64 d.

A simple, fast and sensitive screening LC-ESI-MS/MS method for antibiotics in fish

The objective of this study was to develop and validate a fast, sensitive and simple liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the screening of six classes of antibiotics (aminoglycosides, beta-lactams, macrolides, quinolones, sulfonamides and tetracyclines) in fish. Samples were extracted with trichloroacetic acid. LC separation was achieved on a Zorbax Eclipse XDB C18 column and gradient elution using 0.1% heptafluorobutyric acid in water and acetonitrile as mobile phase. Analysis was carried out in multiple reaction monitoring mode via electrospray interface operated in the positive ionization mode, with sulfaphenazole as internal standard. The method was suitable for routine screening purposes of 40 antibiotics, according to EC Guidelines for the Validation of Screening Methods for Residues of Veterinary Medicines, taking into consideration threshold value, cut-off factor, detection capability, limit of detection, sensitivity and specificity. Real fish samples (n=193) from aquaculture were analyzed and 15% were positive for enrofloxacin (quinolone), one of them at a higher concentration than the level of interest (50µgkg-1), suggesting possible contamination or illegal use of that antibiotic.

Fatty acid profiles in meat from Caiman yacare (Caiman crocodilus yacare) raised in the wild or in captivity

Chemical composition and fatty acid profiles were determined in Caiman yacare meat originating from the neck and tail cuts of animals raised in the wild (n=6) or in captivity (n=6), slaughtered at a live weight of approximately 6 kg. All experimental methods were approved by the appropriate environmental protection agencies. Most chemical components were affected by the origin-cut interaction, with the tail cut of wild animals having the highest amount of intramuscular fat (19.2% of DM) and the lowest of moisture (71.8%) and protein (77.0% of DM). Yacare meat had low amounts of SFA (35.1%), which were similar (P>0.05) in the cuts and origins studied. The total amount of PUFA was higher (P<0.05) in wild (31.0%) than in captive animals (23.6%), and n-3 fatty acids had means of about 5% and 2% for the same groups, respectively (P<0.05). In general, the FA profile of intramuscular fat in yacare meat had a desirable PUFA/SFA ratio above 0.4.

Old beagle dogs have lower faecal concentrations of some fermentation products and lower peripheral lymphocyte counts than young adult beagles

The effects of age on microbiota composition, gut fermentation end-product formation and peripheral lymphocyte numbers were compared between old and young adult Beagle dogs fed four kibble diets differing in yeast cell wall contents. The experiment had a double 4 × 4 Latin square design, one with four mature dogs (4 years old) and the other with four old dogs (10 years old), with four replicates (diets) per dog. In each period a 15 d adaptation period preceded a 5 d total collection of faeces for the digestibility trial. On day 21, fresh faecal samples were collected for the determination of bacterial enumeration, pH, biogenic amine and short-chain fatty acid. Flow cytometry was used for immunophenotypic evaluation. Dogs were fed four kibble diets with similar composition with 0, 0.15, 0.30 and 0.45 % of yeast cell wall (as-fed), respectively. Data were evaluated using general linear models of Statistical Analysis Systems statistical software (P < 0.05). No evidence of a difference in faecal bacteria counts between ages was found (total aerobes, total anaerobes, Bifidobacterium, Lactobacillus, Clostridium and Escherichia coli: P>0.15). Faecal concentrations of butyrate, histamine, agmatine and spermine were lower (P ≤ 0.05) and faecal pH was higher (P = 0.03) in older dogs than in mature adult dogs, suggesting an alteration in bacterial metabolic activity, or in the rate of intestinal absorption of these compounds. Concentrations of T-lymphocytes, T-cytotoxic lymphocytes and B-lymphocytes were also lower (P ≤ 0.01) in older dogs than in mature adult dogs. The study confirmed alterations in peripheral lymphocytes and revealed a reduced concentration of some fermentation end products in the colon of old dogs.

Optimization of the analytical extraction of polyamines from milk.

Polyamines play an important role as growth promoters, in the maturation of the intestinal tract of infants and in the modulation of the immune response; consequently, the importance of polyamines in the diet of infants and adults is well established. However, information on the occurrence and levels of polyamines in cows milk and milk from other species (including human milk) is contradictory. Furthermore, the methods used for the extraction of amines from these samples vary widely. Therefore, a method for the accurate analysis of amines in milk from different species and in milk products is needed. A sequential strategy of experimental designs was used to optimize the analytical extraction of polyamines from milk. The dependent variables that significantly affected the recoveries were screened through a Plackett-Burman design. Sulfosalicylic acid (SSA) provided better recoveries compared to trichloroacetic acid. Centrifugation time and speed during extraction were independent variables. The Central Composite Rotational Design used to optimize the dependent variables indicated that the optimal conditions for the extraction of polyamines were 40s vortexing, four successive extractions, and an SSA concentration of 1.5%. These conditions provided recoveries ≥ 92.8% and CV ≤ 5.8%. The experiments confirmed the predicted results, indicating that the optimized conditions and models used were effective in the determination of amines from milk. Samples of raw milk and milk beverages were observed to be poor sources of spermine and spermidine, whereas human milk contained both amines.