The effects of residual blood of carcasses on the microbiological quality of poultry

To prove the residual blood factors that are responsible for high contamination of carcasses, this study was conducted to compare the microbial level in poultry both perfectly and imperfectly bled. At 3°C storage temperature, the average number of bacteria of perfectly bled poultry was 7.05 × 102 ufc/g which was significantly (P≤ 0.05) lower than the average number of bacteria of imperfectly bled poultry (1 .78 × 104 ufc/g). At 7°C storage temperature, the average number of bacteria of perfectly bled poultry was 6 .18 × 103 ufc/g which was significantly (P≤ 0.05) lower than the average number of bacteria of imperfectly bled poultry (3.60 × 104 ufc/g). The meat samples were taken from the chest and thigh to reflect the heterogeneity of the contamination. The rise in the storage temperature increased the bacteria in the two types of poultry; but the number of bacteria of perfectly bled poultry was still minimal. The residues of blood increased the degree of contamination of carcasses. It was found out that there were effects of season on the results of 80 samples from chicken carcasses (n = 80; 40 were used in the winter and 40 in the summer).Keywords: Residual blood, total aerobic mesophilic flora (TAMF), perfectly bled poultry, imperfectly bled poultr

Combinations of nisin with salt (NaCl) to control Listeria monocytogenes on sheep natural sausage casings stored at 6°C

This study evaluated the effect of combinations of nisin with salt (NaCl) to control Listeria monocytogenes on sheep natural sausage casings. Casings were inoculated with 3.0 x 105 cfu/g final inocula of L. monocytogenes, stored at 6°C in different solutions of nisin at 0, 100, 150 and 200 ìg/g.Each combined with salt at 0, 4, 7 and 12% (w/v). Samples were taken at day 0, 10, 20, 35, 60 and 90 post-inoculation and the number of bacteria present was determined. The bactericidal effect of nisin against L. monocytogenes cells was evident where nisin was applied in combination with salts. In all treatments, nisin/salt mixtures induced a bacterial growth inhibitory effect greater than salt alone. These results indicate that nisin and salt synergistically and significantly inhibit the growth of L.monoctogenes in sheep natural casings. The use of nisin combined with salt as antibacterial agent will be appropriate for applications on natural sausage casing industries as natural preservatives to control foodborne pathogens. They can be used as growth inhibitors of L. monocytogenes, an important foodborne pathogens and spoiling bacterium. The main reason for their appropriateness is their natural origin, which consumers find comforting. These beneficial characteristics could increase casings safety and shelf life

Effect of genotype on callus induction and plant regeneration from leaf explants of sugarcane (Saccharum sp.)

Nine sugarcane genotypes (CP59-73, CP63-588, CP80-314, SP71-1081, F160, L62-96, CP70-321, CP57- 614 and Clone III) were evaluated for their callus induction capacity, embryogenic callus production and plant regeneration ability. Leaf cylinders were used as explants using Murashige and Skoog (MS) based medium supplemented with 3 mg l-1 2,-4 dichlorophenoxyacetic acid. Plant regeneration was accomplished on hormone free modified MS medium supplemented with casein hydrolyzate. The genotypes tested showed high callus induction percentage (69 to 95%) and high embryogenic callus percentage (60 to 100%). These genotypes also showed excellent regeneration capacities, with regeneration percentages ranged between 88 and 100%. Significant differences were observed between genotypes for callus induction capacity, embryogenic response and plant regeneration ability indicating that these criteria are genotype dependent. Plant regeneration ability is highly correlated with embryogenic callus production. The in vitro regenerated plants were successfully rooted and well acclimatised in growth cabinet conditions

Antibacterial and antioxidant activities of Origanum compactum essential oil

In the present study, essential oil of Origanum compactum was analysed and its chemical composition was identified by gas chromatography coupled to mass spectrometry (GC-MS). Among thirty two assayed constituents, carvacrol (30.53%), thymol (27.50%) and its precursor g-terpinene (18.20%) were found to be the major components. The oil was investigated for its in vitro antibacterial activity against a panel of standard reference strains using well diffusion and broth dilution methods. In solid medium, the oil was found to be remarkably active against all tested strains except Pseudomonas which showed resistance. In liquid medium the Minimum Inhibitory Concentrations (MICs) and Minimum Bactericidal Concentration (MBCs) ranged from 0.0078 to 0.25% (v/v). The antioxidant activity was investigated by three different methods; 1,1-diphenyl-2-picryl-hydrasyl (DPPH) radical scavenging assay, -carotenebleaching test and reducing power. The results of this study revealed evidence that the essential oil of O. compactum possesses a good antioxidant effect with all assays; the antioxidant activity isdependent on the oil concentration and can be attributed to the phenolic compounds present in the oil

Antimicrobial activities of the bacteriocin-like substances produced by lactic acid bacteria isolated from Moroccan dromedary milk

A total of 450 different colonies, isolated from 25 samples of dromedary milk collected from Laâyoune region of Morocco, were tested for antimicrobial compounds production. Out of these, 30 were determined to be lactic acid bacteria (LAB) and able to inhibit the growth of the indicator strain Listeria innocua CECT 4030. Seven isolates were selected by the large and clear zones of inhibition when tested by the agar well diffusion assay. They were classified by phenotypic and biochemical analysis as two Enterococcus durans (E204 and E214), two Lactococcus lactis (R75 and R76), one Enterococcus faecium R111, one Lactococcus cremoris R112 and one Enterococcus avium R122. Their antimicrobial compounds were detected in cell-free culture supernatant fluids under conditions that eliminate acid and hydrogen peroxide inhibition. The antimicrobial activity was altered after treatment with trypsin, -chymotrypsin, pepsin or papain which confirms the proteinaceous nature of the inhibition. It was heat stable even at autoclaving temperature (121°C for 15 min) and also active over a wide pH range (2 to 10). This fact suggests that bacteriocin-like produced by the seven LAB strains may find application as biopreservatives in food products.Key words: Dromedary milk, lactic acid bacteria, bacteriocin-like substances, antimicrobial activity

Growth, proline and ion accumulation in sugarcane callus cultures under drought-induced osmotic stress and its subsequent relief

Calli obtained from two sugarcane cultivars (R570 and CP59-73) were exposed to different osmotic stress intensities followed by a period of stress relief. Relative rate growth, callus water content and changes in organic and inorganic solutes were determined at the end of stress and relief periods. After the stress period, calli derived from both cultivars showed a decrease in RGR, but at lesser extent in R570 than CP59-73 cultivar. Same tendency was recorded in the callus water content under mannitolinduced osmotic stress. The inorganic solutes seemed to have no contribution in the osmotic adjustment in mannitol-stressed calli since K+ and Ca2+ concentrations decreased drastically while Na+ and Mg2+ concentrations were not affected. The accumulation of proline occurred in both cultivars and was more marked in CP59-73 than R570 cultivar. At the end of the relief period, we observed that all the considered parameters have recovered completely to reach the control levels. According to these results, we conclude that the drought stress-induced changes are reversible, at the least at the cellular level, in sugarcane cultivar

In vitro culture techniques as a tool of sugarcane bud germination study under salt stress

Germination was the first stage confronted to soil salinity and it is important to determine salt effects on this stage. In this study, we reported an in vitro procedure for studying sugarcane bud germinationand shoot growth under salt stress with different NaCl concentrations (0, 17, 34, 68 and 102 mM) using cultivar NCo310. Germination percentage of control was about 92% after 8 days. Germination of buds,plant fresh and dry mass decreased with increasing salinity. Data indicated that in vitro culture techniques could be used to evaluate salt stress effects in sugarcane at the germination stage