763 research outputs found

    Comunicación corta. Aflatoxina y ochratoxina A totales en hígado, riñones y plasma de pollos contaminados experimentalmente

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    Mycotoxicosis, particularly that caused by aflatoxins and ochratoxins, is a serious problem for the poultry production industry. The aim of this study was to determine the total aflatoxin and ochratoxin A levels in liver and plasma, and kidneys and plasma, respectively, of chickens for fattening fed experimentally contaminated diets, and to assess the impact of these toxins on body weight increase and the feed conversion ratio (FCR). Forty eight 21 day-old Ross breeder chickens (n = 12 x four treatments) were fed diets containing different levels of mycotoxins: grower diet + ochratoxin A (200 mg/kg of feed) + total aflatoxin in different concentrations (T1 = 60 microg/kg of feed; T = 50 microg/kg; T3 = 30 microg/kg). Control chickens (T4) were fed only the grower diet. No significant differences were seen in the weight increase of chickens subjected to the different treatments. However, lower FCRs were seen in those exposed to T1 and T2. In general, the amount of total aflatoxin and ochratoxin A found in the liver, kidneys and plasma (determined by ELISA) were directly related to the amounts added to the experimental diets and feed consumption. Plasma ochratoxin A was always higher than kidney levels; this relationship was not seen for total aflatoxin.Las micotoxicosis, en particular las aflatoxicosis y ocratoxicosis, son un serio problema sanitario en la producción avícola. El objetivo de este trabajo fue determinar el nivel de aflatoxinas y ochratoxinas A en hígado y plasma, y riñones y plasma, respectivamente, de pollos alimentados con dietas experimentalmente contaminadas e investigar el impacto de estas toxinas en el peso corporal y el cociente de conversión del alimento (FCR). Se alimentaron 48 pollos Ross de 21 días de edad (n = 12 x cuatro tratamientos) con dietas conteniendo diferentes niveles de micotoxinas: una dieta de crecimiento + 200 mg/kg de ochratoxina A + aflatoxina total en diferentes concentraciones (T1 = 60 microg/kg; T2 = 50 microg/kg; T3 = 30 microg/kg). Lo pollos control (T4) fueron solamente alimentados con la dieta de engorde. No hubo diferencias significativas en el aumento de peso de los pollos sometidos a los diferentes tratamientos; sin embargo, se detectaron FCRs menores para los expuestos a T1 y T2. En general, la cantidad de aflatoxina total y ochratoxina A detectadas por ELISA en hígado, riñones y plasma fueron directamente proporcionales a los niveles de las micotoxinas añadidas a las dietas experimentales. La ochratoxina A en plasma fue siempre superior a la encontrada en riñón; esta relación no se detectó para la aflatoxina total

    Control of Autochthonous Spoilage Lactic Acid Bacteria in Apple and Orange Juices by Sensorially Accepted Doses of Citrus Spp. Essential Oils Combined with Mild Heat Treatments

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    This study assessed the compromised acceptance threshold (CAT) and rejection threshold (RT) of Citrus lemon (CLEO) and Citrus reticulata essential oil (CREO) in apple and orange juices. The efficacy of CLEO and CREO concentrations below the RT were evaluated alone and combined with mild heat treatment (MHT) (54 °C, up to 12 min) to inactivate the autochthonous spoilage bacteria Lactobacillus brevis, Lactobacillus plantarum, and Leuconostoc mesenteroides in apple and orange juices. The CAT of CLEO and CREO varied from 0.15 to 0.17 µL/mL in orange and apple juices. The RT of CLEO was approximately 0.58 µL/mL in apple and orange juices, and the RT of CREO was 0.68 µL/mL in both juices. When CLEO and CREO were assayed alone, the highest concentration (0.50 µL/mL) decreased counts of all strains approximately 2 log 10 CFU/mL after 12 min of exposure to 54 °C. All concentrations of CLEO or CREO in combination with MHT acted synergistically against L. brevis, L. plantarum, and L. mesenteroides. Decreases in counts varied with the strain, CLEO and CREO concentrations, juice type, and exposure time to the combined treatment. CREO was more effective than CLEO in combination with MHT against the strains in apple and orange juices. Effective combinations of CLEO or CREO with MHT to control the autochthonous spoilage bacteria did not compromise the quality parameters (°Brix, pH, and titratable acidity) that characterize unsweetened juices. These results indicate CLEO or CREO at concentrations below the sensory RT in combination with MHT as a feasible technology to control autochthonous spoilage bacteria in fresh fruit juices. Practical Application: The present study provides novel information concerning the efficacy of sensorially accepted doses of CLEO and CREO combined with MHT against autochthonous spoilers in fruit juice. The valuable synergistic effects that can be observed when combining CLEO and CREO with MHT reveal a feasible preservation technology and alternative to traditional treatments that are successful because they help reduce treatment intensity, thereby avoiding adverse effects on the sensory, physicochemical, and nutritional properties of these products

    In vivo assessment of possible probiotic properties of Zymomonas mobilis in a Wistar rat model

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    In recent years the incorporation of probiotic bacteria into foods has received increasing scientific interest for health promotion and disease prevention. The safety and probiotic properties of Zymomonas mobilis CP4 (UFPEDA-202) was studied in a Wistar rat model fed the 109 colony forming units (cfu)/mL-1 of the assayed strain for 30 days. No abnormal clinical signs were noted in the group receiving viable cells of Z. mobilis and water (control) during the period of the experiment. There were no significant difference (p > 0.05) in feed intake and weight gain among mice fed the Z. mobilis in comparison to the control group. No bacteria were found in blood, liver and spleen of any animals. Mice receiving Z. mobilis showed significantly differences (p < 0.05) in total and differential leucocytes count, excepting for neutrophils, after the experimental period. Otherwise, it was not found in control group. Histological examination showed that feeding mice with Z. mobilis caused no signs of adverse effects on gut, liver and spleen. From these results, Z. mobilis CP4 (UFEPEDA-202) is likely to be nonpathogenic and safe for consumption, and could have a slight modulating effect on immunological performance in mice

    Primeiro levantamento de mosca das frutas (Diptera: Tephritidae) e diversidade de parasitoides entre frutos de myrtaceae em todo o Estado da Bahia, Brasil

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    The objective of this study was to evaluate the diversity of fruit fly (Diptera: Tephritidae) species that use myrtaceous fruit, particularly guava, as hosts in several localities in the state of Bahia and to determine the infestation rates, pupal viability rates, and fruit fly-parasitoid associations. Sampling of myrtaceous fruit was carried out in 24 municipalities in different regions in the state of Bahia. Four fruit fly species, Anastrepha fraterculus, Anastrepha zenildae, Anastrepha sororcula, and Ceratitis capitata were obtained from the collected fruit. Three parasitoid species (Hymenoptera: Braconidae) emerged from Anastrepha larvae/pupae, Doryctobracon areolatus, Utetes anastrephae, and Asobara anastrephae. Doryctobracon areolatus emerged from A. fraterculus, A. sororcula and A. zenildae; Utetes anastrephae emerged from A. fraterculus and A. zenildae; and Asobara anastrephae emerged from A. fraterculus. Fruit fly and myrtaceous fruit associations are reported for the first time in several municipalities in the state of Bahia. A. zenildae was found infesting Syzygium malaccense for the first time in Brazil

    Engineering Branch-and-Cut Algorithms for the Equicut Problem

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    A minimum equicut of an edge-weighted graph is a partition of the nodes of the graph into two sets of equal size such hat the sum of the weights of edges joining nodes in different partitions is minimum. We compare basic linear and semidefnite relaxations for the equicut problem, and and that linear bounds are competitive with the corresponding semidefnite ones but can be computed much faster. Motivated by an application of equicut in theoretical physics, we revisit an approach by Brunetta et al. and present an enhanced branch-and-cut algorithm. Our computational results suggest that the proposed branch-andcut algorithm has a better performance than the algorithm of Brunetta et al.. Further, it is able to solve to optimality in reasonable time several instances with more than 200 nodes from the physics application

    Moscas-das-frutas (Diptera: Tephritidae) em um pomar de goiabeira, no semiárido brasileiro

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    As moscas-das-frutas (Diptera: Tephritidae) são pragas-chave na cultura da goiabeira Psidium guajava L., com predominância de diferentes espécies de acordo com a região produtora no Brasil. Os objetivos do presente trabalho foram conhecer a diversidade e analisar parâmetros faunísticos das moscas-das-frutas obtidas em um pomar de goiabeira, no município de Cruzeta, Rio Grande do Norte, situado no semiárido brasileiro. As moscas-das-frutas foram coletadas semanalmente, com auxílio de armadilhas McPhail, tendo como atrativo proteína hidrolisada a 5% v/v. Foram registradas cinco espécies no pomar estudado: Ceratitis capitata (Wied.), Anastrepha zenildae Zucchi, Anastrepha sororcula Zucchi, Anastrepha obliqua (Macquart) e Anastrepha dissimilis Stone. Ceratitis capitata foi a espécie mais frequente, constante e dominante, considerada como uma praga invasiva, potencial em pomares de goiabeira no semiárido brasileiro
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