Avaliação do potencial antibacteriano do extrato aquoso de alho (Allium sativum) em hambúrgueres de carne bovina e sua correlação com a qualidade sensorial / Evaluation of the antibacterial potential of aqueous garlic extract (Allium sativum) in bovine meat hamburgers and its correlation with sensory quality

O risco de Doenças Veiculadas por Alimentos - DVA em hambúrgueres pode ser minimizado pelo uso de antimicrobianos naturais. O objetivo do presente trabalho foi avaliar a eficiência de diferentes concentrações do Extrato Aquoso de Alho - EAA na inibição de Escherichia coli, Salmonella enterica, Cronobacter sakazakii, Listeria monocytogenes, Staphylococcus aureus e Bacillus cereus e avalia r sensorialmente as amostras de hambúrguer adicionadas de EAA. Os resultados indicaram que o EAA inibiu o crescimento das cepas bacterianas, sendo a ação inibitória proporcional às concentrações usadas sendo que a refrigeração a 7°C por 72 h do EAA não afetou seu efeito inibitório. Na análise sensorial, houve boa aceitabilidade e intenção de compra positiva para as amostras, com destaque para aquelas com maior concentração de EAA (1000μL/mL).

Patogenicidad de especies de Fusarium asociadas a la pudrición basal del ajo en el centro norte de México / Fusarium species associated with basal rot of garlic in North Central Mexico and its pathogenicity

El ajo en México es uno de los cultivos de hortalizas más rentables, más del 83% de esta superficie es aportada por los estados de Zacatecas, Guanajuato, Sonora, Puebla, Baja California y Aguascalientes. La pudrición basal ocasionada por Fusarium spp. se encuentra ampliamente distribuida a nivel mundial; esta enfermedad se ha convertido en una limitante en zonas productoras de cebolla y ajo, no solo en México, sino también en otros países, En México, se ha informado la presencia de Fusarium oxysporum en plantas en Guanajuato y en semillas de ajo en Aguascalientes. En el estado de Morelos se ha reportado la presencia de Fusarium culmorum en cultivares de cebolla. Asimismo, en Aguascalientes se tienen antecedentes de otras especies como Fusarium proliferatum, Fusarium verticillioides, Fusarium solani y Fusarium acuminatum. Para este trabajo se planteó como objetivo identificar las especies de Fusarium encontradas en los estados de Zacatecas, Guanajuato y Aguascalientes, y evaluar su patogenicidad. Se realizaron recolectas de plantas con síntomas de la enfermedad en los estados antes mencionados. De los muestreos realizados se identificaron las especies F. oxysporum, F. proliferatum, F. verticillioides, F. solani y F. acuminatum; las cepas de Aguascalientes identificadas como AGS1A (F. oxysporum), AGS1B (F. oxysporum) y AGSY-10 (F. acuminatum) fueron las que presentaron bajo condiciones de invernadero un mayor índice de severidad.

Garlic in Mexico is one of the most profitable vegetable crops, grown in almost 5,451 ha; out of which more than 83% are located in Zacatecas, Guanajuato, Sonora, Puebla, Baja California and Aguascalientes. Blossom-end rot caused by Fusarium spp is widely distributed worldwide and has been a limiting factor in onion and garlic production regions, not only in Mexico but also in other countries. The presence of Fusarium oxysporum has been reported in Guanajuato and Aguascalientes. Fusarium culmorum has been reported in onion cultivars of Morelos; and Fusarium proliferatum, Fusarium verticillioides, Fusarium solani and Fusarium acuminatum have been previously reported in Aguascalientes. The goal of this work was identifying the Fusarium species found in Zacatecas, Guanajuato and Aguascalientes, to assess their pathogenicity. Plants with disease symptoms were collected from hereinabove mentioned States. The samples resulted in the identification of: F. oxysporum, F. proliferatum, F. verticillioides, F. solani and F. acuminatum species; out of which Aguascalientes AGS1A (F. oxysporum), AGS1B (F. oxysporum) and AGSY-10 (F. acuminatum) strains showed higher severity under greenhouse conditions.

Antifungal activity of metabolites of the endophytic fungus Trichoderma brevicompactum from garlic

The endophytic fungus strain 0248, isolated from garlic, was identified as Trichoderma brevicompactum based on morphological characteristics and the nucleotide sequences of ITS1-5.8SITS2 and tef1. The bioactive compound T2 was isolated from the culture extracts of this fungus by bioactivity-guided fractionation and identified as 4β-acetoxy-12,13-epoxy-Δ9-trichothecene (trichodermin) by spectral analysis and mass spectrometry. Trichodermin has a marked inhibitory activity on Rhizoctonia solani, with an EC50 of 0.25 µgmL-1. Strong inhibition by trichodermin was also found for Botrytis cinerea, with an EC50 of 2.02 µgmL-1. However, a relatively poor inhibitory effect was observed for trichodermin against Colletotrichum lindemuthianum (EC50 = 25.60 µgmL-1). Compared with the positive control Carbendazim, trichodermin showed a strong antifungal activity on the above phytopathogens. There is little known about endophytes from garlic. This paper studied in detail the identification of endophytic T. brevicompactum from garlic and the characterization of its active metabolite trichodermin.

Estudio microbiológico de ajo(Allium sativum L.) y cebolla (Allium cepa L.) deshidratados / Microbiological study of garlic (Allium sativum L.) and onion (Allium cepaL.) dehydrated

En este trabajo se efectuó un estudio microbiológico durante la deshidratación y el almacenamiento de ajo (Allium sativum L.) y de cebolla (Allium cepa L.). Al ajo se le efectuó un proceso de escaldado y a la cebolla un salmuereado previo a la deshidratación. En las materias primas los recuentos promedio expresados en UFC/g fueron: bacterias aerobias mesófilas entre 1,2 x 102y 1,6 x 103, mohos y levaduras entre 60 y 1,6 x 103, Lactobacillus spp. y Leuconostocmesenteroidessubesp. mesenteroides entre 10 y 50.Se identificaron: Penicillium spp., Monilia spp. Lactobacillus brevis,Leuconostoc mesenteroides subesp. mesenteroides y levaduras en ajo; Mucor spp., Penicillium spp., Monilia spp., Lactobacillus brevis y levaduras en dos tipos de cebolla. Leuconostoc mesenteroides subesp. mesenteroides sólo se detectó en un tipo de cebolla. En ajos deshidratados y durante el almacenamiento se hallaron Penicillium spp., Monilia spp., Lactobacillus brevis y levaduras mientras que los mismos con escaldado no presentaron desarrollo. Mucor spp., Penicillium spp., Monilia spp. y Lactobacillus brevis se identificaron en los dos tipos de cebolla deshidratadas. Con la incorporación del salmuereado la microflora se redujo significativamente hallándose solamente Penicillium spp. La utilización de barreras adicionales de control microbiano tales como escaldado y salmuereado produce un aporte importante a la estabilidad microbiológica de los productos.

A microbiological study during the process and the storage of garlic (Allium sativum L.) and onion (Allium cepa L.) dehydrated, with the additional barriers of blanching or brine immersion, was made. In all raw materials the average counts of aerobic mesophilic bacteria expressed in CFU/g ranged from 1.2 x 102to 1.6 x 103, molds and yeasts from 60 to 1.6 x 103, Lactobacillus spp. and Leuconostocmesenteroides subsp. mesenteroides between 10 and 50. Microorganisms identified were Penicillium spp., Monilia spp., Lactobacillus brevis, Leuconostoc mesenteroides subsp. mesenteroides and yeasts in garlic; Mucor spp., Penicillium spp., Monilia spp., Lactobacillus brevis and yeasts in both types of onions. Leuconostoc mesenteroides subsp. mesenteroides was detected in only kind of onion. In dehydrated garlic storage, Penicillium spp., Monilia spp., Lactobacillus brevis and yeasts were detected. In garlic, when a blanching step was carried out no microflora was detected. Mucor spp., Penicillium spp., Monilia spp. and Lactobacillus brevis were identified in both types of dehydrated onions. When brine immersion was included the microflora detected was significantly lower and only Penicillium spp. were found. The use of additional barriers such as blanching or brine immersion produces an important effect on the microbiological stability in these products.

Identification of phytopathogenic bacteria associated with a Post-Harvest Disease of garlic cloves in relation to cell-wall-degrading enzymes

Five bacterial isolates were isolated from soft rot of garlic cloves collected from different markets in Menia Governorate. The isolated bacteria caused soft rot of wounded cloves when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in the specific symptoms induced in the different hosts. Furthermore, new hosts for the isolated pathogens were recorded under experimental conditions. The isolated pathogenic bacteria were identified as Bacillus subtilis [three isolates], Bacillus pumilus [one isolate] and Bacillus coagulans [one isolate]. Furthermore, they proved active in degrading parenchymatous tissue of many tested plant organs. The extracts of experimentally diseased garlic cloves were active in pectinase [at pH 5 and 8] and carboxymethyl cellulase at pH 6. On the other hand, no enzyme activities for the tested enzymes were detected in healthy tissues. Some biological changes occurred during pathogenesis were investigated

antimicrobial effect of garlic [Allium sativum] extract on mouth microflora

Five strains of mouth normal microflora containing staphylococcus epidermidis, streptococcus mutant, lactobacillus acidophilus, Actinomyces viscosos and candida albicans, were isolated and identified then cultured and purified on different media by using routine methods in microbiology. Extract of 3 garlic samples south [Khuzestan], north [Mazanderan] and Hamedan garlics, were affected on these microbial cultures using Bauer and Kirby method. The effects were compared with antimicrobial effects of erythromycin. The results show all three used extracts have antimicrobial effects. The extract had a bactericidal effect on bacteria but a fungi static on candida albicans