Artículos y presentaciones en Congresos
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Examinando Artículos y presentaciones en Congresos por Autor "De Antoni, Graciela Liliana"
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Acceso Abierto Antifungal Activity against Aspergillus parasiticus of Supernatants from Whey Permeates Fermented with Kefir Grains(Scientific Research Publishing, 2015) Gamba, Raúl; Ni Colo, Carolina; Correa, Mariana; Astoreca, Andrea; Alconada, Teresa; De Antoni, Graciela Liliana; León Peláez, ÁngelaAspergillus parasiticus, a common fungal contaminant in food, produces aflatoxin B1, which is classified as human carcinogen. Kefir is an ancient fermented beverage obtained by the fermentation of different substrates with kefir grains. A very important waste produced by the dairy cheese industry is the whey permeate, which nowadays is a strong ambient contaminant. The aim of this work was to assess the effect of whey permeates fermented with kefir grains against A. parasiticus growth, aflatoxin B1 biosynthesis, and the kefir microorganisms protection against the cell damage produced by aflatoxin B1. It was observed that kefir-cell-free-supernatants (CFS) produced fungal inhibition. A fungicidal effect was observed with 65% v/v of CFS in the culture medium (final pH 4.55 and total undissociated lactic and acetic acid concentration 34.08 mM). Under these conditions, aflatoxin production was not detected. Finally, it was found that non-viable kefir microorganisms protected HepG2 cells from the damage produced by aflatoxin B1. - Artículo
Acceso Abierto Novel Functional Whey-Based Drinks with Great Potential in the Dairy Industry(2015) Pereira, Carlos; Henriques, Marta; Gomes, David; Gomez-Zavaglia, Andrea; De Antoni, Graciela LilianaThis work focuses on the production of liquid whey protein concentrates by ultrafi ltration followed by thermal denaturation and homogenization of the ultrafi ltrated concentrate, as well as on the production of ultrafi ltrated permeates concentrated by reverse osmosis. Kefi r grains (fresh and thawed) and/or commercial probiotic bacteria were inoculated in both liquid whey protein concentrates and concentrated ultrafi ltrated permeates and grown at 25 °C for 24 h for the manufacture of fermented drinks. The physicochemical characterization (pH, titratable acidity, viscosity, and content of total solids, ash, fat and proteins) of the obtained drinks was then assessed and compared. Enumeration of viable microorganisms was carried out immediately aft er inoculation (at 0 h), during the fermentation period (at 12 and 24 h) and during refrigerated storage (at 48, 168 and 336 h). The fermented drinks showed acceptable physicochemical and sensorial properties, and contained above 7 log CFU/mL of lactococci and lactobacilli and 6 log CFU/mL of yeasts aft er 14 days of refrigerated storage, which is in agreement with the standards required by international organizations like European Food Safety Authority (EFSA) and Food and Drug Administration (FDA) for products containing probiotics. In summary, the strategy developed in this work contributes to the expansion of the applications of products derived from whey fractionation for the design of novel functional foods. - Artículo
Acceso Abierto Safety Characterization and Antimicrobial Properties of Kefir-Isolated Lactobacillus kefiri(Hindawi Publishing Corporation, 2014) Carasi, Paula; Díaz, Mariángeles; Racedo, Silvia M.; De Antoni, Graciela Liliana; Urdaci, María C.; Serradell, María de los ÁngelesLactobacilli are generally regarded as safe; however, certain strains have been associated with cases of infection. Our workgroup has already assessed many functional properties of Lactobacillus kefiri, but parameters regarding safety must be studied before calling them probiotics. In this work, safety aspects and antimicrobial activity of L. kefiri strains were studied. None of the L. kefiri strains tested caused α- or β-hemolysis. All the strains were susceptible to tetracycline, clindamycin, streptomycin, ampicillin, erythromycin, kanamycin, and gentamicin; meanwhile, two strains were resistant to chloramphenicol. On the other hand, all L. kefiri strains were able to inhibit both Gram(+) and Gram(−) pathogens. Regarding the in vitro results, L. kefiri CIDCA 8348 was selected to perform in vivo studies. Mice treated daily with an oral dose of 108 CFU during 21 days showed no signs of pain, lethargy, dehydration, or diarrhea, and the histological studies were consistent with those findings. Moreover, no differences in proinflammatory cytokines secretion were observed between treated and control mice. No translocation of microorganisms to blood, spleen, or liver was observed. Regarding these findings, L. kefiri CIDCA 8348 is a microorganism isolated from a dairy product with a great potential as probiotic for human or animal use.