Hydrolysis of raw fish proteins extracts by Carnobacterium maltaromaticum strains isolated from Argentinean freshwater fish

Lactic acid bacteria (LAB) isolated from freshwater fish (hatcheries and captures) from Paraná river (Argentina) were analyzed by using culture-dependent approaches. The species belonging to Carnobacterium (C.) divergens, C. inhibens, C. maltaromaticum, C. viridans and Vagococcus (V.) salmoninarum were identify as predominant by RAPD-PCR and 16 s rRNA gene sequencing. C. maltaromaticum (H-17, S-30, B-42 and S-44) grew in raw fish extract and slightly reduced the medium pH (5.81–5.91). These strains exhibited moderate fish sarcoplasmic protein degradation (≤ 73 %) releasing small peptides and free amino acids, being alanine, glycine, asparagine and arginine concentrations increased in a higher extent (17.84, 1.47, 1.26 and 0.47 mg/100 mL, respectively) by S-44 strain at 96 h incubation. Interestingly C. maltaromaticum H-17 was able to inhibit Listeria monocytogenes. Results suggest that these strains would contribute to the development of new safe and healthy fishery products with improved nutritional and sensory characteristics.Fil: Dallagnol, Andrea Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Materiales de Misiones. Universidad Nacional de Misiones. Facultad de Ciencias Exactas Químicas y Naturales. Instituto de Materiales de Misiones; ArgentinaFil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Gamarra Espínola, Natalia. Universidad Nacional de Misiones; ArgentinaFil: Vera, Mariela Natalia. Universidad Nacional de Misiones; ArgentinaFil: Vignolo, Graciela Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Characterization of Aminopeptidase N from Streptococcus Thermophilus TW43

Se estudiaron las características bioquímicas y cinéticas de Aminopeptidasa N (PepN) de Streptococcus thermophilus TW43. La máxima actividad de la enzima fue determinada a pH 6,8 y 40ºC. El EDTA y la o-fenantrolina inhibieron fuertemente a PepN, en consecuencia se la consideró una metalopeptidasa. El imidazol inhibió parcialmente la actividad enzimática sugiriendo que la histidina es responsable de la unión del ión metálico en el sitio activo. Dentro de los cationes divalentes solo el Cu++ exhibió una leve inhibición, mientras que el Co++ aumentó la actividad enzimática aproximadamente cinco veces. La PepN se mantuvo activa bajo las condiciones de maduración sugiriendo que Streptococcus thermophilus TW43 puede contribuir al desarrollo del flavor en quesos a través de su función en la producción de aminoácidos libres.Biochemical and kinetic characteristics of the general Aminopeptidase N (PepN) from Streptococcus thermophilus TW43 were studied. Maximal activity of the enzyme was determined at pH 6.8 and 40ºC. Pep N was strongly inhibited by EDTA and o-phenanthroline. Therefore, it was considered to be a metallopeptidase. Imidazole partially inhibited enzyme activity suggesting histidine is one of the amino acids related to metal binding in the active site. Among the bivalent cations only Cu++ exhibited slight inhibition while Co++ increased enzymatic activity nearly fivefold. PepN remained active under ripening condition (pH 5.0 and 15ºC) suggesting that Streptococcus thermophilus TW43 may contribute to flavor cheese development through its role in production of free amino acids.Fil: Marguet, Emilio Rogelio. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; ArgentinaFil: Vallejo, Marisol. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pescuma, Micaela. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Trelew; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Biotransformation of Selenium by Lactic Acid Bacteria: Formation of Seleno-Nanoparticles and Seleno-Amino Acids

Selenium (Se) is an essential micronutrient for the majority of living organisms, and it has been identified as selenocysteine in the active site of several selenoproteins such as glutathione peroxidase, thioredoxin reductase, and deiodinases. Se deficiency in humans is associated with viral infections, thyroid dysfunction, different types of cancer, and aging. In several European countries as well as in Argentina, Se intake is below the recommended dietary Intake (RDI). Some lactic acid bacteria (LAB) can accumulate and bio-transform selenite (toxic) into Se-nanoparticles (SeNPs) and Se-amino acids (non-toxic). The microbial growth, Se metabolite distribution, and the glutathione reductase (involved in selenite reduction) activity of Se-enriched LAB were studied in this work. The ninety-six assayed strains, belonging to the genera Lactococcus, Weissella, Leuconostoc, Lactobacillus, Enterococcus, and Fructobacillus could grow in the presence of 5 ppm sodium selenite. From the total, eight strains could remove more than 80% of the added Se from the culture medium. These bacteria accumulated intracellularly between 1.2 and 2.5 ppm of the added Se, from which F. tropaeoli CRL 2034 contained the highest intracellular amount. These strains produced only the seleno-amino acid SeCys as observed by LC-ICP-MS and confirmed by LC-ESI-MS/MS. The intracellular SeCys concentrations were between 0.015 and 0.880 ppm; Lb. brevis CRL 2051 (0.873 ppm), Lb. plantarum CRL 2030 (0.867 ppm), and F. tropaeoli CRL 2034 (0.625 ppm) were the strains that showed the highest concentrations. Glutathione reductase activity values were higher when the strains were grown in the presence of Se except for the F. tropaeoli CRL 2034 strain, which showed an opposite behavior. The cellular morphology of the strains was not affected by the presence of Se in the culture medium; interestingly, all the strains were able to form spherical SeNPs as determined by transmission electron microscopy (TEM). Only two Enterococcus strains produced the volatile Se compounds dimethyl-diselenide identified by GC-MS. Our results show that Lb. brevis CRL 2051, Lb. plantarum CRL 2030, and F. tropaeoli CRL 2034 could be used for the development of nutraceuticals or as starter cultures for the bio-enrichment of fermented fruit beverages with SeCys and SeNPs.Fil: Martínez, Fernando Gabriel. Universidad Complutense de Madrid. Facultad de Ciencias Químicas. Departamento de Química Analítica; . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Moreno Martin, Gustavo. Universidad Complutense de Madrid. Facultad de Ciencias Químicas. Departamento de Química Analítica;Fil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Madrid Albarrán, Yolanda. Universidad Complutense de Madrid. Facultad de Ciencias Químicas. Departamento de Química Analítica;Fil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Food prospects of selenium enriched-Lactobacillus acidophilus CRL 636 and Lactobacillus reuteri CRL 1101

Selenium, which is present as SeCys in selenoproteins, is involved in cancer prevention, thyroid functioning, and pathogen inhibition. Lactobacilli can biotransform inorganic Se into seleno-amino acids. Growth, Se accumulation and seleno-amino acid formation by Lactobacillus acidophilus CRL636 and L. reuteri CRL1101 in a Se-supplemented medium were studied. Moreover, survival of Se-enriched strains to different pH values and bile salts was analyzed. L. acidophilus CRL636 showed low growth rate in the presence of Se while differences were less evident for L. reuteri CRL1101, which displayed higher amounts of intracellular SeCys and SeMet than the CRL636 strain. Interestingly, both lactobacilli could produce Se-nanoparticles. Se-enriched lactobacilli showed lower growth rates than non-Se exposed cells. The adverse effect of bile salts and the ability to survive at pH 4.0 diminished for the Se-enriched L. reuteri strain. The studied lactobacilli could be used as Se-enriched probiotics or as a vehicle for manufacturing Se-containing fermented foods.Fil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentina. Universidad Complutense de Madrid; EspañaFil: Gomez Gomez, Beatríz. Universidad Complutense de Madrid; EspañaFil: Perez Corona, Teresa. Universidad Complutense de Madrid; EspañaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Madrid Albarrn, Yolanda. Universidad Complutense de Madrid; EspañaFil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; Argentin

Functional fermented beberages enriched in seleno-amino acids and seleno-nanoparticles

Selenium (Se) is an essential micronutrient for human health, which is found as selenocysteine (SeCys) in the active site of Se-dependent enzymes involved in the response to oxidative stress and in thyroid functions. The main inorganic Se forms, selenite and selenate are toxic. Some lactic acid bacteria (LAB) can reduce Se salts into seleno-nanoparticles (SeNPs) and seleno-amino acids, which are non-toxic and highly bioavailable forms. In several European countries, as well as in Argentina, Se intake is below the recommended dietary intake (RDI). Se-enrichment of foods is an attractive strategy to increase its ingestion. We aimed to formulate a fermented fruit juice-milk beverage (FJMB) bio-enriched in Se. The fruit-origin strains Fructobacillus tropaeoli CRL 2034 and Levilactobacillus brevis CRL 2051 were grown with or without 5 mg/L of Se prior to co-inoculation (1% of each strain) in the FJMB and were incubated 14 h at 30 °C. The survival of the strains under storage conditions (6 °C, 52 days), and after digestion [using an in vitro gastrointestinal system (GIS)] was analyzed. The strains grew (up to 8.6 U log each) and acidified FJMB reaching a final pH of 4.6. Sugar metabolism and organic acid production were similar for control and selenized cells (RP-HPLC); while mannitol production by selenized cells of the Fructobacillus was lower (0.18 ± 0.03) than control cells. The studied strains could not degrade the proteins present in the FJMB (SDS-PAGE). Selenized cells increased the beverage total Se concentration (ICP-MS, 84.9 ± 4.5 μg/L) and biotransformed selenite into SeCys (39.1 ± 0.4 μg/L) and SeMet (6.1 ± 0.1 μg/L) as detected by LC-ICP-MS. Moreover, SEM images of the fermented FJMB revealed the presence of SeNPs attached to the cell surface of both strains. Interestingly, microbial resistance at the end of the shelf life was greater (between 0.5 and 0.7 U log) for selenized than non-selenized cells. However, no differences were observed in the sugar and organic acid concentrations between treated and non-treated cells and a lower (0.29 ± 0.04 g/L) mannitol production was detected at 28 day incubation by the treated strains. After GIS digestion, a decrease in the cell counts of F. tropaeoli and L. brevis (1.60 and 0.80 U log, respectively) was observed. Interestingly, 64.3 ± 3.3 μg total Se/L partly as SeCys (25.8 ± 2.3 μg/L) and SeMet (2.4 ± 0.2 μg/L) were found in the FJMB supernatant after intestinal digestion, highlighting the bioaccessibility of these compounds. Remarkably, 250 mL of the FJMB could cover 64% of the Se RDI (25 μg/day), from which 28% is composed by seleno-amino acids. Our results suggest that selenized cells of F. tropaeoli CRL 2034 and L. brevis CRL 2051 could be used for formulating functional Se-enriched beverages to improve this micronutrient intake in humans.Fil: Martínez, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Complutense de Madrid. Facultad de Ciencias Químicas; EspañaFil: Moreno Martin, Gustavo. Universidad Complutense de Madrid. Facultad de Ciencias Químicas; EspañaFil: Madrid Albarrán, Yolanda. Universidad Complutense de Madrid. Facultad de Ciencias Químicas; EspañaFil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaLVI Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; XV Annual Meeting of the Argentinean Society for General MicrobiologyVirtualArgentinaSociedad Argentina de Investigación en Bioquímica y Biología MolecularSociedad Argentina de Microbiología Genera

Biogenic selenium nanoparticles with antifungal activity against the wood-rotting fungus Oligoporus pelliculosus

Selenium nanoparticles (SeNPs) have antimicrobial and antifungal activity. SeNPs using Se resistant bacteria is a low cost and eco-friendly technology. Fungal contamination of wood during drying is one of the main causes of economic losses in the wood industry. The bacterium Delftia sp. 5 resistance to Se and its ability to produce SeNPs able to inhibit the growth of the wood brown-rotting fungus Oligoporus pelliculosus was analyzed. The strain showed an optimal SeNPs production when selenite concentration was 160 mg L−1. The SeNPs were spherical with an average size 192.33 ± 8.6 nm and a zeta potential of -41.4 ± 1.3 nm. The SeNPs produced by Delftia sp. 5 (33.6 ± 0.1 mg L−1 Se) inhibited the growth of O. pelliculosus in agar plates and in Nothofagus pumilio (Lenga) wood samples. Delftia sp. 5 SeNPs could be used for embedding lenga wood prior to drying for preventing the growth of the deteriorating fungi O. pelliculosus.Fil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Aparicio, Francisca. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Zysler, Roberto Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Lima, Enio Junior. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche | Comisión Nacional de Energía Atómica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología. Unidad Ejecutora Instituto de Nanociencia y Nanotecnología - Nodo Bariloche; ArgentinaFil: Zapata, Claudia. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; ArgentinaFil: Marfetan, Jorge Ariel. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vélez, María Laura. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ordoñez, Omar Federico. Centro de Investigación y Extensión Forestal Andino Patagónico; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Fermentación de jugos y bebidas a base de frutas

Las frutas constituyen una fuente de carbohidratos, ácidos, minerales, polifenoles, vitaminas hidrosolubles (vitamina C y del grupo B), provitamina A, aminoácidos, compuestos aromáticos, carotenoides, fibras, fitoesteroles y otras sustancias bioactivas en la dieta humana. Estos compuestos pueden prevenir patologías crónicas, cáncer, mortalidad prematura, enfermedades coronarias y disminuir el riesgo de accidente cerebrovascular. Las frutas se consumen frescas o mínimamente procesadas y tienen una vida útil corta ya que son susceptibles al deterioro microbiano. La fermentación láctica es una tecnología simple, sostenible y de bajo costo para mantener y/o mejorar las propiedades nutricionales y sensoriales de las materias primas y extender la vida útil de las frutas bajo condiciones de seguridad sanitaria. La fermentación por bacterias lácticas (BAL) puede contribuir al aroma y sabor de los jugos, así como incrementar la biodisponibilidad de los compuestos fenólicos presentes en la fruta potenciando su actividad antioxidante. Además, los jugos pueden ser fermentados por bacterias probióticas que contribuyan con la seguridad por medio de la producción de metabolitos antagónicos (bacteriocinas, peróxido, etc.) o tengan un efecto inmunomodulador sobre el huésped. De esta manera, los jugos de fruta podrían ser una fuente de probióticos para veganos o personas intolerantes a la lactosa. El jugo fermentado de fruta más ampliamente consumido es el vino; esta bebida alcohólica es el resultado de interacciones complejas entre levaduras, bacterias y las condiciones físico-químicas del mosto de la uva. Al consumo moderado de vino tinto se le han atribuido diversos efectos benéficos para la salud, siendo el resveratrol el compuesto fenólico más estudiado y popularmente conocido. Las BAL intervienen en la fermentación maloláctica durante el proceso de vinificación disminuyendo la acidez de los vinos, fermentación que también permite mejorar las características aromáticas del producto a través del metabolismo de ácidos orgánicos, carbohidratos, polisacáridos, aminoácidos y la producción de enzimas como glicosidasas, esterasas y proteasas, que generan compuestos volátiles que modifican el flavor del producto final. El desarrollo de bebidas frutales fermentadas no-alcóholicas en nuestro país constituye un área de vacancia científico-tecnológica. La posibilidad de producir un sinergismo entre el metabolismo de las BAL y los compuestos bioactivos de las frutas, dirigido a la producción de bebidas con metabolitos bioactivos de mayor biodisponibilidad y/o funcionalidad representa un desafío para el desarrollo de nuevos alimentos fermentados funcionales que incluya a consumidores con hábitos veganos o personas que poseen alergias alimenticias provocadas por alimentos lácteos o intolerancia a la lactosa.Fil: Ruiz Rodríguez, Luciana Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Mendoza, Lucia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Van Nieuwenhove, Carina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Fermentation of quinoa and wheat slurries by Lactobacillus plantarum CRL 778: proteolytic activity

Quinoa fermentation by lactic acid bacteria (LAB) is an interesting alternative to produce new bakery products with high nutritional value; furthermore, they are suitable for celiac patients because this pseudocereal contains no gluten. Growth and lactic acid production during slurry fermentations by Lactobacillus plantarum CRL 778 were greater in quinoa (9.8 log cfu/mL, 23.1 g/L) than in wheat (8.9 log cfu/mL, 13.9 g/L). Lactic fermentation indirectly stimulated flour protein hydrolysis by endogenous proteases of both slurries. However, quinoa protein hydrolysis was faster reaching 40-100% at 8 h of incubation while wheat protein hydrolysis was only 0-20%. In addition, a higher amount of peptides (24) and free amino acids (5g/L) were determined in quinoa compared to wheat. Consequently, greater concentrations (ca. 2.6-folds) of the antifungal compounds (phenyllactic and hydroxyphenyllactic acids) were synthesized from Phe and Tyr in quinoa by L. plantarum CRL 778, an antifungal strain. These promising results suggest this LAB strain could be used in the formulation of quinoa sourdough to obtain baked goods with improved nutritional quality and shelf life, suitable for celiac patients.Fil: Dallagnol, Andrea Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); Argentina. Universidad Nacional de Misiones. Facultad de Ciencias Exactas, Química y Naturales. Departamento de Microbiología; ArgentinaFil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); ArgentinaFil: Font, Graciela Maria. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Rollan, Graciela Celestina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); Argentin

Fermented mango and passion fruit juices bio-enriched with selenium using selenized lactic acid bacteria

Fruits are fundamental sources of bioactive compounds and their consumption can prevent the development of chronic pathologies. Selenium (Se) is a vital micronutrient for humans; however, excessive intake of Se salts can be toxic. Lactic acid bacteria (LAB) are able to biotransform inorganic Se into Se-nanoparticles and Se-amino acids. The objective of this work was to formulate a mango-passion fruit juice bio-enriched with Se. Lactiplantibacillus paraplantarum CRL 2051 and Fructobacillus tropaeoli CRL 2034 were grown in MRS with fructose and with the addition of 10 mg/L sodium selenite, and were incubated at 30 °C 24 h. L. paraplantarum CRL 2051 accumulated 1.68 ± 0.08 mg Se/L intracellularly, while F. tropaeoli CRL 2034 2.18 ± 0.04 mg/L (ICP-MS). Selenized and control cells (without selenite) of the assayed strains, were inoculated alone or in co-culture in pasteurized mango-passion fruit juices. The strains grew between 1.43 and 2.04 log cfu/mL and decreased the pH between 0.93 and 1.34 U after 24 h fermentation. The °Brix of the non-inoculated juice was 4.90 ± 0.14 and decreased to 4.07 ± 0.12 and 4.67 ± 0.28 after fermentation. The titratable acidity of the fermented juices increased, being higher when using non-selenized cells of L. paraplantarum CRL 2051 (76 ± 5,66 °D) and the co-culture (71,00 ± 7,07 °D). Carbohydrates present in non-inoculated pasteurized mango-passion fruit juice were sucrose (33.08 ± 2.97 g/L), glucose (5.94 ± 0.63 g/L) and fructose (6.00 ± 0.63 g/L). L. paraplantarum CRL 2051 showed homofermentative behavior producing only lactic acid (5.13 ± 0.99 g/L) and no differences were observed between control and selenized cells. On the other hand, an increase of 0.42 g/L of lactic acid and 0.22 g/L of acetic acid was detected using the selenized fructophilic strain compared to the control cells, while no difference was observed in the production of mannitol (6,94 ± 0,23 g/L). The total content of soluble phenolic compounds in the juices fermented with selenized mixed cultures increased 30% compared to the non-fermented juice. The highest ABTS values were observed when the juice was fermented by the selenized mixed culture (15%), while the highest DPPH values were observed for the L. paraplantarum CRL 2051 fermented juices, and the ones inoculated with the selenized cells of F. tropaeoli CRL 2034 (14.78 ± 0.07; 13.16 ± 0.01 and 14.78 ± 0.04 TEAC, respectively). The total Se concentration in the non-inoculated mango-passion fruit juice pellets was 20 µg/mL while it was higher in the fermented juices by selenized cells (60,58 ± 0,44; 64,77 ± 0,40 and 68,27±0,24 µg/mL for L. paraplantarum CRL 2051, F. tropaeoli CRL 2034 and the mixed culture). Results show that selenized cells of the studied LAB could be used as a starter culture for fermenting a mango-passion fruit beverage enriched with Se; 200 mL of the obtained beverage offers 40% of the Se daily requirements, according to the Argentinean CODEX.Fil: Crespo, Laura Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaVIII Congreso Internacional de Ciencia y Tecnología de los Alimentos CórdobaCórdobaArgentinaGobierno de la Provincia de Córdoba. Ministerio de Ciencia y Tecnologí

Whey-derived valuable products obtained by microbial fermentation

Whey, the main by-product of the cheese industry, is considered as an important pollutant due to its high chemical and biological oxygen demand. Whey, often considered as waste, has high nutritional value and can be used to obtain value-added products, although some of them need expensive enzymatic synthesis. An economical alternative to transform whey into valuable products is through bacterial or yeast fermentations and by accumulation during algae growth. Fermentative processes can be applied either to produce individual compounds or to formulate new foods and beverages. In the first case, a considerable amount of research has been directed to obtain biofuels able to replace those derived from petrol. In addition, the possibility of replacing petrol-derived plastics by biodegradable polymers synthesized during bacterial fermentation of whey has been sought. Further, the ability of different organisms to produce metabolites commonly used in the food and pharmaceutical industries (i.e., lactic acid, lactobionic acid, polysaccharides, etc.) using whey as growth substrate has been studied. On the other hand, new low-cost functional whey-based foods and beverages leveraging the high nutritional quality of whey have been formulated, highlighting the health-promoting effects of fermented whey-derived products. This review aims to gather the multiple uses of whey as sustainable raw material for the production of individual compounds, foods, and beverages by microbial fermentation. This is the first work to give an overview on themicrobial transformation of whey as raw material into a large repertoire of industrially relevant foods and products.Fil: Pescuma, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); ArgentinaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); ArgentinaFil: Mozzi, Fernanda Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Centro de Referencia Para Lactobacilos (i); Argentin