Lactic fermentation as a strategy to improve the nutritional and functional values of pseudocereals

One of the greatest challenges is to reduce malnutrition worldwide while promoting sustainable agricultural and food systems. This is a daunting task due to the constant growth of the population and the increasing demands by consumers for functional foods with higher nutritional values. Cereal grains are the most important dietary energy source globally; wheat, rice, and maize currently provide about half of the dietary energy source of humankind. In addition, the increase of celiac patients worldwide has motivated the development of gluten-free foods using alternative flour types to wheat such as rice, corn, cassava, soybean, and pseudocereals (amaranth, quinoa, and buckwheat). Amaranth and quinoa have been cultivated since ancient times and were two of the major crops of the Pre-Colombian cultures in Latin-America. In recent years and due to their well-known high nutritional value and potential health benefits, these pseudocereals have received much attention as ideal candidates for gluten-free products. The importance of exploiting these grains for the elaboration of healthy and nutritious foods has forced food producers to develop novel adequate strategies for their processing. Fermentation is one of the most antique and economical methods of producing and preserving foods and can be easily employed for cereal processing. The nutritional and functional quality of pseudocereals can be improved by fermentation using Lactic Acid Bacteria (LAB). This review provides an overview on pseudocereal fermentation by LAB emphasizing the capacity of these bacteria to decrease antinutritional factors such as phytic acid, increase the functional value of phytochemicals such as phenolic compounds, and produce nutritional ingredients such as B-group vitamins. The numerous beneficial effects of lactic fermentation of pseudocereals can be exploited to design novel and healthier foods or grain ingredients destined to general population and especially to patients with coeliac disease.Fil: Rollan, Graciela Celestina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Yogurt, ancestral milk base food of current great validity. Main nutritional, functional and technological aspects

El yogur es el alimento lácteo fermentado de mayor consumo a nivel internacional debido a sus propiedades organolépticas distintivas, su valor nutricional y elevada digestibilidad. Asimismo, numerosas investigaciones atribuyen a este producto efectos beneficios para la salud debidos principalmente a la presencia de bacterias lácticas (BAL) y a su alto contenido de calcio. El proceso de producción de yogur es sencillo, ya que consiste en una fermentación de leche pasteurizada por dos tipos de microorganismos (Streptococcus thermophilus y Lactobacillus delbrueckii subsp. bulgaricus) queactúan en forma simbiótica generando cambios fisicoquímicas y organolépticas. A pesar de ser considerado un proceso tecnológico simple, el desarrollo de etapas estandarizadas con control de puntos críticos es necesario para contribuir al desarrollo de atributos deseables y distintivos de este producto. En este trabajo se revisarán aspectos relevantes relacionados con las etapas de producción, formulación, efectos benéficos del yogur y nuevas tendencias en el mercado.Yogurt is the fermented dairy food with the highest internationally consumption due to its distinctive organoleptic properties, its nutritional value and high digestibility. Also, numerous researches attribute health benefits to the yogurt consumption, mainly due to the presence of lactic bacteria and to its high content of calcium. The process of yogurt production is simple, since it consists of a fermentation of pasteurized milk by two types of microorganisms (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) that act in symbiotic form generating physicochemical and organoleptic changes. Despite being considered a simple technological process, the development of standardized stages with control of critical points is necessary to contribute to the development of desirable and distinctive attributes of this product. In this work we will review relevant topics related to the beneficial effects of yogurt, the conventional processing of milk for its manufacture, as well as the main stabilizers used and their effect on the texture and final taste.Fil: Bustos, Ana Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; ArgentinaFil: Torres Quinteros, Lourdes. Universidad Nacional de Santiago del Estero; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Iturriaga, Laura Beatriz. Universidad Nacional de Santiago del Estero; Argentin

Influencia del aceite esencial de orégano en la elaboración tradicional de quesos: Efecto sobre el fermento láctico

The aim of this work is to study the oregano essential oil (OEO) composition from Northwestern Argentinean regions and to evaluate its effect on the lactic starter cultures. The oregano used, Origanum vulgare var hirtum, was obtained from Andalgalá, Catamarca. The essential oil presented high amounts of α-terpinene (10%), γ-terpinene (15.1%), terpinen- 4-ol (15.5%) and thymol (13.0%) as the main components. No negative effect on growth or metabolic activity of lactic acid bacteria Streptococcus thermophilus CRL 728 and CRL 813, Lactobacillus delbrueckii subsp. bulgaricus CRL 656 and CRL 468, and Lactococcus lactis subsp. lactis CRL 597 up to the maximum concentration (200 μg/g) assayed was observed. No differ-ences in the organoleptic characteristics of semi-hard cheeses flavored with oregano essential oil (200 μg/g) and homemade cheeses flavored with oregano leaves were found. With respect to the microbiological quality of the products, neither enterobacteria nor mold and yeast were detected during ripening in essential-oil flavored cheese compared to control cheese (enter-obacteria 2 × 103 UFC/g) and cheese flavored with oregano leaves (mold/yeast 4 × 104 CFU/g). Our results showed that the use of oregano essential oil and lactic starter culture considerably improved cheese quality.Fil: Marcial, Guillermo Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Nuñez, Martha Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Centro de Referencia Para Lactobacilos; ArgentinaFil: Coll Araoz, Maria Victoria. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schuff, Carola. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; 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; Argentin

Lactic acid bacteria from artisanal tanneries: isolation and evaluation of acidifyng ability

The tanning process allows to transform animal skin in stable and non-putrescible products namely leather. This process consists in various steps such as washing skins, liming, depilation, lime removal by washing, purging and tanning. During purging, the skins are immersed in a cereal mix which is let to ferment for 12-24 h at room temperature (18ºC-37°C). After this period, the pH decreased to 4.5-5.0, a condition that is required for the final steps. Under these homemade working conditions, the cereal fermentation is quite variable and affects the quality of the leather. The objective of this study was to isolate lactic acid bacteria (LAB) from the fermented cereal mixture in artisanal tanneries and to evaluate in vitro the acidifying activity of the strains. This is the first step for the formulation of a starter culture for tanneries to normalize the process.Samples of fermented cereals were taken from a tannery located in San Pedro de Colalao, Tucumán, Argentina, and colonies were isolated in MRS agar medium. The primary identification of the isolates included Gram stain, microscopic observations and catalase reaction. Gram positive, catalase negative strains (23) were cultured in a CERELA medium formulated for the production of lactic ferment and incubated at 18°C and 37°C for 24 h. At intervals, pH and titratable acidity (TTA) were determined. In most samples, a prevalence of cocci (95%) respect to bacilli was observed. The total isolated strains (56), 23 strains were Gram (+) and catalase (negative) which were selected. At 37 °C, most strains (21) acidified the culture medium within the first 8-h reaching a final pH ≤ 5.0 and a TTA ≥100ºD. At 18 °C, all strains showed a lower growth; however, the decrease in pH was 4.5-5.0 and the acidity developed (100-140ºD) after 24 hours of fermentation were similar to values obtained at 37°C. The best acid-producer strains were identified as Enterococcus faecium CRL 1943 and Leuconostoc citreum CRL 1945 by phenotypic and genotypic techniques. Currently, studies are being conducted to formulate a lactic inoculant on the basis of these strains and their metabolites for artisanal tanning.Fil: Correa Deza, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Martos, Gladys Irma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Nuñez, Martha Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Fiori, Mario. Instituto Nacional de Tecnología Industrial; ArgentinaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaXI Congreso Argentino de Microbiología GeneralCórdobaArgentinaSociedad Argentina de Microbiología Genera

Inorganic polyphosphate from the immunobiotic Lactobacillus rhamnosus CRL1505 prevents inflammatory response in the respiratory tract

Lactobacillus (L.) rhamnosus CRL1505 accumulates inorganic polyphosphate (polyP) in its cytoplasm in response to environmental stress. The aim of this study was to evaluate the potential effects of polyP from the immunobiotic CRL1505 on an acute respiratory inflammation murine animal model induced by lipopolysaccharide (LPS). First, the presence of polyP granules in the cytoplasm of CRL1505 strain was evidenced by specific staining. Then, it was demonstrated in the intracellular extracts (ICE) of CRL1505 that polyP chain length is greater than 45 phosphate residues. In addition, the functionality of the genes involved in the polyP metabolism (ppk, ppx1 and ppx2) was corroborated by RT-PCR. Finally, the possible effect of the ICE of CRL1505 strain containing polyP and a synthetic polyP was evaluated in vivo using a murine model of acute lung inflammation. It was observed that the level of cytokines pro-inflammatory (IL-17, IL-6, IL-2, IL-4, INF-γ) in serum was normalized in mice treated with ICE, which would indicate that polyP prevents the local inflammatory response in the respiratory tract. The potential application of ICE from L. rhamnosus CRL1505 as a novel bioproduct for the treatment of respiratory diseases is one of the projections of this work.Fil: Correa Deza, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Rodríguez de Olmos, Antonieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Suárez, Nadia Elina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Salva, Maria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Efecto antifúngico y antimicotoxigénico de lactobacillus plantarum CRL 778 a diferentes valores de actividad de agua

Ocratoxina A (OTA) es una micotoxina producida por hongos filamentosos con un alto impacto en la seguridad alimentaria debido a su toxicidad. En la última década se ha reportado ampliamente a nivel mundial, la presencia de OTA en diversos alimentos. En este estudio se evaluó in vitro, la capacidad de Lactobacillus (L.) plantarum CRL 778 de controlar el crecimiento y la producción de OTA por Aspergillus (A.) niger 13D, a diferentes valores de actividad de agua (aw): 0.955, 0.964, 0.971, 0.982 y 0.995). La cepa láctica redujo significativamente (p < 0.05) ambos parámetros, siendo el efecto dependiente del valor de aw. La mayor inhibición del crecimiento (46.9%) se obtuvo a aw = 0.995, valor más adecuado para el crecimiento y producción de metabolitos antifúngicos (ácido láctico, ácido acético, ácidos fenil-láctico e hidroxi-fenil láctico) por la cepa láctica. Además, se observaron cambios morfológicos en las colonias de A. niger 13D, crecidas en presencia de L. plantarum CRL 778 a valores de aw de 0.971 y 0.995. El porcentaje máximo de reducción en la producción de OTA (90%) por la cepa láctica se observó a un valor de aw = 0.971, mientras la inhibición del crecimiento fúngico fue mayor cuando aw = 0.995. Estos hallazgos sugieren que L. plantarum CRL 778 podría emplearse para el control de la contaminación por hongos ocratoxigénicos en alimentos con valores de aw comprendidos entre 0.971-0.995.Ochratoxin A (OTA) is a mycotoxin produced by filamentous fungi with high impact in food safety due to its toxicity. In the last decade, the presence of OTA was widely reported in different foods. In this study, the ability of Lactobacillus (L.) plantarum CRL 778 to control growth and OTA production by Aspergillus (A.) niger 13D strain, at different water activity (aw) values (0.955, 0.964, 0.971, 0.982, and 0.995) was determined in vitro. Both parameters were significantly (p < 0.05) reduced by the lactobacilli and the effect depended on aw. Greatest growth rate inhibition (46.9%) was obtained at aw = 0.995, which is the most suitable value for growth and production of antifungal metabolites (lactic acid, acetic acid, phenyllactic and hydroxyl-phenyllactic acids) by L. plantarum CRL 778. Besides, morphological changes and inhibition of melanin synthesis were observed in colonies of A. niger 13D in presence of L. plantarum CRL 778 at aw ranged between 0.971 and 0.995. In addition, maximum reduction (90%) of OTA production took place at aw = 0.971, while inhibition of fungi growth was more evident at aw = 0.995. These findings suggest that L. plantarum CRL 778 could be used for control of ochratoxigenic fungal growth and OTA contamination in different fermented foods with aw values between 0.971 and 0.995.Fil: Dallagnol, Andrea Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Bustos, Ana Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero; ArgentinaFil: Martos, Gladys Irma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Font, Graciela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Selection and Performance of Antifungal Lactic Acid Bacteria in Corn Mini-Silos

Silage is a method of forage conservation based on lactic fermentation. In order to improve the fermentative performance in corn silages, the aims of the present work were as follows: (I) to screen lactic acid bacteria with acidifying activity, (II) to study their antifungal activity against filamentous fungi and yeasts and (III) to evaluate their performance as antifungal in mini-silos. The acidifying activity was determined by measuring the pH and total titratable acidity. Those most acidifying bacteria were incubated in plates together with fungal markers strains to observe the presence or absence of inhibition halos, in addition to studying the nature of the antifungal metabolites by means of the treatment with proteases. The strain with the widest spectrum of action was selected to formulate an inoculum used in corn mini-silos. During storage, both silos determined humidity, acidification and microbiological composition, and then aerobic stability. The results showed that Lactoplantibacillus (L.) plantarum cultures had a higher production of lactic acid (7.7–17.5 g/L) than Pediococcus (8.8–10.9 g/L). L. plantarum CRL363 could inhibit the growth of filamentous fungi and some yeasts and consequently it was used in mini-silos. Compared to the control, the inoculated silo presented low pH values (4.02–4.85) and low fungi and yeast count until 20 days of storage, demonstrating the great potential of CRL363 strain for the formulation of inoculants for corn silage.Fil: Carrizo, Natalí Ivana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Carabajal Torrez, José Agustín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Molina, Fatima Romina Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Fornaguera, Maria Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Martos, Gladys Irma. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Bustos, Ana Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santiago del Estero. Universidad Nacional de Santiago del Estero. Centro de Investigaciones y Transferencia de Santiago del Estero; ArgentinaFil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Lactic Acid Fermentation Improved Textural Behaviour, Phenolic Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Dough

U radu su izolirane autohtone bakterije mliječno-kiselog vrenja iz tijesta s dodatkom chia (Salvia hispanica L.) sjemenki, te razvrstane prema kinetici zakiseljavanja i proteolitičkoj aktivnosti. Soj C8 identificiran je kao soj bakterije Lactobacillus plantarum C8, te je upotrijebljen kao starter kultura za dobivanje kiselog tijesta s dodatkom chia sjemenki. Mliječno-kiselim vrenjem povećan je maseni udjel organskih kiselina (mliječne na 12,3 g, octene na 1,0 g i fenilacetatne kiseline na 23,8 μg po kilogramu tijesta), te antioksidacijska aktivnost, koja je porasla za 33-40 % u usporedbi s nefermentiranim tijestom s dodatkom chia sjemenki. Osim toga, ukupni se udjel fenolnih spojeva uvećao za 25 %, a njihov se sastav bitno promijenio nakon 24 h fermentacije s pomoću soja bakterije L. plantarum C8. Klorogena je kiselina pronađena jedino u fermentiranom tijestu (2,5 mg/g), dok je ferulinska kiselina detektirana već na početku vrenja, i to u 32 % većoj količini u kiselom tijestu s dodatkom chia sjemenki (5,6 mg/g). Upotrebom fermentiranog kiselog tijesta s dodatkom chia sjemenki poboljšana su ukupna svojstva bijelog kruha, uključujući fizikalna (npr. smanjena tvrdoća i otpor krušnih mrvica pri žvakanju) i antioksidacijska svojstva (u prosjeku za 25 %). Dobiveni rezultati pokazuju da kiselo tijesto s dodatkom chia sjemenki poboljšava tehnološka i antioksidacijska svojstava pšeničnog kruha. Osim toga, u radu je po prvi puta prikazano da bakterije mliječno-kiselog vrenja mogu fermentirati tijesto s dodatkom chia sjemenki, čime poboljšavaju ukupna svojstva kruha.In this work, autochthonous lactic acid bacteria (LAB) were isolated from chia (Salvia hispanica L.) dough and selected on the basis of the kinetics of acidification and proteolytic activity. Strain no. C8, identified as Lactobacillus plantarum C8, was selected and used as starter to obtain chia sourdough. Lactic acid fermentation increased the organic acid mass fractions (lactic, acetic and phenyl lactic acids to 12.3 g, 1.0 g and 23.8 μg per kg of dough respectively), and antioxidant activities, which increased by approx. 33–40 % compared to unfermented chia flour dough. In addition, total phenolic content increased 25 % and its composition was strongly modified after 24 h of fermentation by L. plantarum C8. Chlorogenic acid was only found in the fermented dough (2.5 mg/g), while ferulic acid was detected from the beginning of fermentation, being 32 % higher in chia sourdough (5.6 mg/g). The use of fermented chia sourdough improved the overall characteristics of white bread, including physical (e.g. reduced hardness and chewiness of the crumb) and antioxidant properties (25 % on average), compared to the white bread. These results indicate that the use of chia sourdough could be a promising alternative to improve the technological and antioxidant properties of wheat bread. In addition, this work has shown, for the first time, that lactic acid bacterium is able to ferment chia dough, improving its overall characteristics

Lactic Acid Fermentation Improved Textural Behaviour, Phenolic Compounds and Antioxidant Activity of Chia (Salvia hispanica L.) Dough

U radu su izolirane autohtone bakterije mliječno-kiselog vrenja iz tijesta s dodatkom chia (Salvia hispanica L.) sjemenki, te razvrstane prema kinetici zakiseljavanja i proteolitičkoj aktivnosti. Soj C8 identificiran je kao soj bakterije Lactobacillus plantarum C8, te je upotrijebljen kao starter kultura za dobivanje kiselog tijesta s dodatkom chia sjemenki. Mliječno-kiselim vrenjem povećan je maseni udjel organskih kiselina (mliječne na 12,3 g, octene na 1,0 g i fenilacetatne kiseline na 23,8 μg po kilogramu tijesta), te antioksidacijska aktivnost, koja je porasla za 33-40 % u usporedbi s nefermentiranim tijestom s dodatkom chia sjemenki. Osim toga, ukupni se udjel fenolnih spojeva uvećao za 25 %, a njihov se sastav bitno promijenio nakon 24 h fermentacije s pomoću soja bakterije L. plantarum C8. Klorogena je kiselina pronađena jedino u fermentiranom tijestu (2,5 mg/g), dok je ferulinska kiselina detektirana već na početku vrenja, i to u 32 % većoj količini u kiselom tijestu s dodatkom chia sjemenki (5,6 mg/g). Upotrebom fermentiranog kiselog tijesta s dodatkom chia sjemenki poboljšana su ukupna svojstva bijelog kruha, uključujući fizikalna (npr. smanjena tvrdoća i otpor krušnih mrvica pri žvakanju) i antioksidacijska svojstva (u prosjeku za 25 %). Dobiveni rezultati pokazuju da kiselo tijesto s dodatkom chia sjemenki poboljšava tehnološka i antioksidacijska svojstava pšeničnog kruha. Osim toga, u radu je po prvi puta prikazano da bakterije mliječno-kiselog vrenja mogu fermentirati tijesto s dodatkom chia sjemenki, čime poboljšavaju ukupna svojstva kruha.In this work, autochthonous lactic acid bacteria (LAB) were isolated from chia (Salvia hispanica L.) dough and selected on the basis of the kinetics of acidification and proteolytic activity. Strain no. C8, identified as Lactobacillus plantarum C8, was selected and used as starter to obtain chia sourdough. Lactic acid fermentation increased the organic acid mass fractions (lactic, acetic and phenyl lactic acids to 12.3 g, 1.0 g and 23.8 μg per kg of dough respectively), and antioxidant activities, which increased by approx. 33–40 % compared to unfermented chia flour dough. In addition, total phenolic content increased 25 % and its composition was strongly modified after 24 h of fermentation by L. plantarum C8. Chlorogenic acid was only found in the fermented dough (2.5 mg/g), while ferulic acid was detected from the beginning of fermentation, being 32 % higher in chia sourdough (5.6 mg/g). The use of fermented chia sourdough improved the overall characteristics of white bread, including physical (e.g. reduced hardness and chewiness of the crumb) and antioxidant properties (25 % on average), compared to the white bread. These results indicate that the use of chia sourdough could be a promising alternative to improve the technological and antioxidant properties of wheat bread. In addition, this work has shown, for the first time, that lactic acid bacterium is able to ferment chia dough, improving its overall characteristics

Antifungal activity of Lactobacillus fermentum CRL 251

Spoilage of food is mainly due to fungal growth. In addition to the great economic losses derived from the presence of mould, another concern is the potential mycotoxin production that may cause public health problems. In recent years, bio-preservation [the use of microorganisms and/or their metabolites to prevent spoilage and to extend the shelf life of foods] has gained increasing interest due to consumers? demands. Lactic acid bacteria (LAB) as bio-preservation organisms are of particular interest: they have been used for centuries as starter cultures in the food industry and are able to produce different kind of bioactive molecules, such as organic acids, peptides, fatty acids, hydrogen peroxide and bacteriocins. The present study was undertaken to evaluate the potentiality of Lactobacillus fermentum CRL 251 to inhibit mould and yeasts growth and characterize the metabolite/s involved. L. fermentumCRL 251 was grown in MRS broth (pH 6.5) at 37ºC for 24 h. The cell-free supernatants (CFS) was sterilized by filtration and used in the antifungal assays. The antifungal activity on various species of molds and yeasts was performed using the Microtitre Plate Well Assay. Conidial germination or yeast growth was determined during 48 h at 30ºC by measuring the optical density (OD580nm). The activity of CFS was determined in both neutral (pH 7, CFSn) and acidic (pH 3.8, CFSa) conditions. The activity of CFSn at different conditions of temperature (50, 100, 121ºC), pH range (3.0-8.0), and water activity (aw 0.995-0.901) was also determined. In addition, the effect of agitation on the antifungal compound/s production was evaluated. The resultsdemonstrated thatL.fermentum CRL 251 has inhibitory effect against a broad range of filamentous fungi (molds) and, to a greater extent, against spoilage yeasts in both, neutral and acidic conditions. The production of the antifungal compoundsstarts during the exponential phase and reaches the maximum value in the stationary phase where the activity (70-80 % inhibition)remained constant.The LAB growth under agitation condition not showedsignificant effect (p≤0.05) on the antifungal compounds production.The activity was stable during heat treatment and it remained constant even after autoclaving (121°C for 15 min). Maximum activity was determined at pH values between 3.0 and 5.0; at higher pH values no activity was observed. The inhibitory activity was stable at aw values between 0.995-0.937. No inhibitory activity was detected at awlower than 0.937. The antifungal peptides were partially purified and the molecular mass was estimated (approximately ≤ 10 kDa). This is the first report on a proteinaceous antifungal compound(s) productionby L. fermentum.Fil: Gerez, Carla Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Conci, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Rollan, Graciela Celestina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaV International Symposium on Lactic Acid Bacteria: Benefiting from Lactic Acid Bacteria. Progress in Health and FoodSan Miguel deTucumánArgentinaConsejo Nacional de Investigaciones Científicas y Técnicas. Centro de Referencia para Lactobacilo