ABSTRACT
Currently, the growing demand for non-dairy functional foods leads to the constant development of new products. The objective of the present work was to obtain a soy-based fermented beverage employing the strains Lactiplantibacillus plantarum CIDCA 8327 or Lacticaseibacillus paracasei BGP1 and to analyze the effect of post-fermentation addition of inulin of low or high average polymerization degree on the bacterial resistance. Also, the antimicrobial and antioxidant activity of the fermented soy-based beverages were analyzed. The soy-based matrix was shown to be a suitable substrate for the growth of both lactic acid bacteria, and the fermented beverages obtained presented bioactive properties such us antioxidant activity and bactericidal effect against pathogen microorganisms. The addition of inulin after the fermentation process avoid the hydrolysis and so, preserve its polymerization degree and thus the potential prebiotic effect. The incorporation of inulin to the soy-based fermented beverages increased the bacterial count after 30 days of refrigerated storage up to 8.71 ± 0.15 and 8.41 ± 0.10 log CFU/mL for L. paracasei and L. planatrum respectively. The resistance to the gastrointestinal conditions of the strain L. paracasei BGP1 in the fermented beverage was improved up to 70% when inulin of high polymerization degree was added. Meanwhile the strain L. plantarum CIDCA 8327 showed a survival of 97 and 94% in the fermented beverage added with inulin of low or high polymerization degree, respectively. These results contribute to the development of non-dairy products containing inulin and probiotics and the diversification agri-based functional foods.
Subject(s)
Inulin , Probiotics , Antioxidants/metabolism , Antioxidants/pharmacology , Beverages/microbiology , Fermentation , Fermented Beverages , Inulin/metabolism , Inulin/pharmacology , Prebiotics , Probiotics/metabolismABSTRACT
Resumen El efecto sinérgico de la microencapsulación en geles de pectina e inulina extraída de cultivos nativos de topinambur se evaluó como una estrategia natural para aumentar la supervivencia de Lactobacillus paracasei subsp. toleraos F2, bacteria seleccionada por sus propiedades probióticas sobre la trucha arco iris (Oncorhynchus mykiss). La cepa fue capaz de crecer y fermentar la inulina de topinambur en caldo MRS modificado, lo que condujo al incremento del número de células (~+5 unidades logarítmicas) y la disminución neta del pH (6,2 ±0,2 a 4,0±0,5). La encapsulación de F2 en microgeles de pectina en presencia de inulina mejoró su supervivencia no solo a lo largo del almacenamiento sino también en condiciones donde se simuló el pasaje por el tracto gastrointestinal. Después de 56 días de almacenamiento a 4 °C, se registraron números significativamente mayores de células viables microencapsuladas en presencia del prebiótico (8,2-8,4 log UFC/g) que sin él (~7,00 log UFC/g). Estos resultados alientan la aplicación de estas técnicas para la formulación de alimentos funcionales utilizando fuentes alternativas naturales de inulina que incrementan la viabilidad del probiótico almacenado y su digestibilidad.
ABSTRACT
The synergistic effect of microencapsulation in pectin microgels and inulin extracted from native crops of Jerusalem artichoke (JAI) was evaluated as a natural strategy to increase the survival of Lactobacillus paracasei subsp. tolerans F2 selected for its probiotic properties in Oncorhynchus mykiss. The strain was able to grow and ferment JAI in modified MRS broth, increasing cell population (â¼+5 log units) with a net decrease in pH (6.2±0.2 to 4.0±0.5). Encapsulation of F2 in pectin microgels in the presence of JAI improved the survival of the strain not only during storage but also after exposure to simulated gastrointestinal conditions. Viable entrapped cells in the presence of the prebiotic were significantly higher (8.2-8.4log CFU/g) than without it (â¼7.00log CFU/g) after 56 days at 4°C. These results encourage further implementation of these techniques for the formulation of functional feeds using natural alternative sources of inulin with greater viability on storage conditions and digestibility.
Subject(s)
Helianthus , Inulin/chemistry , Lactobacillus , Pectins/chemistryABSTRACT
In this study the operational extraction variables to obtain higher yields of inulin from Jerusalem artichoke tubers (JAT), as well as the optimal conditions to obtain a stable and dispersible powdered product by either spray or freeze drying, were studied. With this purpose, the powder yield, moisture content, water activity and flowability or products obtained by different experimental conditions were analyzed. Inulin rich carbohydrates (IRC) extraction was performed from lyophilized and ground tubers employing distilled hot water as solvent. It was proved that the solid:solvent ratio (S:S) was the critical variable in the extraction process, followed by temperature. Thus, the IRC extraction was optimal without ultrasound assistance, at 76°C, employing a S:S of 1:16, during 90min. In addition, the powder obtained by freeze-drying of the IRC extract showed advantages respect to powders obtained by spray-drying regarding the yield and considering that maltodextrin was not necessary as encapsulation agent. In another hand, spray drying process provided IRC powered materials with appropriate flow properties, and taking into account cost and time of production, this method should be considered as an alternative of freeze-drying.
