Desarrollo de jalea de yacón de reducido valor calórico: caracterización físico-química, microbiológica y sensorial / Development of a low calorie yacon jam: physico chemical, microbiological and sensory characterization

This study aimed to evaluate the physical-chemical, microbiological and sensory characteristics of four formulations of yacon jams. The following characteristics were analyzed: chemical composition, soluble solids, pH, microbiological presence of total coliforms and salmonella at 45 °C, and presence of fungi and yeasts. The yacon jams exhibited high moisture content (> 62%) as well as high concentrations of carbohydrates (> 28%) and total dietary fiber (2.5%), mainly fructooligosaccharides (> 0.9%). The average energy value was 124.6 kcal/100 g. The average pH was 3.8 and the soluble solids measured 27.6 °Brix. All yacon jams complied with standard microbiological requirements and received high acceptance scores, especially the yacon jam and yacon jam with cinnamon. Yacon jam products may offer an excellent alternative to more common jams due to their lower concentrations of simple sugar, lower calorie value, increased presence of dietary fibers, and desirable sensory characteristics.

Este estudio tuvo como objetivo evaluar las características físico-químicas, microbiológicas y sensoriales de cuatro formulaciones de mermeladas de yacón. Las características analizadas fueron: composición química, contenido de sólidos solubles, pH, presencia microbiológica de coliformes totales, coliformes y salmonella a 45 °C, y la presencia de hongos y levaduras. Los atascos de yacón mostraron alto contenido de humedad (> 62%), así como altas concentraciones de hidratos de carbono (> 28%) y fibra dietética total (2, 5%), principalmente fructooligosacáridos (> 0, 9%). El valor energético promedio fue de 124, 6 kcal/100g. El pH promedio fue de 3, 8 y los sólidos solubles mide 27, 6 ° Brix. Todas las mermeladas de yacón cumplido con los requisitos microbiológicos estándar y recibió altos puntajes de aceptación, en especial la mermelada de yacón y mermelada de yacón con canela. Productos de mermelada de yacón pueden ofrecer una excelente alternativa a los atascos más comunes debido a sus concentraciones más bajas de azúcar simple, un valor más bajo de calorías, el aumento de la presencia de fibras dietéticas y las características sensoriales deseadas.

Growth and antibacterial activity of Lentinula edodes in liquid media supplemented with agricultural wastes

Antibacterial activity of Lentinula edodes against Bacillus subtilis was evaluated in cell-free filtrates obtained after growth in 14 different culture media. The highest B. subtilis growth inhibition was promoted by filtrates of growth media supplemented with rice bran, vermiculite or molasses. L. edodes dry mycelial biomass in liquid culture with 0.5% added rice bran was 3.2 mg/ml, after growth for 30 days at 25ºC without shaking, and 4.3 mg/ml under orbital shaking (150 rpm). However, antibacterial activity, detected between 20 and 24 days of incubation of stationary cultures, was absent in filtrates of aerated cultures. Temperatures of 20-25ºC enhanced both growth and antibacterial activity. Optimum pH for L. edodes mycelial growth was 3.0-3.5, while for production of antibacterial substance(s) it was 4.5. Our results indicated that incubation conditions that enhance mycelial growth are quite different from those necessary for production of antibacterial substance(s) by L. edodes.