RESUMO
Here, we report for the first time on the mechanisms of action of the essential oil of Ruta graveolens (REO) against the plant pathogen Colletotrichum gloeosporioides. In particular, the presence of REO drastically affected the morphology of hyphae by inducing changes in the cytoplasmic membrane, such as depolarization and changes in the fatty acid profile where straight-chain fatty acids (SCFAs) increased by up to 92.1%. In addition, REO induced changes in fungal metabolism and triggered apoptosis-like responses to cell death, such as DNA fragmentation and the accumulation of reactive oxygen species (ROS). The production of essential enzymes involved in fungal metabolism, such as acid phosphatase, ß-galactosidase, ß-glucosidase, and N-acetyl-ß-glucosaminidase, was significantly reduced in the presence of REO. In addition, C. gloeosporioides activated naphthol-As-BI phosphohydrolase as a mechanism of response to REO stress. The data obtained here have shown that the essential oil of Ruta graveolens has a strong antifungal effect on C. gloeosporioides. Therefore, it has the potential to be used as a surface disinfectant and as a viable replacement for fungicides commonly used to treat anthracnose in the postharvest testing phase.
Assuntos
Antifúngicos , Colletotrichum , Óleos Voláteis , Espécies Reativas de Oxigênio , Ruta , Colletotrichum/efeitos dos fármacos , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Ruta/química , Antifúngicos/farmacologia , Antifúngicos/química , Espécies Reativas de Oxigênio/metabolismo , Doenças das Plantas/microbiologia , Testes de Sensibilidade Microbiana , Fragmentação do DNA/efeitos dos fármacosRESUMO
In recent years, people have become interested in consuming low-fat foods as this reduces the risk of obesity and cardiovascular disease. For this reason, this study optimized the incorporation of passion fruit epicarp (PFE) as a partial fat substitute in dairy ice cream. For this purpose, a central composite rotational design 22 was performed and 5 response variables were optimized, of which 4 variables were maximized (percentage overrun, hardness, adhesiveness, and color coordinates L*, a*, b*), while the melting rate was minimized as a function of two factors (% PFE and % fat). The stability of three types of ice cream was then evaluated: experimental ice cream (3% milk fat and 0.97% PFE), commercial ice cream (4% milk fat and 2% vegetable fat) and control ice cream (3% milk fat without PFE added), according to their physicochemical and sensory properties during 57 days of storage (-22 °C, 85% relative humidity). The results showed that it was possible to reduce the milk fat by up to 25% by adding PFE (0.97%), which significantly reduced the melting rate and resulted in higher hardness (N), adhesiveness and increased yellowness compared to the commercial samples. The optical microscopy analysis also showed that PFE keeps the air bubbles immobile due to the increased viscosity in the serum phase during the 57-day storage.
RESUMO
Yeast starters for cocoa fermentation are usually tested according to their enzymatic activities in terms of mucilage degradation and flavor improvement, disregarding their influence on the production or elimination of toxic compounds as biogenic amines (BAs), important for human health. In this work, we tested 145 strains belonging to 12 different yeast species and isolated from the Colombian fermented cocoa beans (CB) for their capability of producing BAs in vitro. Sixty-five strains were able to decarboxylate at least one of the amino acids tested. Pichia kudriavzevii ECA33 (Pk) and Saccharomyces cerevisiae 4 (Sc) were selected to evaluate their potential to modulate BAs, organic acids, and volatile organic compounds (VOCs) accumulation during a simulated cocoa fermentation. The growth of Sc or Pk in the presence of CB caused a significant reduction (p < 0.05) of 2-phenylethylamine (84% and 37%) and cadaverine (58% and 51%), and a significant increase of tryptamine and putrescine with a strong influence of temperature in BA formation and degradation. In addition, our findings pointed out that Pk induced a major production of fatty acid- and amino acid-derived VOCs, while Sc induced more VOCs derived from fatty acids metabolism. Our results suggest the importance of considering BA production in the choice of yeast starters for cocoa fermentation.
RESUMO
RESUMEN La fibra dietética ayuda a reducir el riesgo de padecer algunas enfermedades crónicas, a pesar de esto, su ingesta mundial es menor que los niveles recomendados. Este hecho motiva a la industria alimentaria a incorporar fibra dietética, obtenida de fuentes vegetales en productos alimenticios, como el yogurt. El presente estudio tuvo como objetivo evaluar las principales características de calidad de diferentes formulaciones de yogurt, en función de la incorporación de epicarpio de maracuyá deshidratado (EMD), con alto contenido de fibra dietaria (71,4 ± 0,04%), en concentración de 0 y 0,5% y el efecto que ejerce la grasa láctea presente en la leche cruda de vaca, en concentración de 0, 0,5 y 3,0%. Algunas propiedades fisicoquímicas, tales como pH, acidez titulable (%), viscosidad (cP) y parámetros de color por método CIELab fueron evaluadas en seis formulaciones diferentes. De acuerdo con los resultados obtenidos, se realizó un análisis sensorial y se evaluó la estabilidad de dos formulaciones de yogurt, durante un periodo de almacenamiento de 29 días, a 4°C. La incorporación de EMD contribuyó significativamente al incremento de acidez y la viscosidad en el producto. El EMD favoreció la estabilidad del gel y permitió obtener resultados aceptables en atributos sensoriales hasta el día 15 de almacenamiento. La incorporación de EMD en la elaboración de yogurt permitió enriquecer el valor, debido al aporte de fibra dietaria, la cual, puede actuar como sustituto funcional de la grasa láctea.
ABSTRACT Dietary fiber helps to reduce the risk of suffering from some chronic diseases. Despite this, the global average intake of this component is still lower compared to the recommended levels. This fact has motivated to the food industry to incorporate dietary fiber obtained from vegetable sources in food products. The aim of the present study was the evaluation of the main quality characteristics of different yogurt formulations, as the function of the incorporation of dehydrated passion fruit epicarp with a high dietary fiber content (71,4 ± 0,04%), and concentrations of 0 - 0,5% and the effect of dairy fat present in raw cow milk in concentrations of 0, 0,5 and 3,0%. Some physical-chemical properties such as pH, acidity (% of lactic acid), viscosity (cP) and color parameters by use of CIELab system method were evaluated in 6 different formulations. According to the results, a sensorial analysis was conducted and the stability of two yogurt formulations was determined during a storage period of 29 days at 4°C.The incorporation of EMD significantly contributed to the increase of the acidity and viscosity of the product. EMD favored the stability of yogurt gel and allowed to obtain acceptable results in sensorial attributes until day 15 of storage. The incorporation of EMD in the elaboration of yogurt, allowed the enrichment of the nutritional value due to the contribution of dietary fiber, which can act as a functional substitute of dairy fat.