Solid-State Fermentation with Aspergillus niger GH1 to Enhance Polyphenolic Content and Antioxidative Activity of Castilla Rose (Purshia plicata)

This work was performed to study Castilla Rose (Purshia plicata) as a potential source of polyphenols obtained by solid-state fermentation (SSF)-assisted extraction using the microorganism Aspergillus niger GH1 and to evaluate the antioxidant activity of the extracted compounds. First, water absorption capacity (WAC) of the plant material, radial growth of the microorganism, determination of best fermentation conditions, and maximum accumulation time of polyphenols were tested. Then, a larger-scale fermentation, polyphenols isolation by column liquid chromatography (Amberlite XAD-16) and recovered compounds identification by HPLC-MS were made. Finally, the antioxidant activity of the recovered compounds was tested by ABTS, DPPH, and lipid oxidation inhibition assays. The best fermentation conditions were temperature 25 °C and inoculum 2 × 106 spores/g, while the maximum extraction time of polyphenols was 24 h (173.95 mg/g). The HPLC/MS analysis allowed the identification of 25 different polyphenolic compounds, and the antioxidant activity of the obtained polyphenols was demonstrated, showing ABTS assay the most effective with inhibition of 94.34%.

Estudio exploratorio de la extracción de pigmentos de Curcuma longa L. por fermentación en estado sólido utilizando cinco cepas fúngicas

Curcuma longa L. es una especia aromática originaria del sudeste asiático, su rizoma tiene aplicaciones en las industrias de alimentos y farmacéutica debido a que su principal fitoquímico es la curcumina, la cual se ha extraído por diversos métodos (maceración, Soxhlet, ultrasonido, microondas etc.). El objetivo del presente trabajo fue explorar la extracción de pigmentos de la cúrcuma asistida por fermentación en estado sólido (FES) empleando cepas fúngicas. Se utilizaron 3 g de material seco con 70% de humedad del rizoma como soporte suplementado con el medio Czapek-Dox para el crecimiento de Aspergillus niger GH1 y PSH, Aspergillus oryzae DIA-FM, Aspergillus sp. ITV, y Aspergillus terreus ITV. Las condiciones de fermentación fueron 25 °C por 240 h, midiendo el crecimiento radial cada 24 h y cuantificando a tiempo final el contenido de curcumina. Los resultados obtenidos demostraron la capacidad de crecimiento de cada cepa sobre el material vegetal, siendo A. niger GH1 y PSH las que tuvieron mayor velocidad de crecimiento (0.039 h-1 y 0.036 h-1 , respectivamente) así como la mayor capacidad para liberar curcumina (58.42 y 58.21 mg/g). La FES es un método útil para la extracción de curcumina utilizando cepas del género Aspergillus.

Ellagic acid production by solid-state fermentation influenced by the inert solid supports

Ellagic acid and ellagitannins are defense phytochemicals and dietary polyphenols found in fruits and nuts and implicated with strong antioxidant, anticancer and antiatherosclerotic biological properties. Unfortunately, there are few reports on the bioconversion studies from ellagitannins to ellagic acid. The objective of the present work was to use of partially purified ellagitannins from pomegranate peels as inducers for production of ellagic acid by Aspergillus niger GH1 in solid-state fermentation on inert supports (perlite, polyurethane foam and nylon fiber). For total pomegranate polyphenols (TPP), two methodologies were compared. Higher recovery of TTP (70 g kg-1 peel) in a short time (2 h) were obtained by filtering through a muslin cloth followed by centrifugation at 3000 rpm for 15 min. Production of ellagic acid and ellagitannase enzyme were evaluated. Maximum ellagic acid production (231.22 mg g-1 TPP) at 24 h cultivation with an ellagitannase activity of 3213 U L-1 was obtained when using polyurethane foam as inert support. Polyurethane foam was the best solid support to produce high yields of ellagic acid production.