Solid state fermentation of fig (Ficus carica L.) by-products using fungi to obtain phenolic compounds with antioxidant activity and qualitative evaluation of phenolics obtained

• Published in: Process biochemistry (1991) 2017-11, Vol.62, p.16-23
• Main Authors: Buenrostro-Figueroa, J.J., Velázquez, M., Flores-Ortega, O., Ascacio-Valdés, J.A., Huerta-Ochoa, S., Aguilar, C.N., Prado-Barragán, L.A.
• Format: Article
• Language: English
• Subjects: Agroindustrial by-products; Antioxidants; Byproducts; Chlorides; Chromatography; Confidence intervals; Design optimization; DPPH; Feasibility studies; Fermentation; Ficus carica; Fungi; High performance liquid chromatography; Liquid chromatography; Mineral composition; Moisture; Optimization; pH effects; Phenolic compounds; Phenols; Polyphenols; Potassium chloride; Solid state; Solid state fermentation; Spectrophotometry; Valorization
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2017.07.016

[Display omitted] •Fig by-products as an important source of phenolic compounds.•Solid-state fermentation (SSF) of fig by-products by fungal strains.•Study of culture conditions for total phenolic compounds (TPC) release.•The TPC and antioxidant levels increased significantly under optimized SSF conditions.•Food and agroindustrial by-products valorization though fungal processes. An optimized method of solid-state fermentation (SSF) is reported for the valorization of fig (Ficus carica L.) by-products. Four fungal strains were screened for their capacity to enhance the release of total phenolic compounds (TPCs). Temperature, pH, moisture, and mineral composition were evaluated and optimized using a Box–Hunter–Hunter design and then central composite design was performed. The optimized SSF conditions were as follows: A. niger HT4 for 36h at 40°C; moisture, 60%; pH: 5.0; mineral composition (g/L): NaNO3: 0.57; KH2PO4: 3.04; MgSO4·7H2O: 1.52; and KCl: 5.37. Under the optimal SSF conditions, the experimental values (10.19±0.04mg of GAE/g of dm) matched with those predicted (10.37mg of GAE/g of dm) within a 95% confidence level. A total of eight phenolic compounds were identified by High Performance Liquid Chromatography-Mass Spectrophotometry (HPCL-MS). The optimized SSF bioprocess increased the TPC release and antioxidant activity values up to 5.48 and 98.54 times, respectively, showing its feasibility as a reliable alternative for the use of fig by-products.