Upgrading the phenolic content, antioxidant and antimicrobial activities of garden cress seeds using solid-state fermentation by Trichoderma reesei.

AIMS: This study aims to evaluate the impact of solid-state fermentation (SSF) by Trichoderma reesei on the phenolic content, antioxidant and antimicrobial activities of garden cress seeds (GCS). METHODS AND RESULTS: The factorial statistical design was employed to optimize the SSF conditions, incubation time, pH, temperature and moisture, for maximum production of the phenolic content and microbial carbohydrate-cleaving enzymes from GCS. The total phenolic content significantly increased from unfermented GCS (401 mg gallic acid equivalent (GAE) 100 g-1 ) to fermented GCS (3600 mg GAE 100 g-1 ) by ninefold. The total antioxidant activity significantly increased in fermented GCS. Fifteen phenolic compounds were detected in fermented GCS with high concentrations compared to 14 in unfermented GCS using high-performance liquid chromatography. A strong correlation between the production of the carbohydrate-cleaving enzymes and the phenolic content of fermented GCS was observed. The phenolic compounds of fermented GCS showed higher antimicrobial activity. CONCLUSIONS: The fermented GCS is a powerful source of phenolic compounds with high antioxidant potentials, which can be used as dietary supplement and antimicrobial agent. SIGNIFICANCE AND IMPACT OF THE STUDY: Solid-state fermentation is a promising technique used for production of added-value bioactive compounds. SSF increased the total phenolic content and antioxidant activity of GCS several folds compared to germination process, which recently studied.

Solid-state fermentation by Trichoderma viride for enhancing phenolic content, antioxidant and antimicrobial activities in ginger.

The phenolic content of methanol and water extracts of ginger fermented by Trichoderma spp. using solid-state fermentation (SSF) was evaluated and was compared with unfermented ginger. The total phenolic content in fermented ginger increased several times. The highest phenolic content in ginger was detected after SSF by T. viride. The optimal physiological conditions for the maximum production of phenolic compounds and ß-glucosidase activity of fermented ginger by T. viride were detected at day 7 incubation, pH 6·0, 30°C and 30% moisture. The SSF of ginger by T. viride greatly enhanced the antioxidant potency of phenolic compounds and was evaluated using DPPH and ABTS assays. A potent antibacterial activity of the phenolic compounds of fermented ginger was observed against all the tested human-pathogenic bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report to investigate the optimal physiological conditions of solid-state fermentation (SSF) of ginger by Trichoderma viride for enhancing its phenolic content and antioxidant capacity. In addition, the phenolic compounds of fermented ginger could be potentially used as a dietary adjunct and an antibacterial agent.