Enhancing phenolic and lipid compound production in oat bran via acid pretreatment and solid-state fermentation with Aspergillus niger

• Published in: New biotechnology 2024-11, Vol.83, p.91-100
• Main Authors: NEMES, Silvia Amalia, FĂRCAS, Anca Corina, RANGA, Floricuta, TELEKY, Bernadette-Emoke, CĂLINOIU, Lavinia Florina, DULF, Francisc Vasile, VODNAR, Dan Cristian
• Format: Article
• Language: English
• Subjects: antioxidant activity; Antioxidant compounds; Aspergillus niger; Avena sativa; bioactive compounds; bioavailability; Bioprocess; biotechnology; Cereal by-products; Chemical pretreatment; Fatty acids; functional foods; human nutrition; lipid composition; lipids; oat bran; oats; polyphenols; solid state fermentation; vanillic acid
• ISSN: 1871-6784; 1876-4347; 1876-4347
• DOI: 10.1016/j.nbt.2024.07.003

Oat (Avena sativa) processing generates a large amount of by-products, especially oat bran. These by-products are excellent sources of bioactive compounds such as polyphenols and essential fatty acids. Therefore, enhancing the extraction of these bioactive substances and incorporating them into the human diet is critical. This study investigates the effect of acid pretreatment on the solid-state fermentation of oat bran with Aspergillus niger, with an emphasis on the bioaccessibility of phenolic acids and lipid profile. The results showed a considerable increase in reducing sugars following acid pretreatment. On the sixth day, there was a notable increase in the total phenolic content, reaching 58.114 ± 0.09 mg GAE/g DW, and the vanillic acid level significantly rose to 77.419 ± 0.27 μg/g DW. The lipid profile study revealed changes ranging from 4.66 % in the control to 7.33 % on the sixth day of SSF. Aside from biochemical alterations, antioxidant activity measurement using the DPPH technique demonstrated the maximum scavenging activity on day 4 (83.33 %). This study highlights acid pretreatment's role in enhancing bioactive compound accessibility in solid-state fermentation and its importance for functional food development. [Display omitted] •Acid pretreatment increased monosaccharides like maltose, glucose, and fructose.•The analysis of phenolic compounds showed a wide variety, including cinnamic acids, benzoic acids, and avenanthramides.•Vanillic acid increased during fermentation, indicating a synergistic effect with acid pretreatment.•The analyzed samples exhibit low levels of PUFAs/SFAs ratio.