Fermented rice bran: an alternative ingredient in baking

The idea that associated agro-industrial by-products only with the production of animal feed has been gradually being replaced, as the scientific community is interested in these products, as low-cost nutrients for the composition of food and/or culture media in research biotechnological to increase or improve nutrients or characteristics inherent in the raw material. Thus, this work aims to characterize input for baking with claim of natural fortification from the fermentation by Saccharomyces cerevisiae. For this, biomass was characterized in terms of its composition (ashes, fibers, lipids, proteins, and carbohydrates) 1 Trabalho apresentado no CBCP 2020 Congresso on-line Brasileiro de Tecnologia de Cereais e Panificação, selecionado para publicação na forma de artigo completo. Research, Society and Development, v. 9, n. 11, e45491110225, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.10225 2 and antioxidant activity of phenolic compounds. The results show an increase in nutrients such as ash, proteins and fibers, in addition the free and bound phenolic compounds present in the biomass showed antioxidant potential. Therefore, fermented rice bran is a potential input to be used in baking.

developed, promote an increase in the supply of nutrients and functional compounds in foods formulated with this biomass (Christ-Ribeiro et al., 2017;Aalim et al., 2019).
Among the functional compounds, phenolics have a recognized role in preventing diseases such as cancer, diabetes, heart, neurodegenerative and cardiovascular diseases and aging (Christ-Ribeiro et al., 2016;Mark et al., 2019;Furlong et al., 2020). They are found in different forms depending on their association with the food matrix, such as free and soluble esters or linked conjugated and insoluble forms (Zhang et al., 2020). Therefore, the objective of the work was to evaluate the proximal composition and the antioxidant capacity of free and bound phenolic compounds from rice bran fermented by S. cerevisiae aiming at the potential application as input for baking.

Experimental procedure
This is a quantitative study carried out through experimental laboratory research, generating precise and safe original numerical results. The raw material used will be defatted rice bran. For fermentation with yeast, the method described by Feddern et al. (2007) was used, where the rice bran was subjected to solid-state fermentation with yeast S. cerevisiae previously hydrated (3% pp-1) with distilled water, reaching 30% humidity. The process was carried out in an oven with air circulation at 30 °C for 0, 2, 4, and 6 h to check the best condition as a natural fortification of rice bran.
To assess the best fermentation time, the proximal composition was performed, determining moisture, ash, fibers, lipids, proteins and carbohydrates by difference, according to AOAC (2000). The phenolic compounds were extracted according to Christ-Ribeiro et al.
(2019) using methanol in the proportion of 1:8 (w/v). The mixture was submitted to orbital agitation, 160 rpm, for 2 h. After resting for 15 min, another 10 mL of solvent was added and agitated for more 1 h. The methanolic extracts were evaporated in a route-evaporator and resuspended with distilled water. The resulting extract was clarified, centrifuged, and filtered.
The total content of phenolic compounds was determined by spectrophotometer at 750 nm with Folin-Ciocalteau reagent and quantified using gallic acid standard curve (2 to 30 μg ml -

Resultados e Discussão
The bran was fermented, and at each fermentation time, the proximate composition determinations were performed, as shown in Table 1.  As shown in Table 2, we can see a significant difference between the fermentation times and the type of phenolic compounds. The free phenolic compounds are more available than the bound ones, which was already expected due to the greater ease of extraction because they do not perform complex bonds with other compounds. This relationship is opposite to the linked phenolic compounds, which are characterized by being covalently linked or esterified to sugars and other low molecular weight components, such as fatty acids (Mira et al., 2008;Zhang et al., 2020). The fermentation time of 6 h is the one with the greatest supply of phenolic compounds, indicating that yeast can interact in complex bonds, increasing the availability of both compounds. Table 3 shows the antioxidant activity of phenolic compounds extracted from fermented bran. Development, v. 9, n. 11, e45491110225, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i11.10225

Conclusion
Biotechnology can add value to an agroindustrial co-product, resulting in improved bioavailability and nutritional enrichment, combined with antioxidant capacity, making biomass a promising alternative as an input in the bakery industry.
Thus, the application as an ingredient in the manufacture of cookies and cakes is promising, mainly for gluten intolerant consumers. Future studies may complement the development of new products, such as breads and cookies, in addition to the claim of functionality of the phenolic compounds present in this input.