The aim of this work was to obtain a functional flour with enhanced nutritional properties, and antioxidant and antihypertensive potential from black bean seeds by optimizing the solid state bioconversion (SSB) process using a Rhizopus oligoporus strain. Response surface methodology was applied as optimization technique. A central composite experimental design with two factors [fermentation temperature (FT) = 30-40 °C/fermentation time (Ft) = 6-108 h] and five levels was used (13 treatments). The bioprocessed cotyledons from each treatment were dried, milled, and blended with its previously dried-milled seed coats. The best combination FT/Ft of SSB to obtain the functional flour was 38 °C/100 h. SSB increased the calculated protein efficiency ratio (from 1.59 to 2.40), antioxidant activity (from 13 948 to 22 733 µmol ET/100 g, dw), total phenolic compounds (TPC) (from 190 to 432 mg EGA/100 g, dw) and antihypertensive potential (IC(50) from 95.57 to 0.0321 µg/mL). SSB is an effective strategy to improve the TPC of common beans for enhanced functionality.

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Spent coffee grounds are waste material generated during coffee beverage preparation. This by-product disposal causes a negative environmental impact, in addition to the loss of a rich source of nutrients and bioactive compounds. A rotating central composition design was used to determine the optimal conditions for the bioactivity of phenolic compounds obtained after the solid state fermentation of spent coffee grounds by . To achieve this, temperature and fermentation time were varied according to the experimental design and the total phenolic and flavonoid content, antioxidant activity and antimicrobial activity were determined. Surface response methodology showed that optimum bioprocessing conditions were a temperature of 37 °C and a fermentation time of 39 h. Under these conditions, total phenolic and flavonoid contents increased by 36 and 13%, respectively, in fermented extracts as compared to non-fermented. In addition, the antioxidant activity was increased by 15% and higher antimicrobial activity was observed against Gram positive and negative bacteria. These data demonstrated that bioprocessing optimization of spent coffee grounds using the surface response methodology was an important tool to improve phenolic extraction, which could be used as an antioxidant and antimicrobial agents incorporated into different types of food products.

The use of whey as a natural culture medium to produce hydrolysates with antimicrobial from Bacillus clausii is the objective of this research. The fermentation process was carried out at 25 ℃ for five days, where proteolytic activity, soluble peptides quantification, and antimicrobial activity using the disc diffusion method were determined every day. The fermented whey reached values ​​of proteolytic activity between 90 and 260 U ml and a production of soluble peptides between 100 and 2070 µg ml. The maximum values ​​were reached after three days of fermentation to all determinations. In addition, the inhibition zone of fermented whey against Salmonella Typhimurium, Escherichia coli, Shigella flexneri, Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis strains were 13.7, 13.2, 14.4, 14.6, 9.8, 15.7 mm, respectively. The hydrolysates inhibited the 2, 2'-azinobis (3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radicals by 85 and 80%, respectively. The whey was used to allow the growth of B. clausii and to generate peptides with antioxidant and antimicrobial activity through the hydrolysis of proteins present in the natural culture medium. This process could be used for the development of new dairy products added with probiotics.