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Brewers' spent grain (BSG) is the main by-product derived from the brewing industry, where it accounts for 85% of the total waste generated. The total annual production worldwide of this waste is 39 million tons. This lignocellulosic material is traditionally used as cattle feed and sold at a low retail price (~USD 45.00 per ton). However, efforts for the revalorization of this by-product are emerging since research has established that it can be used as a low-cost source of bioactive molecules and commodity chemicals that can bring value to integral biorefinery ventures. Among commodities, phenolic compounds have attracted attention as added-value products due to their antioxidant properties with applications in the food, cosmetic, and pharmaceutical industries. These phytochemicals have been associated with antiaging and anticancer activities that have potential applications on cosmetic products. This mini-review summarizes the most relevant extraction techniques used for the recovery of phenolic compounds from BSG while discussing their advantages and shortcomings and the potential applications from BSG bioactive extracts in the cosmetic industry and their reported beneficial effects. This mini-review also makes a brief comment on the role of phenolic compounds extraction in the economic feasibility of an integral BSG biorefinery.

Establishing of a bio-based and green society makes it possible to take actions to exploit high value resources that can be converted into valuable biological ingredients. Brewer's spent yeast is a natural byproduct from the brewing industry with high biological and nutritional richness. In the present research, the effect of autolysis and subsequent hydrolysis of spent brewer's yeast, using an extract of Cynara carduncuius was investigated by response surface methodology, to define the optimal conditions with maximized angiotensin converting enzyme inhibitory activity (ACE-I). The models describe maximum autolysis obtained at 70 degrees C for 5 h followed by hydrolysis at 4% (v/v) E/S ratio for 4.5 h, where the peptide extract obtained had IC50 of 146 mu g mL(-1) of protein content. Nanofiltration allowed to produce a fraction with < 3 kDa exhibiting highest inhibitory activity (IC50 84.2 mu g mL(-1)) and showed to be stable in vitro gastrointestinal system maintaining its activity. The results suggest an alternative use of brewer's byproduct as source of beneficial ingredient in the prevention and/or treatment of hypertension, where the protein hydrolysis improves ACE-I activity.