Purification of bioactive peptides from spent yeast autolysates

Spent brewer's yeast have been described as an important source for bioactive peptides, with their properties well proven over the years. Besides the brewing sector, growing of large-scale processes on synthetic biology industry has generated a substantial amount of spent engineered yeast with further potential to be valued in a circular economy approach. In line with this perception, in this work, peptide-rich fractions were obtained from spent yeast peptide-rich extract autolysate ("ESY1"), using two different techniques, namely protein ultrafiltration and size-exclusion chromatography (SEC). Both methods allowed the production of different peptide fractions with diverse protein content, molecular weight distribution and peptides sequences. Overall, fractions with higher protein content and more purified reveal higher bioactivities, namely antihypertensive and anticholesterolemic, emphasizing that the purification process is an important step to include in production process of a dietary supplement with these specific features. In addition, significant antioxidant capacity values for peptide fractions purified by SEC were obtained, highlighting their potential use in economic sectors where antioxidant capacity has a massive impact, such as cosmetics.