Membrane Fractionation of Protein Hydrolysates from By-Products: Recovery of Valuable Compounds from Spent Yeasts

Abstract

Spent brewer’s yeast (Saccharomyces sp.), the second most generated by-product from the brewing industry, contains bioactive and nutritional compounds with high added value such as proteins (40–50%), polysaccharides, fibers and vitamins. Molecules of interest from agro-industrial by-products need to be extracted, separated, concentrated, and/or purified so that a minimum purity level is achieved, allowing its application. Enzymatic hydrolysis has been successfully used in the production of peptides and protein hydrolysates. The obtained hydrolysates require efficient downstream processes such as membrane technology, which is an important tool for the recovery of thermolabile and sensitive compounds from complex mixtures, with low energy consumption and high specificity. The integration of membrane techniques that promote the separation through sieving and charge-based mechanisms is of great interest to improve the purity of the recovered fractions. This review is specifically addressed to the application of membrane technologies for the recovery of peptides from yeast protein hydrolysates. Fundamental concepts and practical aspects relative to the ultrafiltration of agro-industrial protein hydrolysates will be described. Challenges and perspectives involving the recovery of peptides from yeast protein hydrolysates will be presented and thoroughly discussed.

Antioxidant and Angiotensin I-Converting Enzyme (ACE) Inhibitory Peptides Obtained from Alcalase Protein Hydrolysate Fractions of Hemp (Cannabis sativa L.) Bran

“… 8 − 10 Many other examples exist in the literature for the fractionation of protein hydrolysates from other matrices. 12 , 14 The addition of a purification step (such as ultrafiltration or chromatographic separation) raises the processing costs; however, on an industrial scale, the added cost may be justified by the greater commercial value of the product due to the increased bioactivity. Further advantages in the fractionation of hydrolysates could derive from the increased resistance to physiological digestion and the higher bioavailability of low MW peptides with respect to mixtures of more complex MW distribution.…”

“…A classic approach for the preparation of these hydrolysates is the enzyme-catalyzed treatment of extracted proteins. The proteolytic reaction breaks down the primary sequence, producing mixtures of peptides with many positive health effects (antioxidant, antihypertensive, anti-inflammatory, anticancer, and antimicrobial, among others). , The bioactivity of the crude hydrolysates can be enhanced by chemically or physically based downstream separation processes, which concentrate the bioactive peptides in mixtures of lower complexity. − Purified peptides from these mixtures could provide even higher potency and greater specificity, but the costs associated with the large-scale purification of peptides have impeded the commercial exploitation of these products …”

Scale-Up and Long-Term Study of Electrodialysis with Ultrafiltration Membrane for the Separation of a Herring Milt Hydrolysate

“…More specifically, electrodialysis with ultrafiltration membrane (EDUF) is a technology of choice for the separation of bioactive molecules since it can simultaneously separate molecules by both their charge and size. Dlask and Václavíková [ 5 ] reported different types of hydrolysates that have been fractionated by EDUF in the past years (beta-lactoglobulin, soy, flaxseed, snow crab and, more recently, spent yeasts [ 6 ]) for the recuperation of a variety of bioactive peptides having a huge potential to be used as functional foods. Therefore, in order to produce large amounts of bioactive peptides from a hydrolysate, the development of an industrial scale EDUF process is necessary [ 7 ].…”

Special Issue “Membrane Technologies for Sustainable Biofood Production Lines”

“…This indicates that the separation of lactic acid from complex feed solution is still a challenge. Other recent developments were presented in the reviews of Vollet-Marson et al [ 11 ] and Bazinet et Geoffroy [ 7 ]. Hence, Vollet-Marson [ 11 ] emphasized the recovery of valuable peptides from hydrolysis of spent yeasts, the second most generated by-product from the brewing industry.…”

“…Other recent developments were presented in the reviews of Vollet-Marson et al [ 11 ] and Bazinet et Geoffroy [ 7 ]. Hence, Vollet-Marson [ 11 ] emphasized the recovery of valuable peptides from hydrolysis of spent yeasts, the second most generated by-product from the brewing industry. They first focused on the current strategies, challenges, and solutions for the application of conventional pressure-driven membrane technologies to the downstream processing of protein hydrolysates.…”