Podpora B., Świderski F., Sadowska A., Rakowska R., Wasiak-Zys G. The use of yeast extracts as a natural and valuable additive ingredient intended for the production of functional food and dietary supplements were demonstrated. The chemical composition, amino acid analysis, determination of protein molecular weights, antioxidant properties, and sensory evaluation were carried out for two yeast extracts. It was found that the tested extracts are characterised by high essential amino acid content, exceeding the levels of reference protein developed by the FAO/WHO, and high antioxidant activity. Sensory characteristics of tested extracts may favourably influence the quality of the proposed functional foods and dietary supplements. The obtained results indicate that the tested extracts can be utilised as a source of free amino acids and peptides in the design of functional foods and dietary supplements.

The aim of the work was to obtain autolysates derived from spent brewer's yeast and demonstrate their potential capabilities as a natural and valuable ingredients intended for functional food and dietary supplements production. The research material consisted of yeast Saccharomyces cerevisiae which was the remains after the beer production process. In these autolysates the following analyses were performed -protein, dry matter and amino acids content, determination of molecular weight of proteins, antioxidant properties and sensory quality. It was found that the tested autolysates were characterised by a high content of essential amino acids, exciding the amount present in the reference protein developed by FAO/WHO. The sensory quality of the tested autolysates was dependent on the degree of autolysis process of the yeast protein which further determined their usage in a food production. Precise time control of the autolysis process allows obtaining a product with the designed functional properties, characterised by the desired content of free amino acids, peptides with a specific molecular weight and high antioxidant properties. Based on the obtained results it can be concluded that the post-fermentation yeast may be a valuable raw material for the preparation of yeast autolysates which may be new and valuable component in functional food and dietary supplements production.