Dados do Trabalho

Título

Improving the enrichment of biomass of brewer’s spend yeast with vitamin D3 by plasmolysis pretreatment

Introdução

Vitamin D3 (cholecalciferol) plays a crucial role in human health. However, its high sensitivity to environmental influences hinders its effective incorporation into food matrices. To overcome these difficulties, the use of a protective matrix, such as brewer’s spend yeast residues, is an economical and efficient solution. Yeast has significant advantages as a protective matrix/biosorbent that enables the incorporation and protection of this micronutrient. Although yeast cell wall is porous, pretreatments such as plasmolysis can increase permeability and improve biosorption efficiency. This study aimed to enrich biomass of brewer's spend yeast (BSY), specifically Saccharomyces pastorianus, with vitamin D3 by biosorption and subsequent spray-drying and to investigate the effects of plasmolysis on the efficiency of biosorption.

Material e Métodos

The yeast biomass was washed and divided into two equal portions, the first not pretreated (intact yeast) and the second subjected to plasmolysis with NaCl (plasmolyzed yeast). Both treatments were loaded with vitamin D3 (80µg/mL) through the biosorption process, using 70mg yeast biomass. After incorporation, the material was dried in a spray dryer. The particles obtained from drying were characterized for moisture content, water activity, zeta potential, morphological structure and vitamin stability over 60 days of storage.

Resultados e Discussão

The biosorption efficiency was 44.89% for intact yeast and 80.83% for plasmolyzed yeast. The moisture content varied between 8.39% and 8.58% between intact and plasmolyzed particles, while the water activity was about 0.45 in both treatments. Plasmolysis caused morphological transformations on the cell surfaces, resulting in a rough texture and an increase in contraction factor. In addition, the electronegativity of the zeta potential increased, indicating greater stability of the suspensions in plasmolyzed cells. After 60 days of storage, 43.73% and 45.85% of vitamin D3 remained in the intact and plasmolyzed yeast cells, respectively.

Conclusão

This reduction is attributed to the degradation of the free or adsorbed vitamin on the surface, which facilitates the exchange with the external environment. The combination of the biosorption technique with spray-drying in conjunction with the applied pretreatment is promising to improve the incorporation and stability of vitamin D3 in biomass of BSY and thus contribute to the production of foods enriched with this micronutrient.