Dados do Trabalho

Título

MICROENCAPSULATION OF POTENTIALLY PROBIOTIC YEASTS ISOLATED FROM AMAZONIAN FRUITS USING DIFFERENT CRYOPROTECTANTS

Introdução

Microencapsulation is a widely used technology for preserving microorganism cells, aiming to maintain their characteristics and viability. Among the techniques employed, freeze-drying stands out for being cost-effective and causing less damage to microorganisms. The growing concern with the viability of probiotic microorganisms drives the application of this technology. Probiotics are live microorganisms that, when consumed in adequate amounts, provide health benefits to the host. Although bacteria are traditionally recognized as probiotics, yeasts have gained prominence in recent decades for their probiotic potential. This study investigates the use of cryoprotectants during the freeze-drying of potentially probiotic yeasts isolated from Amazonian fruits.

Material e Métodos

Three yeast strains (LTC 13, LTC 24, and LBC 77) were tested with distinct cryoprotectants at a concentration of 10%: glucose, chitosan, and skim milk. Cell viability was assessed at different time points: before freezing, immediately after freezing in liquid nitrogen, and after 24 hours, 7 days, 14 days, 21 days, and 30 days of freeze-drying.

Resultados e Discussão

The results indicated a reduction in cell concentration immediately after freezing in liquid nitrogen, regardless of the cryoprotectant used. However, yeasts without cryoprotectants experienced a significant reduction in cell viability, approximately 98.71%, 99.00%, and 99.99%, respectively, suggesting that they would not remain viable after the freeze-drying process. Among the tested strains, yeast LTC 13 exhibited the highest viability (107 CFU/mL) after 30 days of freeze-drying. Among the cryoprotectants, 10% glucose provided the best protection, followed by 10% skim milk. These results are promising, as glucose is a low-cost and easily accessible product. The effectiveness of cryoprotectants is related to their ability to minimize physical and chemical stress caused by freezing and thawing of the cells, stabilizing membranes and proteins. The literature supports the effectiveness of glucose as a cryoprotectant in probiotic yeasts.

Conclusão

In conclusion, the use of cryoprotectants, especially 10% glucose, proved effective in preserving the viability of probiotic yeasts isolated from Amazonian fruits during freeze-drying. These results highlight the importance of selecting appropriate cryoprotectants for the efficient cryopreservation of microorganisms, enhancing their use in industrial and biotechnological applications.