Doces de leite com café adicionados com probióticos: caracterização e viabilidade durante o armazenamento e simulação gastrointestinal

Abstract

Microencapsulation is used to provide protection and maintain the viability of probiotic strains during processing, storage, and adverse conditions in the gastrointestinal tract. The objective of the work was to develop dulce de leche with coffee reduced in fats added with probiotic microspheres. In the microencapsulation of the probiotics tested probiotics the technique of external ionic gelation with atomization by pressurized air was used using the two-fluid air atomizing nozzle of the Spray Dryer Equipment. To select the strain, microencapsulation of L. paracasei and L. acidophilus was performed, and the physical characteristics, microencapsulation efficiency, thermal resistance, and viability in simulated gastrointestinal conditions and storage for 90 days at 4 °C were evaluated. The microencapsulated strains of L. paracasei showed higher encapsulation efficiency and viability during storage for 90 days at 4 °C, of 7.82 log CFU/g. Compared to L. acidophilus, they maintained counts above 6 log CFU/g in 20 minutes of exposure to a temperature of 70 °C and maintained viability above 7.20 log CFU/g in simulated gastrointestinal conditions. Thus, microencapsulated cells of L. paracasei were chosen to be applied to dulce de leche with coffee. The viability of L.paracasei microspheres added to conventional and light dulce de leche was evaluated throughout the storage period and at gastrointestinal conditions. It was possible to prepare conventionally and light dulce de leche with coffee with a reduction of 37.0% in the fat content and 19.30% in the sugar content. The additions of the microspheres in the dulce de leche did not significantly influence the texture and the dulce de leche that received the microspheres showed a lighter color. The microbiological standard for total coliforms, Salmonella sp., coagulase-positive staphylococci and fungi and yeasts in dulce de leche with coffee met the requirements of the legislation. After 90 days of storage at 4 °C, the microencapsulated cells showed average viability of 7.13 log CFU/g in conventional and light dulce de leche with coffee and a daily serving (20 g) of dulce de leche would provide 2.7x108 CFU/20g of L. paracasei. In simulated gastrointestinal conditions after 90 days of storage, the viability of free cells was lower and those of microencapsulated cells presented sufficient amounts to claim a functional product. Dulce de leche with coffee proved to be a good alternative vehicle for microencapsulated L. paracasei. In simulated gastrointestinal conditions after 90 days of storage, the viability of free cells was lower and those of microencapsulated cells presented sufficient amounts to allegation a functional product. Dulce de leche with coffee proved to be a good alternative vehicle for microencapsulated L. paracasei.