Bacterial cell count was enumerated by taking 1 ml of cell suspension in the feed solution prior to spray drying. After serial dilutions, an aliquot of 0.1 ml was transferred and plated on MRS agar and incubated at 30 C for 48 h. Cell counts before spray drying were calculated as CFU g1 of dried matter based on the initial total solids content of the feed solution before spray drying.
Similarly, 0.1 g of spray dried powder was dissolved in peptone water, allowing 20–30 min for it to dissolve, followed by serial dilutions and plating.
The bacterial count was expressed as CFU g1 of dried powder and cell survival calculated as: % survival ¼ ðN=NoÞ 100
where N and No are number of bacteria per gram of dried matter after and before spray drying, respectively.