Studies on survivability, storage stability of encapsulated spray dried probiotic powder

Awareness about probiotic food and their health benefits is increasing tremendously. However, probiotics have to withstand the harsh conditions that come across during their processing, handling, storage, and gastrointestinal conditions. Encapsulating technologies can be used to protect the probiotics during their passage through the gastrointestinal system of the human gut. Probiotics as an ingredient in dry powder form can be easily handled, stored, and used in developing the probiotic functional products. In the present study, probiotic cells (Lactobacillus acidophilus) were encapsulated by spray drying technology to produce a probiotic powder using 20% of maltodextrin and varied concentrations of gum arabic. The effect of processing conditions such as inlet air temperature (130-150 °C) and gum arabic concentration (0-10%) on the encapsulation efficiency and physical properties were studied. Further, the free and encapsulated probiotic cells were exposed to the simulated-gastric intestinal (SGI) fluid conditions and different storage conditions for their viability. For all the tested formula, moisture content, water activity, encapsulation efficiency, hygroscopicity, and wettability obtained were in the range of 4.59-9.05% (w.b.), 0.33-0.52, 65-89.15%, 12-21.15 g H₂O/100g dry weight, and 116 s-353 s, respectively. The Fourier transform infrared (FTIR) results have shown that gum arabic and maltodextrin have structural stability during spray drying. The encapsulated probiotic cells have shown a positive effect and exhibited better viability after exposure to a SGI solution at different pH levels and duration compared to free cells. The viability of encapsulated cells stored at refrigerated condition (4 °C) was found to be higher than the viability of cells stored at room temperature (25 °C).