The internal aqueous phase gelation improves the viability of probiotic cells in a double water/oil/water emulsion system

Abstract

This research studied the viability of probiotic bacterium Lactobacillus plantarum (L. plantarum) encapsulated in the internal aqueous phase (W1) of a water‐in‐oil‐in‐water (W1/O/W2) emulsion system, with the help of gelation and different gelling agents. Additionally, the physicochemical, rheological, and microstructural properties of the fabricated emulsion systems were assessed over time under the effect of W1 gelation. The average droplet size and zeta potential of the control system and the systems fabricated using gelatin, alginate, tragacanth gum, and carrageenan were 14.7, 12.0, 5.1, 6.4, and 7.3 μm and − 21.1, −34.1, −46.2, −38.3, and −34.7 mV, respectively. The results showed a significant increase in the physical stability of the system and encapsulation efficiency of L. plantarum after the W1 gelation. The internal phase gelation significantly increased the viability of bacteria against heat and acidic pH, with tragacanth gum being the best gelling agent for increasing the viability of L. plantarum (28.05% and 16.74%, respectively). Apparent viscosity and rheological properties of emulsions were significantly increased after the W1 gelation, particularly in those jellified with alginate. Overall, L. plantarum encapsulation in W1/O/W2 emulsion, followed by the W1 gelation using tragacanth gum as the gelling agent, could increase both stability and viability of this probiotic bacteria.

An Updated Comprehensive Overview of Different Food Applications of W1/O/W2 and O1/W/O2 Double Emulsions

“…The storage stability of the encapsulated cells in DE after 42 days of storage at 37 • C indicated a gradual decrease in the cells until the 21st day and then a sharp decrease until the end of storage (survival rates of about 95% and 62% in the 7th and 42nd days of storage were reported, respectively) [59]. Abbasi, et al [60] investigated the viability of L. plantarum encapsulated in the inner phase of a W 1 /O/W 2 DE under the effects of heating and pH in the presence of various gelling agents (gelatin, alginate, tragacanth gum, and carrageenan) in W 2 . They reported that the initial count of free cells (9.95 log CFU/mL) reached 9.97, 8.10, 6.37, and 0 log CFU/mL after 2 min of heating at 30, 50, 63, and 72 • C, respectively.…”