Applied Food Biotechnology (Jul 2020)
Incorporation of Lactobacillus casei into the Inner Phase of the Water-in-Oil-in-Water (W1/O/W2) Emulsion Prepared with β-Cyclodextrin and Bacterial Survival in a Model Gastric Environment
Abstract
Background and objective: Literature contains extensive researches on use of multiple emulsions in a variety of areas such as foods, pharmaceuticals, and health products. Water-in-oil-in water double emulsion (W1/O/W2) was used in the present study for entrapping Lactobacillus casei where balance in gastric system is under influence of probiotics release mechanism. Role of β-cyclodextrin emulsifier presented in the external aqueous phase of the test emulsion was explainable through emulsion characterization analyses (Fourier Transform Infrared spectroscopy, particles size distribution and Scanning Electron Microscopy). Cells viability was determined in terms of first-order kinetics and by applying the probability concept and survivability in gastric system was evaluated probabilistically using the exponential distribution. Material and methods: Three different ratios of W1/O:W2 [40:60, 50:50, 60: 40] were used for preparing W1/O/W2 emulsions to encapsulate Lactobacillus casei into the inner phase with using β-cyclodextrin emulsifier. Dynamic light scattering was used for determination of emulsion particle size. Presence of the functional groups was detected using infrared spectroscopy and recording the relevant peaks in the region of 4000 to 400 cm-1. The differential equation for first-order kinetic (dx/dt = kx) was used for the cells viability determination. Exponential probability distribution in terms of failure time (reflection of the cells not being able to be released) was also used in this study (f(t) = λe-λt). Results and conclusion: By preparation of gastric environment in terms of the bile salts and in a pH-controlled media, viability of the encapsulated cells was monitored and the following expression for the first-order rate constant was obtained for the test emulsions (k(60:40) < k(50:50) < k(40:60)). Emulsification appears to be feasible industrially since the composition of the emulsions used for Lactobacillus casei entrapment was entirely edible. Conflict of interest: The authors declare no conflict of interest.
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