Effects of double emulsification on Lactobacillus plantarum NBRC 3070 stability and physicochemical properties of soursop juice during storage

Abstract

Sufficient number of probiotics in product are required to confer its health benefits to consumers. However, the viability of probiotics can detriment during processing. An approach of emulsion method to provide a physical barrier of probiotics against adverse environmental conditions has received considerable level of interest. Various matrices were used to emulsified probiotics in food product. However, the usage of water/oil/water (W1/O/W2) base to emulsify probiotics for beverages application remained scarce. Thus, this study was to determine the suitability of using W1/O/W2 base to emulsify Lactobacillus plantarum NBRC 3070 to be incorporated into pasteurized soursop juice (Annona muricata L.). Hence, emulsion efficiency (EE%) of L. plantarum NBRC 3070 in W1/O/W2 base, the stability of emulsified cells (log10 CFU/mL) and physicochemical changes of soursop juice (pH, titratable acidity, total soluble solid, viscosity, colour, sensory) during storage were determined. In this study, emulsified L. plantarum NBRC 3070 (109 CFU/mL) was incorporated into soursop juice and stored at 4°C for four weeks. Results obtained with 86.02% ± 0.69 emulsion efficiency (%) of L. plantarum NBRC 3070. Insignificant changes (p>0.05) were notified from viability of emulsified probiotics, pH, titratable acidity and viscosity during storage. Meanwhile, satisfactory parameters (colour, sensory and coliform counts) were obtained at the satisfactory level. As for the conclusion, W1/O/W2 base was able to maintain the survivability of L. plantarum NBRC 3070 in soursop juice during storage and quality of the product. Optimization of parameters such as water/oil compositions and storage time can be further explored to enhance product quality.