Formulation Factors Affecting the Microbial Stability of Oil-in-Water Food Emulsions

CAMPOS, CARMEN A.; GLIEMMO MARÍA F; ZALAZAR, ALDANA L.; LARA, VIRGINIA

An In-Depth Guide to Oil-in-Water Emulsions

Nova Science Publishers, Inc.

Año: 2021; p. 181 - 226

Oil-in-water emulsions can support the growth of pathogens and spoilage microorganisms and their microbial stability is strongly influenced by oil level, the inclusion of additives, preservation factors and the structure provided by the amount of oil and other additives such as hydrocolloids used as stabilizers. Regarding oil level, its concentration may vary between 3-5% in the case of milk, from 10 to 40% in salad dressings and can be as high as 85% in mayonnaise. Furthermore, oil droplets can be used as delivery systems to encapsulate, protect, and release bioactive hydrophobic compounds such as flavors, nutrients, antimicrobials and antioxidants. It must be stressed that the system structure modifies the form of microbial growth, in the case of liquids, it occurs planktonically. But in structured emulsions, the mobility is restricted; microorganisms are immobilized and grow as colonies. Moreover, the system pH and stress factors applied determine the type of microorganism able to grow. The main objective of this chapter is to review the bibliography concerning the formulation factors affecting microbial stability in oil-in-water emulsions. Additionally, the relationship between microbial growth and the emulsion stability was also taken into account. This information will aid in the selection of formulations and conditions that will contribute to the improvement of the food safety and quality in oil-in-water food emulsions.