Preservatives are ingredients that are added to a product to prevent or retard microbial growth, avoiding product damage and helping it to remain safe for the customer and to perform as intended during its shelf life.
Most formulations need the use of a preservative, for instance, water-based products or products that can easily be contaminated by the customer, through use need to be preserved. While choosing a natural preservative, one of the most important features to be observed is its spectrum of activity, an information that describes the preservative
antimicrobial performance against the various forms of microorganisms. For instance, a broad spectrum preservative can have an antimicrobial performance against mould, yeast, Gram positive and Gram negative bacteria. Sometimes, more than one preservative can be combined to cover the antimicrobial activity needed in a product.
The preservative’s solubility, the pH range where it develops its activity and its thermal stability are also characteristics to be observed. Each preservative is different and has its own particularities, and has to be chosen while taking the formulation into consideration. E.g. some preservatives have a small pH range of activity and can turn ineffective with pH changes, while others are stable in a bigger range of pH, so the final pH of the product needs to be taken into
consideration. (Rephrasing further)
Reference: https://www.sciencedirect.com/science/article/pii/S163107481630162X
