Antimicrobials are used to inhibit bacterial growth in exposed or open edibles. Many products first go through high-pressure processing (HPP) to inactivate bacteria. Exposure to ultraviolet (UV) light is another option. Some antimicrobials (e.g. phages) target specific bacteria; some such as mustard either directly or indirectly kill bacteria.
Natural Antimicrobials
(Based on an article in the July 2015 issue of Prepared Foods.)
Celery powder (natural nitrates; nitrite when cultured)
Cherry powder (replaces synthetic sodium ascorbate?) – acerola
Blueberry extract, cranberry extract, blackberry juice
Rosemary extract
Mustard powder (flour) or de-oiled mustard meal (see quotes below)
Vinegar powder (acetic acid) – buffered with potassium or sodium
Alginic, citric, and lactic acids (from fermented carbohydrates)
Oregano essential oil
Bacteriophages (phages) such as Listex (from sea water, soil, or animal intestines)
Nisin (from lactococcus bacteria)
Natamycin (Streptomyces natalensis – soil bacteria)
Lysozyme (from hen egg whites)
Tocopherols (vitamin E from a number of sources)
Ascorbic acid (vitamin C)
L-malic acid (from apples)
Thyme essential oil
Clove extract
Cinnamon extract
Hops (used in beer)
HPP
High-pressure processing (HPP) evenly applies cold water at up to 87,000 psi for one to three minutes. HPP extends the shelf life of dense, solid or liquid, high acid foods by two to three times by neutralizing bacteria. The effect is bacteriostatic rather than bactericidal; the effect is lost once the package is opened.
UV
Exposure to ultraviolet (UV) light neutralizes bacteria and in produce, UV neutralizes ethylene gas and kills or sterilizes insects and microorganisms.