In the continual search for natural preservatives, Active Micro Systems (AMS), Piscataway, NJ, offers a line it calls “alternative preservative solutions.” One of the them is AMS Leucidal Liquid (INCI: Leuconostoc/ radish root ferment filtrate).
   
The impetus for this product came from observations made by researchers who noticed that there were fewer cases of avian flu along the Korean pennisula. They theorized that consumption of kimchii, a root vegetable  widely eaten in Korea, might offer resistance to the virus. As anyone who has eaten the vegetable can attest, the odor of cooked kimchii alone might be potent enough to kill microbes! The Leuconstoc bacteria used in AMS Leucidal Liquid is a lactic acid bacteria which tries to retrict competition from other microorganisms by acidifying its environment. The particular bacillus used, Leuconstoc kimchii. also produces an antimicrobial peptide. The product sold by AMS is an isolated peptide. Minimum Inhibitory Concentrations were created using a standard agar dilution method. Gram positive bacteria and mold were tested to evaluate the ability of AMS Leucidal Liquid to protect against microbial contamination. No mention of testing vs. Gram negative bacteria is mentioned. The results were satisfactory. The material is also non-irritating to eyes and skin.
   
Although the product is active under both acidic and basic conditions, there is a loss of activity at pH 9. It is also recommended that it should be added to the formula below 60°C.
   
Another natural preservative from AMS is PhytoCide Aspen Bark Extract Powder (INCI: Populus tremuloides (Aspen) bark extract). The product is derived from the Quaking Aspen tree found in northern and western North America. Apparently, the bark is rich in salicylates which may function as a defensive mechanism against invading parasites. Medicinal barks have been used for centuries as analgesics and fever reducers. As an analgesic for lower back pain, the recommended dose is 1-3 grams of bark, which contains 60-240mg of salicylates.
   
PhytoCide Aspen Bark powder contains a salicylate concentration of 54-60%. Initial efficacy tests revealed thatt this product inhibits the growth of mold, yeast, E. coli, S. aureus, B. subtilis and P. aeruginosa. It is water-soluble and should be used at a pH between 3 and 9. Incorporation in a formula should be between 60°C and the suggested use level is 0.2 to 3%. The cost is about $120 per kilo.     Other botanical preservative extracts, including one based on black currant, are available. The formula below is a good example of how to formulate with PhytoCide Aspen Bark Extract along with several other AMS extracts.

Soothing Face Cleanser

Ingredients:                                        %Wt

Phase A

Water                                                    q.s.
Sodium phytate                                    0.20
PhytoCide Aspen Bark Extract           2.00
Phase B
Sodium lauryl sulfoacetate                 19.00
(and) disodium laureth
    sulfosuccinate
Wheat germamidopropyl betaine    10.00
Cocamide DEA                                    4.00
Phase C
Sodium cocoyl hydrolyzed                5.00
    wheat protein
Lactobacillus/phoenix dactylifera    1.00
    (date) fruit ferment extract
Water (and) phospholipids                1.00
    (and) retinyl palmitate (and)    
    ascrobyl palmitate (and)
    tocopherol acetate
Water (and) propylene glycol             1.00
    (and) erythroxyum catuaba
    bark extract)
Water (and) zingiber officinale            4.00
    (ginger) root extract (and)
    mentha piperita (peppermint)
    leaf extract
Water (and) caprylyl glycol (and)         2.00
    pentylene glycol (and) wasabia
    japonica (wasabi) root extract
    (and zingiber officinale (ginger)
    root extract (and) allium sativum
    (garlic) bulb extract
Fragrance                                                0.06

Procedure:

Add water to tank and add phase A. Begin heating to 70°C. At 70°C, add phase B individually. Begin cooling. Add phase C at 45°C.

About the Author
Harvey Fishman has a consulting firm at 34 Chicasaw Drive, Oakland, NJ 07436, [email protected], specializing in cosmetic formulations and new product ideas, offering tested finished products. He has more than 30 years of experience and has been director of research at Bonat, Nestlé LeMur and Turner Hall. He welcomes descriptive literature from suppliers and bench chemists and others in the field.