Headspace protection

Packaging is critical for the successful preservation of personal care products. Airless packs, pumps and tubes can help limit the introduction of microorganisms during a products life in use, while pipette applicators allow for the precise and hygienic application of products to the skin.

Cosmetic products may become contaminated when cosmetic packaging does not provide adequate preservation1. Headspace preservation can also be an issue when cosmetic packaging does not provide adequate protection from fungal contamination. This can stem from different sources throughout the product lifecycle, from the manufacturing environment to poor storage conditions or consumer use.

Market demands and everchanging regulations have driven the personal care industry away from synthetic materials to focus on natural solutions. With claims such as “preservative free” still being popular, additional pressure is placed on the choice of allowed preservative systems. Consequently, there is a distinct need for natural antimicrobials, which can support different packaging types and protect against headspace contamination.

Preservatives

Parabens and phenoxyethanol are synthetic volatile preservatives, which are commonly utilised to prevent contamination of a formula as well as headspace microbial growth. However, the potential for skin sensitisation associated with the use of these preservatives2, as well as stricter global regulations, has pushed formulators to explore alternative options.

The Bacillus ferment and saccharomyces ferment filtrate (BFSFF) is a product of co-fermentation with Bacillus subtilis and Saccharomyces boulardii in a defined growth medium. Inspired by advances in both agriculture and nutrition, the filtrate was developed to address headspace protection. This active can be used in conjunction with a broad-spectrum antimicrobial, or alongside any preservative system, for boosted protection against potential yeast and mould growth associated with packaging.

Natural composition

Bacillus spp. are well-known rhizosphere residents of many crops, including tomato, corn, and soybeans. These bacteria produce non-volatile and volatile secondary metabolites that exhibit anti-fungal activity as a mechanism of biocontrol to promote healthy plant growth3,4.

The volatile organic metabolites produced by Bacillus subtilis are shown to naturally reduce and prevent plant diseases commonly caused by airborne fungal spores.

Saccharomyces boulardii is a probiotic strain of yeast, first isolated in 1934 by the French scientist Henri Boulard from lychee and mangosteen fruit. Saccharomyces boulardii has sparked interest within the scientific community specifically due to its wide variety of interactions with other microbes, as well as its ability to inhibit gastrointestinal disorders and symptoms of gastrointestinal distress.

Current research within the food industry has examined the ability of Saccharomyces spp. and bacteria, such as Bacillus spp., to enhance the production of volatile compounds when co-inoculated5,6.

The co-inoculation of Saccharomyces boulardii with Bacillus subtilis enhances the bioactivity of volatile metabolites. Using bio-fermentation and various filtration techniques, the volatile organic metabolites are isolated and extracted from the bacteria cell to deliver a volatile anti-fungal active for effective headspace protection. This patented process successfully produces a naturally derived, high-potency material that also delivers skin-moisturising properties.

Investigate effectiveness

A headspace preservation test was conducted over a period of 28 days to evaluate the preservation adequacy of 1% BFSFF compared to 1% phenoxyethanol (positive control) and an unpreserved base cream formula (negative control). Penicillium brevicompactum and Fusarium sp. were isolated from the environment via passive sedimentation to observe a “real-life” example of contamination from manufacturing areas, storage conditions or consumer use.

The base cream formula used to perform the test was filled into individual cosmetic containers at 45°C in order to create an optimal environment for mould to grow under the test conditions. Each cosmetic jar was filled to approximately 75% of its capacity (~25ml) leaving 25% capacity of each jar empty as headspace. 1% BFSFF compared to 1% phenoxyethanol were subsequently added separately. Each cap of the cosmetic jars was inoculated with the contaminants. Each cap was then evaluated on days 7, 14, 21 and 28 following the initial inoculation.

Results

Tables 1 and 2 represent the percent reduction of viable organisms after being introduced into the test packaging. The moulds were reduced to 0 (>99.9%, 3 log) and remained at this level throughout the whole cycle. The results indicate that the BFSFF has an efficient activity against Penicillium brevicompactum and Fusarium sp., comparable to that of phenoxyethanol.

As with all cosmetic raw materials, aspects of safety and sustainability are of upmost importance. The filtrate is both mild and gentle on the skin, supported by a complete dossier of toxicological data, including but not limited to repeat insult patch test, skin sensitisation, mutagenicity, phototoxicity and dermal and ocular irritation.

Derived through a sustainable biotechnology, sourced from a probiotic bacteria and yeast, this filtrate does not compete with the food chain and is readily biodegradable.

Conclusion

Through the co-fermentation of Bacillus subtilis with Saccharomyces boulardii, it is possible to create a natural, multifunctional active, which can provide skin-moisturising benefits while simultaneously promoting volatile anti-fungal protection for a cosmetic formula, a cosmetic container, and a cosmetic container headspace. 

Bacillus ferment and Saccharomyces ferment filtrate

• INCI (PCPC/IECIC): Bacillus Ferment & Saccharomyces Ferment Filtrate & Propanediol
• Appearance: hazy liquid
• Origin: biotechnology
• Suggested use level: <1%
• Suggested applications: anti-fungal, conditioning, moisturising

References:

1 US Food & Drug Administration. Microbiological Safety and Cosmetics. Available: https://www.fda.gov/cosmetics/potential-contaminants-cosmetics/microbiological-safety-and-cosmetics 

2 Lee, E., An, S., Choi, D., Moon, S., and I. Chang. 2007. “Comparison of objective and sensory skin irritations of several cosmetic preservatives.” Contact Dermatitis. 56: 131-136.

3 Fiddaman PJ, Rossall S. 1994. Effect of substrate on the production of antifungal volatiles from Bacillus subtilis. J. Appl. Bacteriol. 76:395–405.

4 Gu Y-Q, Mo M-H, Zhou J-P, Zou C-S, Zhang K-Q. 2007. Evaluation and identification of potential organic nematicidal volatiles from soil bacteria. Soil Biol. Biochem. 39:2567–2575.

5 Durate, WF, de Sousa, MV, Dias, DR, Schwan, RE. 2011. Effect of co-inoculation of Saccharomyces cerevisiae and Lactobacillus fermentum on the quality of the distilled sugar cane beverage cachaça. J Food Sci. 76(9):C1307-18

6 Antalick, G, Perello, MC, de Revel, G. 2013. Co-inoculation with Yeast and LAB Under Winery Conditions: Modification of the Aromatic Profile of Merlot Wines. S. Afr. J. EnoL Vitic., VoL 34, No. 2. 223-231.