Rosemary Preservatives: New Developments

The antioxidant strength of rosemary (Rosmarinus officinalis) makes this herb a favorite preservative of food and cosmetic markets. Rosemary extract can be used to slow microbial growth on food products, and it can prevent oxidation of various oils in formulations; but, like most plants, this one has its limitations-at least traditionally.

Recently, a pair of rosemary extract suppliers improved their rosemary ingredients in ways that are sure to please finished-product manufacturers.

Sensory Characteristics

It’s easy enough to identify the challenges in rosemary’s sensory profile. The odor, bitterness, and color of rosemary all have potential to affect the final product, or at least create a need for ingredients that mask these properties. To do away with this extra step, rosemary extract supplier Vitiva (Markovci, Slovenia) has developed Substar, a deodorized rosemary extract with low bitterness and low color capacity.

Manufacturers can use Substar to prevent oxidation in cosmetics, mild foods, pet food, and animal feed. While pets are usually very sensitive to the odor of rosemary, Vitiva says Substar’s low odor makes this rosemary extract uniquely useful.

Vitiva’s rosemary extract arrives to market at just the right time because tocopherols-another popular preservative, especially for pet food-are rising in price and scarcity. The demand for tocopherols to prevent oxidation in biodiesel has risen so much that Vitiva says tocopherol performance in various food and cosmetic applications is not currently justifying its high cost. The company says that Substar demonstrated greater activity than potent delta-tocopherols in side-by-side tests.

Substar is available for use in both oil- and water-soluble applications.

Performance and Supply

Smells and tastes aside, perhaps the biggest challenge with commercial-grade rosemary is growing it. Rosemary is traditionally grown wild in countries including Tunisia, Spain, and Morocco, according to rosemary extract supplier Kemin (Des Moines, IA). In these locations, plants may be clear-cut from hillsides, reducing any chance of additional harvests until the plants grow back to maturity.

By contrast, Kemin grows its own rosemary plants on roughly 1000 acres in New Mexico and Texas where each plant is merely trimmed, allowing for harvests in spring and summer before plants regenerate in winter. The method ensures that rosemary leaves are picked at optimal times of the year, that each plant is of the same age, and that each plant will see out its full life cycle.

“Each plant is like every other plant in the field,” says Marsha Bro, marketing director for Kemin’s personal care division. “It’s the exact same plant and the exact same breed, so there isn’t variation in the plant that we would ultimately have to deal with when preparing ingredients for our customers.”

But Kemin’s specialized farming program goes further. With the help of bee pollination, the company is able to selectively breed hardier rosemary plants that are standardized for key molecules that give rosemary its antioxidant activity.

Kemin offers a range of rosemary extracts, but its newest is Rosamox, specifically intended for oil-soluble applications in cosmetic products, including skin care lotions, lip moisturizers, soaps, base oils, and sun and hair care products. Rosamox is purportedly low in odor and color-an important factor especially when manufacturing white or lightly colored lotions. Thanks to a solvent-free supercritical dioxide extraction process and a basic washing process, Rosamox even has clean-label advantages.

“Primary positioning for Rosamox is to protect against oxidation, but we’re also looking at active benefits on the skin,” says Bro. “There is some published research on this, but that’s something we’re right in the middle of testing.”

What more could you ask for from your rosemary extracts?