First, the good news: Herbs are back. Frost & Sullivan’s (San Antonio, TX) latest research indicates that plant-based extracts and ingredients are generating strong interest around the globe. From North America and Europe to the Middle East, Asia, and Oceania, manufacturers are integrating botanicals into a multitude of supplements and functional foods.
Indena's Mirtoselect bilberry extract contains 25%
anthocyanins. A recent study in the Journal of
Agricultural and Food Chemistry showed that bilberry
content could be verified by HPLC. Photo courtesy
Now, the bad news: Herbal product recalls are back as well (see sidebar at right). Food safety agencies issued several serious warnings about herbal supplements in February and March. In Australia, the Therapeutic Goods Administration (TGA) publicized a recall of a dieter’s tea product contaminated with unacceptable levels of microbes, and TGA’s Adverse Drug Reactions Advisory Committee also reported a case of heavy- metal poisoning related to ayurvedic medicine. In Canada, health officials warned consumers not to use Sleepees, an herbal sleep aid adulterated with the prescription sedative estazolam. And in the United States, FDA said it had detected the presence of the erectile dysfunction drug animotadalafil in the botanical supplement Rhino Max.
Recalls may be rare, but they are still a source of concern for manufacturers. Fortunately, there are several ways to avoid them, including the use of new sterilization technologies. Moreover, manufacturers can augment their sterilization programs by relying on additional quality control (QC) procedures such as analytical testing.
STERILIZATION METHODS OF CHOICE
Microbial contamination has the potential to be a serious problem for herbal supplement manufacturers. The nature of herbs makes them susceptible to contamination by microorganisms such as bacteria, molds, and fungi. However, several of the most effective sterilization methods are not recommended for use in foods and supplements and are prohibited by various regulatory bodies.
For instance, ethylene oxide (EtO), a chemical sometimes used to produce antifreeze, has strong antimicrobial properties and has been shown to reduce microbial load in plant-based materials. EtO is a very effective decontaminant for medical equipment when used in small doses, and it also functions as an insecticide in very small amounts. However, it is also considered a potential carcinogen, and exposure to eyes, skin, and respiratory passages may cause irritation in humans. Because of EtO’s safety concerns, regulations in Europe, Asia, the United States, and elsewhere prohibit or limit its use in food and supplements. EtO is also banned in California under Proposition 65.
Another well-known method, irradiation, is similarly controversial. FDA approved some forms of food irradiation in 1999, but public fears about its safety have hampered its commercial potential. In the April 3 edition of the Federal Register, FDA proposed changing its labeling rules to make irradiation more attractive to consumers. Currently, irradiated food labels must contain the radura symbol and indicate treatment with irradiation. FDA’s proposed revision would require special labeling only when irradiation changes the food’s appearance, nutritional value, or health benefits. Still, consumers remain reluctant to embrace the technology, and suspicions about irradiation’s effects on food safety and nutritive value persist. International and domestic food and supplement regulations tend to be less restrictive of irradiation than of EtO, but the process is still banned or limited in many countries.
Study: Ayurvedic Extract Relieves Joint Discomfort
A botanical extract derived from the herb Boswellia serrata provided significant relief from joint discomfort among people with osteoarthritis, according to a new study published in the January/February 2007 issue of the Indian Journal of Pharmacology.
In the study, researchers randomly assigned either 1000 mg of B. serrata extract or 10 mg of valdecoxib per day for six months to 66 people with osteoarthritis of the knee. To measure the effects of the treatments, the researchers recorded WOMAC scores for the subjects at baseline, monthly intervals, and at the end of the trial. Verdure Sciences (Noblesville, IN) provided the herbal extract, which is sold under the brand name Wokvel.
At the end of the trial, the researchers concluded that while valdecoxib provided relief within one month of treatment which lasted throughout the trial, Wokvel provided relief within two months of treatment which lasted at least one month after the end of the trial.
“In terms of safety, efficacy, and duration of action, the present study shows that B. serrata extract was superior to valdecoxib, except for the slower onset of action compared to valdecoxib,” wrote the researchers.
On the other hand, several alternative sterilization methods may be just as effective. In 2005, for example, Blue California (Rancho Santa Margarita, CA) started using ozone sterilization to purify herbal ingredients at its manufacturing facility in China. The process, which creates ozone by exposing oxygen molecules to electricity, has a long history of use in industrial applications as a disinfectant.
Steam sterilization is another useful option that is becoming more popular. In 2006, BI Nutraceuticals (Long Beach, CA) introduced its Protexx HP process, which is certified organic and reduces microbial loads as efficiently as EtO and irradiation. The technology uses superheated dry steam to sterilize more than 700 species of herbal ingredients without creating residue. Because the Protexx-sterilized herbs are EtO and radiation free, they are also easier for manufacturers to ship overseas.
A third alternative, heterogeneous biphase sterilization (HBS), also reduces microbial contamination without relying on EtO. Naturex (Avignon, France), which holds a U.S. patent on the process, uses the method to sterilize its Pure Powder line of botanical extracts. HBS works in ambient pressure by exposing plant materials to nascent oxygen molecules or hydroxyl radicals. Because the molecules possess strong germicidal properties, the process quickly oxidizes microbial contaminants.
Sterilization can make big improvements in product quality and safety. But as this year’s batch of product recalls indicates, reducing microbial load is just one problem. Like contamination, adulteration can also damage a product. To prevent spiking and ensure that their raw materials are genuine, many manufacturers also depend on rigorous analytical testing procedures that are implemented either by in-house staff or trusted suppliers.
BI, for instance, tests for heavy metals, pesticides, and species before it begins the Protexx process. Similarly, in 2005, Indena (Seattle) started implementing a comprehensive QC system that tracks more than 30 parameters, beginning with raw materials and ending with finished products. Indena records the entire process in a Master Batch Record to ensure consistency and traceability.
A recent indication of Indena’s success can be found in a study published in the August 29, 2006, issue of the Journal of Agricultural and Food Chemistry. In the study, Australian researchers described how HPLC analysis could be used to detect adulterants in two bilberry (Vaccinium myrtillus) extracts, both of which claimed to contain 25% anthocyanins. Using UV-VIS analysis, Indena’s Mirtoselect bilberry extract and another commercial extract both appeared to contain 25% anthocyanins. However, under HPLC analysis, the researchers were able to prove that while Mirtoselect actually did contain the 25% anthocyanins, the other extract contained only 8%.
Given the investment required to develop a branded herbal supplement, it makes sense for manufacturers to make QC a priority. Manufacturers should carefully consider how their raw materials are evaluated and sterilized, in addition to sourcing their materials from reputable vendors. The costs of preventing contamination and adulteration may be high, but the costs of enduring a product recall and lost credibility are even higher.
Full Steam Ahead
Steam has had a long career as an engine of progress. It has powered vessels like boats and locomotives. It has energized factories. It has been used to generate electricity, heat houses, and clean textiles. And now it is being used to purify herbal extracts.
When BI Nutraceuticals (Long Beach, CA) began exploring different sterilization technologies four years ago, it had a short list of requirements: The technology needed to be natural, organic, and capable of efficiently sterilizing hundreds of different herbal extracts. The result, BI’s Protexx HP process, is a welcome addition to steam’s long list of career accomplishments. Protexx HP rapidly eliminates microbes by injecting high levels of steam into a chamber filled with raw herbal materials.
Protexx HP produces a microbial load that is as low or lower than the load produced by ethylene oxide (EtO), says BI president and CEO George Pontiakos. “A lot of the alternative sterilization methodologies out there are not consistent in terms of reducing microbial load across a large amount of species,” he says. “You may see them consistent in one or two species, but we do it across 700-plus.”
Matt Phillips, BI’s vice president of marketing and sales for the Americas and Europe, adds that the process sterilizes each herbal species using a unique set of parameters. “For other technologies, there is one program for every raw material,” he says. “In our process, every raw material has its own profile.”
BI also pays attention to the condition of the raw materials before they are processed. The company tests the herbs before processing to ensure that they are free of pesticides and heavy metals, haven’t been irradiated, and are the correct species. Moreover, in 2006, the company initiated a qualification program for its Asian vendors to ensure that materials sourced from the region meet its quality standards.