Picking Botanical and Herbal Ingredients

Picking Botanical and
Herbal Ingredients
June 1999 -- Applications

By: Lynn A. Kuntz
Editor

  Rose hips, echinacea, ginger, chamomile, garlic and more. Today's hottest ingredients resemble nothing so much as an ancient herbalist's collection of cures and physics. Burgeoning interest in natural foods and dietary supplements, and the increasing recognition that, if we aren't exactly what we eat, what we eat makes us the way we are, have contributed to the rising popularity of herbal and botanical ingredients. Once relegated to funny-looking tablets or strange herbal teas in health food stores, these ingredients are fast becoming part of the food technologists' larder.

  Depending on what categories are included, the market for these products is substantial. According to a February 1999 New York Times article by Jane Brody, the annual retail market for botanicals is nearly $4 billion and increasing at a rate of about 18% per year.

  Echinacea, ginseng, gingko biloba, St. John's wort, goldenseal and saw palmetto rank as some of the most popular herbal supplements, according to Chris Tower, product manager, extracts, Botanicals International, Long Beach, CA. "You see them in tablet form next to traditional vitamins and minerals, but you're also seeing them in beverages, health and energy bars, and they are starting to turn up in things like breakfast cereals."

  The wealth of different products out there makes it difficult to know where to start, particularly when a certain substance has not been widely used in modern foods. Still, it's not all a jungle out there. Some ingredients have been commonly used and available for years. Others might seem a bit more foreign, but the botanical industry has taken steps to identify and standardize the products it sells.

Classifying the plants

  First off, what exactly are botanical and herbal extracts? There's no one strict definition; it's a bit in the eye of the beholder. In the loosest definition, most any minimally processed product that is derived from a plant source might be called a botanical product. That can include products made from roots, leaves, stems, fruits or nuts, says Gary Hainrahar, vice president, sales, Kalsec Inc., Kalamazoo, MI. In the food industry, it usually means one of the generally recognized as safe (GRAS) substances or food additives, often a spice or herb, that can be used as a foodstuff, or in a food as a coloring or flavoring agent. For those involved in designing dietary supplements, it generally refers to plant-derived products that have some beneficial effect on health, either proven scientifically or through anecdotal evidence.

  The two industry categories are not mutually exclusive. The FDA lists GRAS substances in 21CFR182. Section 182.10 lists spices and other natural seasonings and flavorings that are GRAS, and Section 182.20 includes essential oils, oleoresins (solvent-free) and natural extractives (including distillates) that are GRAS and that are derived from the materials in 182.10. On this list are a number of ingredients that any self-respecting herbalist would be happy to use, such as clover, ginger, tea and peppermint. "This regulation says that these are appropriately labeled as natural flavors," says Hainrahar.

  In addition, certain botanical extracts, such as turmeric and paprika, are listed as color additives exempt from certification in 21CFR73. "Paprika oleoresin is considered a color in the United States," points out Hainrahar. "In Europe, it is considered a flavor unless the pigment content is above a certain percent, and then it is considered a color and requires an E number." This distinction is purely regulatory, not functional. "Paprika can contribute flavor to some food products," he says. "It just has to be labeled as a color. And turmeric, which is rich in yellow color, is the principal ingredient in curry. So if you added turmeric extract to curry, it would be labeled as a color, even though it's added for flavor, too." While these types of ingredients may possess some nutraceutical benefits, most product designers don't add them for that attribute.

  The FDA also considers some botanicals to be approved food additives falling under the category of natural flavoring substances and natural substances used in conjunction with flavors. These are listed in 21CFR172.510. This includes ingredients such as valerian and guarana, and even St. John's wort - as long as it contains no hypericin and only is added to alcoholic beverages. "That regulation will have some herbs and botanicals listed, and where they are acceptable for use within the food industry," points out Michael Petteruti, vice president and COO, Folexco, Inc., Montgomeryville, PA. "It gives the levels and what forms they need to take. It also outlines specifically where some of these herbs can be used. You'll find several botanicals that are used in the supplement industry for their efficacious and beneficial effects. These are extracts that the food industry has used for many, many years as flavoring agents."

  On the other hand, many of the popular nutraceutical botanicals, such as echinacea and saw palmetto, have not been granted GRAS or food additive status for use in food products. That means that if they appear in a food product, the FDA will consider that food adulterated. However, the passage of the Dietary Supplements and Education Act of 1994 (DSHEA) opened the door for products containing "a vitamin; a mineral; an herb or other botanical; an amino acid; a dietary substance for use to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract, or combination of any of the previously mentioned ingredients."

  DSHEA does not specifically name any particular herb or botanical material allowed for use as a dietary supplement. It does, however, require that these ingredients are safe, and that they do not present "a significant or unreasonable risk of illness or injury." If the ingredient was not marketed in the United States prior to October 1994, the manufacturer must provide evidence of safety, such as history of use. However, if the government feels a hazard exists, it can step in. For example, in June 1997, the FDA submitted a proposed rule to regulate the use of ephedrine alkaloids. These alkaloids, including ephedrine, pseudoephedrine, norpseudoephedrine, norephedrine, methylephedrine and methylpseudoephedrine, are naturally occurring chemical stimulants found in raw botanicals and extracts from the herb Ma Huang, or ephedra. The FDA maintains a list of potentially dangerous herbal ingredients, singling out products such as comfrey, chaparral and lobelia.

Classifying the product

  "There seems to be rising interest in botanicals on the part of major food companies," says David N. Wilson, president and CEO, Folexco, Inc. "So far it's been mostly the smaller companies that have introduced products using them. However, that's what happened with the botanicals sold as supplements; the smaller, non-mainstream companies filled the shelves and now the major supplement companies have followed with products of their own."

  According to Petteruti, some food companies might fear that there's a stigma attached to introducing a product as a supplement under DSHEA, rather than a food. "There's some substantiation to their hesitancy in that the exhaustive studies everyone is looking for aren't there. A major food company doesn't want to take the risk that an ingredient will cause someone to break out in hives and go into anaphylactic shock. What I often counter with, is that, with the GRAS list, most of those ingredients were grandfathered in. After all, have you ever seen any exhaustive studies done on the use of black walnut hulls as a flavoring? If you look at anecdotal history and there are no legitimate side effects or health hazards with these ingredients - whether you use the German E Monographs or proven Chinese medicine for substantiation - that's just as meaningful as the GRAS list in my view."

  The caution in product introduction might result from a wait-and-see attitude toward consumer acceptance or science, but it also might result from the fuzzy legal line between a food and a dietary supplement. Recently, several companies have positioned and labeled a group of food-like products containing botanicals as dietary supplements. These include products such as Hain Food Group's, (Uniondale, NY) Kitchen Prescription^TM soup-style herbal supplements, including creamy split pea with St. John's wort, and Chicago-based F&F Foods' Happy Health Candies^TM supplements, with its echinacea- and green-tea-fortified Combatz^TM. Botanically flavored and fortified teas and beverages seem to crop up with increasing regularity, as do bar products designed to enhance energy or memory and supply a host of other benefits.

  The FDA doesn't exactly make it easy to draw a distinction. On one hand, DSHEA says that a dietary supplement should not be represented for use as a conventional food or the sole item of a meal or diet. On the other hand, in its final rule on Food Labeling; Statement of Identity, Nutrition Labeling and Ingredient Labeling of Dietary Supplements published in the Federal Register of September 23, 1997 (Volume 62, Number 184), the FDA states that "dietary supplements may be similar to conventional foods in composition and form. Whether a product is a dietary supplement or a conventional food, however, will depend on how it is represented. To be a dietary supplement, a product must bear the term 'dietary supplement' as part of its common or usual name."

  Allowable claims is the other legal can of worms encountered. If an herb or botanical is being added to promote health, manufacturers are limited to the ambiguous structure/function claims. Echinacea may "promote wellness" but it may not "help lessen the duration and severity of colds and flu." Of course, a statement to the effect of "These statements have not been evaluated by the FDA and this product (or information) is not intended to diagnose, treat, cure or prevent any disease," is also required. (The same statement would apply to any information that refers to the reported health benefits written here.)

  Given the recent travails of dietary supplements in margarine form and other high-profile label battles, it's best to leave the final interpretation to the lawyers. Just keep in mind if the product is to enter the market as a food, the choices of permitted botanical ingredients are much narrower than those allowed in a dietary supplement.

A Brief Herbalcopoeia

Forms for function

  Although whole-foods advocates may argue for the incorporation of fresh or dried plants to reap maximum benefits, large-scale processing and the requirement for consistent raw materials typically dictates the use of an extract. Extracts provide another benefit in addition to consistency: they eliminate many of the microbiological concerns of fresh or dried herbs and spices, therefore eliminating the need for gas or irradiation sterilization.

  According to Tower, extracts can be produced in several different ways: physical, aqueous, solvent or supercritical gas extraction. A physical crushing is typically practiced on juice-type ingredients, and these are often subjected to heat and/or vacuum concentration. Gas extractions use CO₂, which can provide high-quality, but expensive, ingredients.

  An aqueous extraction can be likened to making a tea; or it can be achieved by distilling with steam - only the water-soluble components are removed in this way. Steam-distilled products are frequently termed as essential oils. "Essential oils are volatile," says Hainrahan. "They can evaporate when boiling the plant material in water. You can condense and collect them, so you are, in a sense, fractionating the differing components out of the plant material."

  Typically the industry uses solvent extraction for herbs and botanicals. Often, in the case of spices and herbs, these are called oleoresins. Traditionalists may call them tinctures when a hot water/alcohol extraction is made and the solvents are retained in the finished product.

  "Solvent extraction removes more compounds than steam distillation," says Tower. "It extracts both the volatile and non-volatile components of the plant. This more closely matches the flavor of the dried botanical and typically contains more active ingredients than an essential oil. The process and the solvent used affect the actual content of the extract."

  Common solvents include hexane, ethanol, methanol and acetone, usually combined with water. After extraction, the solvents are removed, concentrating the remaining liquid. Minute traces of the solvents might still be retained in the finished extract.

  Concentrated extracts can be plated on a neutral dry carrier, such as maltodextrin, or diluted in a medium such as vegetable oil. Some companies use the dried herb itself as the carrier, for an all-natural, yet standardized, ingredient. The carrier too can affect ingredient choice. "Some ingredients can be more useful than others in a particular application," notes Tower. "For example, if you were trying to form tablets, there are carriers than would lend themselves to the process."

  Essential oils and oleoresins are oil-soluble, but technology can make them useable in aqueous systems and emulsions. "We have - through a patented process - taken oleoresins, emulsified them and made them both oil- and water-dispersible," Hainrahar explains. "It makes them easier for food processors to use and imparts some functional benefits, such as making the flavors more available to the sensors on the palate." When used as a coloring agent for an emulsified product, these plant-based pigments can color both oil and water phases. This may allow a reduced usage rate that achieves the same color, according to Hainrahar.

Raising the standard

  One of the biggest challenges in the world of botanical extracts is standardization. Amounts and types of components in the plants "vary widely depending on the species and the growing conditions," says Tower. "You can even have two plants from the same field that are different because they are exposed to different conditions - level of sunlight, amount of water and factors like that." The time of harvest and the methods used for processing and storage also affect an extract's content, he warns.

  Identifying the plants themselves might pose a problem. Echinacea, for example, exists in several different varieties; in addition to Echinacea purpurea, the most well-known variety, there are E. angustifolia, atrorubens, pallida, anguinea, paradoxa, laevigata, tennesseensis and simulata.

  The difficulty of the standardization process depends on the end use. "Standardization can mean many different things to people throughout the industry," Petteruti points out. "It might be identifying a chemical constituent that is unique to the botanical you're working with and processing the product so the amount is the same every time. It also means that, if you are not measuring a specific chemical component, then you are measuring the amount of actual botanical extracted the same way every single time in a finished product. It also means standardization of some of the physical properties of the extract, like color. It could also take into effect organoleptic considerations."

  For botanically derived coloring agents, the process is fairly straightforward. "We're looking for the highest level of the desired constituent in the plant material," says Hainrahar. "In paprika, we are looking for the highest content of extractable color from the paprika pod. The higher the color content of the raw material, the more efficient the extraction process is, and the better the yield." In oleoresin paprika, an extract of Capsicum annum, the red and orange hues are due mainly to carotenoids - especially capsanthin, capsorubin and beta-carotene. The yellow color of turmeric oleoresin is due to curcumin and related compounds.

  The composition affects the color, so the industry uses spectrophotometric assays to standardize the products. According to Hainrahar, the most generally agreed upon method of analysis in this case is an ASTA (American Spice Trade Association) assay method. In paprika, for example, "there are aberrations in the plant materials that would cause the composition or the ratios of pigments to vary; not just the ratio of beta-carotene to xanthophyll (including capsanthin and capsorubin) pigments, but also the level of five or six xanthophylls that will cause the extract to be redder or yellower," he continues. "Generally there's not a great deal of difference, but there are instances where a certain cultivar grown in a certain location will produce a different hue than that which is typical." A standard product for coloring is produced by selecting raw material or by blending.

  For those herbs and botanicals used for therapeutic effects, standardization is an ongoing challenge. Plants contain a multitude of chemical compounds; the number can go into the thousands. The ginger plant, for example, contains over 300 identified compounds, from acetic acid to zingiberone. For flavonoids, a potentially important group of phytochemicals, scientists have identified at least 5,000 different structures. The challenge is to identify and isolate the compounds that give the plant a specific functional or medicinal effect, determine if they work alone or in concert, and then develop test methods that accurately measure the composition.

  Typically, test methods involve what is called a marker compound. This is a compound thought to be largely responsible for the plant's biological effect. However, there's an ongoing debate whether the measurement of specific compounds is valid. For example, labs assay St. John's wort for hypericin to standardize the botanical. But, there appears to be at least ten compounds with anti-depression activity in the plant, and some experts have hypothesized that hypericin might not even be the most significant one. On the other hand, there's no proof that the hypericin level is not related to the ingredient's potency. Research has also indicated specific compound/benefit relationships, for example, the one between the polyphenol epigallocatechin 3-gallate in green and black tea and cancer inhibition; still, no one is convinced that this is the only tea chemical with an anti-cancer effect. If one is looking to promote the relaxing qualities of a green tea beverage, researchers have fingered an amino acid, g-ethylamino-L-glutamic acid, as the active compound. Or, if tea's positive effect on heart disease is sought, the catchecin and theaflavin content might be of most interest.

  Despite these caveats, these types of tests are currently the best methods available, says Tower. To this end, the botanical industry is funding the Methods Validation Program (MVP) to develop standardized test methods. After peer validation, the methods are submitted for review and publication in US Pharmacopoeia and AOAC journals. The methods developed test for marker compounds that indicate consistency. Currently the following methods have been established: ginkgo for flavonol glycosides (by HPLC), kava kava for kavalactones (by HPLC), panax ginseng and American ginseng for ginsenosides (by HPLC) and constituent identification of St. John's wort (by HPLC). Others in process include pseudohypericin and flavonoids in St. John's wort, total polyphenols in echinacea, and ginkgoterpenoids in ginkgo biloba, all by HPLC. The group's goal is to approve test methods for 15 botanicals by 2000.

  Many in the industry rely on the German E Monographs. These were developed for Germany's Institute for Drugs and Medical Devices by a panel of physicians, toxicologists, epidemiologists and other scientists. The Complete German Commission E Monographs - Therapeutic Guide to Herbal Medicines is available through the American Botanical Association. The book contains information on over 380 botanicals, including appropriate use, contraindications, possible side effects, dosage and potential interactions with other herbs or drugs.

  The American Herbal Pharmacopoeia^TM is also developing a series of monographs. These monographs provide information on utilizing, prescribing and manufacturing botanical products. It lists product name, history, identification, sources, constituents, analytical methods, therapeutic and toxicological data, and official international status.

Herbs on the Web

Tasting buds

  If the last decade of product development has shown anything, it's that in order to sell, a product must taste good. Medicinal properties aside, that will probably prove true of botanical-laced products.

  "One of the decisions you face is whether you are going to add these ingredients at an efficacious level, or if you are just looking for marketing appeal," Petteruti says. "They are very distinct strategies." This will impact the level used and the resulting flavor.

  Most of the spice and herb ingredients are traditionally used to impart pleasant flavors to products we eat. Extracts allow designers much more latitude in achieving just the right flavor. "Because extracts are liquids, you can recombine to standardize flavor profiles or ratios of flavor to pungency," notes Hainrahar. "With black pepper extract you can manipulate the ratio of piperene to essential oils, so you can have something that has very little pungency or bite to it, but has lots of black pepper flavor. Or, you can do the inverse and make something very pungent with low flavor."

  However, many of the non-flavoring botanicals have unpleasant notes, especially at higher use levels. One of the more unpleasant, according to Petteruti, is kava kava. It tastes particularly bad at levels recommended for health benefits. It's very metallic and earthy, and gives a strong aftertaste and physical mouth-numbing effect. Echinacea is another botanical that numbs the mouth.

  One product that works fairly well from both a flavor and efficacious level is ginseng. The characteristic notes come across as vanilla-like or butterscotchy and most people find it acceptable. The flavor can vary based on the extraction method, but it can work well in vanilla or cream-flavored products and in some citrus blends.

  Picking herbs and botanicals that taste good, look good and are good-for-you can be simple, if you stick to the old familiar food ingredients - or difficult, if the goal is to take advantage of ingredients not traditionally used as foods in this country. However, the heightened interest and potential market is tempting many companies to take a walk in the botanical world of product design. "Many mainstream food companies are looking at using these ingredients, and not too far down the road, someone's going to find a way to do it without hazarding their brand or their consumer loyalty," predicts Petteruti.

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