Entering The “Free-From” Zone: Sourcing Allergen-Free Ingredients and Preventing Contamination

By Steve L. Taylor, Ph.D.

Gluten-free. Dairy-free. Peanut-free. Allergen-free. The marketplace seems to be increasingly featuring packaged foods bearing such claims. In fact, according to Mintel, the gluten-free market alone is expected to reach over 1.3 billion by 2010. Within the category of integrated users of organic products (those who use organic products at least once a day), The Natural Marketing Institute found that 42 percent are looking for gluten-free products and 46 percent are looking for dairy-free products. While the opportunity for free-from product development is there, what are the challenges involved in manufacturing products with such a claim, especially within the realm of organic?

Understanding The Free-From Category
Gluten-free and dairy free, the two biggest segments of the free-from processed foods category, have been small niche food categories for years, but are now experiencing rapid growth due to better awareness. Gluten-free foods are primarily intended for consumers with a condition called “celiac disease” who cannot tolerate the gluten proteins in wheat, rye, barley and related grains (triticale, spelt, emmer, einkorn).

Dairy-free foods have also been marketed for decades and most were originally intended for consumers with lactose intolerance who experience intestinal discomfort from ingestion of dairy products containing lactose, also known as milk sugar. Peanut-free, allergen-free and other such claims have begun to appear more recently and are focused toward consumers with allergies to one or more specific foods.

It’s very important to understand these illnesses in order to determine if your company can safely make special products with “free” claims for these consumers.

True food allergies are abnormal responses of the human immune system to naturally occurring proteins in foods. The most common allergenic foods include peanuts, tree nuts (almonds, walnuts, etc.), crustacean shellfish (shrimp, crab, lobster, etc.), fish, milk, eggs, soybeans and wheat. Some countries have identified additional foods as commonly allergenic including sesame seeds (Canada, EU, Australia), molluscan shellfish (clams, oysters, squid, etc.) (Canada, EU), mustard (EU) and buckwheat (Japan, Korea).

These allergenic foods most typically cause immediate hypersensitivity reactions characterized by a variety of symptoms occurring within minutes to a few hours after eating the food. Symptoms can range from mild and annoying (gastrointestinal complaints or hives) to severe and life-threatening (asthma, severe throat swelling or anaphylactic shock). An estimated 12 to 14 million Americans, or 3.5 to 4 percent of the population, are estimated to have these types of food allergies. The number at risk for severe reactions is unknown but it is estimated that food allergies cause as many as 29,000 emergency room visits and 150 deaths in the U.S. each year. Infants and young children have an even higher prevalence of food allergies, although some will outgrow these conditions over time. Milk and egg allergies are particularly important among infants and young children but are often outgrown.

Celiac disease also involves an abnormal response of the human immune system to a particular type of food protein (gluten). Celiac disease is an example of a delayed hypersensitivity reaction where symptoms occur 48 to 72 hours after eating the offending food. The immune response in celiac disease is confined to the intestinal tract and the intestinal inflammatory process can basically shut down the absorption of nutrients. A range of symptoms can develop including diarrhea, weight loss, anemia and bone pain. Perhaps 1 in every 2000 Americans has symptomatic celiac disease associated with the consumption of the gluten protein components of wheat, rye, barley and related grains. However, mild forms of celiac disease can be challenging to diagnose and an estimated 1 in every 133 Americans is at risk for development of celiac disease.

In contrast, food intolerances are forms of food sensitivity that do not involve abnormal responses of the human immune system. While the potential exists for many examples of food intolerances, a few types tend to be predominant concerns. Lactose intolerance differs from true milk allergy and occurs in individuals who have low levels of an enzyme needed to properly digest lactose for absorption and energy. If the lactose cannot be absorbed, then intestinal bacteria ferment it to CO2, H2 and H2O causing flatulence, abdominal cramps and frothy diarrhea. Lactose intolerance is a rather common illness occurring in more than 50 percent of individuals of Hispanic, Asian or African origin and perhaps 10 percent of Caucasians.

Consumers with food allergies and intolerances must avoid the offending food or food component in their diets. However, with true food allergies and celiac disease, the tolerance for the offending food is incredibly low and virtually complete avoidance must be practiced. Thus, food manufacturers must assure that foods intended for these consumers are truly devoid of these allergen residues. In contrast, lactose-intolerant consumers can often tolerate some lactose in their diets. Thus, a dairy-free product that is acceptable for a lactose-intolerant consumer may be quite hazardous to a milk-allergic consumer.

So, the potential market for consumers with food allergies and intolerances is sizeable but is likely even larger than indicated above. The mere perception of the existence of such a condition can drive consumer behavior. As many as 20 percent of adults indicate they have a food sensitivity and 28 percent of parents believe that they have a child who is affected.

Gluten-free products are even being consumed by individuals who do not have celiac disease because of the perception that these foods are healthier. Peanut-free products, especially chocolate confections, are widely available in Canada and the market exceeds the number of peanut-allergic consumers.

Formulation Challenges
The formulation and manufacturing of such products is quite challenging especially for allergen-free products where the tolerance for the offending food is so low. Fewer challenges exist in making lactose-free products except that such products are usually labeled as dairy-free and may not actually be safe for those with milk allergy.

The first challenge is to find and procure ingredients that are completely free of any traces of the specific allergenic food. This can be more difficult than it would seem. Agricultural production, harvesting and storage and distribution facilities can be shared among multiple crops. U.S. Department of Agriculture grain standards allow some level of other food crops in various commodity foods, e.g., soybeans in corn, wheat in oats, soybeans in wheat, etc. The Food Allergy Research & Resource Program (FARRP) laboratory at the University of Nebraska has found peanuts in unexpected places such as cucumber pickles and baby carrots because of shared farming operations. A manufacturer of peanut-free chocolate confections found peanut residues in a batch of chocolate that was eventually traced back to the re-use of burlap bags for cocoa beans and peanuts by farmers in the Ivory Coast.

The use of supplier questionnaires to determine the presence or possible presence of residues of allergenic foods is a good practice. The questionnaires can ask suppliers to reveal if the allergenic foods of interest are present in the formulation, on shared manufacturing equipment or in the same facility.

However, when making “free” claims, even greater diligence is likely required including testing of representative samples of the ingredients for the presence of allergens.

Some Ingredient Alternatives
Product development and formulation need to be approached with flexibility and ingenuity when making a “free” product. In some cases, the procurement of a suitable ingredient of a particular type may be impossible. Seeking out a substitute ingredient with suitable characteristics may be the only option to consider.

Gluten-free. Gluten-free formulations often contain alternate grains and flours such as corn, rice, amaranth, quinoa, millet, arrowroot, tapioca, potato and sorghum as well as other protein sources such as almonds, beans or pea protein. Some of these flours such as corn and rice tend to be more crumbly while others such as tapioca, potato and arrowroot tend to be more binding. However, not one of these substitute ingredients on its own possess all of the functional attributes of gluten, so formulation gluten-free products will most likely include much trial and error before you find the right combination.

Other functional ingredients can be added to the formulation to help make up for the loss of gluten though. In baking, gluten helps provide structure, volume and texture. Without it you have something like liquid pancake batter instead of dough. Products don’t rise and end up dry and crumbly. Ingredients made from rice bran extract can help counteract this by acting as a dough conditioner/emulsifier and adding protein, fats and nutrients to give a product more stability and water-holding capacity. Inulin, a non-digestible polysaccharide has also been shown to increase volume and stability. It’s also a prebiotic which helps stimulate beneficial bacteria in the colon. Pectin, guar gum and xantham gum have also been used to improve functionality in gluten-free products.

Dairy-free. Milk-free or dairy-free products must not contain the protein fractions of milk (neither whey nor casein) or lactose. While soy products have ruled the dairy-free market, rice milk, coconut milk and almond milk are also popular options, especially for sweets.

Dark chocolate has been an example of a challenging ingredient because it was often manufactured on shared equipment with milk chocolate, and milk protein residues were often found in dark chocolate. While the use of shared equipment between milk and dark chocolate remains the norm, a few chocolate ingredient suppliers have dedicated manufacturing lines for dark chocolate. Thus, it is now possible to procure milk-free dark chocolate from certain suppliers. However, the procurement of milk-free, organic dark chocolate remains difficult.

Other allergen replacements. Soy lecithin is a very popular ingredient derived from a commonly allergenic source. However, other sources of lecithin do exist for food manufacturers seeking an allergen-free or soy-free product. Rice lecithin, sunflower seed lecithin or rice bran extract are examples of emulsifiers made from sources that are not considered as commonly allergenic.

Preventing Contamination
Once good sources of supply are located, ingredient storage in the manufacturing facility can also be important if allergen-containing and allergen-free foods will be manufactured in the same facility. In such situations, ingredient storage must be distinctly separated. Allergenic ingredients should never be stored above other ingredients. A best practice involves the use of separate storage areas for allergenic foods that are walled off from other ingredients. Ingredients should also be well marked to eliminate the possibility of mistakes in formulation. Icons depicting the most common allergenic foods are available from the International Association of Food Protection (www.foodprotection.org).

The optimal way to make allergen-free foods is to use a dedicated facility that does not allow the specific allergenic food to even enter their doors, however, the successful use of shared facilities has been accomplished.

If shared facilities are used between “free” products and other products that contain that allergenic food, then dedication, separation, scheduling and sanitation become key elements in the strategy. If the entire facility cannot be dedicated as “free”, then the next best approach is to dedicate specific lines or even specific pieces of equipment—especially those that are difficult to thoroughly clean such as chocolate enrobers, deep-fat fryers and baking ovens.

When dedicating specific processing lines, the separation from other manufacturing lines is quite important. Walls or heavy plastic barriers are an effective means of separation. Sometimes, shared processing lines and equipment must be used. In those situations, scheduling can be a critical strategy. Make the “free” product first after a major clean-up, and then manufacture products that contain allergens (e.g. milk first, then egg and milk, and then egg and milk and almond). When using shared equipment, effective sanitation to remove allergen residues is clearly essential. Some equipment is very difficult to make “allergen-clean” especially when water is not allowed for use in sanitation. Bakery, dry blending and chocolate manufacturing would be examples of operations that must be dry cleaned. Alternatively, operations where Clean-In-Place systems are utilized can be much more effectively shared between allergen-containing and “free” products. Testing can be used to verify the effectiveness of allergen control programs and especially sanitation in shared use facilities.

The Role of Allergen Testing
When making “free” claims on food products, analytical verification of the “free” status of the products is probably a wise step. As noted above, allergen testing can be used to determine if ingredients meet the “free” specifications that are so critical to success. Allergen testing is also important in shared use facilities to assure that no cross contact occurs with allergen-containing products.

Enzyme-linked Immunosorbent Assays or ELISAs are the test methods of choice for allergens. ELISAs can detect trace residues of proteins from various allergenic sources in a highly specific manner. Since allergens are proteins, ELISAs are detecting the most relevant component of the food. Commercial ELISA kits are available for many of the common allergenic foods including gluten, peanut, milk, egg, almond, hazelnut, soybean flour and crustacean shellfish. ELISAs are available in several formats including 96-well quantitative test methods, swab tests and lateral flow strips (dipsticks). The quantitative methods have limits of sensitivity in the low ppm range, usually 1 to 2.5 ppm while the swab tests and lateral flow strips are qualitative tests that are positive or negative at 5 ppm. Swab tests and lateral flow strips are often used to assess the cleanliness of shared equipment after sanitation because results can be read within a few minutes.

Many food companies are not set up to conduct quantitative ELISAs because such testing requires some specialized analytical equipment. Laboratories can provide confidential analytical services for companies assessing ingredients or the effectiveness of their allergen control programs. Laboratories may also have access to other specialized ELISAs that are not available as commercial kits—walnut, pecan and cashew are examples.

Closing thoughts. The “free-from” market is dynamic and may seem attractive, however, great care is needed to assure that such claims are indeed true and that they will be true 100 percent of the time. When and if mistakes are made, consumers with true food allergies will likely suffer immediate adverse reactions and be able to pinpoint the cause of their symptoms. Attention to detail in sourcing, storage and manufacturing, along with reliable testing, will prevent problems and open up a whole new market for product development to meet the needs of the “free-from” consumer.

Steve L. Taylor, Ph.D., is the director of the Food Allergy Research & Resource Program (FARRP)(www.farrp.org), in the Dept. of Food Science & Technology at the University of Nebraska. FARRP provides allergen research and testing services, as well as consulting, training and information services. Questions can be emailed to farrp@unl.edu.