Industry suppliers employ a range of sophisticated technology to provide stable, active components.
Anything that is unstable is downright scary. Think about it: an unstable building foundation, an unstable stock market, an unstable individual. When we perceive something or someone as being unstable, our reaction is to avoid it.
Supplements are the same way. If it degrades quickly, all value is lost, and there is no meaning to “shelf life.” Further, many consumers believe if the supplement has degraded, it may be harmful or taste disgusting.
Supplements by nature, contain volatile ingredients, and in a large sense, botanical extracts are still “alive.” And you cannot achieve any duration of shelf life—maintaining potency and integrity of the ingredients in the unique constitution of its formula—without ensuring physical stability of the product proper.
“Retailers want a product with a minimum of two years shelf life,” stated Stephen Lukawski BA, MEd, director of global business development, sales and marketing, Fruit d’Or Nutraceuticals, Quebec, Canada. “We aim to protect the health and safety of the consumer prior to the product going on the shelf.”
As the very nature of nature-made ingredients (including pre- and probiotics, living organisms) is one of inherent volatility, it stands to reason that with the vast variety of such ingredients, challenges to impose stability are plentiful.
Gil Bakal, managing director of New Jersey-based A&B Ingredients, Inc., said that there are four major types of challenges: Oxidation, which can cause reduction and degradation in nutrient value, development of anti-nutritional byproducts and development of off flavors; hydrolysis (in beverage applications); microbiological degradation, such as yeasts, molds and spoilage organisms, which can develop in moisture containing products; and textural changes in nutritional bars, which can become hard, brittle and stale over a time period.
Missy Lowery, senior marketing manager, Capsugel, Americas Region, in South Carolina, asserted that moisture and oxygen-sensitive ingredients provide the greatest challenges to stability. Probiotics are hydroscopic and excessive moisture, coming from environment or capsule shell, can prematurely activate them. “Technological advances in low-moisture capsule delivery systems have played a key role in maintaining the viability of probiotic bacteria during processing and storage of product,” she reported. Further, probiotics are also acid-sensitive, so as they transition through the stomach, moisture and acid can cause early activation and degradation. Capsugel, she said, has concentrated on developing innovative delivery systems to help prevent that and provide for targeted release into the intestine, where probiotics prefer to colonize.
Mike Wagner, PhD, food processing engineer with New York-based BI Nutraceuticals, also agreed that moisture is a monster. “Moisture control is critical to formulation stability. Moisture content is important, but often water activity (aw), or the measure of free water in the product available for chemical reaction, is more telling of the stability. Microbial growth, oxidative reactions, enzymatic reactions and protein-protein interactions among others are affected by water activity. Physical properties like flow, hardness and particle interactions can also be influenced by unbound water. Even processing that involves the addition and or removal of water, like steam sterilization, requires close attention and custom solutions to properly control moisture in the product. With so many characteristics linked to one parameter, you may be trying to solve a water activity issue without realizing it,” he explained.
Other ingredients that pose similar challenges, added Lowery, are some enzymes, sports nutrition ingredients, such as sAMe and ALA, which are susceptible to degradation due to stomach acids, while others are not. “These acid sensitive ingredients—just like probiotics—are targeted to work best in the intestines. The challenge here is to create a dosage delivery form that guards against stomach acids.”
Peroxide can be quite pernicious, said Lukawski. “To provide a safe and efficacious product, we must do our real-time testing (minimum one to two years), to show that we can maintain a level of peroxide value that’s low enough to avoid causing stability issues. The presence of peroxide in the product gives evidence of oxygen attaching to the fat and oil molecules, which can result in rancidity, meaning a change in smell (fishy scent) and taste (burning feel on the tongue). The lower the peroxide level is, the fresher the product,” he explained.
RTDs (ready to drinks) have some unique challenges. Frequently, observed Dan Grazaitis, senior food scientist, TIC Gums, in Maryland, nutritional beverages are fortified with various types of protein, minerals and vitamins. These additional ingredients can affect the shelf stability and the amount of perceivable particulates in RTD beverages. “Some protein sources utilized in nutritional beverage formulations have the ability to create strong astringency or texture defects,” he said. “Other ingredients, such as cocoa powder and minerals, can settle and cause the beverage to separate. Texture and separation can both cause an inconsistent flavor throughout the beverage.”
Extras That Support Stability
Consumers who enjoy reading labels often see some extra “things” listed, and quite a few question why they are included. Savvy brand marketers explain in literature or their websites that additives are there in the appropriate amounts to secure promised activity and potency throughout a shelf-life duration. For example, Fruit d’Or’s cranberry seed oil can be added as a stabilizer for omega-3 ingredients, such as fish oil, Lukawski offered. It may also be able to replace synthetic tocophenols often used in soft gels as a true antioxidant. “It may also enhance bio availability,” he added.
According to Lowery, additives are often incorporated to protect and preserve ingredients in packaging and transport, for targeted release, or to mask unpleasant tastes and odors. To address specific stability challenges of product delivery, Capsugel innovated low-moisture polymers with unique properties for its vegetarian capsules, as well as innovated structural features, such as air-tight sealed capsules-within-a-capsule as part of its Licaps capsule technology.
Capsugel provides additive-free capsules that address stability issues, especially as the demand for “clean label” dosage delivery forms soar among consumers. The company recently invested $25 million to increase its global production capacity for its clean-label vegetarian capsules, “because four out of 10 supplement users expect supplement delivery in vegetarian capsules,” Lowery cited. “Three of our four capsule offerings that address stability challenges for moisture-sensitive and acid-sensitive ingredients are plant-based: Vcaps capsules, Vcaps Plus capsules, and DRcaps capsules.
According to Bakal, there are many additives that can play a role in ensuring integrity and viability through shelf life: antioxidants can help prevent oxidation of fats and fat-soluble nutritional components, preservatives are often used to prevent mold and bacterial growth, and glycerine and soluble fibers can help retard firming up of chews and bars.
“Many of us view excipients simply as fillers that take up space in a formula, but in reality they play very specific roles and great attention is given to their selection,” explained Emilio Gutierrez RPh, vice president of technical services, BI Nutraceuticals. “Excipients can help solve simple issues related to excess free water, stickiness and density modification to more complex problems related to solubility, compressibility, disintegration and even bioavailability of active components.” Formulating RTDs that contain supplement ingredients necessitate not only preserving integrity and stability, but ensuring texture and taste remain attractive. For example, said Grazaitis, hydrocolloids are used to combat the negative effects nutritional ingredients have on texture and stability. “Multifunctional in nature, each type of hydrocolloid has a unique purpose to reduce the perception of particulates, reduce astringency and prevent sedimentation.”
For example, he provided, colloidal microcrystalline cellulose (CMC) gives suspension in beverages without significantly altering viscosity. For protein-based beverages, carrageenan is an excellent performer, providing both suspension and texture to a protein beverage. Locust bean gum, guar gum and xanthan gum provide viscosity to assist with suspension, help mask particulates and increase the expected sensation of appropriate mouth feel.
Harking to Lukawski’s earlier comment, retailers want to know that the product will be efficacious and viable for up to two years. Industry suppliers employ a range of sophisticated technology to assess rates of degradation and product preservation. Fruit d’Or’s cranberry seed oil is subjected to peroxide tests, taste and odor in real time versus accelerated tests, Lukawski said. These tests are conducted on every batch on a monthly basis.
Bakal said that it is important to understand the finished product and packaging, and to design tests to mimic worst-case scenarios. A&B Ingredients typically uses incubators and humidity chambers to perform accelerated tests on stability. BI Nutraceuticals, said Gutierrez, controls product stability by reducing the microbial load of the incoming raw material through the use of its steam sterilization process. Product moisture is then closely monitored throughout manufacturing to ensure that the ideal conditions for microbes to grow back are not created. Once the finished product is complete and stored under ambient conditions, the product is generally stable well beyond its expiration dating.
“We have an ongoing product stability program where we have discovered that an ambient real-time study is best suited for our finished products,” he elaborated. “Accelerated stability protocols, which require higher temperatures and/or humidity are often not indicate of real-life situations and can affect the product in ways not seen with the real time results. The higher temperature or humidity of the accelerated study can affect inherent moisture, assay and even the stability of excipients. For example, maltodextrin, which is commonly used as a carrier in standardized extracts, is often unstable due to its low melting point, which causes the powder extract to morph into a solid sticky mass at the completion of the accelerated study.”
At TIC Gums, said Grazaitis, to ensure physical stability and shelf life of RTDs, products are held and inspected for visual separation over a period of time. “This is quantified using various analytical techniques to determine the rate at which sedimentation and creaming occur,” he explained. “These techniques can include a combination of rheological, backscattering, transmittance and particle size measurements.”
For preserving life and activity of acid-sensitive enzymes and probiotics, Capsugel’s DRcaps acid-resistant hydroxypropyl methylcellulose (HPMC) capsules were found in a scintigraphic in vivo study to be viable for ensuring stability, according to Lowery.
“Data and images empirically demonstrated the capsules’ effective protection from early activation caused by stomach acids and, for a majority of study subjects, complete release in intestines where products such as probiotics and enzymes work best,” she reported. “More specifically, the capsules began release in a mean time of 52 minutes after ingestion and when they were about the leave the stomach—a full 45 minutes later than an immediate release capsule. The capsules completely released the ingredients in a mean time of 72 minutes after ingestion and when most of the ingredients would most likely be in the intestines.”
Consumers expect that the supplements and nutra-beverages they purchase will hold up through reasonable time, and deliver the activity promised on the label by the “use by date.” Stability indeed is a good thing. NIE
For More Information:
A&B Ingredients, (973) 227-1390
Bi Nutraceuticals, (973) 334-1633
Fruit d’Or Nutraceuticals, (819) 385-1058
TIC Gums, (800) 889-3953