Softgels for marine oils: Softgel suppliers have found ways to handle tricky marine oils

Photo © iStockphoto.com/brianbalster

Marine oils, such as fish and krill oil, are not the easiest to encapsulate for a major reason: they are prone to oxidation. By the end of a product’s shelf life, this oxidation can result in a product of poor quality and taste. The goal for softgel manufacturers when handling these marine oils is to minimize oxidation at all costs. Softgel suppliers discuss their strategies for handling these tricky ingredients.

“The molecular structure of the two most popular long-chain polyunsaturated omega-3 fatty acids, EPA and DHA, makes them prone to oxidizing easily, and it’s this oxidation that is a large concern to users,” explains Steve Holtby, president and CEO of Soft Gel Technologies Inc. (Los Angeles). “High oxidation can cause unpleasant repeating (fish burps) and can make the oil smell and taste rancid.” Not only that, but oxidation can lower the product’s overall health efficacy and actually render the product unhealthy by producing pro-inflammatory free radicals.

To avoid these problems, softgel manufacturers often seek to manufacture in an oxygen-free environment and at low temperatures. But a high-quality process starts much earlier than that, says Paul Hwang, vice president of quality and regulatory from Captek Softgel International (Cerritos, CA); it involves everything from vendor selection and qualification to material receipt, sampling, warehousing, and more.

“We are acutely aware of marine oils’ characteristics; thus, we have designed tight process controls and systems that ensure we partner with a fish oil supplier who safeguards and consistently delivers the freshest oil to limit the initiation of the oils’ autooxidation,” says Hwang from Captek. From there, the company follows a strict and careful vetting process, including when sampling and handling the oil once received, inspecting the incoming oil, and warehousing. “In the processing of these oils, our Master Manufacturing Records detail specific control parameters and steps to ensure minimal exposure of these oils to, and control against, autooxidation agents and propagation of the oils’ oxidation,” says Hwang.

Soft Gel’s Holtby agrees that these steps are key to a product’s success, including working with high-quality suppliers whose raw materials have low oxidation levels to start with-for instance, ensuring that you’re using a supplier used to supplying ingredients for supplement production and not just supplying byproducts of the fishing industry. The company also warns industry to be on the lookout for manufacturers who will purchase and import fish oil softgels and “repackage” these softgels as domestically produced products. Asking all manufacturers for a batch-specific Certificate of Analysis can help to sidestep fraud.

From there, quality is in the manufacturer’s hands-something Holtby says his company is well-equipped to handle. “The fish oils encapsulated by Soft Gel Technologies Inc. are molecularly distilled, meet stringent standards, and contain natural antioxidants (d-alpha-tocopherol) to prevent rancidity,” he says. “We also test peroxide values and take great care during manufacturing to ensure the oil is protected from oxidation. We limit exposure by pulling vacuum and/or nitrogen blanketing during blending.” And, Holtby says, “Limiting batch sizes to only those that use full drums can help prevent earlier exposure, even when using nitrogen blanketing to limit that initial exposure.” Fats are removed from the oil, and molecular distillation is used to remove heavy metals and other toxins.

Softgel materials themselves can also help to improve the user experience. For instance, says Timothy Chiprich, vice president of product development for Captek Softgel, his company has developed specific formulations for its capsule shells that ensure the capsules resist becoming brittle and leaking “like regular softgels do.” Namely, says Chiprich, the higher the content of long-chain polyunsaturated fatty acids in an oil, the more sensitive the oil will be to oxidation, and the faster oxidation will happen.

Chiprich also points out that krill oil can be even more difficult to encapsulate because its omega-3 fatty acids are “bound to water-dispersible phospholipids rather than water insoluble triglycerides like the omega-3 fatty acids in most fish oils. The phospholipids’ attraction to water tends to affect the softgel shell, making it brittle and prone to leaking over time due to water migration from the softgel shell into the phospholipids in the fill.”

Last fall, Marinova (Cambridge, Tasmania, Australia), a supplier of seaweed extract ingredients, announced a novel way to use its fucoidan ingredient to help better microencapsulate fish oils by reducing oxidation. In a press release, the company described it as a “two-step microencapsulation system with a ‘double shell’ structure using a bioactive seaweed polysaccharide, known as fucoidan.” (The technology was developed by university researchers.) By including fucoidan in the shell material at 7%, researchers were able to “significantly improve oxidative stability of the encapsulated oil and induce better crosslinking of the shell material,” said the company.

“The polyphenols present in the fucoidan extract crosslink to form a tight network of chains with gelatin, which provides this powerful stability,” explained Colin Barrow, a researcher from the Deakin University’s School of Life and Environmental Sciences, who led the team who made the discovery. The researchers wrote about their discovery in the journal Powder Technology last year.¹

References:

1. Barrow C et al. “Anchovy oil microcapsule powders prepared using two-step complex coacervation between gelatin and sodium hexametaphosphate followed by spray drying.” Powder Technology. July 2018.