Conjugated linoleic acid

Grades and forms of conjugated linoleic acid

Conjugated linoleic acid (CLA) is a group of isomers of linoleic acid whose two double bonds are conjugated. In the EU it goes into food supplements as a CLA-rich oil, and its novel-food status must be checked against the Union list. Where an entry applies, the grade you buy must match its specification. Manufacturers use it as an oil for softgels or as a powder for capsules, tablets and sachets.

Commercial CLA is mainly a mixture of the cis-9, trans-11 and trans-10, cis-12 isomers. The isomer profile and the chemical form, free fatty acids or triglycerides, are the first lines to compare on a specification sheet. Both must agree with the specification in the applicable Union list entry.

Conjugated linoleic acid powder

Powder grades carry the oil within or on a carrier matrix, usually made by spray-drying or microencapsulation, often with an added antioxidant. The CLA content per gram is lower than in the oil and is stated on the specification sheet. The carrier and antioxidant may need to appear in your ingredient list, so check their identity before you choose.

The choice between grades comes down to four points:

• Format: oil for softgels, powder for hard capsules, tablets and sachets.
• CLA content per gram: sets the fill mass or tablet mass needed for your label claim.
• Carrier and antioxidant composition: affects labelling and compatibility with your other ingredients.
• Oxidative stability: depends on the antioxidant system, the packaging and, for powders, the quality of encapsulation.

EU regulatory status

Check whether CLA-rich oil appears in the Union list of novel foods, set out in Commission Implementing Regulation (EU) 2017/2470. The list is established under Regulation (EU) 2015/2283. Where it is listed, check the entry’s specification, whether food supplements are among its authorised food categories, and any maximum levels and additional labelling requirements. A CLA ingredient outside that specification would need its own authorisation. The novel food guide explains how to read a Union list entry.

CLA is neither a vitamin nor a mineral, so Annex II of Directive 2002/46/EC does not apply to it. Rules on “other substances” in food supplements remain partly national. Member states may also require notification of a supplement when it is placed on the market. Check the requirements of each market with its competent authority.

General labelling follows Regulation (EU) No 1169/2011, alongside the supplement-specific rules covered in the labelling guide. Any claim on pack falls under Regulation (EC) No 1924/2006. Check the EU Register of nutrition and health claims and the health-claims guide before writing any wording.

Formulation notes

CLA is a polyunsaturated fatty acid, and conjugated double bonds oxidise readily. Limit exposure to air, light and heat during storage and processing. Nitrogen blanketing of opened containers and a tocopherol-based antioxidant are common measures. Keep pro-oxidant metals such as iron and copper salts out of direct contact with the oil where you can.

Softgels. The oil is a direct fill for softgels, in shells made from gelatin or plant-based materials. It can be blended with other oils, such as those covered in the omega-3 guide. The whole blend then needs the same oxidation control.

Capsules and tablets. Powder grades suit hard capsules, including HPMC shells. In tablets, high compression force can rupture microcapsules and release oil. That can cause sticking and faster oxidation, so test hardness against stability.

Powders and sachets. In powders, check dispersion in water and fatty or oily off-notes, which encapsulation reduces but rarely removes entirely.

Label-claim arithmetic. Divide the declared CLA per serving by the CLA content stated on the certificate of analysis. For example, with a content of c (as a fraction), a claim of 500 mg needs 500 / c mg of ingredient. Declare CLA on the same basis the Union list entry uses, as fatty acid or as oil. Add any stability overage with the overage calculator. Ask for the grade and form you need in the quote form.

The wider Fatty Acids & Lipids category lists related oils and carriers.