As virtually all hydrocolloids carry E numbers, it would be logical to assume they are on the list of undesirable ingredients that food manufacturers are looking to remove from product labels.
Not so, according to Niels Thestrup, vice president, business unit hydrocolloids, with DuPont Nutrition and Health. He points out that all hydrocolloids are derived from natural raw materials and food manufacturers can use the generic name on their labels.
"Therefore, when food manufacturers attempt to clean up labels, hydrocolloids are typically not among the most critical ingredients to delete," he says.
Nevertheless, not all hydrocolloids have managed to escape the cull. The distinction between acceptable and unacceptable hydrocolloids is woolly, but seems to be based on how alien- sounding the name is and whether the ingredient has gone through a chemical or physical production process, rather than any scientific definition.
Carboxymethyl cellulose (CMC) is one hydrocolloid that fails on both counts, and is consequently falling out of favour with food manufacturers.
"If there was a definition of natural, CMC might not match it, as although it comes from a natural source, the ingredient has been modified to make it water soluble," says Jane Schulenburg, global marketing director at CP Kelco.
That said, the tide may be turning following a change in the law, according to Xavier Martin, commercial development manager with FMC BioPolymer.
"CMC was a concern for some countries but recent changes in legislation allowing food producers to declare CMC as cellulose gum instead of carboxymethyl cellulose are changing this negative perception," he says.
Xanthum gum
Another hydrocolloid with an image problem is xanthan gum.
"Xanthan gum is an ingredient that can cause concerns around clean labelling due to consumers' lack of familiarity with it," says Marilyn Stieve, business development manager, Glanbia Nutritionals.
Last year Glanbia conducted a survey asking consumers what they thought about xanthan gum on a label versus its flaxseed gum OptiSol 5000, which can be declared as 'milled flaxseed'. 63% of consumers stated that they preferred to see milled flaxseed over xanthan gum on the label.
OptiSol 5000 is marketed as a replacer for xanthan and other gums in tortillas, gluten-free baked goods, cakes, cookies and bars. Functionally, it is said to provide a variety of hydrocolloid benefits, including moisture control, shelf-life extension, viscosity generation and cryoprotection.
One function of xanthan gum that may prove difficult to replicate, however, is its extremely high viscosity. Rachel Wilson, principal technical adviser with Leatherhead Food Research, explains: "Xanthan gum has a unique ability to suspend a quality that is useful to manufacturers of sauces and dressings that contain particulates such as herbs. So, in that situation, the manufacturer might conclude that it is more important that the product looks good on shelf than that it is clean-label."
While some hydrocolloids are viewed as less consumer friendly, others enjoy a more positive image.
Thanks to its jam-making associations, pectin, in particular, is becoming more popular, according to Schulenburg, who says: "We have a programme to help customers minimise additives, and a few have emerged as more attractive. One that jumps out is pectin. It does have an E number but is based on nature and well known by consumers."
However, its uses are limited; as Martin points out, non-modified pectin can only be used in low pH applications where specific cultures and proteins could be considered more clean-label.
"Carageenan is still the most clean-label product available to provide gelation at neutral pH," he adds.
Bar a few exceptions, feedback from suppliers is that manufacturers are more interested in trying to reduce the overall number of thickening and texturising ingredients than in trying to eliminate certain hydrocolloids from formulations.
Schulenburg cites chocolate milk which uses cellulose and carageenan gum as a dual system for stability and shelf-life as an example of how the number of hydrocolloids might be reduced.
"These two ingredients could be replaced with gellan gum, which is very functional from two perspectives: it provides mouthfeel and gives suspension without viscosity impact, so you don't have to mess around with the thickness," she says.
In emulsifiers, which are distinguished from hydrocolloids by their ability to hold oil and water together, the clean-label drive is mainly focused on modified starches and polyglycerol esters of fatty acids.
However, according to Wilson, the clean-label alternatives are extremely limited.
"Within the emulsifiers sector there are very few clean-label options. Some proteins, such as egg, whey and casein, do have emulsification properties, but they are not as functional, as, say PGPR [polyglycerol polyricinoleate, E476, an emulsifier usually made from castor bean oils], which is used in margarine for spattering," she says.
Ingredient suppliers would argue that clean-label solutions exist but that formulators aren't taking advantage of them.
For example, although National Starch Food Innovation has been producing clean-label starches (functionalised by a physical process) under its Novation brand for 15 years, it claims there is still a lack of knowledge in the market about functional native starches.
"We were at the PLMA private label show recently, and found that retailers were not always aware of the solutions available. For food manufacturers, it's easier to use ingredients they have got," said Cathrin Kurz, marketing manager with National Starch, explaining why she thinks some manufacturers are still using modified starches.
Balance shifts
Albeit gradually, the balance is shifting in favour of functional native starches. National Starch reports that the clean-label market for starches is growing a lot faster than the market for modified food starches. This is boosted by the growth of the clean-label trend and spread of consumer ingredient awareness in Europe.
Despite the breadth of National Starch's Novation range, there are some applications which, Kurz admits, are still a challenge for functional native starches specifically dairy applications that involve a lot of shear, freezing and thawing. A long shelf-life is required, although Kurz hints that a solution could be on the horizon.
Another ingredient that is being promoted as a clean-label emulsifier is alpha-cyclodextrin (aCD). It may not sound that consumer friendly, but Wacker, a Germany-based supplier of aCD, points out that it is a soluble dietary fibre with novel foods status in Europe and, as such, does not carry an E number.
"It forms an emulsifier-like substance in-situ once oil, water and aCD are mixed," explains Dr Philipp Osterloh, who is responsible for business development with Wacker Biosolutions. "The resulting amphiphilic structure is very well suited to stabilise emulsions and depending on the usage-level it is also capable of increasing the viscosity of a product."
Ultimately, Wilson believes the future of clean-label emulsifiers lies in using enzymes to form emulsifiers in situ. So rather than adding an emulsifier to, say, a bakery product, you add an enzyme and it acts on the fats that are present naturally in the flour to form an emulsifier.
"The beauty of this approach is that enzymes are classed as processing aids and don't have to be labelled. This is the area I think is most likely to develop further in the future."