You could be forgiven for coming away from the UK Food Standards Agency (FSA)'s www.salt.gov.uk website with the impression that cutting the sodium content in processed foods was a relatively straightforward and uniform process.
Not, of course, that the content is misleading in that regard. It is more an illusion created by the Who's Who of companies and percentage reductions - 50% here, 33% there - plastered across the Industry Activity page. As if salt reduction came down to a few minimal insights and a maximum of steely resolve, rather like an audacious price cut.
But as one of the companies on that list explains, there is nothing simple or uniform about it. Brakes may be dealing with caterers rather than consumers, but the wide range of products it supplies makes the challenge of meeting the FSA's new 2012 targets especially gruelling.
Head of health & nutrition Eileen Steinbock says: "The problem for an organisation like Brakes is that we sell everything from bread and processed meats to soups and ready meals, all of them with their own salt reduction targets. That involves a lot of specific technical expertise across many different areas."
She adds: "We're on-course to meet 2010 targets. But even once you've got your new recipe, there's a significant amount of administration to ensure that the legal labelling and specification is correctly updated. There's a fair amount of technical knowledge needed for that process as well."
But of course, long before this implementation stage, time and effort need to be put into each salt-containing product to reach that specification. Quite apart from the all-important issue of taste-perception and consumer acceptance, there are often processing, shelf-life and cost considerations. For each product, the relative importance of these issues, and possible routes to reduction, will differ.
At Dutch research organisation TNO, business development manager Maurits Burgering has a frequent refrain: "Salt reduction is a multi-dimensional problem."
And TNO's scientists should know, having devoted much of their time to studying the effects of salt reduction on bread, in particular. And as the UK bakery industry is only too aware, bread is in the front rank of products targeted by government for aggressive reductions.
The UK Federation of Bakers believes that going anywhere beyond the FSA's 2010 bread target of 430mg sodium/100g will be nigh on impossible. "There may be technical developments in future, but at the moment, it's extremely difficult." The implication is that, if levels go any lower, they will impact sales as well as taste buds.
Yet TNO's Burgering underlines the ways in which salt is understood to influence the breadmaking process. And these, as much as consumer taste perceptions, may be central to the concerns of the bakery industry. "If you leave salt out altogether, the yeast ferments too quickly, and can get out of control more easily," Burgering reports. "It acts as a constraint. But also, without salt, different structures form inside the bread, leading to texture problems."
Implementing tighter time and temperature controls at the preparation stage might be a first step in addressing these issues. But he is the first to admit: "These sorts of controls might work in the lab, but it may be much more difficult to implement them in a production environment."
On the perception side, TNO is exploring a new line of attack. "We taste contrast rather than specific concentrations, and we're working on concepts which will enhance this kind of contrast," Burgering explains. "As things stand, a lot of sodium is 'lost' in the bulk matrix, rather than being made available to the flavour profile."
Aimed as it is at maximising the impact of salt, this approach appears to share something with the Soda-Lo micro-salt product developed by Eminate in the UK.
Technical director Stephen Minter explains: "We recrystallise the salt so it goes from being a rhomboid of 500 microns to a hollow ball of less than 10 microns. This means it actually gets into the taste buds for immediate impact and long flavour length. As it's hollow, we can also pack it with additional flavours."
Eminate is currently running trials on bread, achieving salt reductions of up to 70%. "The standard bread we've made has the same rise height and crumb structure as well as flavour," Minter claims.
In fact, Minter suggests that Eminate's work is bringing into question some of the basic assumptions about the relationship between salt content and bread quality.
Minter talks about on-cost in terms of "less than a penny per product in high volumes". But comparing the cost of salt can be misleading, he says. "You're not selling salt, you're selling the reduction."
Then again, the greater the complexity of the product, the more opportunities there are for flavour - and cost - engineering. For Brakes, says Steinbock, it has proved easier to reformulate strongly-flavoured recipe dishes than, say, simpler bouillons.
At the Synergy flavours business, customer marketing manager Donna Rose talks about "multiple benefits" from its Saporesse range of dairy-derived and yeast-based flavourings for more complex dishes.
"As well as salt reduction, the products offer natural monosodium glutamate replacement, mouthfeel (umami) enhancement, dairy enhancement and flavour lengthening and extension," says Rose. These benefits can combine to create 'cost-in-use' reductions, she argues.
Claudia Cascia, product manager for yeast extracts at DSM Food Specialities, points out that layers of flavour and enhancement can be built up in imitation of the 'kitchen' preparation and cooking process. Its Gistex range, for instance, can provide a basic bouillon taste, while other layers can mimic the presence of protein. Its nucleotide-heavy Maxarome yeast extract can offer flavour enhancement.
This cumulative process allows for a reappraisal of other ingredients, Cascia adds. "You can see whether there might be an option to reduce other elements, look at the total, and maybe reduce costs." Examples of expendable elements might be tomato or cheese powder, she says.
Flavour company Givaudan makes a similar point about potential overall cost reductions. Global head of savoury Andreas Haenni says: "It might mean looking at the top flavour notes, anything that can give us more manoeuvrability in the total system."
Looking beyond mere flavour, Haenni says: "The biggest challenge is where salt has a functional benefit, whether it's an antimicrobial role in meat products or to do with water retention, or where salt plays a role in the extrusion process of cereal-based products, for instance."
At Brakes, Steinbock is all too aware of this, particularly when it comes to the shelf-life of products such as bacon. "There's been something of a bubble blown here. Statutory reductions in the amount of nitrates that can be used in the curing process have left us less scope to reduce salt - voluntarily - without further reducing shelf-life." Changes have already meant that product life, normally several weeks, has already been cut by a week, she says.
There are further sets of issues around all-important clean labelling and allergen declarations, as well as reliance on the supply chain. A supplier of Stilton for a soup, for instance, may be reluctant to alter its own product, says Brakes.
Just as these challenges are multi-dimensional, so too are the solutions. This means that different types of food and flavour will each require their own approach. But as targets become tougher, partial solutions can be combined in each case. This may be to address the other knock-on effects, alongside flavour. But even on its own, the question of flavour perception may elicit multiple answers.
Here, Burgering at TNO endorses Unilever's declared strategy, which identifies at least four distinct and complementary paths to salt reduction. Top of the list is 'adaptation' or 'educating the consumer's palate'. Then there is salt substitution. Thirdly, the multisensory approach works on the principle that an increased stimulus based on smell can compensate for reduced flavour impact. Fourth comes the idea of the 'salt booster', to amplify the perception of salt present.
But it is no accident that consumer adaptation heads Unilever's list. Whatever breakthroughs are made elsewhere, this must, longer-term, remain the cornerstone of industry strategy. At Brakes, Steinbock insists: "To a great extent, our strategy is about wanting people to accept food with a less salty flavour, and to accept this taste profile as being 'normal'." FIHN