Three global suppliers talk about what they learned from creating low-carb, high-protein bars — from reduced product-development cycles to sweeteners and fibres. Is some rendition of a low-glycaemic index the natural evolution from low-carb? Todd Runestad investigates
In 2004, low-carb king Atkins Nutritionals offered 340 products, and seemingly overnight you couldn't walk into a grocery store without seeing aisles of weight-loss bars, pasta, shakes and the like. Today, Atkins is emerging from bankruptcy with a lean suite of 60 products.
What were the reasons for the low-carb bust? More to the point, what did formulators learn from the heyday of working with obscenely high quantities of protein?
The common denominator in the low-carb lifestyle tended toward high levels of protein, fibre and sweetener alternatives like polyols.
At the height of the low-carb fad, bars would pack 20g or more of protein, which created formulator headaches because protein has an affinity for water, with the end result being a hard bar with short shelf life. A combination of lower protein demands today — say 8-10g per bar — along with new protein sources, makes for bars that will ultimately better appeal to consumers' tastes.
And that, some would say, is the primary reason low-carb went bust — because the products on store shelves just didn't taste very good. You can blame that on fast product-development cycles that pushed formulators to get the product out the door without the requisite full-scale taste workup.
From marketing divisions on down, everyone today seems to be taking a more judicious approach to make sure they get it right the first time.
Others say an over-reliance on polyols led to gastrointestinal upset on the part of consumers. Opinions vary whether the heyday of polyols is over.
"To a large extent, low-carb relied on polyols," said Diane Carnell, R&D director for the Kerry bar team. "I'd say the backlash against the polyols is very significant. We still sell polyol-based materials, but very few for new work based on polyols. Compared to 18 months ago, it's very little."
Atkins may have been right on this score because its products always avoided polyols, preferring fibre instead.
In lieu of polyols, Carnell sees a range of fibre sources coming into play. These include crude fibres, soluble fibres, prebiotic fibres, micro-encapsulated fibres, resistant starches and new slow-release sugars such as isomaltulose. As crude fibres tend to turn bars into bricks, encapsulated fibres give you the benefits without any formulation issues.
The other innovative area Kerry is working on is protein. Hydrolysing proteins can address some of the shelf-life issues, but that technology in and of itself is not without its challenges.
"With hydrolisation, the bar will stay softer longer but you'll have flavour issues," said Peter Murray, who works in R&D technical applications for Kerry's Nutriant division, which deals exclusively with nutraceuticals ingredients such as soy. "For instance, one of the problems with whey protein is it's very water-loving. Let's say you hydrolyse it, a combination of whey and soy since soy helps with the flavour. Once you start hydrolysing so it performs well in a bar, it's very bitter, so you have to be cautious about your inclusion rate in order for it to taste good." Soy is less expensive than whey, and working with particular combinations of both can give formulators a specific texture that neither can give alone.
"We're getting much more into the realms of very specialised proteins," said Carnell. "For example, yes we have soy protein isolate, we have milk protein isolate that gives you a high protein bar but gives you great texture. We can also put that protein into lots of different textural formats. We can give you high-protein crisps, we can give you specialist dough-type proteins, we can give you micellar proteins (a milk fraction) in powder or crisp form.
"It's not just about the amount of protein now, it's about the quality of the protein, about what you want those proteins to do," she said. "A lot of the market is looking at things like satiety, which leads into specialised proteins for satiety and also into fibre."
Agribusiness giant ADM has ready access to the full range of commodities, and it has used some of that access in the pursuit of fibre research derived from every grain and seed oil it processes. This will lead to a greater diversity of fibre sources in the near future.
The demands put upon ADM from the beginning of the low-carb fad for quick delivery of high-protein products that had never been made before drove many changes within facilities, according to Bob Rasmus, ADM's sales director, health and nutrition.
"When the soy health claim came out in 1999, then the move toward low-carb hit hard in 2004, we learned things about protein you wouldn't even consider," said Rasmus.
Particularly with nutrition bars, formulators were learning how to fine-tune the water activity, improve flavours and control viscosity of highly soluble protein in high concentrations.
"As bars moved into textures that incorporated soy nuggets and extruding proteins at high levels of proteins, you get into big questions about controlling viscosity and even into what exactly is the distribution of molecular weight proteins that you have," said Rasmus. "When you really started to push the protein inclusion rate, those all came to the forefront right away, whether it was bar hardening or bar taste. It really drove changes within facilities. Most bar manufacturing lines were not made to handle something as viscous as a highly soluble protein in a high concentration."
Different protein sources have different solubility curves relative to pH, but Rasmus said ADM likes soy both because of cost and the health claim.
"All protein loves water, and it's something you have to learn how to manage," said Rasmus. "That's what drove soy crisp formulation more than anything else, was including high levels of protein in a form where the protein had been denatured using heat and steam, and it knocked the solubility of the protein down to where it really didn't have any draw on moisture."
On the issue of hydrolysing protein to make bars softer longer — but in the process adding bitterness — Rasmus said ADM's answer is the use of enzymes.
"Hydrolysis primarily controls viscosity, or how thick or thin it is once it's in a mixture with other ingredients. But the bitterness would be imparted by how much hydrolysis and also what kind of enzymes were used," he said. "Exomatic enzymes typically will leave you with a better profile than endomatic enzymes, though exomatic is more expensive. This was something that was learned over the course of low-carb."
Cargill is significantly more optimistic about the future of polyols. In the last year, Cargill invested $100 million in polyol expansion projects in Italy, Germany and the US.
"The polyol industry is certainly alive and well," said Ron Perko, director of sales for Cargill Sweetness Solutions. "Sugar and caloric reduction both remain big trends in the food industry that are driving growth in polyol consumption."
Cargill's sweetener suite includes two brand-new products in its Xtend family of all-natural, fully digestible, slow-release carbohydrates that deliver the full energy of sugar — at about 70 per cent the sweetness — but are digested more slowly in the body.
Xtend sucromalt is a syrup derived from sucrose and maltose through an enzymatic process. Xtend isomaltulose is its granular cousin.
"In food processing, isomaltulose, because it's a dry product, is going to work in a similar fashion as sugar. It's a drop-in. So if you know how to handle sugar, you know how to handle isomaltulose," explained Anne Mollerus, product manager for Cargill Sweetness Solutions. "For sucromalt, the liquid equivalent, if you know how to handle corn syrup, it's a drop-in and handles just like corn syrup."
If a bar maker is concerned about getting more sweetness, just add more Xtend. If you are concerned about calories, substitute a high-intensity sweetener or polyol.
"We have done prototype work with a health bar," said Mollerus. "We've kept it isocaloric. We've used sucromalt in place of high-fructose corn syrup and maltodextrin. So you can clean up the label and replace some things. High-fructose corn syrup is used for its sweetness value and both corn syrup and maltodextrin from a bulking standpoint. With the development of this product and isomaltulose, we've done the homework our customers have been asking for from marketing, applications and technical standpoints."
Not coincidentally, this homework creates new ingredients that formulators can use in developing the next generation of low-glycaemic index products. Is low-GI the natural evolution of low-carb? Only time will tell.