Feeling the pulse

Remember that packet of lentils gathering dust in the back of your cupboard? Why haven't you opened it? Probably, you just haven't found the right moment. Cooking with dry pulses requires imagination and creativity - not something in ready supply after a hard day at work.

Given that this is unlikely to change anytime soon, it's up to food manufacturers to give us pulses in a form that's convenient, tasty, and inspiring if they are serious about upping consumption. So how are they doing? With a few exceptions, not very well, according to experts gathered at Canada's first pulse symposium in Toronto.

As pulses are some of the most nutritious foods on the planet, this is somewhat frustrating, points out Gary Fread, president of Guelph Food Technology Centre (GFTC).

"I did a check on what new products had been introduced containing pulse ingredients in the last two years, and it was something like 135 - and that was a global search! There really isn't much going on! I found some pastas with navy bean flour, poppadums with lentil flour, lentil and bean soups, pea fibre, cereals with pinto flour, and some pretty good artisanal breads with bean flours, but quite often, pulses were way down the ingredients list. They were not the core ingredient and they were certainly not used to sell the product."​

He adds: "This is a real missed opportunity. Where are the ready-to-eat meals based on pulses? Where are the snacks? In my mind there is no question that you could blow the market apart if you innovate with these ingredients. But a massive marketing and education effort is needed."​

And supermarket buyers, as well as consumers, are in dire need of education, he points out. "If a manufacturer does come up with something innovative based on pulses, buyers are probably scratching their heads saying, 'Where's the evidence that consumers actually want them?'"​

One company attempting to address this issue is North American canning giant Bush Brothers & Company, which has recently launched a consumer marketing campaign pushing the bean as the 'vegetable with more', given that most consumers are actively trying to increase their fruit and vegetable intake.

By contract, positioning the bean as a pulse or a meat/protein replacement is less likely to strike a chord with punters, claims Sara Rose, strategic business development director.

"95% of Americans don't even know what a pulse is and 40% don't know what a legume is. They don't want to replace their chicken or their meat with beans. But everyone knows they should eat more vegetables, so why not eat more beans?"​

Pulse ingredients​

Aside from persuading punters to eat their beans as well as their greens, the pulse industry in Canada - the world's largest exporter of lentils and peas - is also trying to persuade manufacturers that pulse ingredients (flour, proteins, starch and fibres) could help them offer consumers something more compelling (gluten-free, high fibre, cholesterol-busting) than wheat, dairy or soy-based products.

Key to this has been research conducted at the Food Research & Development Centre at Saint Hyacinthe, Quebec, exploring the technical properties of pulse starch and protein.

Tests on water holding capacity, fat absorption, protein solubility, flavour, emulsifying/foaming qualities and rheology are still in progress, but there are encouraging early results with lentil, flour, pea fibre and chickpea flours in salad dressings; pea protein in fruit juices - albeit in small amounts; and various pulse fractions in yoghurts. Researchers at the University of Saskatchewan have also achieved good results by replacing up to 30% of wheat flour in pasta with lentil or chickpea flour.

Linda Malcolmson, director of special crops, oilseeds and pulses at the Canadian International Grains Institute, says pulses need to get out of the can and into mainstream food products as an ingredient. Manufacturers just need some hook to hang their marketing on, she says, as the functionality is there, provided you know what you're doing.

"You can make a fantastic cranberry apple muffin with 50% navy bean flour which is high in fibre and slowly digestible [resistant] starch and a lemon blueberry muffin with 50% pea fibre. That's a lot - 10g of fibre in a very small muffin, far far more than you'll find in a large bran muffin​." It is also possible to make tortillas with up to 50% black bean flour or pinto bean flour, she adds.

"A tortilla made with 35% pea fibre has 8g of fibre compared to 4g in a whole wheat tortilla. The water absorption is also higher, so you get increased shelf-life."​ Pasta made with 30% chickpea flour is also possible without adverse sensory effects, she says. "We've developed great pasta with 20% pea cell wall fibre and 10% pea hull fibre."​

It's not a case of doing away with wheat, however. "Pulse flour does not have to replace wheat flour,"​ says Malcolmson. "Unless you are targeting coeliacs, you probably want some gluten in lots of baked goods for its technical functionality, so why not use a blend of wheat and pulse flours?"​

Results of sensory testing on pulse-based crackers, breakfast sausages, bologna, meat analogues and snack products have been encouraging so far, says Dr Kevin Swallow at the Leduc Food Processing Development Centre in Alberta. "We've made a pretty good meat analogue using pea protein isolate, potato starch and canola oil, but we probably need to add wheat gluten for a better texture." ​

Sausages with pea fibre went down well, while extruded snacks with chickpeas were also well received.

However, far more work is needed before these products hit the mainstream, says Dr John Michaelides at the GFTC, who believes we have barely scratched the surface when it comes to squeezing added value out of peas and beans.

"We're probably where the soy industry was 10 years ago. Now they're selling isoflavones, biodiesel, soy lecithin, meat analogues, fibres, proteins, flours and oils, and what are we selling?"​

Unlike soy, pulses are non-allergenic, non-GM and environmentally far more attractive given their ability to lock in nitrogen from the air and the fact that we are not cutting down rainforests in order to grow them. With more research, he predicts, they could potentially play a massive role, not just in the food industry, but in cosmeceuticals, pharmaceuticals, biomaterials and nutraceuticals.

Pulse of the nation

In the global pulse stakes, Canada is a serious player, with production quadrupling to more than 4.8Mt in the last 15 years, turning Canada into the world's largest exporter of lentils and peas and a leading exporter of dry beans and chickpeas.

However, the pressure is on to squeeze maximum value out of the country's fastest growing crop, something that will only happen if the industry does a better job of spreading the word about its nutritional and environmental credentials, and produces more convenient products for consumers, says industry body Pulse Canada.

Pulse crops draw nitrogen directly from the atmosphere, so farmers do not have to buy vast quantities of nitrogen fertiliser to grow them, points out director of market development Jackie Blondeau. They also require far less energy and water than animal-based proteins to produce. While some bean farmers are switching to other crops such as corn in order to cash in on the biofuels craze, the fact that pulses require far less fertiliser actually makes them a more appealing option to many farmers as fertiliser costs continue to rise, she says.

As for nutritional benefits, while many of us know that pulses are good for you, results from a series of clinical trials initiated by Pulse Canada and supported by Agrifood Canada should help give the industry more insight into precisely why, which will help inform marketing campaigns and health claims applications in the future, says Blondeau.

Pulses and weight management​

Epidemiological studies suggest that a diet rich in pulses can help people maintain a more healthy weight, although precisely why is a subject of debate.

The hypothesis is that as a source of resistant starch (RS) and fibre, pulses delay gastric emptying and make people feel fuller earlier during a meal. Their bulking effects may also increase satiety after a meal and reduce subsequent food intake.

Fibre and RS might also delay the absorption of glucose and fat, increasing insulin sensitivity, decreasing blood sugar after a meal and altering the secretion of hormones linked to satiety. Christina Wong is studying pulses' potential to battle the bulge at the University of Toronto via short-term food intake studies.

The good news is that all of the pulses lowered food intake in subsequent meals - great news for weight watchers. Interestingly, she hasn't found a clear correlation between the glycaemic index (GI) of pulses and their bulge-battling abilities. Indeed, lentils, the pulses most effective at reducing food intake at subsequent meals, have a higher GI than ultra-low-GI chickpeas, which proved less effective at staving off the hunger pangs.

Pulses and sports nutrition​

Who eats lentils? Well, one group of people who should certainly consider doing so is elite athletes. Researchers at the University of Saskatchewan discovered that eating lentils before exercise could delay the onset of fatigue and improve endurance.

Dr Gordon Zello, who led a recent study, took 13 male athletes and gave them a low-GI, high protein meal, a high-GI, high protein meal, a high-GI, low protein meal or water and engaged them in a simulated soccer match. He measured expired breath and blood to assess the utilisation of carbs and fat as fuel during exercise, plus subjective effort ('How tired do you feel?').

The group that had taken the lentil-based low-GI, high protein meal performed better, felt less fatigued, and were able to draw upon glucose reserves throughout the match as the lentils released energy slowly. They also drew on fat reserves, making lentils a potentially interesting fat burning ingredient.

Pulses and the gut​

The prebiotic effects of pulses haven't been widely studied - until now. Dr Alison Duncan at the University of Guelph, is coming to the end of a study exploring the effects of pulses on gut bacteria and blood lipids. In her 'free living' study, 24 healthy males ate chickpea, pea, lentil or a 'control' soup daily over four 28-day periods.

Duncan then collected faeces (testing for pH, microbial profile, short chain fatty acids, bacterial enzymes) and blood (for cholesterol, homocysteine, triglycerides), and measured subjects' body composition and weight. Results are due shortly, so watch this space!

Pulses and heart health​

In combination with other cholesterol-busting ingredients such as soy, almonds, oats and plant sterols, pulses can produce "quite spectacular, statin-like results", according to Dr Cyril Kendall at the University of Toronto.

The portfolio diet, which contains a complex of pulses, fibres, soy, nuts and plant sterols, has consistently been shown to lower 'bad' LDL cholesterol by up to 30% (individually, these components typically deliver reductions of five to 10%), claims Kendall. The precise mechanism of action is still not known, however.

But it's not just their cholesterol-lowering potential that has got scientists excited about pulses. Other studies suggest that flavonoids in beans and peas could also have beneficial effects on blood vessel function, says Dr Peter Zahradka at the University of Manitoba.

"Flavonoids like formononetin can improve arterial stiffness and reduce cholesterol. Anthocyanins in beans can also stimulate the adipocytes to secrete adiponectin, a hormone known for its protective effects on vascular function."​

Zahradka, who has just completed a study exploring the effects of pulse consumption on markers of atherosclerotic disease plus novel biomarkers linked to endothelial dysfunction, has also been looking for the first time at pulse consumption and changes in gene expression. Preliminary results suggest improvements in peripheral vascular arterial flow, weight loss and cholesterol reduction, he says. Full results will be available later this year.

Finger on the pulse of innovation​

Best Cooking Pulses (BCP) is a family-owned yellow and green pea company run by Trudi Heal and Margaret Hughes, who have been instrumental in exploring new opportunities to broaden the application of pulses.

They have also stayed at the cutting edge of research, supplying pea fibre and flour to researchers at the Richardson Centre for Functional Foods and Nutraceuticals at the University of Manitoba in Winnipeg who are studying their effects on blood lipids, body composition, fat oxidation, glucose tolerance and antioxidant status.

BCP is also working with manufacturers to develop new applications for value-added pea-based products, from gluten-free bread with pea flour to roasted pea snacks, high fibre sausages and baked goods. Pea fibre works well blended with wheat flour in applications where manufacturers are looking to up their fibre content and stick to natural ingredients, says Hughes.

For gluten-free bread with pea flour, xantham gum is needed for texture. For meat products, wheat bran or mustard seed can also be replaced with pea fibre in order to achieve allergen-free status.

Seeing red. InfraReady slashes pulse cooking times​

One company making pulses more convenient is InfraReady Products, which partially pre-cooks them using infra-red technology. President Mark Picard says: "This causes water molecules in pulses to heat up and vibrate and turn into steam. It also preserves nutrient content."​ Typically, many beans and peas require pre-soaking and then cooking for two-three hours, says Picard.

"Our peas don't need pre-soaking and cook in 30-45 minutes. By 'bumping' [flattening of the pulse], we can further reduce cooking time to 15-30 minutes."​ Pre-cooked peas and beans can also be ground into a powder and used as natural thickeners in soups, gravies, stews and casseroles, he says.

"Pre-cooked grains and legumes absorb more water, more quickly, and by inactivating enzymes and reducing microbial counts, come with increased stability​." The process also eliminates many of the undesirable flavours and textures in pulses, he adds.

Separately, InfraReady is also doing a roaring trade in ancient grains including quinoa, kamut, antho grain (purple wheat) and spelt, says Picard. "These are becoming much more popular as consumers tap into the whole grain trend."​

Key Contacts​

Pulse Canada: http://www.pulsecanada.com​

Ontario White Bean Producers: http://www.ontariobeans.on.ca​

Saskatchewan Pulse Growers: http://www.saskpulse.com​

InfraReady Products (pre-cooked pulses): http://www.infrareadyproducts.com​

Best Cooking Pulses (peas, pea flour, fibre, bran): http://www.bestcookingpulses.com​

ADM (edible beans): http://www.admworld.com​

Nutri-Pea (pea protein, fibre, starch): http://www.nutripea.com​

Mountain Meadows (pea-butter): http://www.peabutter.ca​

Bush Brothers & Co (beans): http://www.bushbeans.com​