SPECIAL REPORT: Thickeners – Why They’re Sticking Fast in the Health Food Industry

01 Mar 2016 --- Thickening agents have gained a lot of attention recently. Last month, not only were a selection of 2016 industry reports focusing on food thickeners released, but the EFSA also called for an update on the specifications and manufacturing processes of certain starches and celluloses authorized as food additives in the EU – important, as more and more health foods available on the market are containing them. NutritionInsight sets the scene on how foods using novel thickening and gelling agents are growing the global health food industry, and notes their effect on consumers.

A thickening agent, or thickener, is a food additive which can increase viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used in the food industry to thicken sauces and soups without altering their taste. These are frequently based on either polysaccharides (starches, vegetable gums, and pectin), or proteins. Well known powdered starches include arrowroot, cornstarch, katakuri starch, potato starch, sago, tapioca and their starch derivatives – all of which are flavorless. Vegetable gums used as food thickeners include cellulose, alginin, guar gum, locust bean gum, and xanthan gum. Starches and cellulose are also known as hydrocolloid thickeners. 

Cellulose is a common food additive made from wood pulp. It is indigestible and present in all plant food, and is added to food to give texture. Companies could use powdered cellulose from celery or broccoli in their products, but “it would be a waste of food,” so says John Coupland, a Pennsylvania State University professor of food science and president-elect of the Institute of Food Technologists. The lack of taste is part of the reason it's found in so many products. 

Guar gum, extracted from guar seed, is used to thicken products like ice cream, bread, pasta, sausages and pastries. In the 2015 monsoon season, India produced 1.7 million tons of guar seed, making it the largest producer with about 80 percent of world production. However, guar seed prices have dropped 10 percent since the beginning of the year and analysts see no sign of recovery.

Gum arabic is a thickening agent used in fizzy drinks and confectioneries. It is a natural gum made of the hardened sap of various species of the acacia tree. Like guar gum it can be hard to come by – although last year, National Center for Agricultural Utilization Research (NCAUR) scientists discovered that the frost grape sap had both chemical and functional similarities to gum Arabic. Additionally, it lacks a protein allergen found in gum Arabic. Experiments showed that the polysaccharide can also be made into a white powder, viscous liquid, or clear gel – which explains its commonality in health food store products. 

Health research
Although these natural additives are beneficial for use in the food industry as thickeners, gels or emulsifiers, emerging research is highlighting the possible downside of these additives in our foods. In a study published in Autoimmunity Reviews in 2015, scientists from Israel and Germany identified glucose, salt, emulsifiers, gluten, organic solvents and nanoparticles among a group of additives that might affect cells in the gut lining and contribute to "leakiness" in the gut wall and, hypothetically, increase the risk of autoimmune disease.

Although this study is only based on what happens in cells grown in a laboratory – not in living humans or animals – other research has found that in animal studies emulsifiers (found in foods such as bread, cakes, salad dressings, ice-cream and margarine) can cause gut leakiness, Eliana Marino, head of Monash University's Department of Immunology and Diabetes says. 

Studies on a simulated human gut have added further evidence that emulsifiers, found in most processed foods, might be linked to obesity, diabetes and inflammatory bowel disorders.

Last year, a mouse study by Benoit Chassaing of Georgia State University published in the journal Nature found evidence that emulsifiers like carboxymethyl cellulose (CMC) "can alter the gut bacteria" and cause intestinal inflammation leading to a higher likelihood of "inflammatory bowel disease, metabolic syndrome and significant weight gain." The researchers behind this study witnessed effects even when subjects consumed one-tenth of the concentration of emulsifiers permitted by the FDA. Chassaing is now enrolling volunteers for the first human trial to look at the effects of emulsifiers on gut and metabolic health. Carrying out this study won’t be easy, he says, as the participants’ diets will have to be strictly controlled.

Study developments
Therefore, there is a need for developing foods with novel thickeners that also aid in health. Last year microbiologists at Oregon State University (OSU) discovered and helped patent and commercialize a new type of food thickener, which could add probiotic characteristics to the products in which it’s used. This product, a polymer called Ropy 352 produced by a natural bacterium that was isolated in Oregon, gives fermented food and liquid products a smooth, thick, creamy property. The global market for polymers such as this approaches US$7 billion, and there are estimates that Americans spend up to US$120 billion a year on probiotic health food products such as yogurt, sour cream and buttermilk. 

Janine Trempy, lead scientist for the Ropy 352 biopolymer told NutritionInsight how is it used in commercial foods and for health: “Oregon State University has successfully licensed this technology to several food ingredient companies.” 

“The Ropy 252 biopolymer producing bacterial strain is suitable for use in sour cream, yogurt, kefir, buttermilk, cream cheese and artisan soft cheeses; as well as in liquid products for the elderly (protein drinks), the diet industry and in nutraceuticals.”

Industry advances
A recent addition to the market of health foods containing novel thickening agents is food containing the east Asian tuber Konjac. Konjac fiber, which is now gaining international recognition, has the highest viscosity soluble fiber in nature: 40-60 percent glucomannan (a water-soluble polysaccharide that is considered a dietary fiber) is found in the dried root. According to medical research, the higher the viscosity, the better it is in controlling blood sugar levels, therefore it also has important health properties. 

Konjac flour finds application in the food industry as thickener for soups, sauces, gravies, puddings and pie fillings, without adding calories, fat, or carbohydrates. It can also be added to lower-calorie baking products such as cookies, cakes, bread, and biscuits. As it dissolves directly, it can easily be used in hot or cold diet beverages.

Health functions for Konjac flour include improving bowel health, and lowering cholesterol, diabetes, hypertension. It also improves satiety (feeling of fullness), reduces fat absorption and aids weight loss.

UK based firm Konjac Innov, part of NAH Foods Ltd, announced their partnership with leading international seafood processors Thai Union last year in order to tap into the diet food market. NAH Foods won “Best Healthy Food” Category at the 2016 Product of The Year Awards for their revolutionary slimming range Slim Pasta, Slim Rice and Slim Noodles which contains Konjac. Ash Patel, Co-founder of Slim Pasta told NutritionInsight: “We’ve worked incredibly hard over the past few years to develop a premium Konjac product that not only suits consumer tastes but also retains a low calorie content – something that our competitors have failed to do.”

Unlike other Konjac brands, which “use traditional, standard Konjac recipes and often receive criticism due to their translucent look and rubbery texture,” Konjac Innov developed a novel recipe called Juroat C and launched it under the brand Slim Pasta, Slim Noodles and Slim Rice in 2013. This gives the Konjac food itself a much closer resemblance to traditional pasta, noodles and rice.
  
NAH Foods have seen an impressive rise in sales since they launched the brand in 2012. The Slim range has become available in 13-15 countries including Germany, Spain, Netherlands, Portugal, Italy, and the United Arab Emirates. It is reported that 1 percent of the UK population regularly eats Slim Pasta, Slim Noodles and Slim Rice as part of their regular diet. NAH foods have also recently introduced new low-calorie, two pot lunchbox ready meals to their range.  

These types of innovative ways of using thickening agents in functional foods and other health products prove that they are set to be employed for time to come.

by Kerina Tull