Believe it or not, hydrocolloids (also known as gums) played a major role in my initial interest in going to school. My favorite part of kindergarten was when it was time to have chocolate milk, and I remember that milk being so rich and creamy. Because I could not make such good chocolate milk at home, I was eager to go to school every day. Only much later, when I studied food science, did I learn that it was the use of the hydrocolloid carrageenan that gave the creamy texture to that chocolate milk.
Of course, bakers have used many different types of gums over the years to improve their products, and the primary functionality is to modify texture.
How hydrocolloids function
As a baker, my first experience using gums was in the production of flour tortillas. When it comes to consumer use, there are few things more aggravating than to have a taco or burrito burst open and, as a consequence, all the fillings spill out.
However, because flour tortillas are so thin, they can dry out easily and lose their “rollability,” especially if the tortillas are stored under refrigeration. By using a small amount (around 0.10%) of the right blend of hydrocolloids, this problem can be effectively managed. The hydrocolloid blend binds water and slows moisture migration, and this allows the tortilla to maintain its flexibility for a longer time.
Control of moisture migration is important in nearly all bakery products, especially those exposed to drastic changes in temperature. For this reason, hydrocolloids are often used in products that will be frozen and thawed. They are also used to stabilize products exposed to high temperatures during transport and storage.
A good example of this functionality is the use of hydrocolloids in icings and fillings. “Homemade” icings and fillings, made without hydrocolloids, will quickly break down or “weep.” This process is called syneresis, and hydrocolloids will inhibit this unwanted reaction.
Because hydrocolloids bind water, they can improve product softness. This is important in snack cakes, energy bars and some breads. Generally speaking, the cookie and cracker industry will use hydrocolloids much less because most of these products have low moisture content.
Hydrocolloids can also act as an oil barrier in fried foods. In frozen dough, they help control the size of ice crystals, giving the dough more stability and longer shelf life. Ice crystal control is also important in freezing fully baked products.
With recent changes in consumer interests, there have been increased applications of hydrocolloids. For example, making saleable gluten-free bread is nearly impossible without the use of hydrocolloids. By replacing wheat flour with a blend of starches, the product will eventually gelatinize in the oven, and the dough will lack stability and gas retention; these functions are supplied by hydrocolloids. The usage level for a gluten-free product is normally between 2 and 5%.
Another more recent application is as part of an egg-replacer system. Eggs provide structure, softness and natural emulsification. Because most hydrocolloids are sourced from natural substances such as seaweed, tree sap, wood and seeds, most are considered natural and therefore “label-friendly.” In fact, some hydrocolloids are certified organic. It should also be noted that most hydrocolloids are non-GMO.
Use and size of market
The use of hydrocolloids in foods is widespread. According to Dennis Seisun of IMR International, a San Diego-based hydrocolloid research and consulting firm, the total economic value of hydrocolloids in foods is $7.3 billion. Xanthan gum, the most commonly used hydrocolloid, has a production of 40,000 to 50,000 tons per year. Other commonly used hydrocolloids include guar, carboxymethylcellulose (CMC), agar, alginates, carrageenan (kappa, iota and lambda forms), gum arabic (also called acacia), gelatin, gellan and pectin. Chemically, nearly all of these are polysaccharides, but gelatin is a protein.
Which of these gums are most commonly used in baking? It really depends on who you ask.
Guar, xanthan and psyllium husk powder are the most popular, according to Mark Reuber, manager of R&D, Caremoli Group, Ames, IA. “Total guar consumption was estimated to be about 250,000 metric tons (MT) worldwide in 2014, worth an overall market value of about $550 million,” he said. It is estimated that between 10 and 12% of the guar consumption is in the baking industry. However, the price volatility of guar has greatly affected consumption, which has decreased from 630,000 MT in 2011 and 330,000 MT in 2012.
According to Joshua Brooks, vice-president of sales and gum technology at Ingredion, Westchester, IL, “Xanthan, guar, cellulose gum, agar and locust bean are the most widely used in terms of dollar sales.” Mr. Brooks pointed out that xanthan and guar are often used in gluten-free applications.
Likewise, Steven Baker, senior food scientist at TIC Gums, White Marsh, MD, said guar, cellulose and xanthan gums are most often used in baked goods. “For glazes and icings, the most commonly used gums are agar, gum acacia, cellulose gum and xanthan gum,” he noted.
According to Linda Dunning, regional product manager, DuPont Nutrition & Health, New Century, KS, “The most commonly seen hydrocolloids in the bakery are guar gum, cellulose gum and xanthan.” Ms. Dunning also mentioned pectin, locust bean gum and agar for icings and glazes.
“In dry mixes, hydrocolloids like xanthan and guar gum can help add to batter viscosity and keep final products moist and tender,” said Andrea Peck Moeller, technical specialist, Cargill Texturizing Solutions, Wayzata, MN. Ms. Peck Moeller also mentioned the use of agar, alginates and pectins for icing stability, and pectins, carrageenans, alginates and locust bean gum for proper texture, clarity and stability of fillings.
Stability of supply and pricing
In today’s baking industry, it is not enough to create a good formulation for your product and then continue production without needing changes in the future.
The primary reason for concern is the volatility of supply and pricing of hydrocolloids. Bakers learned this lesson the hard way in 2012 when prices for guar gum went from less than $1 per lb to more than $10 per lb. In this case, the primary driver for the short supply was the use of guar in the petroleum industry. However, supply and prices are also affected by climate change and geo-political pressures.
For example, the government of Morocco recently imposed harvest limits and export limits on agar. Fortunately, availability of agar from Indonesia, China and Chile has stabilized the supply and pricing of agar.
This year, there are concerns about the supply and pricing of locust bean gum, gelatin and pectin. For example, the 2015 crop of locust bean gum in the Mediterranean area is expected to be 20 to 30% lower. One supplier mentioned concerns over the pricing of xanthan gum, which is considered the most stable hydrocolloid in terms of supply and pricing. This issue is due to production delays from China, the source of the majority of xanthan. “Non-Chinese xanthan prices are double to triple the price of Chinese xanthan,” Mr. Reuber noted.
In addition to pressure on supply and prices, there are also questions about consistency of quality. “Two suppliers could meet the specifications, but the baker will not get the same final product,” Mr. Seisun said. For this reason, it is important for bakers to test the ingredients and also to have open communications with their suppliers.
To control costs, it is important for bakers to devise alternative solutions to substitute other hydrocolloids for those that are presently used. Possible substitutions for the most commonly used hydrocolloids include other celluloses such as hydropropyl methyl cellulose, methylcellulose and microcrystalline cellulose as well as other plant-based gums such as konjac, ghatti, karaya, tragacanth, fenugreek, locust bean, psyllium, tara, flax seed and furcellan.
Starches and modified starches are also used as hydrocolloid substitutes.
Synergies and buying behaviors
Bakers need to understand that hydrocolloids have synergistic properties, which means the functionality gained is greater than the sum of the parts. This not only helps when developing a standard formulation, but it also helps when formulating substitute plans.
The most common synergy seems to be xanthan and guar. Other reported synergies include konjac with xanthan, guar with locust bean, tara with xanthan, locust bean with xanthan, carrageenan with xanthan, carrageenan with locust bean, agar with gellan, konjac with tara, CMC with gum arabic, agar with locust bean, and alginate with xanthan.
Some hydrocolloids also have synergies with emulsifiers. For example, iota carrageenan has synergy with sodium stearoyl lactylate, and there are also synergies with starches and gums.
The supplier community encourages bakers to look at the “whole system” of the formulation rather than focusing on a single ingredient. This allows for greater flexibility in the purchase of hydrocolloids. Bakers do not like to change formulations that are working well, and this attitude is evidenced by the fact that guar usage is not even close to the 2011 usage level. Once bakers had to change formulations, they were not eager to reformulate, despite that guar pricing has been relatively stable for the last three years.
Cost often is the primary factor driving buying decisions, but it is not the only factor. Avoiding the expense of reformulating, reducing the number of ingredients and vendors active in the baker’s purchasing portfolio, achieving cleaner labels, and making innovative products such as gluten-free, low-fat, or eggless products were other factors that are influencing buying decisions.
Many buyers are also interested in GMO-free, organic and sustainable sourcing. Moving forward, to protect the brand, bakers will have to monitor research and public opinion in the area of wellness. For example, one recent study mentioned that CMC promotes the growth of microbes in the gut that are associated with diabetes and obesity. While further study is needed to substantiate or refute these claims, it is just an example of the kinds of factors that influence buying habits.
As consumers continue to ask for healthier products, the industry will continue to look for ways to enhance the positive view of their products. For example, gum acacia is composed of 85% dietary fiber. While the small amount of hydrocolloids used in bakery products would not cause the amount of dietary fiber in a serving to drastically change, touting the increased dietary fiber could influence a consumer’s perceptions of the product.
While supply and pricing will drive formulation changes, for bakers to “keep it together,” it is imperative that product quality remains consistent. When using hydrocolloids, it is vital to implement specific production controls.
Ensure the ingredients are obtained from a reputable supplier and that the quality of material is consistent. Store hydrocolloids in a dry area; if these ingredients get wet, they will lump. If the production employee who either scales the ingredient or loads the mixer discovers that the hydrocolloid is lumpy, it should be addressed immediately; a hydrocolloid that is not free-flowing is not functional.
Spot-check particle size. If this changes, the functionality will also change because particle size impacts hydration rate.
Ensure accurate weighing of the hydrocolloids. Not only are they expensive ingredients, but they also can cause product defects if under-used or over-used. If under-used, the product will not be stable.
I did some consulting work earlier this year with a baker outside the US who was not using any hydrocolloids in the icing formulation. The day after production, most of the icing was in a pool rather than on the product. When we reformulated the icing using agar and locust bean gum, the product achieved the necessary stability. If the hydrocolloid is over-used, the product can have a gummy texture. In gluten-free products, over-usage of gums will increase dough viscosity, resulting in problems with product symmetry.
Develop and follow a standard procedure for hydrating a dry hydrocolloid. The objective is to spread out the particles as far as possible to prevent clumping. Some bakers blend the gums with flour; some blend the hydrocolloid with sugar, and others develop a slurry.
Be sure to know if the hydrocolloid is cold-water or hot-water soluble and adjust your process accordingly. For example, agar is hot-water soluble, so you have to cook the icing mixture to gain the functionality. On the other hand, CMC is cold-water soluble, so cooking a mixture of CMC before use is a waste of time.
Ensure that the mixture (sponge, dough, filling or icing) is properly hydrated. If used in a sponge-and-dough process, I prefer to use the hydrocolloid in the sponge, because the fermentation time will help with hydration.
Take care that the final moisture of the baked product is consistent. This is one reason that hydrocolloids are also called gums — the product will tend to be gummy if not properly baked. Some oven adjustments may be necessary. For example, if the product is gummy due to improper baking, the baker needs to decrease baking temperature and increase baking time. I recommend establishing a target final internal temperature of the product coming out of the oven.
Check the temperature of the product and the icing so that they are controlled at the point of application. Good industry averages for the temperature of the icing are 113 to 122° F (45 to 50° C), and good average temperatures of the product at the point of icing are 95 to 101° F (35 to 38° C).
From a formulation standpoint, hydrocolloids play a significant role in new product development.
Hydrocolloids are used to give batters needed viscosity, which also helps gas retention. Without gluten — even with bread — the dough now becomes a batter. With a lack of viscosity, there will be a lack of product volume. With too much viscosity, there will be a lack of symmetry and difficulty in packaging.
Hydrocolloids can also give structure and emulsifying properties in low-egg or egg-free products. One of the most challenging applications is in the production of eggless cakes. Based upon total flour, the percentage of eggs used in traditional cakes is normally in the range of 40 to 80%, which is a large amount of ingredient to replace. Fortunately, 75% of the weight of egg is water, so replacing water is the easy part. The difficulty lies in replacing the protein, fat and lecithin in the egg solids. In addition to hydrocolloids, other parts of the eggless cake system may include emulsifiers, other proteins, starches and other fat replacers.
The benefits and challenges presented by hydrocolloids create an opportunity for bakers to get excited about improving bakery products, just as I was inspired to go to school by the joy of drinking chocolate milk.