Thanks to the rise of the whole-food movement, fruit and vegetable powders are in stronger demand than ever before. They can deliver gorgeous, vibrant colors and delicious flavors to powdered supplements, ready-to-drink beverages, snack foods, cereals and more.
In addition, dehydrated powders get points for some practical attributes, such as a longer shelf life than frozen and refrigerated materials. Better yet, powders help pack in vitamins and minerals for optimal health and wellness.
But—and this is key—if powders are subpar, none of these benefits apply. Washed out colors and bland flavors plague powders that aren’t extracted, dried, processed and stored responsibly.
In this feature, learn how high-quality powders are made and why they are a cut above the rest.
High and Dry
The drying of fruit and vegetable pieces, purees or juices is a huge part of transforming a juicy berry into a beautiful and nutritious powder. Industry has many drying techniques at its disposal, and each has its pros and cons. Says Baptiste Demur, category manager at Naturex, Avignon, France, “There is no magic bullet! No gold-standard drying technology is appropriate for all needs.”
Ryan Goularte, general manager of Sensient Natural Ingredients (SNI), Turlock, CA, says his firm uses methods like air, freeze and vacuum drying. “We select our drying technique based on how our customers desire our product to function in their application. All SNI vegetable powders begin as a whole vegetable, the majority of which are harvested from our own fields. The vegetables move through a dehydration process, then are further milled into various piece sizes, which include powders,” he explains.
Now, let’s look at some of the most popular dying techniques in use today.
Air drying. Air drying is often used for food ingredients and herbs. According to Dan Goral, director of business development at Powder Pure, The Dalles, OR, air drying is cost effective, but there can be some tradeoffs. “It is extremely low tech, but the product quality suffers and micro loads can often be high,” he states.
Demur agrees that the microbiological load is high in air-dried powders, adding that the process also bears a “serious risk of contamination with foreign materials.”
Since the specifications of powders are a bit harder to control with air drying than with other methods, some extra waste may be created from unusable product. This is a key consideration because many companies (and consumers) want to keep food waste to a minimum.
Given these limitations, if your supplier uses this method, choose a partner that is responsible and performs the necessary analyses to ensure the end product is free of contamination and microbes.
Spray, vacuum and drum drying. Spray, vacuum and drum drying are some of the most common ways companies are dehydrating fruits and vegetables. “These three technologies are cost effective and ensure a very good microbial quality while allowing for a level of product tailoring not achievable with air or freeze drying,” says Demur.
Spray drying involves low to medium temperature and is often used to make fine powders. Andrew Wheeler, director of marketing, Futureceuticals, Momence, IL, says his firm mainly uses spray drying to produce “economical versions of soluble fruits and vegetables, mainly for the RTM/RTD sector.”
Meanwhile, vacuum-belt drying is performed at low temperatures and can deliver a range of particle sizes. “Both methods allow good preservation of nutrients and organoleptic quality and, when mastered, can be used without any carrier,” says Demur.
But he points out an advantage of vacuum-dried products: they are instantly soluble in water. “In non-aqueous products, they remain crispy and add to the mouthfeel, such as in chocolate products in which vacuum-dried products can deliver crispiness along with a bursting flavor,” says Demur.
And then there’s the widely used drum-drying technique, which Wheeler says is “a more cost-effective method for manufacturers looking for a high-quality and low-micro product.”
Raw materials are first pureed and then run over a heated drum until they dry into thin sheets. This creates textures “from very thin, light flakes to thick, crunchy flakes that do very well in many types of food products,” says Demur.
Heat degrades some of the nutrients, but much is left intact, says Wheeler. To use the least amount of heat necessary, Demur adds, “it requires fine tuning not to degrade organoleptic and nutritional quality.”
Heat is definitely a consideration for Stephen Lukawski, director of sales and business development for Fruit d’Or Nutraceuticals and CEO of RS Specialty Ingredients, Quebec, Canada. He states, “Drying systems that use low temperatures over a longer period of time are proven to produce a powder with a higher integrity of biomarkers. Too much heat in the drying process degrades the biomarkers and creates an inferior ingredient.” This could negatively affect the positive role that cranberry should play in urinary and digestive health.
He uses an example of beneficial proanthocyanidins (PACs) in cranberry, which can be destroyed with high-temperature drying. “When using a low-heat drying system, our test results indicate a higher potency of PACs than other cranberry suppliers,” says Lukawski.
In addition to PACs, the prebiotics and other nutrients derived from the cranberry seed must be dried at low temperatures so they aren’t destroyed. Lukawski states, “When dried under low temperatures, the natural components within the seed can provide protein, fiber, amino acids and omegas-3, -6 and -9. The cranberry seed powder contains nitrogen and carbon that provides a source of fuel to feed certain probiotic strains.”
Something else to consider is whether carriers are needed as processing aids. Certain drying methods like spray and drum drying often involve spraying the fruit or vegetable juice onto a carrier like maltodextrin before drying it. But, suppliers that specialize in natural ingredients are improving this process. “To meet our clients’ expectations for all-natural foods, we have pioneered new all-natural carriers that can replace maltodextrin and silica dioxide,” says Wheeler.
Freeze drying. Many companies also implement freeze drying, which Wheeler says retains the raw material’s shape, color and phytonutrients better than other drying methods. “The dietary supplement and functional food sectors gravitate toward whole foods, nutrient and enzymatic retention and, in some cases, the shape and color of the fruit or vegetable,” he states. “This is where freeze drying excels, and will continue to excel into the future. The whole food trend is here to stay.”
Demur seconds the fact that freeze drying “provides a good preservation of organoleptic and nutritional qualities,” but he raises the point that it isn’t the most cost-effective method on the market and results can be uneven if the supplier is not careful. He also notes that as with air drying, “freeze-dried products remain insoluble in water with fruit and vegetable particles providing a chewy or grainy texture that can settle down or float in liquids…This can be a problem for many applications where solubility is required.”
Another issue to consider is that freeze drying and vacuum belt drying “tend to pull off volatile flavor components, removing many of the ‘top notes’ and delicate fresh flavors,” says Goral. This may not be a problem for certain projects, while others want to capture these flavors.
Wheeler says that another positive aspect of freeze drying is that it creates materials with a very low moisture content, which helps support a long shelf life. He adds that drum drying makes slightly higher moisture content, “but both techniques contribute to a low micro ingredient at the time of production as well as on the shelf. This is one important way, if not the most important way to control shelf life.”
But Goularte says that very low moisture content isn’t always desirable. “The old adage in the dehydration industry of ‘the dryer the better’ doesn’t always apply,” he believes. “Each dehydrated vegetable and spice powder has an optimal moisture range for product stability…A very low moisture will ensure a water activity level that inhibits non-enzymatic browning and microbial growth, but some products need a little more residual moisture to obtain that same stabilizing effect.”
In some cases, we actually add fiber in the form of blended fruit and veggie mixes to improve processing of high-sugar fruit items. —Dan Goral, Powder Pure
Aside from moisture content, he says shelf life can also be supported with packaging materials that minimize oxygen and moisture exposure such as foil layers on drums and inner polyethylene liners inside drums.
Infrared light. Goral speaks of a patented technology from his company (Infidri) that uses infrared light to prepare powders in a way that kills microbes and targets water, which drives it out of the material. This preserves complex colors, flavors and nutrients. With this technology, whole fruit and vegetable powders can be made without carriers or added processing aids, while juice powders only need a minimal amount of carrier. “We want our dried fruit and vegetable powders to have as much color, flavor and nutrition as possible so they will be appetizing and healthy to eat,” he states.
Another advantage of this method is that it helps reduce oxidation, a major cause of food degradation. “The rate of oxidation is directly related to the surface area of the powder particles in which the greater the surface area, the faster oxidation will occur,” Goral explains.
Powders made with the firm’s patented infrared process contain high-density particles with a low surface area, which reduces the oxidation potential, according to Goral. He says the powders have a three-year stated shelf life.
Goral adds that his company’s process is being used to minimize food waste. “We are working with large farms to make shelf-stable powder products from high-quality perishable foods that can’t be sold because of over supply or physical imperfections,” he states.
Food waste. Speaking of food waste, experts interviewed for this piece say that dehydration creates very little food waste in general, since many parts of the raw material can be used, and even opens the door to some innovation.
“We believe that every part of the ingredient is useful. Some parts of fruits and vegetables that are usually discarded actually have benefits all their own,” says Steve Siegel, vice president of Ecuadorian Rainforest, LLC, Belleville, NJ.
He offers up avocado seed as an example, which is often discarded but contains lots of antioxidants and fiber. “We offer avocado pit powder, which is perfect for a wide range of applications. We aim to offer powders and powdered extracts with little to no waste, if possible,” he states.
No matter which technique is used, choose powder specialists that can adjust their processes to meet your end-product needs. For instance, Demur states, “A carrot puree can be blended with an optimized level of carrot juice prior to drying in order to achieve a unique profile with fine-tuned sweetness/acidity/flavor freshness, along with a brilliant color and an optimized nutrient content—all from carrot.”
Given the diversity of the powder market, can any fruit or vegetable be dehydrated into a stable powder that still has a high nutrient yield? According to experts, drying high-sugar fruits isn’t exactly the easiest of projects. “Fruits with a high brix are a real pain,” says Wheeler. He says they need carriers when drum dried because “they tend to stick to everything.”
In agreement is Lukawski, who notes that the sugars in cranberry can be a “serious problem” in high-temperature drying. “These sugars become burned in the drying process and the natural oil in the cranberry can become rancid,” he states. “Depending on the drying system, some cranberry manufacturers will add ingredients such as lecithin in the drying process so the cranberry will not burn onto the equipment.” For these reasons, Lukawski prefers low-heat drying of cranberries.
Goral makes the point that high-sugar products can be problematic for certain processes like spray drying. “In some cases, we actually add fiber in the form of blended fruit and veggie mixes to improve processing of high-sugar fruit items,” he states.
Certain materials like herbs and leafy greens have the double issue of being delicate as well as at an increased risk for pathogens. According to Goularte, “Fragile plants must be processed in a very narrow window in order to avoid decay and spoilage. As many of these vegetables are harvested in the warmer months, heat is often a major factor of degrading raw material quality after removal from the land, similar to the effect of flowers wilting after being put into a dry vase.”
He says his company overcomes this by working with farmers to optimize harvest timing with a field hydration and picking schedule. Processing time is also key. “In some of our more delicate raw materials, our product is processed in less than 12 hours from harvest,” states Goularte. And since unwanted heat can degrade the quality of delicate materials, the firm processes at night in some instances, and has custom-built unloading and washing systems that “gently separate and cleanse raw materials without incurring breakage or other wastes,” he says.
Powder specialists often have a huge repertoire of items in their catalogs. Which are the current faves of customers and their clientele?
Goral says coconut water is popular because it tastes great and contains electrolytes for sports recovery.
Siegel agrees, noting, “Consumers love coconut water powder because of its hydration benefits and potassium content.”
A similar ingredient growing in the sports nutrition category is watermelon juice powder. “Watermelon juice is just as nutritious as coconut water, providing potassium, B vitamins and beta carotene,” says Siegel. “Watermelon juice’s main draw is its use for muscle soreness relief and recovery.”
Likewise, “Freeze-dried tart cherry has taken off as of late, mostly because of demand in the sports nutrition and recovery market,” says Wheeler.
Also in the sports nutrition arena are high-nitrate products (e.g., beet, celery and kale), which boost nitric oxide levels in the blood for improved cardiovascular health and sports recovery.
And, culinary powders are big, says Goral, like the company’s new shiitake mushroom powder and sriracha sauce powder.
Demur says greens (like kale) and superveggies are seeing an uptick in interest. He states. “Vegetables have a healthy halo, especially thanks to the many initiatives promoting increased vegetable consumption. Much of NPD in the industry bets on the introduction of vegetables in processed foods, beverages and supplements to enhance their healthy appeal and attract specific categories of consumers—Millennials, for instance.”
One hot veggie, according to Jean Shieh, marketing manager at Sensient Natural Ingredients, is beetroot. “SNI’s primary consumer research confirms the growing interest in root vegetables, and specifically, we are seeing a strong trend in utilizing beetroot powder in the better-for-you snacks category.”
She explains that part of the appeal is that it’s high in calcium, iron, folic acid, vitamin A and vitamin C, which are preserved with the “proper drying process.”
Always hot in the powder world are superfruits and those with strong antioxidant activity like acerola, cranberry, acai, camu camu and goji powders.
Given this latter trend, clients may want powder experts to account for antioxidant capacity. Demur says that a powder’s guaranteed ORAC value—an indicator of its antioxidant capacity—is often provided to his firm’s clients. “When possible we prefer to guarantee a content in a specific compound known to have outstanding antioxidant capacity, like we do for our acerola powders that are standardized to up to 34% naturally occurring ascorbic acid (vitamin C), for instance,” states Demur.
Some believe the ORAC value is not always the most useful way to gauge a material’s antioxidant capacity. Goral says his company sends materials to an independent lab that tests for the actual antioxidant compounds like phenolics and anthocyanins. This information is then included on the material’s certificate of analysis. In addition, the company has done some proprietary work: “We’ve also developed an electrochemical test method for Total Antioxidant Activity that is very accurate and sensitive.”
Lukawski also believes testing for certain components is key to gauging the efficacy of certain materials and making sure there is standardization. Again, this need is spurring innovation. He explains that Christian Krueger, Ph.D., a research manager at the University of Wisconsin Madison, created new analytical tools to measure soluble and insoluble PACs (e.g., the butonal method) and introduced new reference standards (e.g., C-PAC standard) to establish more accurate test results. “This, in my opinion, is the most reliable test method and reference standard in measuring PAC content of natural cranberry powder,” Lukawski states.
Innovation is also happening at Futureceuticals, which believes the best way to test antioxidant capacity is in a human body, something that had not previously been done when referencing antioxidants with the ORAC assay. Says Wheeler, “In late 2014, we became the first manufacturer to measure real-time in the human body the impact of a natural material on reduction of Reactive Oxygen Species.”
In fact, his firm’s line of Spectra powders doesn’t use the term “capacity” with respect to antioxidant value. Instead, says Wheeler, they refer to antioxidant action in the human body, supported by its testing methods.
One last powder trend comes from Demur, who says that there’s been movement away from fruit juice powders. “There has been quite a backlash against fruit juices lately as they have been pointed out as not-so-healthy options because they can contain quite a significant amount of sugars,” he observes.
Instead, Demur says customers are looking for dry fruit ingredients made with fruit juice as well as fruit puree because it is more “complete,” and includes “all the good constituents of fruits and not concentrating sugar at the expense of nutrients or fibers.” WF
Published in WholeFoods Magazine October 2016