New Gums, Fibers and Starches Add Function, On-Trend Appeal
The Starch Set: The proliferation of plant-based products, especially those replacing animal products, has spurred an unparalleled demand for starches, fibers, and gums.
A snapshot of plant-based products that have recently taken the market by storm includes the meat, poultry, and seafood analogs from Gardein, Inc. (now a part of Conagra Brands, Inc.); the comprehensive lines of meat and poultry analogs from Beyond Meat, Inc., and Kellogg Co.’s Morningstar Farms brand; Maple Leaf Foods, Inc.’s Lightlife line of veggie hot dogs; the Impossible Burger from Impossible Foods, Inc.; and Garden Gourmet-brand “Incredible Burger” from Nestlé SA, just launched in McDonald’s restaurants in Europe (and due to launch soon in the US as the “Awesome Burger” under the Sweet Earth brand name).
The unsung heroes of all these plant-based meat analogs? Starches, fibers, and gums.
Starches, fibers, and gums are co-products constituting the majority composition of plant materials. They are emerging as destination ingredients in a market that is increasingly averse to synthetic ingredients and also questioning the regular use of animal-based ingredients.
Driven by an unprecedented consumer shift favoring plant-based food products, starches, fibers, and gums are filling in where plant protein functionalities fall short.
Plant-based foods are emerging in the market predominantly in products designed to either substitute for or recreate the taste, texture, and overall eating experience of many animal-derived foods. From milk to yogurt to burgers, taste and texture are supreme — but overall quality has to be of the highest caliber for successful center of the plate applications, whether the product serves as a substitute or an analog.
Concurrently, health is a top concern for Millennials and older Americans, while concern for the environment is a close second for the younger consumers. Plant-based foods check both the health and environment boxes, or at least that’s the prevailing perception, according to Mintel Group, Ltd.
Starches such as potato starch and modified food starch, fibers such as methylcellulose and carboxymethylcellulose, and gums such as modified vegetable gums (alginate, guar gum, locust bean gum, and xanthan gum) and sugar polymers (agar, pectin, and carrageenan) are used to help the finished product appear like the original and bind together the various proteins, oils, and other food additives for an adhesion that mimics the sustained elastic resistance and chewiness of an animal-based product.
Instead of using a modified starch, functional native starch, or native waxy rice starch or flour, manufacturers can take advantage of a new advance in flours: multifunctional flours. These new flours that do more are available in rice and tapioca bases and come with a simple “flour” label.
Multifunctional tapioca flour helps improve product stability, shelf life, and quality. Plus, it has a viscosity and gel strength comparable to those of modified starches. It offers a smooth texture with no gelling or syneresis and provides a cleaner flavor and longer-lasting mouthfeel compared with benchmarks.
Tapioca flour delivers a superior surface appearance in terms of smoothness and gloss compared with alternatives. It also provides enhanced texture stability over a product’s shelf life, as well as excellent freeze/thaw performance compared to other clean-label flours.
Multifunctional rice flours also improve product stability, shelf life, and quality. These rice flours create smooth, creamy textures without compromising flavor. In gluten-free sauces, the new flours maintain opacity that is otherwise lost when replacing wheat flours. The starches and flours from tapioca and rice are just a few of the available ingredients in the modern clean-label and gluten-free toolbox for product developers, especially in the categories of baked products, extruded products, and animal protein alternatives.
Where texture meets flavor and health, you’ll find today's starches, fibers, and gums.
PHOTO COURTESY OF: Good PLANeT Foods, LLC (www.goodplanetfoods.com)
Dairy alternatives such as non-dairy milk, non-dairy yogurt, and non-dairy cheese are experiencing buoyant growth due to the growing numbers of vegans, flexitarians, and meat-reducers. These strong demographic groups are increasing the demand for sustainable and healthy products with robust environment credentials, such that vegan products are no longer a niche. Moreover, the trend shows no sign of abating. This is readily evidenced by the pace of new product releases across a multiplicity of food and beverage categories in retail as well as in foodservice catering.
Good PLANeT Foods, LLC, uses modified potato starch and tapioca starch in its cheddar-style shredded cheese product for sustained meltable characteristics in deli foods like vegan mac and cheese. The Specialty Food Association recently reported several national restaurants offering Good PLANeT vegan cheese on the menu, citing desirable flavor and melting power for a full range of culinary uses, including pizza, nachos, pasta dishes, sandwiches, wraps, and salads.
The aforementioned tapioca starch helps reproduce creamy spreadability, an attribute of immense importance to consumers when they choose dairy-free analogs of cream cheese and yogurts. Daiya Foods, Inc., incorporates modified tapioca starch along with modified potato starch to minimize syneresis in its vegan cream cheese, while replicating the texture, taste, and eating experience of dairy cheese.
In plant-based yogurts and cream cheeses, fava bean starch provides a very clean flavor and short texture, helping to make plant-based products just as consumer-friendly as their dairy counterparts. Pea starch has an additional property: pea starches can replace hydrocolloids such as pectin and gelatin in gummi products without toning down flavor as do starches from corn and tapioca. For carb-conscious consumers, amylose-rich starches such as pea starches mean a lower glycemic load when consuming such treats.
While plant-based milk alternatives made from almonds, oats, coconut, and peas have caused quite a stir in mainstream retail markets, their appearance as ingredients in food production and hot beverage applications remains rather limited. Processors complain that emulsions of milk alternatives are not robust enough to withstand the temperatures, pressures, and shear associated with processing conditions and yield an oily film instead of the creaminess of their animal-based counterparts.
Print and Cut
One emerging technology for the manufacture of food in different shapes and structures is 3D food printing. The new technology allows manufacturers to make shapes and components that were not possible with traditional molding and forming equipment. The technology relies on three kinds of ingredient mixtures depending on the extrusion techniques: cold extrusion, hot-melt extrusion, and gel-forming extrusion.
To function properly, the 3D printing feedstock must have the appropriate rheological properties and printability (shape fidelity) to ensure the desired appearance, eating quality, and shelf life of the finished products. The ingredients must have liquid-like characteristics to flow under the shear during mixing and extrusion and solid-like characteristics to form a self-supporting structure once the applied shear is removed when printed.
Hot-melt extrusion that is used to create customized 3D chocolate products relies on the cocoa starch and fiber in concert with its fat to extrude as a semisolid at a relatively high temperature. It should solidify almost immediately after extrusion and weld to the previous layer. Cocoa fat and sugar alone would not work.
The fiber methylcellulose works well for cold extrusion-based printing, where the formed shape is then subjected to freezing, frying, or baking. Methylcellulose offers the appropriate rheological properties in terms of viscosity, yield stress, shear moduli, and shear recovery to help the printing or depositing material (or batter for bakery items) to be extruded. Extrusion follows from a nozzle and is deposited into well-formed geometric shapes without slumping, spreading or bridging for shape fidelity of the intended printed structure design.
Potato starch and modified potato starch are proving to be highly viable, clean-label alternatives with the appropriate yield stress and elasticity to replace the printability of methylcellulose.
“Clean label” is rapidly becoming a must as consumers actively seek products free from additives, artificial ingredients, and allergens. Label-friendly functional starches are giving manufacturers desired functionalities while meeting consumer desires for recognizable ingredients they believe will do no harm.
Unique starches are emerging to lend specific textures and shelf-life stability to frozen ready meals; dairy foods, such as custards and puddings; and ambient/chilled soups, sauces, and gravies. Starches sourced from waxy corn and labeled as “starch” or “cornstarch” are holding up in gentle cooking conditions, pasteurization, homogenization, UHT, and retort processing, and replacing modified starches on food labels.
Traditionally, starch applications focus on viscosity (or thickening) but not necessarily on gel strength, stabilization, or other textural effects that are important for consumer acceptance of a plant-based product.
New sources of starch, especially from legumes (peas, lentils, chickpeas, and fava beans), offer unique characteristics that not only translate to clean-label functional alternatives to hydrocolloids, but also boast unique functionalities that traditional grain and tuber starches lack.
Smooth and wrinkled peas contain around 30%–76% amylose — twice as much as is found in traditional starch sources, such as corn, wheat, tapioca, potato, and rice. Pea starch imparts gel strength, film formation, and crispness — properties of significance when replicating the texture of meat products.
In meat analog products, pea starch is a clean-label native starch that delivers on the texture and mouthfeel consumers expect, helping the plant-based versions to meet and surpass the bar set by their meat-derived counterparts.
Starches are generally used to provide binding and structure in cream and cheese applications. Pea and fava bean starches play a critical role in holding moisture and maintaining the mouthfeel of dairy applications while being on target as allergen-friendly, economical ingredients that are inherently non-GMO. They also are commonly available as organic ingredients, grown with regenerative agriculture, and processed in the US.
Fabanaise is an example of a vegan mayo made with aquafaba, the naturally occurring combination of starches, fibers, and gums in chickpeas.
PHOTO COURTESY OF: Kensington & Sons, LLC (www.sirkensingtons.com)
For vegans and persons with allergies, egg ingredients must be avoided. Yet, eliminating egg means losing the high functionality eggs provide, especially as a stable emulsion necessary for the structure and texture of bakery products. Egg replacement is not a one-for-one trade; no other single ingredient can match the multifaceted functionality of eggs. This is where a crafty combination of various starches, fibers, and gums is proving useful.
When applied in the right balance, starch blends or starch and gum blends can recreate the required stabilization for building the appropriate structure and eating quality of a product. The demand for simple ingredient lists continues to help expand the starch category.
What's in a Label
The increasing focus on label claims and quality has driven processors to be more mindful of the compositional profiles of their starchy ingredients. Certified organic and non-GMO label claims promise higher premiums and sustainable sales growth. Large-scale food production through extensive cultivation of modified crops with elevated amylose content has an issue with regard to starch yield. Processors of organic and non-GMO products can take comfort in knowing that mutant or transgenic lines with high amylose content generally have lower grain yield than the wild type, dispelling concerns about price implications.
Fava bean starch is currently one of the more popular starches used in egg replacement systems. It behaves like waxy cornstarch and has minimal effect on color. It does not compromise organoleptic characteristics in products in which it replaces eggs, nor does it alter texture or shelf life stability. This also means that the level of inherent flavor compounds will not be an issue in taste- and color-sensitive applications, such as cream fillings and dressings.
Because fava bean starch tends to swell up more than cornstarch, the enhanced viscosity lends the application richer taste and texture without blunting the flavor of the spices as cornstarch and potato starch tend to do. Fava bean starches are promising ingredients for foodservice soups and stews in supermarkets and buffets because of their increased and sustained viscosity during extended heating.
In addition, the hydrophilic properties of starches help minimize syneresis by controlling the expulsion of free water or brine in seafood products like surimi and vegan cheese to consistently and cost-effectively help preserve a texture that is as close as possible to that of the original food.
The demand for starches, initially driven by their versatility in various applications, is soaring further because of their growing consumer appeal and the favorable supply-demand dynamics of high-protein and plant-based foods. Understanding how structure and content affect starch functionality and physiological effects is critical to enhancing nutrition without compromising form or sensory quality.
High‐amylose starches, although not a recent innovation, are growing in popularity because of their unique functional properties and enhanced nutrition. Joining the ranks of the stalwart high-amylose corn, barley, and potato are new commercially available high-amylose variants of wheat, rice, and banana starches.
The molecular and microstructural features of resistant starches contribute to digestive enzyme resistance, an increasingly relevant factor in formulations. During heating, high-amylose starch will form and retain dense molecular structures, including helices (type-2 resistant starch [RS]), re-associated glucan chains (type-3 RS), and lipid–amylose complexes (type-5 RS) All of these structures resist enzyme degradation.
Physical and chemical modification techniques can lower susceptibility to enzyme action and the production of glucose. The degree of modification through physical techniques is limited, while chemical modification is shunned by consumers as not being “clean label.” Biological techniques are emerging as the preferred method for increasing amylose content, and both conventionally bred and transgenically modified high-amylose cereals allow for a range of starch structures with a corresponding cascade of functional and nutritional implications.
The location of amylose in starch granules is also important. When aligned with the radial orientation of amylopectin chains, amylose has greater chances for entanglement and double-helix formation and the resulting blunting of the glycemic response.
In potatoes, amylose and amylopectin are relatively more separate than they are in corn. This means there is a greater tendency for the amylose to leach out from potatoes than it does from corn, in which the closely aligned amylose and amylopectin form crystalline clusters with greater enzymatic resistance and heat stability. Crystallinity limits water uptake during processing and baking and therefore determines the extent of gelatinization and the subsequent glycemic response of the finished product.
High-amylose starches retain the traditional properties of starch (i.e., light color, characteristic particle shape and size, and neutral flavor) but have significantly different thermal and pasting behaviors, which affect sensory and physiological properties of applications. They also typically have a higher gelatinization temperature and an increased rate of retrogradation.
The higher gelatinization temperature is an advantage for attaining desirable eating qualities such as crunchiness and crispness, along with a higher resistant starch content. However, it also can pose a challenge with certain processing methods because it necessitates an extended cooking time and higher cooking temperature.
Combining high-amylose content with extended cooking to increase the extent of starch gelatinization can enhance gelling capacity and associated properties — such as rigidity, cohesiveness, and resilience — along with greater resistance to digestion in foods containing the retrograded starch.
Resistance to digestion plateaus above a certain amylose content. Most formulations will not need an 80% high-amylose maize starch and can opt for a 40% or 50% counterpart.
The advantages of starches and fibers from legumes such as fava beans includes not only versatility and gluten-free status but maximum sustainability.
PHOTO COURTESY OF: Prairie Fava, Ltd. (www.prairiefava.com)
Amylose in Action
Dough-making is an essential processing step to transform flours into consumer favorites such as bread, pasta, and noodles. Compared to regular wheat flour, high-amylose wheat flour tends to produce a tougher and more viscous dough that hinders swelling of granules, controls the expansion of dough during baking, and retards recrystallization. These traits work to a processor’s advantage when it comes to reducing bread-staling and hardness.
In pasta, higher amylose content provides increased resistance to overcooking, greater resilience (chewiness) and firmness (al denté texture), and a lower glycemic index.
A respectable range of high-amylose versions of major starchy food crops is now available. These expand the selection of cereal/tuber varieties for foods with enhanced nutrition and functional attributes.
The current understanding of biological and structural aspects of high-amylose starch is supporting the incorporation of high-amylose starch for foods with enhanced nutritional value. As research continues to support the cross-functional benefits of this fiber-like starch component, processors increasingly are shifting high-amylose starch ingredients from an auxiliary partial replacement to a major ingredient for total replacement of the original ingredient in appropriate formulations.
The 2016 FDA definition of “dietary fiber” separates dietary fiber ingredients that are naturally occurring from those that are isolated or synthetic. Declaration as “dietary fiber” in the Nutrition Facts label requires FDA approval based on scientific evidence of physiological benefits of human health. Under the current ruling, high-amylose starch (RS2) from grains is a “dietary fiber,” unlike other types of “synthetic” RS (retrograded (RS3), chemically modified (RS4), and synthesized with lipids (RS5)).
Regulations around the world support recognition of the physiological benefits of Resistance Starch (RS). The European Food Safety Authority (EFSA) approves an RS‐relevant health claim that “Replacing digestible starch with RS induces a lower blood glucose rise after a meal” (EFSA, 2011). Food Standards Australia New Zealand (FSANZ) considers RS a dietary fiber and that scientific studies demonstrate RS promotes modulation of blood glucose through reducing peak postprandial blood glucose concentration and promoting laxation.
In the US, the FDA allows manufacturers to use terms such as “resistant” or “indigestible” in food labeling with legally approved and clearly labeled starches. The FDA also permits a qualified health claim that, “High-amylose maize resistant starch, a type of fiber, may reduce the risk of type 2 diabetes, although FDA has concluded that there is limited scientific evidence for this claim.”
For calorie labeling, RS has a lower energy value (2 kcal/g) compared to standard carbohydrates (4 kcal/g) in Europe, Australia and Japan, but is assigned 0 kcal/g in the US.
Pearls and Potatoes
Tapioca starch (Manihot esculenta) has experienced a big revival in food production recently. As a clean-label, gluten-free, non-GMO starch source, it hits all the right consumer targets. And processors love its thickening and gelling properties: It forms smooth, soft, transparent gels particularly suited for delicately textured desserts. Favorites such as flán and crème brulée are perfect vehicles for showing off tapioca starch as it has no aroma and forms a clear paste that is not sticky.
Vegan marshmallows were able to become the big trend they are largely due to tapioca starch in combination with carrageenan, the popular seaweed-derived gum. It acts as a plasticizer and prevents tapioca from recrystallizing, allowing it to retain its soft, chewy eating quality. This soft gel property also is useful in crafting foods for older seniors and persons with dysphagia.
Starch from sweet potato (Ipomoea batatas) possesses unique molecular, granular, and physicochemical properties ideally suited for noodles, chips, and baked goods. An added benefit of sweet potato starch is that it is a natural source of dietary fiber, proteins, vitamins, minerals, and bioactive phytochemicals such as carotenoids, anthocyanins, and phenolic acids. These have helped earn this ingredient a health halo that is a beacon for consumers.
Recently, some unique starch sources have been emerging to fulfill certain industrial demands. Starch from fruit by-products, such as mango seed and jackfruit seed, are rapidly transitioning from being underutilized waste materials to serving as a valuable source of new and unconventional flours and starches.
Formulators seeking a break from the taste, texture, and functionality of the four most commonly used starches (wheat, corn, potato, and rice) also are attracted to the gluten-free and non-GMO qualities of these exotic sources. Both mango seed starch and jackfruit seed starch act as good gel stabilizers and are poised to serve as clean-label replacements for synthetic emulsifiers.
In gluten-free versions of consumer-favorite foods like cookies and pasta, the gluten replacement ingredients rarely duplicate the original textural characteristics that consumers expect in these two foods. However, flour from unripe plantains can replicate the typical texture and eating qualities of wheat flour while also contributing as much as 20% fiber and lowering the glycemic index.
A new generation of fiber ingredients is offering expanded means of imparting viscosity, gelation, and stringiness while addressing clean-label concerns and yielding nutritional benefits. Increasing environmental concerns, the aforementioned clean-label concerns, and the continuing “free-from” demands have influenced companies to initiate product reformulation with these fibers.
Since the FDA specified that only intact dietary fibers could be claimed as dietary fiber in the Nutrition Facts Panel, product developers have been on the lookout for ingredients that comply. The carbohydrate fractions that remain after the extraction of oils and proteins from nuts and seeds have become attractive to formulators for partial or whole replacement of the base flour in cookies and pancakes.
Other examples of up-and-coming fiber sources include sesame pomace and the protein- and fiber-rich byproducts of oil extraction from almonds, walnuts, hazelnuts, and seeds such as sunflower seed and chia seed. These fibers provide functional and nutritional attributes in a number of good-for-you products with a nuttier, crunchier, and more tender friable texture than the dry, hard taste attributes commonly associated with fiber-rich foods.
One growing trend among ingredient technologists is that of using upcycled processing by-products, such as citrus pomace, as dietary fiber sources. PepsiCo, Inc., recently obtained GRAS status for orange pomace, a fiber-rich waste byproduct of orange juice production.
A common complaint about gluten-free products is that the ingredients popularly used to make a gluten-free version of a product often lack dietary fiber. Supplementation with refined fiber does not, however, appear to have the same health benefits as supplementing with intact dietary fiber.
Orange pomace can be used at levels ranging from as little as 1% to as much as 50% as a nutrient source, stabilizer, thickener, and texturizer in juice and juice blends, smoothies, spoonable sauces, nutrition bars, hot cereals, fillings for pies and other pastries, salad dressings, condiments, fruit butters, and fruit leathers.
In addition to their structural advantages, citrus fruit fibers, with their larger non-digestible dietary fiber fraction, travel undigested into the colon for fermentation by resident microbiota while the soluble dietary fiber fractions, beta-glucan and pectin, help lower blood lipids and attenuate postprandial hyperglycemia.
Chia seed fiber has gained attention recently as a multifunctional fiber that can improve dough yield and elasticity. It also possesses a high oil- and water-retention capacity, and in whole-grain baked items, it can help preserve crumb volume and improve final product appearance. It will enhance texture and flavor while reducing glycemic index and caloric load.
Gums and Hydrocolloids
Gums are hydrocolloids, i.e., they form gels or provide viscous dispersion in the presence of water and a wide range of rheological properties that make them invaluable for product developers.
The sources and chemical makeup range from microbial and vegetable gums (alginate, guar gum, locust bean gum, and xanthan gum), to proteins and animal sources (collagen, albumin, and gelatin) and sugar polymers (agar, carboxymethylcellulose, methycellulose, pectin and carrageenan).
Hydrocolloids are structurally diverse, with highly complex rheology and hierarchical structures that cover a wide range of the nano- to macro-scale. While the rheological properties of some gums can be similar, if all of the properties do not match up, they do not function alike.
Crumb hardening and cardboard-like dryness is a common complaint about products formulated to be better-for-you with label claims of added fiber, lower fat, lower sugar, and whole grain. This is especially so for gluten-free versions of popular baked goods, which tend to harden rapidly due to starch retrogradation (the formation of hard crystalline structures) during storage.
Hydrocolloids (such as gum arabic, carrageenan, guar gum, locust bean gum, konjac-glucomannan, and xanthan) that are high molecular weight polysaccharides with many hydroxyl groups act as plasticizers to prevent the formation of hard crystalline structures and the accompanying hardening or staling. Brown and red seaweeds yield alginate, agar, and carrageenan; each of these has a distinct physicochemical functionality and all of them work well as thickeners and stabilizers.
Gummi candies rely on the multi-stage gelation of carrageenan for the right flow characteristics during mixing and deposition. Carrageenan provides for a rapid set time with shape fidelity, heat stability during storage, and clean flavor release. It also is what helps give gummies their characteristic stickiness to the teeth while also offering desirable textures ranging from soft and easy-to-chew to a firmer, short bite.
Guar gum and locust bean gum are close to carrageenan in some of their rheological aspects but not in all properties; therefore, they are not printable. Gellan gum is even closer to carrageenan and has high printability. It works particularly well as a syneresis inhibitor, a foam stabilizer, and a food palatability/body-improving agent for jellies and freeze/thaw-resistant jelly foods that contain sugars, fruit juices, milk ingredients, wine, or cacao ingredients.
Traditionally, starch applications have been used to enhance viscosity and thicken, but not necessarily to provide gel strength, stabilization, or unique textural demands expected in packaged foods today. This requirement is especially pronounced when it comes to mimicking specific organoleptic properties of today’s highly demanded dairy and meat analog products coupled with the equally sought-after nutritive enhancement functions.