The New Starches

The New Starches
February 1998 -- Cover Story

By: Ronald C. Deis, Ph.D.
Contributing Editor

  Food product designers have come to rely on starches to provide an ever-expanding range of functionalities: viscosity, texture, pH, heat and freeze-thaw stability, moisture-binding, gel formation, encapsulation, film formation, aeration, crispness, volume control, dispersion, solids, suspension...the list continues on. Starch is a multi-functional ingredient, tailored by the supplier to meet changing consumer needs.  Examining the market for starch emphasizes its position in the food industry. Total world starch production in 1996 was approximately 40 million short tons, according to the Corn Refiners Association. Corn dominates this production (83%), followed by wheat (6%), potato (6%), tapioca (4%), and other crops (1%). The United States produced 59% of the world's starch, followed by the European Union (15%) and Japan (6%), with the rest of the globe picking up the remaining 20%. Due to economics of production, the U.S. market is even more dominated by corn starch; Corn Refiners Association statistics indicate that approximately 5.6 billion lbs. of starch products (corn starch, modified starch and dextrins) were shipped in 1996.  Foodservices account for 25% of unmodified food starch use at 184 million lbs., followed by brewing (9%), retail (6%), confectionery (5%) and baking (5%), according to Larry Fernandez, national accounts manager, specialty products, Corn Products International, Summit-Argo, IL. Modified food starches are largely dominated by waxy maize (approximately 80% to 90%), and the leading user categories are soup (15%), gravies (8.5%), salad dressings (7%) and sauces (7%).Granule ideas  In most cultures, plants or plant-derived ingredients (such as flour) have long been utilized as thickening agents. In plants, starch is a reserve carbohydrate, deposited as granules in the seeds, tubers or roots.  These starch granules differ in size and shape, depending on the plant source. Granules of rice starch are small (3 to 8 µm), polygonal in shape, and tend to aggregate, thereby forming clusters. Corn starch granules are slightly larger (approximately 15µm), and round to polygonal. Tapioca granules are even larger (approximately 20µm), with rounded shapes that are truncated at one end. Wheat starch tends to cluster in several size ranges: Normal granules are approximately 18µm; larger granules average about 24µm; and smaller granules average approximately 7 to 8µm, with round to elliptical shapes. Potato starches are oval and very large, averaging 30 to 50µm.  It is important to note these variations in granule size and shape, as they yield distinct differences not only in appearance, but in viscosity development, stability, mouthfeel and rate of gelatinization in products.  In general, starch is a carbohydrate polymer, consisting of anhydroglucose units linked together by (-D-(1 ® 4) glucosidic bonds. Starch is made up of two major types of polymers, known as amylose and amylopectin. Amylose is primarily linear, containing anywhere from 200 to 2,000 anhydroglucose units. Amylopectin is a branched polymer, also connected by (-D (1,4) glucosidic linkages, but with periodic branch points created by (-D-(1,6) glucosidic linkages. Amylopectin is typically much larger than amylose, with molecular weights in the millions.  Amylose and amylopectin contain an abundance of hydroxyl groups, creating a highly hydrophilic (or water-loving) polymer that readily absorbs moisture and disperses well in water. Because amylose is linear, it has a tendency to align itself in a parallel nature with other amylose chains, leading to precipitation (in dilute solutions) or retrogradation (in high solids or gels). On the plus side, it also can lead to the formation of strong films, which are extremely useful in certain food applications. The negative side is that amylose can detract from clearer food products by contributing opacity, and also tends to mask delicate flavors.  Because of its branching, amylopectin forms clearer gels -- often favored in the food industry -- that do not form strong films or gels. Retrogradation occurs less readily. In the native form, most starches contain 18% to 28% amylose, with the remainder as amylopectin. Corn and wheat starches contain approximately 28% amylose, while potato, tapioca and rice varieties are closer to 20%. Two genetic varieties of corn have become popular and well-accepted in the industry: "waxy" starch, which contains amylopectin with practically no amylose, and high-amylose starches. Of the high amylose, two varieties exist: approximately 55% amylose and approximately 70% amylose. Obviously, waxy starches develop weak gels with excellent clarity, and are poor film formers. On the other hand, high-amylose starches form very opaque, strong gels, and are excellent film formers. Their properties are very useful in breading, batter and confectionery applications.  As noted, native starch granules vary in shape, amylose content and size. They also vary in gelatinization temperature, which affects the final product. When a starch slurry is heated above this temperature, the hydrogen bonding within the granule weakens, water enters, and the granule begins to swell. This hydration disrupts the highly ordered crystallinity of the granule. Prior to the heating of the granule, this crystallinity can be noted under a polarized light microscope as "birefringence." This is a "Maltese-cross" type pattern that is lost as the granules reach maximum hydration. As heating continues, the granules rupture and collapse, and viscosity drops. For comparison, the approximate gelatinization temperatures (actually a range) of native starches are provided in the chart titled, "Starch Gelatinization Temperatures."  As might be expected, the chemical and physical differences of starch granules from different botanical sources result in a range of viscosity profiles, gel strengths and appearances. With the exception of starches used for specific purposes, such as rice starches or high-amylose starches, native starches are frequently limited in their food applications, due to: cohesive texture (waxy corn, tapioca, potato); heat and shear sensitivity; lack of clarity; opacity; and low viscosity (common corn, wheat). Retrogradation or precipitation can result on storage, posing additional problems.Made to order  While the functional effects of these native granules are quite useful in designing many foods, modern food science has placed more stringent requirements on this ingredient. Because of the number of hydroxyl groups available on the starch polymer, starches are, very fortunately, easily modified for a wide array of food-industry applications. As a result, starches have been made readily adaptable to consumer preferences and trends.  "Gravies and sauces prepared from scratch went to cans, to dry instants, to foodservice, to take-out, to ready-to-eat meal solutions," Fernandez says. "The use categories (of starch) have not changed dramatically in the last 10 years, but I believe the form and distribution of the standard categories has, and will, continue to change."  Native starch from any source is generally recognized as safe (GRAS). Modified food starch, however, is a food additive, and its limitations of modification and use are clearly defined in the Code of Federal Regulations (21CFR 172.892). Some of the most-used modifications are described below.  Acid modification. Thin-boiling starches are produced by treatment with a mild acid at temperatures lower than gelatinization. This cleaves glucosidic linkages, primarily in branched fractions, lowering viscosity. The lowered viscosity permits higher concentrations to be used, forming strong gels in gum candies. Dextrins are formed by acid hydrolysis of starch to cold-water solubility. Again, dextrins are used in high concentrations for forming clear films in pan-coated candies.  Bleaching. Bleached starch is produced through reaction with low-level concentrations of oxidizing agents (hydrogen peroxide, sodium hypochlorite, peracetic acid, ammonium persulfate, and calcium hypochlorite are permitted). This is commonly done to improve whiteness and/or reduce microbiological content.  Oxidation. Oxidized starch is produced through treatment with sodium hypochlorite. These starches improve adhesion in batters and breadings.  Esterification and etherification. Esterified starches, as well as etherified starches, are a mainstay of the food industry for various reasons. Starches are commonly cross-linked through esterification with phosphorus oxychloride or adipic anhydride to create more stable linkages. This has a number of effects on the performance of the starch -- it shortens the gel texture (eliminates the cohesive nature of a waxy corn starch), as well as acid, shear and heat stability. This reduces initial peak viscosity, and slightly delays gelatinization, but a more stable final viscosity is achieved. Starches also can be esterified with acetic anhydride or etherified with propylene oxide. These two modifications are usually part of a dual modification with a cross-linking agent. The acetyl groups or hydroxypropyl groups separate amylose chains within the granule. This inhibits retrogradation; improves freeze-thaw stability; improves the water-holding capacity; and lowers gelatinization temperature of the starch. Peak viscosity is slightly increased, and clarity of the gel is improved.  Other treatments for more minor applications, such as lipophilic starches, also are covered in the Code of Federal Regulations. These modifications have become very important and commonly accepted ingredients in the food industry.  "Modified continue to outpace unmodified in the processed food industry because of their ruggedness and ability to withstand severe process conditions," says Frances Turnak, manager, marketing services, North America, Cerestar USA, Hammond, IN. "The average real growth across the board for modified starches is somewhere between 3% to 4% a year on average. However, some categories have experienced over 8% growth, such as processed meats, where regulatory avenues have opened their increased addition."  Starch manufacturers are becoming more specialized in their approaches to customers -- hiring applications specialists trained in specific target fields, and directing innovation toward solution of specific problems, according to Meera Crain, project leader, Avebe America, Inc., Princeton, NJ.  Crain's viewpoint is shared by Gary Augustine, product manager, food ingredients, A.E. Staley Manufacturing Co., Decatur, IL. "Starches will continue to be used and evaluated as a problem-solving tool to improve the cost, quality and performance of food applications," he says. "Starch suppliers will be called upon more frequently to assist food developers in new product development, product improvements and cost reduction."  The future may see "an emphasis on new methods of using starch rather than the proliferation of derivatives," Fernandez predicts. That means a focus on physical processes or investigating possible synergistic relationships that alter the starch characteristics, rather than using chemical modification.  Cereal scientists Mohamed Obanni and James N. BeMiller emphasized this approach in their paper, "Properties of Some Starch Blends" (Cereal Chemistry 74 (4), 431-436). Using several established methods of observation -- differential scanning colorimetry, Brabender amylograph and light microscopy -- the authors observed the thermal, physical and viscosity profile characteristics of blends of several starches. These starches included common corn, waxy corn, 50% high-amylose corn, wheat, potato, tapioca, rice, and a dual-modified waxy corn.  Although the results are preliminary to any applications verification, they seem to indicate that blends of starches from multiple sources can possess some of the characteristics of chemically modified starches. The researchers suggest that some of this effect could be due to interaction between solubilized portions of one starch with granules of other starches. Another interesting note was that blends, with the exception of a wheat/tapioca combination, exhibited very little retrogradation (these blends were stored at 4°C for two weeks). A subsequent paper by the same authors and Mark R. Jacobson (Cereal Chemistry 74 (5), 511 - 518) notes that retrogradation rates in native starches follow the order of "wheat, common corn > rice, tapioca, potato >> waxy maize."New and improved  Several starch-industry insiders believe the industry's future lies in working very closely with customers to identify specific needs, then tailoring products to fit their partners' needs. These needs might be met by inducing physical, genetic or chemical changes.  Several examples of this type of product already have reached the market in recent years. According to Neil Grimwood, director of marketing and technical services, National Starch and Chemical Co., Bridgewater, NJ, they include: a range of cold-water-swelling starches possessing all the properties of cook-up starches; specific fat replacers for various applications; resistant starches that analyze as a fiber; and native starches that have many of the functions of modified starches, but with a label advantage.  Corn starches continue to lead the industry, and many of the newer starches fall into this category. The new products are a mix: some chemical changes, with new ideas on functionality; physical manipulation to mimic chemical changes; new genetic varieties; and, in some new offerings, a combination of these methods.  Similar to the specialty oils industry, biotechnology is viewed as the new hope for the future -- a way to improve yields and processing, plant disease resistance, and starch functionality. As an example, National Starch and Chemical Co. has announced it has entered into an agreement with DeKalb Genetics Corporation, DeKalb, IL, to develop new maize hybrids with improved starch functionality and to improve the agronomics of existing hybrids.  Within the past year, National Starch has introduced a class of native starches produced with a proprietary process to provide the shear, pH, and heat tolerance of dual-modified starches. Plus, they possess a distinct labeling advantage: They may be labeled as "starch" rather than "modified food starch." An added benefit, according to Grimwood, is that "independent tests show that Novation™ native starches have a favorable impact on flavor release and textural properties in several food systems." The current product line contains two waxy maize cook-up starches with low to high stability, as well as a stable tapioca-based native starch.  The company also has been focusing on resistant starches recently. Resistant starches are starches and products of starch degradation that resist enzymatic digestion and act like dietary fiber, to some extent. They are classified into several different types. RS1 starch is the physically inaccessible starch commonly found in coarsely ground or chewed cereals, grains and legumes. RS2, which may be labeled as "starch" on an ingredient legend, comprises the naturally resistant granules found in bananas, high-amylose starch and raw potato. RS3 starches are generated by retrograding starch during food processing. In the United States and Canada, these are identified as "maltodextrin" on the ingredient label; in Europe, they may be labeled "starch."  In recent years, Opta Food Ingredients, Bedford, MA, developed and patented a process for producing an RS3 starch (marketed as Crystalean™) while independently, National Starch introduced another (Novelose® 330). These contain about 30% total dietary fiber (TDF), are white in color, neutral in flavor, and contain less than 1% fat.  The first commercially available RS2 starch, HiMaize™, developed by Starch Australasia Ltd. and marketed through Del-Val Food Ingredients, Bensalem, PA, won the 1995 Australia Institute of Food Science and Technology (IFST) Industry Innovation Award. It contains approximately 20% to 25% TDF. Recently, National Starch introduced an RS2 starch with a minimum of 40% TDF. The caloric density is about 2.3 to 2.4 kcal/g, and the particle size is about 15µm. "Characteristics include white color; bland, nonsweet taste; small particle size; partial solubility; non-hydrating profile for improved processing; and minuscule fat percentage for healthy labeling," Grimwood says.  A new class of starches, termed "granular" and designed by Staley, is instantized without gelatinization by means of a novel manufacturing process to physically disrupt internal granular structure. This developed into a range of products separated into several functionality groups: gelling, thickening, easy-dispersing, and low pasting temperature. According to Augustine, Staley's Mira-Sperse series of instant agglomerated starches "provide excellent dispersion, sheen and texture in varying viscosity ranges...applications include various dry mixes, gravies, and sauces." The company's Lo-Temp family of starches is designed for low temperature processing and provides a slower hydration rate than traditional cook-up starches. Augustine recommends their use in applications such as microwavable and institutional foods where lower amounts of heat are available for viscosity development.  Physical modification has become a popular approach to simplifying the label, while offering new functionality. "We have been developing physically modified and traditionally modified starches with emphasis on broad applicability, ease of use and cleanup, low flavor/taste contribution, and performance equal to, or better than, traditional derivatives," Fernandez says. These starches include a range of hot- and cold-water-dispersible starches and maltodextrins that have been physically modified to meet certain needs that the company markets under the Snowflake™ name.  Corn Products is focusing on physical modification of starches. New offerings include a special physically modified texturizing starch, as well as a "clean" maltodextrin for flavor-sensitive systems. Also available is a maltodextrin containing no saccharides below DP4, which features no sweetness, little browning, low hygroscopicity, and very little haze.  During the last several years, fat replacement has gained much attention. Recent activity has spawned two potato-based enzymatically converted products from Avebe America, Inc., Princeton, NJ: Paselli® SA-2, and the more recent, cleaner flavor version, Paselli Excel. Due to the degree of hydrolysis required to thin these products, these are labeled as "maltodextrins." The much blander-flavored version is designed to work well with delicate flavors. Gels produced from this product are composed of microparticles 1 to 2 µm in size, and are smooth and creamy. A minimum concentration of 18% is required to form a gel. The dextrose equivalent (DE) of this product is less than 3, and it is recommended for use in frozen desserts, soups, sauces, dressings and dips, dairy foods, and bakery products.  Avebe also recently added an improved taste version of their 6 DE hydrolyzed potato starch, Paselli D-Lite. This is especially recommended for taste-sensitive dairy applications, such as no-fat vanilla ice cream, dairy desserts, dairy beverages, or reduced-fat salad dressings.  National Starch designed a series specifically for fat-replacement systems, tagged N-Lite™, that is labeled as "food starch-modified." One version is recommended specifically for liquid food systems, such as spoonable salad dressings, soups and microwavable cheese sauces, where it provides lubricity without gelling. A pregelatinized version, LP, is specific for cold-process liquid applications. These are part of a series of starches designed to target specific application areas, since different categories require different fat-replacement systems.  Another product designed to function in fat replacement systems, is Staley's Instant Stellar®, a modified corn starch that has been acid-hydrolyzed to produce a loose association of crystallites. Xanthan gum is added to aid dispersion and hydration of these crystallites. When hydrated, it produces a short, thick, fat-like creme, stable from 0° to 70°C. A "particle gel" network effectively immobilizes water in the formulation, creating rheological traits similar to shortening. The product is recommended for baked goods, frostings and fillings, dairy products, salad dressings, cheese products, table spreads, meat products, confections, and frozen dairy desserts.  Many of the new starch products introduced during the last couple of years have been produced in response to specific application needs. Crain believes that in the future there will be "more recognition of starch as a functional ingredient that can replace other ingredients, providing cheaper alternatives or as replacements to price-volatile ingredients." Heavy areas of focus for applications include meats, dairy, confections and snacks.  In addition to their corn-based products, several manufacturers have tapioca starches as part of their product mix, and tapioca and waxy corn are frequently featured as part of the same class or series of product. Tapioca, potato and rice starches have been recognized to provide flavor advantages over corn, and these crops, plus wheat, are recognized as offering allergenicity advantages due to their low protein levels.  "There has been an increase in tapioca starch use, especially the modified tapioca," Turnak says. "They are particularly appreciated in the dairy industry, where the light flavor note is frequently required."  Within the processed meats industry, modified corn, wheat and potato starches compete with proteins as water-binders in low-fat meat applications. Using starches as water binders in a fat-replacement system maintains consistent moisture, flavor and texture throughout product shelf life. Within the confectionery industry, work with potato starch has been focused toward replacement of gelatin, due to volatile pricing and kosher issues, Crain notes. It also has been used as a gelatin modifier to decrease the firmness of the gel, and increase heat stability.  Several starches or starch lines have been created for specific applications in the confectionery industry. Those in the starch industry have long been aware that gum arabic varies from season to season in quality and availability, causing price volatility. Gum arabic has been used as a pre-coating of sugar-free gum, and as an undercoating in panned candies.  Cerestar recently introduced C(AraTex 7501 as a gum arabic replacement in the sugar-free gum application. This acid-thinned hydroxypropylated tapioca starch "considerably lowers coating time, since the viscosity of this starch is low even at 50% of the total layer amount vs. a maximum 40% concentration for gum arabic," says Eric Shinsato, food scientist at Cerestar. "This results in less layers required, resulting in lower coating time."  Common corn-based modified food starches (Pure-Cote®) have been designed by scientists at Grain Processing Corporation, Muscatine, IA, that act as an undercoat in panned candies or as a surface shine on chocolate. "Preparations of 15% to 25% in water are required, cooked at 180°F for 10 minutes, then cooled," says Mike Kramer, food technologist at Grain Processing Corporation. "Maltodextrin, sugar, and possibly corn syrups, are added to increase solids and facilitate drying."  Gum arabic has also been used, as have other gums, to adhere seasonings and flavorings to the surface of cereal-based snack foods. Demand for nonfat adhesives has increased in the low-fat market, since they must replace the fats and oils traditionally used. To fill this need, National Starch introduced a product that is derived from waxy corn starch, and intended as an adhesive for cereal-based snack foods, N-Tack®. At 30% solids, it exhibits a significantly higher tensile strength than other adhesives. It can be sprayed on at 30% to 40% solids, and it develops a tacky texture and dries very quickly.What about wheat?  Although modified wheat starches have been well-known in Europe for many years, American designers have only used them within the last 10 years. In the United States, this technology has been largely confined to the bakery and pasta industries. This is largely due to the compatibility of wheat starch with wheat flour, as well as to promote consistency on the ingredient legend.  Wheat starch is best known for its texturizing and tenderizing capabilities in baked products, such as angel food, doughnuts and pie crusts, but its markets are expanding. To take advantage of the functionalities of wheat starch, Midwest Grain Products, Inc., Atchison, KS, has launched a full line of wheat starches, including cook-up, modified cook-ups, pregelatinized and modified pregelatinized, developed for use in batter mixes, breadings, cereals and snack products.  "Wheat starch is uniquely bright white in color, is low in protein (less than 0.2%), ash (less than 0.2%) and total dietary fiber (less than 0.5%), and contains no residual phosphates," explains Ody Maningat, Ph.D., corporate director, research and development and quality control, Midwest Grain Products. "It often has a more bland flavor compared to other cereal starches, because of its lipid composition. It contains around 1% lipids, which occur mainly as lysophospholipids and predominately mixed with amylose in the granules.  "Compared to corn starch, wheat starch shows a less viscous paste in a Brabender amylograph because of the lower swelling power, lower molecular weight of amylopectin, and higher phospholipid content," Maningat says. "However, wheat starch paste exhibits a dependence on heating rate where at high heating rate, it could match or even exceed the viscosity of corn (common) starch. Wheat starch paste consistently showed higher clarity than corn (common) starch paste as indicated by percent transmittance at a wavelength of 650 nm."  Other advantages include the "melt-in-your-mouth" sensation of a wheat starch paste, with quick release from the palate, Maningat says. This contributes to a more intense flavor in fruit fillings. At concentrations greater than 6%, wheat starch produces stronger gels than corn starch, due to its higher percentage of linear amylose.  What comes next in this developing area? Researchers at the National Agricultural Research Center in Tsukuba, Japan, recently developed several waxy wheat starch mutants through cross-breeding with 99+% amylopectin. Preliminary studies have shown that waxy wheat starch exhibits lower pasting temperatures, higher peak viscosity, and higher breakdown viscosity, compared to nonwaxy wheat starches. Maningat also noted that fractionated small-granule wheat could well be a new product of the future. Its utility lies in its lower amylose content, which gives it some fat-like creaminess in a gel, along with its small size (approximately 3µm), which gives it additional fat-like mouthfeel.Other sources  Potato starch is unique in that the native starch has a lower gelatinization temperature than other starches, as well as a much higher peak viscosity and less resistance to breakdown over prolonged heating. Pastes are extremely clear, with little tendency to retrograde. Modification by cross-linking and substitution produces similarly unique products with applications in several categories; considerable application effort has placed it in a fat-reduction role in processed meats, tortillas, french fries, dairy products and baked products. Recently, Avebe introduced an amylopectin potato starch. Scientists at Avebe inactivated the gene responsible for synthesis of amylose, resulting in a 100% amylopectin potato starch. This product is only available in Europe.  Various modified tapioca starches were presented by Amylum Industrial LTDA, Sao Paulo, Brazil, at the 1997 IFT meeting. These are marketed in the United States through Mitsui & Co., New York, NY. These include a full range of chemically modified tapiocas for many applications, including processed meats, puddings, sauces and baked products, according to Brendan Naulty, director, food additives, specialty chemical department, Mitsui & Co. Included are enzymatically converted tapiocas for fat replacement (3 DE and 5 to 7 DE products), as well as a fermented tapioca starch, termed "sour" starch, used for flavoring and functional purposes in sour starch biscuits and cheese buns. Sour starch contributes unique flavor and texture.  Economic barriers have limited the use of rice starch in the United States. The very fine granule size (2 to 8µm) of rice starch, along with its clean taste and low allergenicity, have found niches in fat replacement, confectionery, baby foods and food specialties. Waxy rice starch, with 98+% amylopectin, is known for its creamy gel texture and natural heat and freeze-thaw resistance. Products distributed commercially in this country by several different companies include rice starch and waxy rice starch. Some are chemically modified and others may use physical processes to change their characteristics while maintaining natural labels.On the horizon  What new advances lie ahead for the starch industry? New areas have been opened up with the advent of physically modified starches and continued research into the value of new varieties. "There are new advances in the performance and evaluation of starches, such as the rapid visco analyzer in the evaluation of starch viscosities over a number of processing variables," Augustine says, "as well as new developments in measuring and understanding the rheological and textural properties of starches."  Will some of these advances lead to changes in the Code of Federal Regulations? Some changes have been made to accommodate new starches over the last several years, and several industry insiders believe other changes are possible. Maningat anticipates possible changes to accommodate modified starches produced by enzyme treatment (such as the branching enzymes pullulanase and isoamylose). The other dual-modified starches, such as oxidized and esterified, may become permissible under the new regulations, Crain says. Others believe that the market will grow with the existing modifications, coupled with physical modification.  The challenges directed toward the starch industry will be to fill the needs of changing world markets, and to meet new consumer product needs. The starch industry must "decrease product development time for quicker market introduction, develop starches with functionalities to address new health issues, and increase new starch types to yield products with varying functionalities," says Keval Bassi, territory manager, marketing and technical sales, wheat starch, Midwest Grain Products.  As with other ingredient categories, physical modifications, biotechnology, intelligent use of native sources, and applications-targeted modifications are rapidly changing the resources available for product development. Resources must change to meet the needs of a global market, and global communication will open new doors for the U.S. market.  "Global market issues will be a major dynamic as we go forward, especially with the variances in raw material base costs around the world," Fernandez says. "Developing global market needs and exports vs. local capital investment decisions will be critical to market success in the upcoming years." Starch Gelatinization Temperatures Source Approximate Gelatinization
Temperature (°C) Common Corn 65 to 73 Waxy Corn 65 to 69 55% High Amylose 84 70% High Amylose 93 Wheat 58 to 64 Tapioca 59 to 65 Potato 57 to 65 Back to top