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Pet Food Info (Menu Foods, Iams, Purina, Hills, Ol'Roy, etc.) => Pet Food Questions and Researching Foods/Ingredients => Topic started by: TBOBINA on March 04, 2009, 10:20:54 AM

Title: Tapioca in pet food?
Post by: TBOBINA on March 04, 2009, 10:20:54 AM
Here is an article about Tapioca in pet food, I still do not believe that any starch is good for our felines, all it is, is a binder for dry kibble. Sorry its long.

Tapioca: Dispelling the Fallacies
By Laura Duclos, PhD

Tapioca and Cassava are NOT the Same
Tapioca is a source of carbohydrate obtained from the roots of the cassava plant (Manihot esculenta), which is indigenous to Latin America. Cassava is not a cereal grain like corn or wheat; cassava is a tuber, an enlarged root of the plant. Moreover, tapioca is not cassava – tapioca is a food ingredient produced from cassava.
Starch makes up the nutritive reserves of many plants. During the growing season, the green leaves collect solar energy and convert it into food energy, the process of photosynthesis. In plants with tuberous roots, the food energy is transported as a sugar solution down to the tubers. It is at the tubers that the sugar is converted to starch in the form of tiny granules occupying most of the cell’s interior. A typical composition of raw cassava root is 24% starch (can be as high as 30%), 70% moisture, 2% fiber, 1% protein and 3% other components. (International Starch Institute;
Cassava has been grown and processed for food in tropical areas of the Americas for over 4,000 years. European traders brought it to the old world where it is now grown and cultivated in many tropical and sub-tropical regions (Howeler, Thai Tapioca Trade Association).
Cassava is valued for its hardiness, namely the ability to withstand drought and animal damage. In many countries (e.g. Thailand, China, India, parts of Africa), it is a primary cash crop and principal source of dietary carbohydrates (food energy). In fact, humans have learned how to utilize and process every part of the cassava plant so toxicity is reduced and no part is wasted. For example, cassava leaves, rich in anti-oxidants and protein, are ensiled and fed to cattle while the fibrous layers of the tubers are used as binding agents for industrial products (
Starch flour, chips and pellets, peels and pulp, and fresh roots are all possible products obtained from the cassava plant. Cassava starch, commonly known as tapioca, can be consumed directly in the form of unmodified tapioca or further processed into modified starches, sweeteners (sorbitol, glucose), alcohol (ethanol), organic acids (citric acid), biodegradable plastics, and amino acid derivatives (lysine, monosodium glutamate).
Modified tapioca starches are common ingredients in human food, specifically gravies, sauces, and baby food. Chips and pellets are non-powdered forms of unmodified tapioca and used mainly for animal or human food. Conversely, low-grade peels and pulp are used for livestock (cattle) and compost (mushroom farming). Direct consumption of the tubers is rare and often follows only after boiling and roasting (Howeler, Thai Tapioca Trade Association).

Cassava and Cyanogenic compounds
The extreme hardiness of cassava is due in large part to its unusual botanical characteristics. Cassava can produce viable seeds without the need for pollen fertilization, a process called apomixis. In times of drought or in extreme habitats, this is a highly desirable trait for any cultivated crop. Additionally, most plants are preyed upon by animal and insect herbivores. Damage inflicted by herbivores can be substantial, potentially killing the plant. Over time, plants with traits that enable them to adapt and survive despite herbivore predators have prospered.
Some plants have developed mechanical defense mechanisms such as thorns, while other plants have developed chemical defense mechanism such as toxins. Cassava has developed such a chemical defense – it produces a cyanogenic glycoside called linamarin and small amounts of lotaustralin. These natural compounds are located predominately in the plant leaves (Sayer, 2003) with lower amounts located in the tuber‘s skin and extreme outer layer of flesh. Glycosides impart an extremely bitter and displeasing taste – an excellent insect and animal repellent.
This characteristic has led some to suggest that the tapioca derived from cassava that is used in commercial food production, including pet food, risks poisoning the animal. All the cyanogenic glycosides are removed in the process of deriving tapioca starch from cassava roots, which is described more fully below. Before reviewing that detail, however, it is worthwhile to complete the discussion of cyanogenic compounds in cassava and other commonly-used food plants.
Linamarin production is highly influenced by plant genetics and physiology, as well as location, and environmental conditions. Cassava produces more linamarin in specific cultivars (“bitter” varieties) and in times of drought. Interestingly, other crop plants commonly used in pet and human food applications, such as corn, sorghum, lima bean, flax, apple, peach, and elderberry, also possess the ability to manufacture their own cyanogenic glycosides (Butler and Conn, 1964; Seigler,1976;
When raw cassava tubers are ingested, linamarin is enzymatically hydrolyzed into glucose and gaseous hydrogen cyanide (HCN), also called prussic acid. Hydrogen cyanide (HCN) is blood-soluble and readily absorbed into the body. Acute HCN poisoning occurs rapidly and often ends in death. Chronic HCN poisoning, while no less dangerous, has a slower onset and less dramatic effects, usually limb paralysis and neuropathies (Diasolua Ngudi et al, 2002; Merck Manual, 1998; Culcea; Leybell).
Once in the body, HCN enters the cells of any tissue and irreversibly binds to metalloenzymes, primarily cytochrome oxidase, preventing the enzyme from functioning and forcing the cell to switch from aerobic respiration to anaerobic respiration, a less efficient method of producing ATP necessary for cell metabolism (see below). The oxidative phosphorylation chain is uncoupled, lactic acid builds up, and the cell eventually dies. Tissues that use a lot of oxygen are the first ones affected by cyanide poisoning, namely the heart and brain.
The body is a unique machine -- it is capable of detoxifying itself within limits by metabolizing HCN into thiocyanate. This new compound, facilitated by the action of another enzyme called rhodanase, is produced by adding sulfur groups from specific amino acids onto the cyanide molecule. Thus, while cassava and many other plants are deficient in amino acids, a properly balanced diet with sufficient protein allows the body to reduce or eliminate the toxicity of low levels of cyanogenic compounds (Oke, 1998)
Raw cassava used as the sole source of food energy is inherently protein deficient – such a diet must be combined and balanced with animal or plant protein for the body to function properly. Diets high in animal protein, however, supply ample amino acids to manufacture rhodanese, the enzyme that detoxifies cyanogens into thiocyanate. Pet foods made from animal, poultry and fish proteins are rich in amino acids. Moreover, those that claim complete and balanced must meet the AAFCO nutrient requirements for amino acids. Some studies suggest that protein malnutrition may be the true cause of cyanogen toxicity because the body cannot manufacture rhodanese (Padmaja, 1996). Because all enzymes are proteins, they require amino acids as raw building materials. A diet low in protein does not supply the body with adequate levels of amino acids critical for enzyme synthesis. Thus, the body will eventually run out of rhodanese.
Cyanogenic compounds are removed in processing cassava into tapioca starch
Tapioca does not contain cyanogens and does not cause cyanide poisoning. There is some consumer confusion over this because not all cassava products are cyanogen and micro-organism free. Native preparations, namely gari and fufu may contain these harmful by-products. Yet, it must be emphasized that these cassava products are not tapioca – they are processed entirely different from the way tapioca is processed. Processing cassava into tapioca removes virtually all cyanogenic compounds. (Obadina et al, 2007; Diasolua Ngudi et al, 2002; Food Safety Network).
Nearly every aspect of large-scale tapioca starch extraction is an exercise in successive separation of liquids and solids. To make tapioca, cassava tubers are peeled to remove the outer cyanogen-rich layers and washed thoroughly to remove dirt and other impurities. The remaining cassava root flesh is grated or chipped in a process called rasping. The goal is to rupture the tuber cells, so that all the starch granules are released. The slurry obtained can be considered as a mixture of pulp (cell walls), fruit juice, and starch.
Within each plant cell is an endogenous enzyme called linamarase, the enzyme responsible for converting cyanogens into hydrogen cyanide. Rasping ruptures the cells, releasing linamarase, which in turn converts cyanogens. Hydrogen cyanide is a water-soluble, volatile compound; it dissolves in the soaking water and quickly evaporates off before the starch is dried. Any remaining cyanogenic glucosides also are flushed away by the water.
If cassava is boiled or roasted before the starch is extracted, linamarase is destroyed and the final cassava product, such as gari, may contain toxic cyanogens. Thus, in poor nations that rely on cassava as a staple food crop, processing cassava for their own food consumption (gari, fufu, boiled tubers) often insufficiently removes cyanogens and is the leading cause of chronic cyanide poisoning or micro-organism contamination (Mahidol, 1997; Sayer, 2003). This contrasts markedly with commercial production, a process which is very effective at removing cyanogens.
In commercial production, the starch from rasped tubers is flushed out through fine sieves, leaving the pulp and fiber behind. The starch is then non-chemically refined through successive dilution and concentration steps, analogous to rinsing soapy laundry in clean water and squeezing out the water until the water runs clear. This is usually done in a series of hydrocyclones (water vortex) that utilize the differing densities of starch, fiber and water to accomplish the successive refinement of the starch product. Finally, the starch slurry is dewatered in a centrifuge as much as possible and dried with heat.
Tapioca purchased for human and pet food in the United States is processed completely and is of high quality. It is neither sun baked nor heap fermented like native preparations. Each lot of commercially prepared tapioca purchased by Nature’s Variety is guaranteed to be free of cyanide and micro-organisms.
Tapioca starch and sugars
Tapioca starch is a rich source of carbohydrates. Carbohydrates can be thought of as a chain of sugar molecules linked together by chemical bonds. Simple carbohydrates are called disaccharides (2 sugar units) and complex carbohydrates, or starch, are called polysaccharides (many sugar units). Digestion breaks these chemical bonds so that even complex carbohydrates are eventually converted to simple sugar (monosaccharide, C6H12O6) in the body.
Mammalian cellular respiration (energy making process) relies primarily on carbohydrates. Ingested food is catabolized to glucose (C6H12O6) and “burned” during cellular respiration. Essentially, the chemical energy stored in glucose molecules is extracted into a useable form called ATP (adenosine triphosphate).
C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy (ATP)
ATP is then available to power work such as movement. Moreover, ATP fuels the body’s anabolic activities such as enzyme production, wound repair, growth, and muscle building. If carbohydrates are unavailable, the body has temporary alternative pathways that can convert fats and proteins into ATP. In humans, exercise and muscle movement relies on carbohydrates, with fat and protein pathways typically less desirable. However, canine and feline muscle fibers are unique and can effectively utilize fat and protein to provide ATP (NRC, 2006 ). Thus, low carbohydrate, high protein diets are ideal for sporting and athletic canines while whole grain and meat diets are ideal for the “traditional family pet.” Yet, not all starches are equally digestible.
Starches, by chemical definition, are made up of the polysaccharides amylose and amlylopectin. Those with high levels of amylose are not as easily digested by the small intestine as those that are primarily amylopectin. Tapioca starch is an amylopectin starch; tapioca is more digestible than corn, wheat, or potato. About 99% of tapioca starch granules are completely digested by the small intestine compared to potato (33%), corn (96%), and wheat (94%) (Weurding et al, 2001). Undigested carbohydrate fractions simply pass into the colon to be fermented by bacteria, an inefficient form of energy production compared to intestinal digestion (Wills and Simpson, 1994).
Among various plant species, the carbohydrate content and biochemical profile will vary (Table 1). Contrary to some authors, the sugar content of tapioca is not comparable to that of sugar cane. Sugar cane is nearly 100% free-sugar (USDA database). The notion that tapioca contributes to diabetes and hypoinsulinoma is unfounded. In fact, when rats were fed tapioca starch there was no evidence of diabetes or pancreatic pathology (Mathangi et al, 2000).

Table 1. Sugar Content of Common Pet Food Carbohydrates (USDA Database)
Plant Carbohydrate % Sugar %
Tapioca 88 3.3
Potato 83 3.5
Corn 77 0.6
Wheat 73 0.4
Brown Rice 77 0.9
Millet 80 0.6
Barley 78 0.8
Oatmeal 69 1.5

Tapioca’s benefits as a pet food ingredient
The benefit to using tapioca in a pet food as the primary carbohydrate source instead of grains is tapioca’s biochemical simplicity. Grains are complex in the sense that they contain proteins and other phytonutrients in addition to carbohydrates. Tapioca is just starch – a combination of amylase and amlylopectin. For animals with allergies, biochemically complex food sources are a potential risk. Food intolerance and food allergies are generally triggered by exposure to proteins in the diet with repeated exposure likely leading to severe hypersensitivity. Dogs and cats that have food allergies or intolerance find relief from bland or simple diets. Tapioca is an ideal carbohydrate source for allergy sufferers because tapioca is virtually devoid of protein and will not cause immune-mediated reactions like those observed in animals fed grain-based diets (NRC, 2006).
There are no known canine or feline allergies to tapioca. The only known reaction to tapioca was documented in a woman with extreme anaphylaxis to latex. Apparently, the body mistakenly identified tapioca for latex, causing a cross-reaction (Gaspar, 2003). This is a rare occurrence and still not completely understood. Many scientific studies investigating food allergy triggers in humans and animals commonly use tapioca as the control diet because there are no allergies to tapioca (NRC, 2006).
Grain-free diets that include tapioca, such as Nature’s Variety Instinct, do not intend tapioca to supply protein or any nutrients other than carbohydrates. Protein is supplied by animal meats and organs. Carbohydrates are supplied by tapioca. Vitamins and minerals are provided by other ingredients and supplemented by direct addition. Some brands that include grains are utilizing them to boost protein content using less-expensive plant proteins, especially in the form of protein concentrates such as wheat gluten, corn gluten meal, soy protein concentrate and rice protein concentrate.

Table 2. Carbohydrate Content of Kibble
Brand Approx. Carbohydrate (by subtraction)
Natures Variety, Instinct 15-18%

For canines and felines, grains are not an ideal protein source, they function as carbohydrates. Like all plants, grains are deficient in certain amino acids, generally methionine and lysine. Formulations relying on grains to provide some portion of dietary protein in addition to dietary carbohydrates must supplement missing amino acids. However, formulations that rely primarily on meat, poultry or fish proteins to provide dietary protein need not supplement the diets – with the exception of a feline’s unique need for taurine, all amino acids are naturally present in animal based meat.
Additionally, the claim that tapioca-based diets deplete the body of amino acids is also false and misleading. This statement assumes that the animal would be eating nothing but tapioca – no meats, no fruits, no vegetables. Nature’s Variety does not manufacture or sell a diet made solely of tapioca. The major components in our grain-free formulations are meat, poultry, fish proteins and organ meats. Likewise, our formulations do not use cassava, they use unmodified, high quality tapioca.
Further, unmodified tapioca does not contain anti-nutritive factors. The statement that tapioca inhibits zinc and iron absorption is a misinterpretation of a scientific article published by Kashida et al (2000). In this research, nutrient mal-absorption was observed with hydroxypropyl-distarch phosphate (HDP), a sub-fraction of cassava isolated from chemically modified tapioca. Unmodified tapioca starch was used as the control in this study. There were no anti-nutritive effects observed with tapioca, only with HDP.
Tapioca used in pet foods is typically unmodified. Modification by chemical or mechanical means is often employed in the human food industry to make functional ingredients that impart unique aspects to a product, such as thickness or texture. These tapioca fractions are costly and bear no resemblance to unmodified tapioca. Nature’s Variety does not use modified tapioca starch. Our starch is sourced from commercial supplies manufactured by reputable vendors. Each lot comes with a Certificate of Analysis, verifying that the product is safe and free of known micro-organisms and other contaminates. We have tested our products for cyanide -- no cyanide was detected because there are no cyanogens in our tapioca starch. We are confident that our grain-free products are safe, wholesome, and nutritious. Instinct provides owners with an expanded selection of high meat diets for their pets, particularly pets allergic to grains or working animals
Title: Re: Tapioca in pet food?
Post by: 3catkidneyfailure on March 04, 2009, 05:54:05 PM
So non-commercially processed tapioca can cause cyanide poisoning in people. And
it's being substituted in pet food to prevent non-lethal allergies. Interesting article
for sure.