Common Gums in Pet Food

What are gums?

Gums are a type of hydrocolloid (non-starchy hydrophilic carbohydrates) that play a pivotal role in preventing separation in the manufacturing process and are common ingredients included in wet pet foods, such as canned food, broths, and gravy toppers. Gums are primarily used for their textural functionality, with their ability to bind water to improve the appearance and texture of the product.² Notably, gums can improve mouthfeel/juiciness and can aid in the easy-use application, such as pouring or spreading the product. In human food, they are common ingredients that might be found in salad dressings, ice cream, and baked goods, just to name a few. Commonly used gums include agar agar, carrageenan, cassia, guar, and carob. The decision for selecting which gum to use is based on its functional properties. An example would be that wet/canned pet food, such as pates/loafs or stews, need a gum that provides upfront viscosity for filling, such as guar gum; and examples of gum(s) needed for post-retort bind and texture are cassia and/or carrageenan. Among the frequently used gums are agar agar, carrageenan, cassia, guar, and carob; chosen based on their specific functional properties.

In considering the health implications of these hydrocolloids, their functionality extends beyond texture and appearance to positively impact pet food with liquid content. The soluble fiber nature of these polysaccharides allows them to serve as functional dietary supplements, facilitating water absorption in the gastrointestinal tract and aiding in bowel movements.³ Given the fermentable prebiotic nature of these fibers, it is advisable to consult with a veterinarian or nutritionist before transitioning to a new pet food format to ensure compatibility.

What is “wet” pet food?

“Wet” pet food, also known as canned food, refers to a blend of ingredients like meats and vegetables, occasionally necessitating emulsion with a starch source that undergoes a cooking process. The processing involved a retort step for cooking, sterilization, and ensuring shelf-life stability. Canned pet foods inherently face challenges of ingredient separation, risking uneven distribution and compromised nutritional balance. To mitigate such risks, a crucial component is a thickening and binding agent, and here, gums prove indispensable. Beyond cans, various wet product formats, including pouches, cups, tubs, sachets, tetras, refrigerated chubs, and fresh/frozen meals, leverage gums for their unique functional properties tailored to each product form.

Noteworthy is the resilience of gums, particularly in comparison to ingredients like tapioca and/or potato starch, regarding resistance to amylase found in uncooked meats or vegetables. Real-world manufacturing scenarios highlight instances where a shift from starch-based gravies to gum-based alternatives resolved post-retort viscosity challenges arising from amylase activity. 

Commonly Used Gums

Agar agar

Agar agar stands out for its versatility, offering both upfront and post-retort viscosity, binding properties, and texture enhancement. Additionally, it serves as a stabilizer in pet food, ensuring consistency and preventing ingredient separation in canned or semi-moist varieties.^4,5 Beyond its functional attributes, agar agar, derived from red algae,¹ is a common food additive with applications in both human and pet food, lending itself to vegan and vegetarian formulations.¹  Additionally, agar agar provides satiety or a sense of fullness; it has also been used to help with an upset stomach.⁵

Carrageenan

Positioned as the fourth-largest hydrocolloid, carrageenan functions as an emulsifier stabilizer, and thickener.⁶ Its applications extend to preventing fat separation in canned pet and human foods, including salad dressings. Carrageenan is extracted by a process that uses a chemical solvent to extract the gum from seaweed.^5,6 Various species of seaweed are collected and washed, dried, and macerated in a hot alkaline solution isolating the polysaccharide portion of the plant. This process can leave behind residue that has been suggested to upset the gastrointestinal tract. Despite concerns about residues from the extraction process, carrageenan retains its General Recognized as Safe (GRAS) status, supported by long-term studies across various species, no credible evidence has been found to support any carcinogenic effect in food-grade carrageenan.^6,7

Cassia

Cassia gum, derived from the seeds of Senna obtusifolia and Sena tora, serves as a thickening agent, enhancing texture, appearance, and stabilization through gelling.⁸ Its compatibility with other gums, such as carrageenan and xanthan, stems from its unique branched chain polysaccharide structure. Cassia gum also has great stability in the retorting process, which makes it a sought-after thickening agent in canned pet food. Safety considerations emphasize the use of purified semi-refined cassia gum;^9,10 particularly, in feline and canine diets. Due to the higher viscosity of refined/purified cassia gum, small quantities can be used to achieve gel strength.

Guar

Guar gum, a soluble fiber extracted from guar plant seeds, finds widespread use as a thickening agent. The guar seed is harvested, and the husk and seed germ are removed from the endosperm portion, which is then mechanically ground into a powder known as guar gum.¹¹ Guar gum can reach maximum viscosity at higher temperatures, which are experienced in the retorting of canned pet food.¹¹  In addition to guar gum being used as a thickener, it is also used as a dietary supplement due to its soluble fiber content. Soluble fiber is good at absorbing water, whether this is added to the texture of foods or dietary fiber source for regulating bowel movements. Guar gum also can help with health problems such as diabetes and heart disease.¹² While acknowledged for its efficacy as an emulsifier, thickener, and stabilizer in canned pet food, it carries a dual identity in industrial applications related to oil drilling and mining. Concerns about potential gastrointestinal upset have contributed to its mixed reputation.

Locust bean

Also known as carob gum, locust bean gum shares structural similarities with guar gum, primarily composed of galactomannan.¹² The seeds are separated from the pods in a process called ‘kibbling’ using chemical peeling with acid and heat or mechanical peeling using heat and mechanical abrasion. These processes facilitate the next step, where the germ is separated from the endosperm, which is then further ground and graded.¹³ Its role as a soluble fiber thickener, particularly in gravies when combined with other gelling agents, stems from its high soluble fiber content. Typically used in modest quantities, it contributes to achieving the desired texture.

In conclusion, the incorporation of hydrocolloids (gums) into pet food represents a significant advancement in the formulation of nutritionally balanced and palatable diets for pets. These natural, water-absorbing ingredients offer numerous benefits such as enhanced moisture retention, improved texture, and increased shelf life. As the pet food industry continues to evolve, the inclusion of gums reflects a commitment to innovation and improvement of the quality and diversity of pet nutrition, ensuring that our beloved pets receive optimal nourishment for a happy and healthy life.

References

1. Dainton AN, Aldrich CG. 2020. The effects of guar gum and other select gums and gelling carbohydrates on appearance, texture, and heating characteristics of wet pet foods. JAS. 98(Suppl 4):57–8. doi: 10.1093/jas/skaa278.104. PMCID: PMC7702389.
2. What is agar agar? https://www.taste.com.au/healthy/articles/how-to-use-agar-agar/7bimvjai
3. Pegg, AM. 2012. The application of natural hydrocolloids to foods and beverages. Natural food additives, ingredients and flavourings. Woodhead Publishing. 175-196.
4. Riaz, MN. 2007. Seaweed Derived Ingredients for Use in Pet Foods. In Pet Food Technology (pp. 273-284). Wiley.
5. Kearsley, MW, Dea, IC. 1992. A simple and rapid method for the determination of the gel strengths of agar and kappa-carrageenan gels. Food Hydrocolloids, 6(1), 29-35.
6. Dog Food Ingredients | Pet Food - Gino Gums & Stabilizers. Gino Gums & Stabilizers, 20 Dec. 2019, https://gumstabilizer.com/applications/pet-food/.
7. Cohen, SM, Ito, N. 2002. A critical review of the toxicological effects of carrageenan and processed eucheuma seaweed on the gastrointestinal tract. Critical Rev Toxicol.  32(5):413-44. doi:10.1080/20024091064282
8. Cassia Gum Powder - Cassia Tora Powder, Goma Cassia, Gomme De Cassia - Avlast Hydrocolloids. Cassia Powder, Guar Gum Powder Processor & Exporter, https://www.avlasthydrocolloids.com/product/cassia-gum-powder. Accessed 1 Feb. 2023.
9. Cassia Gum - Characteristics, Applications and Market Forecast. Welcome Altrafine Gums, 13 Sept. 2022, https://www.altrafine.com/blog/cassia-gum-characteristics-applications-and-market-forecast/.
10. FSA Panel on Additives and Products or Substances used in Animal Feed (FEEDAP); Bampidis V, Azimonti G, Bastos ML, Christensen H, Dusemund B, Kouba M, Kos Durjava M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M, Ramos F, Sanz Y, Villa RE, Woutersen R, Aquilina G, Bories G, Chesson A, Nebbia C, Renshaw D, Innocenti ML, Gropp J. 2019. Safety of cassia gum as a feed additive for cats and dogs based on a dossier submitted by Glycomer GmbH. EFSA J. 17(1):e05528. doi: 10.2903/j.efsa.2019.5528. PMID: 32626074; PMCID: PMC7009261.
11. Maier, Helmut, et al. 1993. Guar, locust bean, rara, and fenugreek gums. Industrial Gums, Elsevier. pp. 181–226, http://dx.doi.org/10.1016/b978-0-08-092654-4.50012-7.
12. Mudgil D, Barak S, Khatkar BS. 2014. Guar gum: processing, properties and food applications-A Review. J Food Sci Technol. 51(3):409-18. doi: 10.1007/s13197-011-0522-x. Epub 2011 Oct 4. PMID: 24587515; PMCID: PMC3931889.
13. Zhu, Bao-Jie, et al. 2019. Functional polysaccharides of carob fruit: A review. Chinese Med.14(1):40.

About the Author: Dr. Katy Miller works as the Director of Veterinary Services at BSM Partners. She previously served for 11 years as the Director of Dog and Cat Health and Nutrition for Mud Bay. She is also a competitive 3-day eventer, licensed falconer, and claims only 2 (Golden and Mini Doxie) of their nine dogs.

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