The flavor factor: using science to make pet food more palatable

Palatability is a complex and dynamic phenomenon, influenced by many interacting factors including taste, texture, shape and odor of food, as well as mouthfeel. As measurements of palatability become more sophisticated, a greater understanding of the role of flavor and aroma profiles in pet food quality and performance can be gained.

Quantifying palatability

Palatability is traditionally measured through amount of the food consumed and through use of A/B preference tests. Advances in measurements of palatability continue however, with methods such as ‘nose in bowl’ to measure a pet’s focus on the food.

False bottom bowls allow the influence of aroma to be studied separate to flavor. E-nose and e-tongue technology, meanwhile, allows us to identify the flavor and aroma profiles of foods.

Factors affecting palatability

Taste and smell

These two senses are interconnected and serve key aspects of palatability. Both dogs and cats’ sense of smell far outweighs that of taste, making aroma crucial for palatability. For cats, umami taste is most appealing. They show no preference for sweet or salty tastes, as humans and dogs do.

Not only do these senses help dogs and cats select appropriate foods, they also enable them to detect rancidity or spoiled products. Cats, as hunters, exhibit this ability more strongly than dogs who evolved as scavengers. Ensuring appropriate preservation and communication of storage conditions is vital to achieving robust product palatability.

Texture and mouthfeel

For cats even more so than dogs, textures and mouthfeel greatly affect food palatability. Textures are varied within the wet food category, from smooth mousse to firm chunks, shreds to gravies. Size and shape are not considered for pates and mousses, but for chunks the size and shape should be optimized for the target pets.

Ensuring the viscosities are desirable, and it’s important that greasiness and separation are avoided and chunks are firm and succulent. Emulsifiers, binders, humectants and hydrocolloids play important roles here to achieve the desired results.

Other factors

Cats often enjoy acidity, preferring foods of pH 4.5-5.5. Maillard reaction products (MRPs), created during the retort process when heating enables a chemical reaction between amino acids and reducing sugars, play a part in wet food palatability.

Protein digestibility is reduced, but MRPs have a positive effect upon palatability, resulting in different flavors being produced and a brown coloration. Palatants can include precursors to MRPs, to improve palatability post-processing.

Research published in 2023 showed that cats evaluate the nutritional content of their diet and moderate their food intake to reach their optimum protein and fat quantities and limit energy from carbohydrates.

Ingredients and palatants

Many professional palatant options are available, varying in their format and ingredients but all designed to boost pet food attractiveness. Palatants are included in wet food formulas prior to retort, or in particular components, such as the chunks, jelly or gravy.

Hydrolysed animal protein is a popular palatant base due to the high quantities of short peptides and free amino acids delivered.

Spray-dried animal plasma is primarily used as an emulsifier and binding agent in a hydrocolloid-type role. It provides benefits for water retention and texture, juiciness and homogeneity.

Studies comparing plasma with wheat gluten found that 1.5-2.5% plasma reduced water loss and increased hardness of wet foods in both chunks in gravy and loaf formats.

2% plasma increased juiciness of wet food chunks by around 20% by increasing water absorption from gravy. Juiciness, defined as the release of moisture from meat when chewed, is well correlated to improved palatability.

Supplementation of particular nutrients can provide positive palatability drives. For instance, 0.3% choline chloride, which has a salt-like flavor, improved palatability for cats when added to food. As cats are not driven by a preference for salt, the process behind this finding is unknown.

Propionic acid inclusion also displayed enhanced palatability and first choice in dogs, through enhancing flavors and stimulating appetite.

Palatability in pet food is both complex and multifactorial, but new research into pet behavior and environment is continuing to further knowledge in this field.