# Chemical Composition and Palatability of Nutraceuticaltical Dog Snacks
## 4 Discussion
### Palatability  
Despite many years of evolution, dogs still share many of their ancestral eating habits. For example, they rely heavily on their sense of smell when given any kind of food. Dogs usually do not invest much time masticating and savoring, instead they eat in a gluttonous manner [22]. Dogs have few taste buds compared to humans. Nevertheless, dogs can distinguish sour, bitter, salty, sweet and umami flavors when these chemoreceptors are stimulated. Dogs have different bite forces that increase with greater body weight and skull size, which may also be affected by chewing enthusiasm, personality and breed of dog [77]. Dogs choose food based on its palatability [78]. Their food preferences may also be determined by genetics and early life experiences [5; 79]. The sensory properties, and hence palatability of pet food products, can be influenced by the types of ingredients used in the formulation, the treats added and the processing factors used. Protein, fat and fiber sources can affect the appearance, aroma, taste and texture of extruded dog food [80]. In the studies by [PERSON] et al. [11], the preferences of a wide population of different breeds of dogs in order to generally verify the suitability of insect attractants were analyzed. As shown in that study, insects can be as effective in influencing dogs as commercial fodder containing flavor, while providing an additional source of high-quality crude protein and fat [11]. The palatability of meat-based pet food was found to be better than that of a vegetarian diet [81]. Interestingly, it has been shown that dogs fed with food with similar palatability values consume different macronutrient compositions. Dogs, on average, chose to consume most of their calories from fat rather than from carbohydrates [78]. The addition of fiber has been shown to reduce palatability. This is not a surprising result given the negative traits associated with fiber in general, including hardness and bitterness. Most dogs do not chew their food very intensively, but the fibrous consistency likely influences the mouthfeel of the food [67]. However, there is little information about how all of these variables can influence food choices in domestic dogs. Knowing the impact of these variables allows to better understand their food selection and food acceptability. Research by [PERSON] et al. [10] provides information on the relationship between the composition of the food and the nutritional preferences of dogs. The choice of diet can reflect the internal needs of the animal, helping it to achieve homeostasis. High dry matter and crude fiber content have been shown to negatively affect dog preferences. As noted in this study, dogs, similar to other mammals, prefer wet and semi-moist food over dry food [10]. In the studies by [PERSON] et al. [80], grain-free dry dog food was compared to dry dog food made from cereals but also to different protein sources due to their aromatic volatile components. The results of that study showed that dry dog foods are products with complex odor characteristics, and grain-free products are less aromatic. Particle size, shape, density, hardness and moisture content of the food affect the palatability of a dog food. In addition, the density affects the contact surface and the degree of fat absorption and the flavor coating on the granules, influencing the perception of food by dogs [82]. Some argue that vegan diets may be less palatable or may endanger animal welfare. Based on caregiver-reported behavior, [PERSON] and [PERSON] [83] found that vegan pet food is generally at least as tasty for dogs and cats as conventional meat or raw meat diets and does not compromise their welfare when other determinants of welfare, such as nutritional requirements, are adequately covered. The effect of the addition of algae on the palatability of food was investigated. A study by [PERSON] et al. [84] investigated the effect of _A. nodosum_ on extruded dog food palatability using the split-plate test. The results suggest that _A.