# Lipid Fraction Properties of Homemade Raw Cat Foods and Selected Commercial Cat Foods
## 4 Discussion
### The FA Composition and Oxidative Stability of Commercial Cat Food  
In light of the obtained results for raw foods, the FA profiles of selected dry and wet commercial foods were determined and presented. The same extraction method (Folch method) was used. The Folch method for fat extraction from dry pet food was also tested by other authors [27; 28]. The determined extracted fat content for commercial cat foods was lower (especially for CW-6 and CW-7) than the producers' statements (Table 2), which means the extraction was not effective. Moreover, in commercial wet foods the percentage of fat in dry matter was lower than in the case of the dry ones.  
The FA composition is presented in Table 2. The differences in FA profiles of commercial and self-prepared foods may be due to the type of meat and the ingredients used (human grade meat, animal by-products, meat meal or mechanically separated meat). Among all commercial dry cat foods CD-3 had the highest content of LA. This is probably due to the presence of plant origin oils (soya and borage oils) in its composition. These oils are rich in PUFA, especially in high content of LA [44; 45]. In the case of wet foods, CW-7 has the lowest LA content and it is the only commercial food that does not contain plants.  
It should be emphasized that the raw diet concept assumes that it is suitable for cats at every stage of life and that tested commercial foods are for adult cats. The American Feed Control Officials and the European Pet Food Industry Federation do not provide recommendations for the minimum levels of some of the EFA (ALA, EPA and DHA) in the diet of adult cats. In the case of CD-1, in which salmon meal (source of omega-3 [39]) is the main component, an increased content of EPA+ DHA in relation to other tested commercial foods was observed (Table 2). For other foods the required omega-6 to omega-3 ratio is not due to the high content of EPA and DHA, but because of the relatively high levels of ALA. Plants are a rich source of ALA [14]. The ingredients of plants origin are added to commercial diets but not to self-prepared ones (Supplemental Materials). Moreover, such ingredients do not contain AA (present only in fat of animal origin [15]). The AA content in commercial foods is relatively low, excluding CD-3 (Table 2). The low level of AA balances the ratio of omega-6 to omega-3 in commercial diets.  
The oxidative stability of commercial cat foods was determined by using the PDSC technique, the same as the self-prepared food. As predicted, \(\tau_{\text{max}}\) for commercial cat foods is much longer than for self-prepared ones. Commercial cat foods contain different antioxidants and preservatives, which increase their resistance to oxidation. Moreover, technological procedures (e.g., baking or extrusion) used during their production reduce the free fat available for oxidation [46]. Self-prepared food contained only natural antioxidants in the form of vitamin E as an essential nutrient and PUFA stabilizer [37]. The BARF diet is stored frozen, inter alia, to provide additional protection against oxidation during storage.