## 3 Results and Discussion
### Answering, Moisture Content and Cooking Loss
The highest cooking loss of meat samples heated at the highest temperature (90 \({}^{\circ}\)C) shown in this study is consistent with the findings of [PERSON] et al. [40]. The authors of the study showed that samples heated at the highest temperature (baking temperature of 180 \({}^{\circ}\)C, core temperature of 80 \({}^{\circ}\)C) were characterised by the highest cooking loss and longitudinal shrinkage. Significantly lower cooking loss values were found in samples heated at low temperatures (53-60 \({}^{\circ}\)C); at the same time, a clear transverse shrinkage was observed, while longitudinal shrinkage occurred to a lesser extent. [PERSON] et al. [50] showed that the heat treatment of beef using the steaming method results in greater cooking loss compared to the sous vide method (34.2% vs. 30%, respectively), and this difference results from the difference in the final heating temperature. [PERSON] et al. [51] indicate the involvement of connective tissue surrounding muscle fibres in the contraction mechanism and its significant role in shaping cooking loss. However, the gelation of collagen fibres at temperatures above 60 \({}^{\circ}\)C and the impact of this process on cooking loss value should be taken into account. [PERSON] et al. [40] showed that the long-time (20 h) cooking of pork at low temperatures (53 \({}^{\circ}\)C and 58 \({}^{\circ}\)C) results in greater cooking loss (28.4% and 33.6%, respectively) than shorter heating (2 h) at 60 \({}^{\circ}\)C (17.4%). Importantly, the authors point out that the indicated differences in the value of cooking loss were not fully reflected in the sensory assessment of juiciness. Similarly to our studies, the samples heated at the highest temperature had the lowest moisture content, and the processing method used and its conditions significantly differentiated the final moisture content. As a result of heating the meat using the SV4, OV80 and OV90 methods, the anserine content increased compared to the content determined in raw meat (Table 3). Only in the SV10 sample was there a decrease in the initial anserine content from 237.97 mg/100 g of meat to 229.28 mg/100 g of meat. The obtained increase in anserine content should be attributed to the increased concentration of dry matter components and the detected cooking loss. All meat samples were heated to obtain the same final temperature in the geometric centre (temp. 65 \({}^{\circ}\)C), which resulted in products with similar final anserine content. The observed reduction in anserine content in the SV10 sample is probably due to the longest heating time used (10 h). The demonstrated cooking loss of heated meat was similar (except for the OV90), while the final moisture content in the samples varied. Therefore, the anserine content determined in wet samples was related to the dry matter content. Based on the amount of anserine in the dry matter, a significant reduction in its initial content was found as a result of the methods and processing conditions used. A greater reduction in anserine was found in SV samples compared to OV, and the SV processing time did not significantly differentiate the dipeptide content, nor did the temperature used in OV processing. The content of histidine dipeptides and their proportions in meat differs depending on the animal species, the type of muscle and its vital activity, as well as the method of breeding, including the method of feeding. In beef, pork and horse meat, the dominant histidine dipeptide is carnosine, while in bird meat, anserine is the dominant one [1,18,19,21]. The initial content of histidine dipeptides identified in meat may change as a result of heat treatment. There are few studies on goose meat that quantitatively characterise the content of histidine peptides and the effect of heat treatment on their content. [PERSON] et al. [1] showed a higher content of anserine than carnosine in the breast muscle of chickens from conventional and animal welfare farms.