## 3 Results and Discussion
### Trace Elements Content in Goose Meat After Heat Processing
In the case of fortified products, iodine stability further depends on the chemical form used--such as potassium iodate (KIO\({}_{3}\)) or potassium iodide (KI)--and on the type of carrier, including wheat fiber, soy protein, salt, or collagen [44; 45; 46]. Iodine derived from iodized salt or preparations like Yodozin has been shown to remain stable and thermotolerant in certain animal-based foods (e.g., semi-finished chicken and turkey meat, emulsion-type sausage type \"Lyoner\", cooked sausage, boiled ham, salami) even after various technological processes such as heating, fermentation, freezing, smoking, and ripening [46; 47]. However, since no iodized salt was used in our study, the applied heat treatments led to a reduction in iodine content in goose breast muscles. There are relatively few studies reporting iodine concentrations in goose meat. The iodine content in poultry meat is primarily determined by its level in feed and by the physiological and individual ability of animals to absorb and utilize this element. Generally, around 80% of iodine is stored in the thyroid gland, with only a small proportion deposited in other tissues, including muscle [48]. According to [PERSON] et al. [49], the iodine content in raw goose carcasses is 40.7 \(\upmu\)g/100 g, whereas food composition databases from several European countries report values ranging from 1.20 to 6.0 \(\upmu\)g/100 g [50; 51]. In Poland, iodine content in raw goose carcasses has been reported at levels between 0.7 and 4 \(\upmu\)g/100 g [52; 53]. In our study, goose breast meat with skin had a significantly higher iodine content than skinless samples (\(p\leq 0.001\)) (Table 2). All heat treatments applied led to statistically significant reductions in iodine levels compared to raw meat (Raw > WBC, G, ORC, PF; \(p\leq 0.001\)). A significant interaction was also observed between the meat type (without skin or with skin) and the heat treatment method (\(p\leq 0.001\)). The lowest iodine content was recorded in PF meat without skin and in OCR and PF meat with skin. In both meat types, a consistent decline in iodine content was observed following each heat treatment relative to raw samples. Iodine is a volatile element, and its loss during cooking is mainly attributed to evaporation at elevated temperatures. Additionally, iodine in its organic form is bound to proteins and lipids, meaning that fat and moisture losses during cooking, grilling, baking, and frying also contribute to overall iodine reduction. During dry-heat processing (e.g., baking), protein degradation leads to the oxidation and volatilization of iodine. The extent of iodine loss depends on both temperature and duration of heat exposure. In our study, iodine losses from heat-treated goose breast ranged from 15 to 20%, which aligns with WHO estimates [12]. Similar findings were reported in studies on minced pork, where heat treatment reduced total and inorganic iodine levels by 18-30%, regardless of the method used [44]. In general, meat--including goose meat--is not considered a major dietary source of iodine. Therefore, strategies to enhance iodine content in animal-derived foods are essential to help combat iodine deficiency in the human population. Our findings are consistent with those of [PERSON] et al. [54], who investigated iodine enrichment in Ross 308 broiler chickens by supplementing feed with KI and Ca(IO\({}_{3}\))\({}_{2}\) at doses up to 5 mg I/kg. Their results showed that even high-dose supplementation did not significantly increase iodine concentrations in breast or leg muscles--only in blood serum, liver, and thyroid--confirming that poultry meat is unlikely to contribute meaningfully to iodine intake. Current enrichment approaches include supplementing animal feed with inorganic iodine compounds or iodine-rich materials (e.g., seaweed) and plant biofortification through fertigation, foliar or soil application, or hydroponic cultivation using iodine compounds [55; 56; 57].