Selenium Content of Goose Breast Meat Depending on the Type of Heat Processing

Abstract

Among the foods frequently consumed by consumers is meat. Among other things, it contains selenium, and the content depends on the amount of consumption of this element by animals, which requires monitoring as a metalloid. The purpose of this study was to: examine the impact of various types of heat processing used by consumers (water bath cooking WBC, oven convection roasting OCR, grilling G, pan frying PF) on the selenium content and its retention in goose breast meat (with and without skin) and estimate the coverage of this element’s daily requirement in adults after consuming 100 g of goose breast meat with skin or without skin. The material used in the study comprised 36 breast muscles cut from carcasses of 17-week-old White Koluda geese. The moisture, ash, and selenium were determined in both raw and thermally processed muscles. It has been concluded that various methods of heat processing significantly impact the cooking loss, moisture, ash and selenium content of meat, but not the selenium retention. The heat processing increased the selenium content of the muscle regardless of the presence of skin, which affects the possibility of covering adults’ Nutrient Reference Values-Requirements (NRV-R) for this element in the range of 33.3–44.8%. Goose breast meat can be a valuable component of a diversified diet. It is also a safe source of selenium. It is unlikely that adult consumers, even those who eat goose regularly, will exceed this element’s upper tolerable intake level. For selenium retention and NRV-R coverage, consumers would benefit most from goose breast meat with or without skin undergoing OCR or G treatment.

1. Introduction

Selenium (Se) is among the bio-elements that should be supplied to the human body with the diet because it performs many vital physiological functions. Selenium’s crucial role in improving the immune system’s functioning has become important in the prevention/treatment of COVID-19 caused by the SARS-CoV-2 virus [1,2]. The development of diseases can be caused by both dietary selenium deficiency (increased oxidative stress, Keshan disease, Kashin Beck, abnormalities in thyroid function, cardiovascular and/or neurodegenerative diseases, type 2 diabetes, asthma, cirrhosis, some malignancies) and excess (selenosis) [3,4]. Selenosis is more studied in livestock, while in humans it still needs to be studied. The most common effects in humans are hair loss, nail deformation, skin rash, joint pain, tooth decay and a specific garlic odour in exhaled air due to the presence of the volatile compound dimethyl selenide. In selenosis, neurological symptoms such as lethargy, dizziness, motor weakness, and paresthesia may also occur, and an excess risk of amyotrophic lateral sclerosis which has been more consistently associated with chronic low-level selenium overexposure, particularly to its inorganic compounds. Also, selenosis increases the risk of metabolic disorders such as insulin resistance, type 2 diabetes, dyslipidemia, cardiovascular disease, and non-alcoholic fatty liver disease (NAFLD). However, Se’s toxicity depends on its chemical form (inorganic forms are more toxic), the size of the ingested dose, interactions with other dietary components, and the body’s physiological state [5]. Compared to other micronutrients, Se has one of the narrowest ranges between its toxic dose (>400 μg/day) and dietary deficiency (<40 μg/day) [4,6]. An extensive review paper has been devoted to its structure of occurrence in nature, functions in the human body, and effects of deficiency and toxicity [7]. Therefore, we avoided this description. This paper focuses on human consumption and its occurrence in the diet.

The principal bioavailable dietary forms of selenium, with a bioavailability of at least 90%, include selenomethionine (SeMet) and selenocysteine (SeC). Inorganic selenium forms such as selenate [SeO₄]²⁻ and selenite [SeO₃]²⁻ also exhibit decent bioavailability at around 60–70%, albeit lower than SeMet and SeC. SeMet is absorbed through the intestines, whereas the inorganic selenium forms like selenate and selenite are absorbed through a simple diffusion process. Once absorbed, these selenium sources are transformed into selenide (HSe²⁻) in the liver, serving the purpose of activating and generating selenoenzymes.Glutathione peroxidase (GSH-Px), type I iodothyronine deiodinase and selenoprotein P were identified as specific selenium-containing Se-Cys proteins. The liver serves as the primary organ responsible for the storage of selenium and the provision of selenium to other tissues as required. Elimination of absorbed selenium in the form of methylated selenium compounds, such as trimethylselenonium, primarily takes place through urine [2,6,8]. The retention of selenium (Se) exhibits an inverse relationship with its intake; reduced Se intake leads to decreased urinary excretion and heightened Se retention within the body [9].

Therefore, the source of this component in the diet is essential. Selenium is found in both plant and animal products. The content of Se in plant foods can be affected by different uptake rates by plants, which can be related to plant type, soil, pH, microbial activity, rainfall and several other biogeochemical parameters [6]. For this reason, the selenium content of plant products is variable. On the other hand, animal tissues show less variation depending on the sources of selenium contained in the feed. Animal products containing selenium are mainly liver, kidney and skeletal muscles.

Goose are waterfowl consumed in some regions of the world [10]. According to the Food and Agriculture Organization of the United Nations (years 1994–2021), the most significant goose meat production is found in China (95.1%), 3.4% is in Europe, and 1.4% in Africa. The most significant amount of goose meat in European countries is produced in Hungary, Poland and Ukraine [11].

The meat obtained from geese can be a good source of minerals in the human diet. However, mineral content in meat is influenced by many factors, including species, breed, gender, age, muscle type, nutrition, genetics, and cooking methods [11,12,13,14]. The role of selenium in the diet and its occurrence in raw goose meat, including as a result of feed fortification, has already been devoted to a review article [15]. It shows that the Se content of goose meat depends on the origin (domestic or wild), breed, type of muscle, presence of skin and cooking treatment used. Fortification of feed with Se (organic and inorganic) increases its content in goose muscles.

The application of heat during household cooking of foodstuffs encompasses a variety of processes, such as boiling, frying, steaming, baking, stewing and roasting, using microwave, steam and traditional ovens. Key benefits of thermal processing include the inactivation of foodborne pathogens, natural toxins or other harmful components, extended shelf life, improved digestibility and bioavailability of nutrients, improved palatability, flavour, texture and aroma, and enhanced functional properties. However, heat processing can also be associated with unintended, undesirable consequences, such as loss of certain nutrients [16]. Despite the emergence of non-thermal processing methodologies, such as irradiation and high-pressure treatment, heat remains the preferred approach for improving the attributes of meat items, encompassing safety and quality [17,18].

In addition, as part of cardiovascular disease prevention or weight reduction, consumers are encouraged to remove the skin and subcutaneous fat from carcass parts before cooking. The skin, occurring on the culinary elements, contains sulfur amino acids, collagen, elastin, fat, cholesterol, fat-soluble vitamins, and minerals [19]. It was interesting to investigate whether the selenium content of goose breast meat with or without skin changes, depending on the cooking technique used, and how these changes affect the coverage of the daily human requirement for this element. According to the U.S. Department of Agriculture database [20]. In other poultry species, the selenium content of raw breast muscle with skin is in chicken, broilers 16.6 µg/100 g; duck domesticated 12.4 µg/100 g; guinea hen—6.3 µg/100 g and turkey 20.4 µg/100 g. In contrast, the selenium content of raw pectoral muscle without the skin is in the chicken broiler—22.8 µg/100 g; duck domesticated—13.9 µg/100 g; guinea hen—17.5 µg/100 g; pheasant—16.7 µg/100 g; quail—18.8 µg/100 g and turkey—22.1 µg/100 g. Considering the selenium content of breast muscles with the skin of other poultry species given different culinary treatments were found in chicken broilers roasted—24.7 µg/100 g; duck domesticated roasted—20 µg/100 g and turkey roasted—29.8 µg/100 g. On the other hand, the selenium content of skinless breast muscles of other poultry species given different cooking treatments is chicken broilers fried, roasted, grilled—26.2, 27.6 and 28.4 µg/100 g respectively; duck domesticated roasted—22.4 µg/100 g and turkey roasted—30.7 µg/100 g.

Information about the selenium content of goose carcass parts with or without skin can be important for consumers when making dietary choices. Taking into account the WHO/FAO [21] recommended intake of 25–26 μg Se per day for women and 33–34 μg/day for men, for example, in the diet of Italians [22] the average intake was 21 μg/day, and lower than recommended. Since there are few scientific reports on the selenium content of goose meat, the purpose of this study was to (1) determine the effect of popular heat treatment techniques on its concentration and retention in breast muscle and (2) estimate the coverage of AI (Adequate Intake), EAR (Estimated Average Requirement), RDA (Recommended Dietary Allowance), RI (Reference Intakes) and NRV-R (Nutrient Reference Values-Requirements) for selenium from 100 g servings of goose meat with skin or without skin in adults.

2. Materials and Methods

2.1. Meat Samples

The experimental material was the breast muscles (Pectoralis major) of 17-week-old White Koluda geese. After fattening, the geese were sold as “Polish oat geese” on the European market. The birds were reared on the same commercial farm and fed the same diet, including a premix containing 0.35 mg of selenium per 1 kg of feed [23]. Before the slaughter, geese were subjected to feed withdrawal for 12 h. Next, the birds were slaughtered in a poultry plant, according to the regulations applied in the Polish poultry industry. The eviscerated carcasses were placed in a 2 °C to 4 °C cooler for 24 hours, and then the breast muscles were cut out of the carcasses. The meat was transported under refrigerated conditions to the Wroclaw University of Economics laboratory. Immediately upon delivery to the laboratory, the muscles intended for heat treatment were divided into groups of similar weight and subjected to particular heat processing. Muscles with skin weighed, on average, 384.7 ± 26.1 g, and without skin and subcutaneous fat, 286.4 ± 54.6 g (N = 36, 12 raw breast muscles = 6 raw with skin and 6 raw without skin, and 24 cooked breast muscles = 6 for every heat treatment: 3 with skin and 3 without skin).

2.2. Heat Processing

Heat treatment methods commonly used in the home processing of poultry meat (boiling in a water bath, grilling, pan-frying without fat, roasting in a convection oven) were selected for this study. No salt (NaCl), spices or food additives were added to the meat. After heat treatment, muscles were allowed to cool to room temperature for about two hours. Each raw and cooked breast muscle was ground separately (3 mm mesh diameter) in an electric mincer (model MM/1000/887 Zelmer, Rzeszów, Poland). Following the USDA [24] food microbiological safety recommendation, goose breasts were heat processed until an internal temperature of 75 °C in the thickest part of the muscle was reached. The temperature was monitored with a hand-held thermometer. When roasting in the oven and grilling Teflon-coated thermocouples (Type T, Omega Engineering Inc., Stamford, CT, USA) connected to a Doric multichannel data logger (VAS Engineering Inc., San Diego, CA, USA) were used.

Water Bath Cooking (WBC). In studies and trials, it is essential to distinguish the purpose of the cooking method—experimental or for consumer use. A regulated water bath is commonly employed for experimental cooking and research. Meat samples are sealed in plastic bags and submerged in water at a temperature below 100 °C for this purpose. Each muscle, wrapped in a thinwall polyethylene bag, was immersed in water at 90 °C (model SW 22, Julabo GmbH, Seelbach, Germany). The bag opening was above the water surface. It took about 30 min to reach a temperature of 75 °C inside the muscle. After cooking the liquid was decanted, and the samples were removed from the bag, carefully dried with filter paper, stored at room temperature and reweighed for the analysis of the percentage of cooking loss (CL)

Grilling (G). Whole muscles were placed between two heating plates of an electric grill (model PD 2020R, Red Fox, Warszawa, Poland), preheated to 200 °C. Processing lasted about 25 min.

Oven Convection Roasting (OCR). Each breast muscle wrapped in aluminium foil was roasted in a forced-air convection oven preheated to 200 °C (model EB7551B Fusion, Amica Ltd., Wronki, Poland). It took approximately 25 min to reach the final processing temperature.

Pan Frying (PF). Pan frying was executed utilizing an electric pan (model 48155, Unold AG, Hockenheim, Germany). The muscles were fried on a preheated pan (at 160 °C) and flipped once they attained an internal temperature of 40 °C. The procedure was finalized when the temperature within the specimen reached 75 °C (approximately 15 min).

2.3. Chemical Analysis

The moisture and ash content (%) of raw breast muscles and the muscles subjected to heat processing were analysed with the use of reference methods [25] and AOAC [26]. Moisture was measured by the oven-drying of 2 g samples at 102 °C for 12 h to a constant weight in a SUP-4M laboratory dryer (Wawa-Med, Warsaw, Poland) (950.46B, p. 39.1.02). Ash, i.e., total mineral content, was determined by incineration at 550°C for ten hours in an FCE 7SHM muffle furnace Czylok (Jastrzębie Zdrój, Poland) (920.153, p.39.1.09).

Selenium (Se) concentrations were determined using Watkinson’s spectrofluorometric method, modified by Grzebuła and Witkowski [27]. The homogenized (IKA T25 Ultra-Turrax, IKA-Werke GmbH & CoKG, Staufen im Breisgau, Germany) samples (1 g each) were digested in HNO₃ (230 °C/180 min) and HClO₄ (310 °C/20 min) in an open system. Then, 9% HCl was added to the samples to reduce selenates (Se VI) to selenites (Se IV). The Se was derivatised with 2,3-diaminonaphthalene (Sigma-Aldrich, Steinheim, Germany), and the complex was extracted into cyclohexane. The Se concentration was determined fluorometrically using a Shimadzu RF-5001 PC (Tokyo, Japan). spectrofluorometer The excitation wavelength was 376 nm, and the fluorescence emission wavelength was 518 nm. The accuracy of the analytical procedure was verified using Certified Reference Material ERM-BB185 (bovine liver) (ERM, Geel, Belgium). The mean recovery was 94% of the reference value.

2.4. Calculation of Indices

Cooking loss (CL) was calculated [28] from differences in the weights before (Wb) and after heat processing (Wt) of the samples cooled down to room temperature.

CL = (Wb − Wt)/Wb · 100%

The following equation was used to calculate the percentage of selenium and ash retention after heat processing of the meat [29]:

$$\% Retention=\frac{Secontent/100 g of heat processed meat}{Se content/100 g of raw meat}\times \frac{meat weight \left(g\right) after heat processing}{meat weight \left(g\right) before heat processing}\times 100$$

2.5. Statistical Analysis

Muscle was the experimental unit. The obtained results were examined for normality of distribution with the Shapiro-Wilk Test and variation of homogeneity with Laven’s test. The data (moisture, ash, and selenium content) were analysed as a completely randomised design using a 2-way ANOVA concerning the kind of muscles (with skin, without skin) and processing (Raw, WBC, G, OCR, PF) as a factorial design (2 × 5), according to the following linear model: Y_ij = μ + A_i + B_j + (AB)_ij + e_ij, where Y_ij = value of trait (the dependent variable); μ = overall mean; A_j = effect of muscle kind; B_j = effect of heat processing or lack thereof; (AB) = interaction, and e_ij = random observation error, using Statistica 13.1 software [30].

The data for ash and selenium retention were analysed using a 2-way ANOVA concerning the kind of muscles (with skin, without skin) and kind of heat processing (WBC, G, OCR, PF) as a factorial design (2 × 4), according to the linear model mentioned above. Statistical significance of differences among the means of the groups was assessed through Tukey’s multiple comparisons test, at the significance levels of p ≤ 0.05 and p ≤ 0.01, utilizing Statistica 13.1 software.The tables show arithmetic means and standard errors of the mean (SEM). All data are reported as means (±SEM) of 2 chemical determinations.

Principal component analysis (PCA) was applied to CL, Se retention and NRV-R also using Statistica 13.1 software [30].

3. Results and Discussion

Heat processing techniques have predominantly been utilized to achieve two primary goals: the cooking of food to enhance its flavour and improve its texture for easier consumption and digestion, and the safeguarding of food safety by deactivating pathogenic microorganisms and enzymes [31]. Heat processes can be classified into three primary groups: moist, dry, and microwave-based. The treatments we used are among the moist (water bath cooking WBC, where the source of heat is usually hot liquid media, such as water) and dry (oven convection roasting OCR, where the source of heat is hot air in ovens and hot surfaces in pan-fried PF or heating plates in grilled G). These are the conventional techniques used by consumers [17,31].

3.1. Cooking Loss

Cooking loss results from the extraction of liquid and soluble components from the meat during the cooking process. The total amount of cooking loss is influenced by the temperature and rate of heating applied [12].

In our study (

Table 1. Cooking loss, moisture, ash content and ash retention of raw and heat-processed White Kołuda goose muscles (Mean, SEM).

Item	Meat	Raw	Heat Processing					SEM	Level of Significance
			Water Bath Cooking (WBC)	Grilled (G)	Oven Convection Roasting (OCR)	Pan-Fried (PF)	Total
									Meat (M)	Heat Processing (HP)	M × HP
Cooking loss (%)	without skin	-	27.2 b	42.5 a	40.6 a	34.9 b	36.3 Y	1.84	0.001	0.001	0.032
	with skin	-	40.4 b	51.7 a	43.6 ab	45.7 ab	45.4 X	1.52
	Total	-	33.8 B	47.1 A	42.1 A	40.3 A	40.8	1.50
	SEM		3.43	2.15	0.82	2.50
Moisture (%)	without skin	73.3	65.3	54	56.9	58	61.5 X	1.88	0.018	0.001	0.084
	with skin	64.5	62.5	56.2	55.1	54.5	58.6 Y	1.41
	Total	68.9 A	63.9 A	55.1 B	56.0 B	56.2 B	60.0	1.19
	SEM	2.66	1.30	0.68	0.78	1.21
Ash (%)	without skin	1.41	1.34	1.63	2.45	1.56	1.48	0.19	0.102	0.001	0.727
	with skin	1.38	1.06	1.63	1.96	1.23	1.25	0.16
	Total	1.39 C	1.20 B	1.63 AB	2.21 A	1.39 B	1.36	0.12
	SEM	0.07	0.18	0.07	0.20	0.13
Ash retention (%)	without skin	-	75.3	70.7	75.9	72.0	73.5	4.80	0.336	0.045	0.117
	with skin	-	94.0	59.9	73.8	44.8	68.1	6.06
	Total	-	84.6 a	65.3	74.9	58.4 b	70.8	3.83
	SEM		5.84	5.51	7.91	8.03

Means within a row followed by different superscript letters differ significantly, including heat processing; ^A,B,C p ≤ 0.01; ^a,b p ≤ 0.05. Means within a column followed by different superscript letters differ significantly including kind of meat ^X,Y p ≤ 0.01.

), both the type of muscle (with or without skin) and the type of heat processing used significantly (p ≤ 0.01) affected cooking loss in goose breast muscles. Significantly higher CLs characterised muscles with skin than without skin (45.4 vs. 36.3%) in all heat processing methods. This is because goose meat, which belongs to waterfowl, contains significant amounts of subcutaneous and intramuscular fat that are lost during heat treatment. Similarly, other authors [9,20] found significantly (p ≤ 0.05) greater CL in the pectoral muscles of White Koluda goose with skin than without skin. In our study, we also observed a significant (p ≤ 0.01) effect of heat treatment on increasing cooking loss in muscle (G, OCR, PF > WBC), even though in our experiment, the final temperature inside the sample was the same (75 °C). Evaporation, dripping, and structural changes cause water loss during cooking, oven convection roasting, grilling, and pan-frying of meat. Contraction during culinary preparation results in the most significant aqueous reduction at 60–70 °C, and it is postulated that liquid is extracted due to the force exerted by the diminishing connective tissue on the watery solution in the extracellular cavity [14].

Similarly, Wołoszyn et al. [20] showed significantly (p ≤ 0.05) the least cooking loss in the pectoral muscles of White Koluda geese under water bath cooking, compared to the other methods: OCR, G and PF. In a study of other thermal treatments, Wereńska [13] showed the lowest value of cooking loss for sous-vide (27.16%) samples compared with microwave (40.16%) cooking and stewing (47.63%).

In our study, the interaction between the type of muscle (with or without skin) and the type of heat treatment used proved significant (p ≤ 0.01). In contrast, Wołoszyn et al. [28] showed no interaction between the type of meat and heat treatment in White Koluda goose.

3.2. Moisture Content

Both the type of muscle (with or without skin) and the type of heat treatment significantly (p ≤ 0.01) affected the moisture content of White Koluda goose pectoral muscles (Table 1). The skinless muscles were characterised by significantly (p ≤ 0.01) larger content of moisture than those with skin (61.5 vs. 58.6%). In contrast, significantly (p ≤ 0.01) larger moisture content in White Koluda goose breast muscles without skin than with skin was found by Goluch et al. [23] and Wereńska et al. [32] (62.5 vs. 58.3% and 62.91 vs. 58.94 respectively).

The content of moisture in the raw muscles (68.9%) and WBC (63.9%) was significantly (p ≤ 0.01) higher than in other heat-treated samples (PF, OR, G). Belinsky and Kuhnlein [33] discovered that thermal treatment has an effect on the moisture level in Canada Goose breast muscles with skin: FR > B > OCR (56.1 > 51.4 > 50.6%, respectively). Conversely, Oz and Celik [34] observed no noteworthy influence of seven varieties of thermal treatment (boiling, grilling, pan frying without fat or oil, pan frying with oil, deep-fat frying, oven roasting, microwave cooking) on the variations in moisture level of Turkish skinless geese breast muscles [33,34].

Unlike the study by Goluch et al. [23], in our study, the interaction between the type of muscle (with or without skin) and the method of heat treatment, in the case of water content, did not prove significant.

3.3. Ash Content

There are no significant differences in ash content between muscle types (with or without skin) (Table 1). However, Goluch et al. [23] and Werenska et al. [32] found significantly (p ≤ 0.01) higher ash content in White Koluda goose breast muscles without skin than with skin (1.40 vs. 1.25% and 1.47 vs. 1.12, respectively).

These studies revealed significant (p ≤ 0.01) changes in the ash content in the muscles depending on the type of heat processing used. The heat processing methods caused a significant general increase in ash content in muscles compared to raw muscles (p ≤ 0.01). Raw meat had the lowest ash content (1.39%) compared to heat-treated meat. The highest ash content was found in OCR-treated meat (2.21%). Goluch et al. [23] also found significantly (p ≤ 0.01) the lowest ash content in raw White Koluda goose muscles (1.10%) and the highest in grilled muscles (1.61%). In the case of ash content, the interaction between the type of meat and the heat processing method was insignificant. In contrast, Goluch et al. [23] found the highest ash content in grilled muscles without skin (1.74%), while in grilled and fried muscles with skin, the content was 1.47 and 1.48%, respectively.

3.4. Ash Retention

Food contains numerous nutrients that are sensitive to heat, including minerals. To preserve these nutrients in food products, it is essential to develop innovative process designs. This is necessary because these nutrients are vulnerable to various physical and chemical factors, leading to loss of biological functionality, chemical degradation, and premature or incomplete release. Maximum destruction during heat processes is of vitamins and minerals [35]. Retention of nutrients in food subjected to heat processing is vital for dietary reasons. Losses of minerals during heat treatment of meat also depend on the form in which they occur. Minerals in the form of soluble dissociated salts (part of sodium, small amounts of phosphorus, calcium and potassium) end up in the leakage. Ingredients such as iron or selenium, which combine with proteins, remain in the meat [36].

In our study, there was no significant effect of either the type of muscle (with or without skin), the heat treatments used or the interaction between them on ash retention. Similarly, Goluch et al. [23] and Wereńska et al. [32] found no significant differences in ash retention in White Koluda goose breast muscles between those without and with skin. In contrast, in studies with thermal treatments different from ours, Wereńska [13] found significantly (p ≤ 0.05) higher ash retention in goose breast muscles treated with sous-vide (93.55%) compared with microwave (89.97%) cooking and stewing (67.16%).

3.5. Selenium Content and Retention

Geese take up selenium with conventional feed in organic (SeMet and Se-Cys) or inorganic (sodium selenite) form. In regions of the world where this element is found to be deficient in the environment, geese can take it up from feed fortified with Se-enriched yeast, selenium chelate, nano-Se, or algae such as Scenedesmus quadricauda and Chlorella. Drinking water is also a source of selenium in goose nutrition. Although the Se content in water is minimal (10–20 μg/L), there are regions of the world where the content of this element in water is high, including areas of the US, Venezuela and China [37,38].

Skeletal muscle is reported to be the major Se body pool, accounting for approximately half of the total body Se. Goose meat contains selenoproteins, of which the main biologically active form of selenium is the amino acid selenocysteine (SeC), 81% of which is absorbed mainly in the small intestine [36,39].

During heat treatment, culinary losses caused by mass transfer are influenced by both cooking conditions—such as the method, surface, temperature, and time—and the properties of the meat, including its moisture, fat and protein content, pH value, and size. Several research papers [8,23,33,34,40] have been devoted to the effect of heat treatment on the content of minerals (Ca, K, Mg, Na, Fe, Cu, Zn, Mn, P, B, Al) in goose meat, but they did not address selenium. Therefore, this study is the pioneering effort to identify the presence of selenium in goose breast meat, both with and without skin, following exposure to different culinary techniques. In our study, muscle type (with or without skin) had no significant effect on the selenium content of White Koluda goose breast muscles. However, a significant (p ≤ 0.01) effect of heat processing on the value of this element in muscles was observed. Raw muscles (15.3 μg/100 g Fresh Mass) had the lowest selenium content, compared to heat-treated ones: R< OCR, G, PF, WBC (25.8; 25.6; 24.3; 21.8 3 μg/100 g FM respectively). The Se content found in raw breast muscles was higher than that determined by Boawei et al. [37], Horak et al. [38], Łukaszewicz et al. [39] and Sobolev et al. [41] (14; 0.035; 13.1; 9.25 μg/100 g, respectively). The differences in the values obtained are due to the origin of goose meat (commercial sales, experimental studies), different breeds (White Koluda, Canada goose, Gray, Gorki breed), sex and diet. There was also a significant (p ≤ 0.01) interaction between the type of muscle (with or without skin) and the heat processing used. Significantly, the highest selenium content was found in OCR-treated skinless muscle (26.7 μg/100 g) compared to raw muscle (17.4 μg/100 g). Grilling and pan-frying also significantly (p ≤ 0.05) increased the selenium content in skinless muscles, compared to raw muscles (24.9 and 24.3 vs. 17.4 μg/100 g). In the case of muscle with skin, all the thermal treatments applied significantly (p ≤ 0.01) increased the selenium concentration, compared to raw muscle: OCR, G, PF, WBC > R.

The higher Se content of roasted meat is due to its retention, which occurs when high temperatures act on muscle proteins. During roasting, when the temperature is between 100 and 140 °C, proteins’ digestibility is reduced by forming intramolecular and intermolecular covalent bonds [42]. In another study, it was shown [28] that a crust is formed during roasting of goose meat, which prevents the escape of water and thus minerals, which explains their higher concentration in cooked muscles.

Since no studies adequate to ours have been found in the literature, it is impossible to compare the results obtained of the selenium content of breast meat after applying various thermal treatments to the results of other researchers. For example, according to data from the U.S. Department of Agriculture database [43], the Se content of raw goose meat with skin is 14.4 µg/100 g and 16.8 µg/100 g without skin, but these values apply to the whole carcass, not just the breast muscles. Similarly, Chen et al. [44] reported a Se content of 34.6 (22.1–49.8) µg/100 g FM in goose meat bought in commercial stores in Taiwan, but the type of muscle, sex of the birds, and presence of skin were not given. It is well known that muscles differ in their histological structure and the nature of their metabolic transformations, which may affect their mineral content, including selenium [45].

Considering the calculated selenium retention (

Table 2. Selenium content and its retention of raw and heat-processed White Kołuda geese breast meat (Mean, SEM).

Item	Meat	Raw	Heat Processing					SEM	Level of Significance
			Water Bath Cooking (WBC)	Grilled (G)	Oven Convection Roasting (OCR)	Pan-Fried (PF)	Total
									Meat (M)	Heat Processing (HP)	M × HP
Se (μg/100 g FM)	without skin	17.4 Bb	20.2	24.3 a	26.7 A	24.9 a	21.8	1.01	0.559	0.001	0.001
	with skin	13.2 B	23.3 A	26.9 A	24.9 A	23.7 A	20.9	1.46
	Total	15.3 B	21.8 A	25.6 A	25.8 A	24.3 A	21.3	0.89
	SEM	0.99	1.22	1.29	0.96	1.12
Se retention (%)	without skin	-	85.1	79.9	91.1	93	87.3	3.28	0.082	0.087	0.913
	with skin	-	113.4	101.5	111.4	99.2	106.4	8.61
	Total	-	99.3	90.7	101.3	96.1	96.8	4.92
	SEM	-	15.4	7.78	10.7	4.78

Means within a row followed by different superscript letters differ significantly including heat processing; ^A,B p ≤ 0.01; ^a,b p ≤ 0.05.

), this study showed no significant differences between the type of meat (with or without skin), the heat processing used, and the interaction between the two. Heat-treated muscles have a higher selenium content than raw muscles due to loss of water and fat However, the diet of about a billion people does not contain enough Se for their good health [46]. Considering the high retention of this element, goose breast meat with skin subjected to OCR (101.3%) and WBC (99.3%) and skinless meat subjected to PF can be a good source of it in consumers’ diets, despite the high cooking loss (43.6%, 40.4%; 34.9%, respectively). This may be because selenium contained in selenoproteins (selenocysteine, selenomethionine) was retained in muscle tissue through the effect of high temperatures due to the strong denaturation of proteins [14,47]. Mineral components, which can be found in the form of soluble dissociated salts (part of sodium (Na), small amounts of phosphorus (P), calcium (Ca) and potassium (K), go to the leakage) [48,49].

3.6. Coverage of Selenium Intake Standards

Recommendations for the amount of selenium intake (Table 3) by adults vary according to gender, age and level of the standard (AI Adequate Intake, EAR Estimated Average Requirement RDA Recommended Dietary Allowance, RI Reference Intakes). Recommendations for Se intake range from 25 to 70 µg/d. For example, WHO/FAO [21] recommends, for women aged 19–65 (at the RI level), an intake of 26 µg/d, and over 66 years of age, 25 µg/d. Similarly, these recommendations for men are 34 and 33 µg/d. Consumption of 100 g of goose meat will therefore cover the recommended Se intake for men and women in different countries in different percentages, depending on the adopted level of the AI, RI, EAR or RDA standard.

Our calculations show that, theoretically, a serving of 100 g of raw goose breast meat without skin will cover the daily Se requirement for women in the range of 24.9–69.6% and for men from 24.9 to 52.7%, depending on the level of standards (Table 3). The same serving of raw goose breast meat with skin will cover the daily Se requirement in a lower percentage: similarly for women 18.9–52.8% and men 18.9–40.0%. However, the consumption of raw goose meat is not widespread, and in most regions of the world, it is subject to various culinary treatments.

Breast meat grilled with skin and OCR without skin (78.5–107.6%) will cover the highest percentage of daily selenium requirements for both men and women. In general, depending on the accepted standard, goose meat (without skin) subjected to various heat treatments will cover the daily selenium requirements of adults in the range of 28.6–106.8%, while with skin in the range of 33.3–99.6%.

It is understood that the above-physiological intake of Se by humans can cause the phenomenon of hyperalimentation and pose a risk of exceeding the Upper Level (UL). In 2006, EFSA proposed the UL of selenium consumption of 300 μg/day for adults [37], which took into account this element from both diet and supplements [50]. However, due to the increase in the consumption of dietary supplements in 2022, EFSA lowered the UL to 255 (μg/day), including for pregnant and breastfeeding women [38].

Table 3. Fulfilment of the demand (%) for selenium of adults by the consumption of 100 g of breast goose raw or after heat processing meat (without skin or with skin), concerning the recommendation, standards and Nutrient Reference Values-Requirements.

Meat	Se (μg /100g)	DACH (2013) [51] AI (μg)		EFSA (2014) [52] HCNL (2018) [53] AI (μg)	NCM (2014) [54] RI (μg)		WHO/FAO (2004) [21] RI (μg)		NIPH-NIH (2020) [55] IOM (2000) [56] EAR (μg)	NIPH-NIH (2020) [55] IOM (2000) [56] RDA (μg)	NRV-R [57] (μg)
		60 ♀	70 ♂	70 ♀♂	50 ♀	60 ♂	25–26 ♀	33–34 ♂	45♀ ♂	55♀ ♂	60 ♀♂
Raw meat without skin	17.4	29.0	24.9	24.9	34.8	29.0	69.6–66.9	52.7–51.2	38.7	31.6	29.0
Raw meat with skin	13.2	22.0	18.9	18.9	26.4	22.0	52.8–50.8	40.0–38.8	29.3	24.0	22.0
Water bath cooking without skin	20.0	33.3	28.6	28.6	40.0	33.3	80.0–76.9	60.6–58.8	44.4	36.4	33.3
Water bath cooking with skin	23.3	38.8	33.3	33.3	46.6	38.8	93.2–89.6	70.6–68.5	51.8	51,8	38.3
Grilled without skin	24.3	40.5	34.7	34.7	48.6	40.5	97.2–93.5	73.6–71.5	54.0	44.2	40.5
Grilled with skin	26.9	44.8	38.4	38.4	53.8	44.8	107.6–103.5	81.5–79.1	59.8	48.9	44.8
Oven convection roasting without skin	26.7	44.5	38.1	38.1	53.4	44.5	106.8–102.7	80.9–78.5	59.3	48.5	44.5
Oven convection roasting with skin	24.9	41.5	35.6	35.6	49.8	41.5	99.6–95.8	75.5–73.2	55.3	45.3	41.5
Pan-fried without skin	24.9	41.5	35.6	35.6	49.8	41.5	99.6–95.8	75.5–73.2	55.3	45.3	41.5
Pan-fried with skin	23.7	39.5	33.9	33.9	47.4	39.5	94.8–91.1	71.8–69.7	52.7	43.1	39.5

♀—female; ♂—male; AI—Adequate Intake; RI—Reference Intakes; EAR—Estimated Average Requirement; RDA—Recommended Dietary Allowance; DACH—Nutrition Societies in Germany and Austria and Switzerland (D-A-CH); EFSA—European Food Safety Authority; HNCL—Health Council of the Netherlands; NCM—Nordic Council of Ministers; NIPH-NIH—National Institute of Public Health-National Institute of Hygiene (Poland); IOM—Institute of Medicine (USA); NRV-R—Nutrient Reference Values-Requirements.

Table 3. Fulfilment of the demand (%) for selenium of adults by the consumption of 100 g of breast goose raw or after heat processing meat (without skin or with skin), concerning the recommendation, standards and Nutrient Reference Values-Requirements.

Meat	Se (μg /100g)	DACH (2013) [51] AI (μg)		EFSA (2014) [52] HCNL (2018) [53] AI (μg)	NCM (2014) [54] RI (μg)		WHO/FAO (2004) [21] RI (μg)		NIPH-NIH (2020) [55] IOM (2000) [56] EAR (μg)	NIPH-NIH (2020) [55] IOM (2000) [56] RDA (μg)	NRV-R [57] (μg)
		60 ♀	70 ♂	70 ♀♂	50 ♀	60 ♂	25–26 ♀	33–34 ♂	45♀ ♂	55♀ ♂	60 ♀♂
Raw meat without skin	17.4	29.0	24.9	24.9	34.8	29.0	69.6–66.9	52.7–51.2	38.7	31.6	29.0
Raw meat with skin	13.2	22.0	18.9	18.9	26.4	22.0	52.8–50.8	40.0–38.8	29.3	24.0	22.0
Water bath cooking without skin	20.0	33.3	28.6	28.6	40.0	33.3	80.0–76.9	60.6–58.8	44.4	36.4	33.3
Water bath cooking with skin	23.3	38.8	33.3	33.3	46.6	38.8	93.2–89.6	70.6–68.5	51.8	51,8	38.3
Grilled without skin	24.3	40.5	34.7	34.7	48.6	40.5	97.2–93.5	73.6–71.5	54.0	44.2	40.5
Grilled with skin	26.9	44.8	38.4	38.4	53.8	44.8	107.6–103.5	81.5–79.1	59.8	48.9	44.8
Oven convection roasting without skin	26.7	44.5	38.1	38.1	53.4	44.5	106.8–102.7	80.9–78.5	59.3	48.5	44.5
Oven convection roasting with skin	24.9	41.5	35.6	35.6	49.8	41.5	99.6–95.8	75.5–73.2	55.3	45.3	41.5
Pan-fried without skin	24.9	41.5	35.6	35.6	49.8	41.5	99.6–95.8	75.5–73.2	55.3	45.3	41.5
Pan-fried with skin	23.7	39.5	33.9	33.9	47.4	39.5	94.8–91.1	71.8–69.7	52.7	43.1	39.5

♀—female; ♂—male; AI—Adequate Intake; RI—Reference Intakes; EAR—Estimated Average Requirement; RDA—Recommended Dietary Allowance; DACH—Nutrition Societies in Germany and Austria and Switzerland (D-A-CH); EFSA—European Food Safety Authority; HNCL—Health Council of the Netherlands; NCM—Nordic Council of Ministers; NIPH-NIH—National Institute of Public Health-National Institute of Hygiene (Poland); IOM—Institute of Medicine (USA); NRV-R—Nutrient Reference Values-Requirements.

The range of selenium intake that is adequate yet non-toxic for the body is quite limited and depends on the chemical form of selenium. Selenosis commonly occurs in areas where the soil and drinking water have high selenium concentrations. It can also be a consequence of consuming dietary supplements [39].

Taking into account our determined selenium content of raw meat and meat subjected to various heat processing, and considering the reference daily intake in different countries, the consumption of a serving of 100 g of goose covers the needs of an adult human (depending on gender) from 18.9% to 107.6%.

In addition, it should be noted that selenium bioavailability can be affected by other dietary factors such as dietary methionine (Met) content, thiols, heavy metals and vitamin C [37]. Dietary Met deficiency results in using Se-Met for protein synthesis (to replace Met), contributing to increased Se content in tissues and thus reduced incorporation into the enzyme glutathione peroxidase (GSH-Px). Glutathione peroxidase transforms the toxic and carcinogenic hydrogen peroxide into harmless water and oxygen. Its activation requires small amounts of Se (selenocysteine), probably substituting sulfur in the glutathione molecule and causing the development of the modified enzyme glutathione peroxidase 4—GPx4 [38]. In contrast, with a diet rich in Met, there is competition in intestinal absorption with Se-Met, leading to a lower state of Se saturation in the body. Some thiols in the gastrointestinal tract increase selenite absorption, probably due to the formation of selenocomplexes with thiol compounds, which are more rapidly absorbed by the intestinal Na+-dependent and independent mechanisms. High vitamin C intake (1 g/d) may result in higher absorption and increased selenium retention, possibly due to vitamin C’s protection of key sulfhydryl groups involved in selenium uptake from the gastrointestinal tract. The interaction of Se with heavy metals reduces Se utilisation in some foods by forming bonds between them. Various arsenic compounds and cysteine, methionine, copper, tungsten, mercury, cadmium, and silver have been noted to reduce the efficiency of inorganic Se absorption in the gut. The effect of a low-protein diet rich in phosphorus on the lowest Se retention was also observed. In addition, fractions of soluble fibre and guar gum increase faecal Se excretion in humans and reduce Se homeostasis in the body due to reduced absorption from the gastrointestinal tract [58,59].

From the consumer’s point of view, the information placed by the manufacturer on the food packaging label is important because it helps consumers make nutritional choices. According to a European Parliament directive [60], the label includes information on energy and nutritional value. This information should also include the daily intake (NRV) reference value. These recommendations are based on the best available scientific knowledge of the daily energy or nutrients needed for good health. In 2014, the Codex Committee on Nutrition and Foods for Special Dietary Uses determined that the NRV-R for selenium is 60 µg [60]. In contrast, in Annex XIII of Regulation (EU) No. 1169/2011 of the European Parliament and of the Council of 25 October 2011, on providing food information to consumers, the NRV-R is 55 μg [59].

Our calculations show that raw meat without skin covers the NRV-R (60 μg) of the consumer (regardless of gender) at 29% and with skin at 22% (Table 2). Goose breast meat subjected to various heat processing covers NRV-R in the 33.3–44.8% range, although OCR without skin and grilled with skin cover the highest percentage (44.8 vs. 44.5%).

A PCA analysis (Figure 1) was conducted to investigate the relationships between Se retention, CL, and NRV-R and to determine which treatment could retain nutritional quality the most. The first two PCs accounted for 53.6% of the total variance. The PC1 explained 32.9% of the variance and had strong positive loadings for CL and smaller loadings for Se retention and NRV-R (

Table 4. Loadings for the first two PCs.

	PC1	PC2
CL	0.87	−0.26
Se retention	0.45	0.37
NRV	0.56	−0.44

). Figure 1 shows a weak correlation between CL and Se retention, confirming that Se remains in the denatured protein without leaking. According to the PCA analysis, despite the higher CL, it would be most beneficial to the consumer if goose breast meat with or without skin were subjected to OCR or G treatment, as it had significant selenium retention and NRV-R coverage (above 40%) (Figure 1). In summary, in our opinion, goose meat, both with and without skin, heat-processed in a 100 g portion can be part of a varied diet for adults. The findings of this study could benefit dietitians in evaluating or designing diets for both healthy and ill individuals for nutritional prevention and diet therapy.

4. Conclusions

Based on the study, it can be concluded that the applied heat processing methods significantly affected the cooking loss, moisture, ash and selenium content in goose breast muscles, compared to raw muscles. The effect of muscle type and type of heat processing on selenium retention was not found. Increases in the Se contents in cooked samples compared to raw counterparts are due the concentration of Se because of the loss of water and fat. The heat treatments used increased the selenium content of the muscles regardless of the presence of skin, which affects the possibility of covering the NRV-R of adults for this element in the range of 33.3–44.8%. Consuming goose breast meat, with or without skin, treated with OCR or G, is beneficial due to high selenium retention and NRV-R coverage. The 100 g portion of goose breast meat can be valuable to a diversified diet, providing selenium and essential nutrients. It is unlikely that adult consumers, even those who consume it regularly, will exceed the upper tolerable intake level for the element. Placing information on the label of food products regarding the value of minerals is voluntary for food manufacturers, so it seems reasonable to encourage them to do so. Then, the consumers can consciously include these compounds in their diet, and the products will thus become competitive in a wide assortment.