The hazelnut skin is waste biomass rich in bioactive compounds that may affect lipid rumen metabolism, ruminant performance, and products’ quality. Therefore, we investigated the effect of dietary hazelnut skin on milk production and composition and on rumen fatty acids in ewes. During 28 days, 20 Comisana lactating ewes received alfalfa hay ad libitum plus 800 g/head/day of pelleted concentrate containing 36% dried beet pulp (CTRL group; n = 10) or 36% hazelnut skin (HS group; n = 10). The protein percentage was lower in HS milk. Milk fatty acids (FA) partially reflected those of rumen content. Total saturated FA (SFA), odd and branched-chain FA, and n-3 polyunsaturated FA (PUFA) were greater in CTRL milk. Total monounsaturated FA (MUFA) and 18:1 trans were greater in HS milk; moreover, HS milk showed a double percentage of oleic acid than the CTRL group. Individual SFA were greater in CTRL milk except for 18:0. Differing from the rumen content, total PUFA, n-6 PUFA, and 18:2 n-6 were comparable between groups. Vaccenic and rumenic acid were greater in HS milk. To conclude, dietary HS slightly reduced milk protein percentage but improved atherogenic index and healthy FA in milk. The content of the somatic cells suggested a healthier udder in the HS group.

The effect of water bath cooking ( WBC ), oven convection roasting ( OCR ), grilling ( G ), pan frying ( PF ) on selected physical properties of goose meat was compared in this study. A measurement of cooking loss, texture, color parameters, and sensory evaluation was carried out. The experimental material covered 96 breast muscles cut from carcasses of 17-week-old “Polish oat geese.” The kind of goose meat (with and without skin) and the type of heat treatment affected cooking loss, shear force ( SF ), and rheological parameters (hardness, cohesiveness, gumminess, and chewiness). The water bath–cooked and pan-fried samples for both kinds of meat were characterized by lower cooking loss than other ones. Goose meat with skin and subcutaneous fat showed higher cooking loss and lower SF value, hardness, gumminess, and chewiness than that without skin for all methods. The water bath–cooked samples were characterized by the lowest SF value, hardness, and chewiness for both kinds of meat. They had the highest value of L∗ parameter and were characterized by a lighter color among others, too. Pan-fried meat showed the highest value of a∗ and lowest of h o parameters; the color of these samples was redder. Moreover, the lower C values of oven convection-roasted and grilled samples showed that they were brighter. According to the Comission Internationale de l’Eclairage classification, the ΔE parameter only for G and OCR indicated noticeable color differences (<2), whereas other pairs had visible differences. The method of cooking affected sensory descriptors such as the intensity of flavor and aroma, tenderness, juiciness, springiness, cohesiveness, and overall palatability of goose meat. The goose samples of PF, G, and OCR were characterized as very good and WBC as extremely desirable overall palatability. However, in the next stage of research, there is a need to study changes in the chemical composition, the degree of lipid oxidation, and the nutritional value of this meat that underwent different methods of cooking. Only then it will be possibly to clearly determine which method of the heat treatment of goose meat is optimal.

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 energy and the nutritional value of goose breast meat (with and without skin). The material used in the study comprised 72 breast muscles cut from carcasses of 17-wk-old White Koluda geese. The energy value (MJ), the chemical composition (water, fat, protein, ash) and mineral composition (phosphorus P, sodium Na, calcium Ca, potassium K, magnesium Mg, iron Fe, zinc Zn, cooper Cu, manganese Mn) were determined in both raw and thermally processed muscles. It has been concluded that various methods of heat processing have a significant impact on the energy and nutritional values of meat. From a dietary point of view, the most beneficial was OCR meat without skin, and WBC, OCR, PF meat with skin as well, since it had the lowest energy value as well as content and retention of fat, phosphorus, and sodium. However, as for the content of the other minerals and their retention, WBC seems to be the optimal form of heat treatment of skinless muscles. 100 g of such meat provides 3.1; 33.7; 145; 180 and 9% Nutrient Reference Values-Requirements ( NRVs-R ) for Ca, Mg, Fe, Cu, and Mn respectively in a diet of an adult person. As for meat with skin, the optimal method of heat processing to retain minerals is grilling. 100 g of meat processed in this way provides 3.9; 39.7; 125.7; 175; 6 and 12.7% NRVs-R of Ca, Mg, Fe, Cu, and Mn. It follows from the above information that goose breast meat, as analyzed here, cannot be considered as a source of calcium since it provides less than 4% of NRVs-R. The results of the study will be useful for the consumers’ nutritional choices. The geese breast meat, depending on the heat processing used and the content of skin, may be a valuable component of a varied diet, providing nutrients and minerals.

In the 20 d experiment, the influence of different concentration and supplementation period of commercial blackcurrant extract (BC) in the broiler diets on the oxidative stability of breast and thigh meat, as well as selected performance indices, was investigated. A number of 120 fifteen-d-old Hubbard Flex male chicks (initial BW 363.5 ± 22.9 g) were randomly allocated to five groups: the control and four treatments (6 replicates, 4 birds per cage in each group). The BC extract was administrated to treatment groups at two concentrations (1.25 and 2.5 g/kg) and in different periods within the trial (i.e., from 15 to 35 d and from 25 to 35 d of life). Body weight gain (BWG) and feed conversion ratio (FCR) were determined during the 20-d experiment. At d 35, two randomly selected birds from each cage were decapitated, and pectoral and thigh muscles were collected. Extent of lipid oxidation after storage at chilling (2-3°C, 1, and 5 d) and freezing conditions (after 90 d, −18°C) was determined. The chickens’ growth performance and FCR were not affected by the concentrations and periods of BC supplementation. The enrichment of grower diet with 1.25 g/kg of BC extract reduced the malondialdehyde (MDA) formation in frozen thigh muscles (P<0.05), and this effect tended to appear (P<0.089) irrespective of duration of the supplementation period. Significant extent of lipid oxidation process was found in 1-d-chilled pectoral muscles of chickens receiving BC diet for 20 d or diet containing 2.5 g/kg of the extract. The results showed that BC extract may be an efficient source of antioxidants in chicken diet, which may increase oxidative stability of frozen dark meat. However, the conditions and ability of some polyphenols to initiate oxidation processes have not been fully understood and further studies are required.

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