Evaluation of the Quality of Guinea Fowl (Numida meleagris) Eggs from Free-Range Farming Depending on the Storage Period and Age of Laying Hens.

The aim of the study was to determine the changes occurring in the eggs of helmeted guinea fowl (Numida meleagris) from free-range farming in relation to the laying season and storage time. The experimental material consisted of 360 guinea fowl eggs, collected in the first, second and third laying seasons and stored for 7, 14 and 21 days. After each period, physical and physicochemical characteristics of the eggs were determined, as well as the basic chemical composition and mineral content of the albumen and yolk and the yolk fatty acid profile. The age of the guinea fowls affected certain physical parameters of the eggs. The egg weight, shape index and shell thickness increased with the age of the laying hens; however, a decrease in the proportion of shell in the egg was demonstrated. Storage time had a significant effect on egg weight, weight loss during storage and air cell height. Significant differences were found in the chemical composition of guinea fowl eggs depending on the age of the laying hens. Eggs obtained from older laying hens were characterized by higher yolk fat content and lower ash content, while the albumen contained higher water content and lower ash content. During the three-year laying period, changes were observed in the mineral composition of the eggs. The fatty acid profile underwent significant changes; however, no important differences were observed in the total content of SFA, MUFA, PUFA and n-6 fatty acids. Conversely, significant differences were found for n-3 acids and the n-6/n-3 ratio. Eggs in the first and second laying seasons exhibited the most favorable composition. The slow dynamics of changes occurring in successive laying seasons and egg storage time indicated that the raw material studied was safe and could be used by consumers.

Evaluation of the Antibacterial Activity of Gentamicin in Combination with Essential Oils Isolated from Different Cultivars and Morphological Parts of Lavender (Lavandula angustifolia Mill.) against Selected Bacterial Strains.

The aim of the study was to investigate the antibacterial effects of essential oils isolated from different cultivars and morphological parts of lavender (Lavandula angustifolia Mill.) in combination with the aminoglycoside antibiotic gentamicin. This in vitro study analyzed the effectiveness of the combinations of gentamicin and lavender essential oils against the following strains: Staphylococcus aureus ATCC 25923, Staphylococcus aureus MRSA and Pseudomonas aeruginosa ATCC 9027. The effect of the combination of lavender oils with gentamicin was tested using the checkerboard method. A synergistic effect against S. aureus strain ATCC 25923 was found when gentamicin was combined with lavender essential oils isolated from flowers and leafy stalks (flowers: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.288; leafy stalks: 'Blue River' FICI-0.192; 'Ellagance Purple' FICI-0.320). A synergistic effect was also observed for the combination of gentamicin with lavender essential oils from flowers against the resistant strain of S. aureus (MRSA) ('Blue River' FICI-0,191; 'Ellagance Purple' FICI-0.263), as well as for the essential oils from leafy stalks ('Blue River' FICI-0.076; 'Ellagance Purple' FICI-0.089). No interaction was observed for the combination of studied essential oils with gentamicin against P. aeruginosa strain ATCC 9027 (FICI = 1.083-1.300).

Post mortem changes in M. iliotibialis lateralis muscle protein profile of emu (Dromaius novaehollandiae).

The available literature lacks information on the metabolic processes taking place in emu muscles after the cessation of circulation. Hence, this study was undertaken to examine the physicochemical characteristics (pH, drip loss, WHC, TBARS, L*, a*, b*) with concomitant changes in protein expression patterns (SDS-PAGE) of femoral muscle (M. iliotibialis lateralis) that occur post mortem and during the first days (0 h, 24 h, 48 h) of its maturation in 1- and 3-year-old emus. Our results indicated that the interaction between emus age and storage time had significant impact on meat pH and all color indicators. Furthermore, we detected 24 differentially expressed protein bands, representing 22 different gene products. ClueGO pathways analysis revealed that these proteins were mainly involved in glycolysis/gluconeogenesis pathway, pyruvate metabolism and pyrophosphate hydrolysis-driven proton transmembrane transporter activity. Based on the results obtained it can be assumed that early post-mortem metabolism of emu muscle is predominantly based on the glycolysis as reflected by the relative abundance alterations of the glycogenolytic and glycolytic enzymes. Moreover, the energy supplies provided by ATP and other high-energy substances degradation is higher in the group of older emus. Our findings also highlighted the complexity of the molecular mechanisms underlying the conversion of muscle to meat.

The influence of age and gender on emu (Dromaius novaehollandiae) fat.

Studies were carried out to determine the influence of age and sex on two types of fat (back fat and abdominal fat) in the emu, as these are factors that influence the composition of animal tissues. The material involved 26 emus at the age 1 (6 males), 3 (6 males) and 15 years (8 females and 6 males), kept on the same farm and fed the feed of the same nutritional value. The basic chemical composition, cholesterol and mineral content, as well as fatty acid profile of back and abdominal fat of emu were determined. Abdominal fat was characterized by higher content of fat and ash, as well as Mn and Ba. Back fat, on the other hand, showed a higher level of protein, cholesterol, C16:1 and the elements K, P, Si, Na, Ca, Mg, Fe, Zn, Se and Cu. With age, regardless of the type of fat tissue, fat content decreased and water content increased. The highest content of protein, ash, cholesterol, some fatty acids (C18:0, C18:1n9c, C18:2n6c), generally higher content of MUFA, PUFA and the elements K, P, Ca, Mg, Fe, Zn, Pb, Se, Cr, Cd, were found in the fatty tissue of 15-year-old emus. Sex did influence the content of Si, Ca, Cu, Sr, which was higher in the fatty tissue of males. The composition of emu storage fat is determined by factors such as age, sex and the location of the fat tissue in the body.

Characterization of structure and protein of vitelline membranes of precocial (ring-necked pheasant, gray partridge) and superaltricial (cockatiel parrot, domestic pigeon) birds.

Of all the known oviparous taxa, female birds lay the most diverse types of eggs that differ in terms of shape, shell pigmentation, and shell structure. The pigmentation of the shell, the weight of the egg, and the composition of the yolk correlate with environmental conditions and the needs of the developing embryos. In this study, we analyzed the structure and protein composition of the vitelline membrane (VM) of ring-necked pheasant, gray partridge, cockatiel parrot, and domestic pigeon eggs. We found that the VM structure is characteristic of each species and varies depending on whether the species is precocial (ring-necked pheasant and gray partridge) or superaltrical (cockatiel parrot and domestic pigeon). We hypothesize that a multilayer structure of VM is necessary to counteract the aging process of the egg. The multilayer structure of VM is only found in species with a large number of eggs in one clutch and is characterized by a long incubation period. An interesting discovery of this study is the three-layered VM of pheasant and partridge eggs. This shows that the formation of individual layers of VM in specific sections of the hen's reproductive system is not confirmed in other species. The number of protein fractions varied between 19 and 23, with a molecular weight ranging from 15 to 250 kDa, depending on the species. The number of proteins identified in the VM of the study birds' eggs is as follows: chicken-14, ring-necked pheasant-7, gray partridge-10, cockatiel parrot-6, and domestic pigeon-23. The highest number of species-specific proteins (21) was detected in the VM of domestic pigeon. This study is the first to present the structure and protein composition in the VM of ring-necked pheasant, gray partridge, cockatiel parrot, and domestic pigeon eggs. In addition, we analyzed the relationship between the hatching specification of birds and the structure of the VM.

Assessment of poultry egg liking scores using sighted and blind people.

BACKGROUND: Of the 18 043 bird species, the eggs of only hen and quail are generally available to consumers. Thus people are deprived of the opportunity to benefit from the huge diversity of eggs offered by nature. Poultry eggs can vary in their color of albumen and yolk, smell, taste and texture. In this study, sighted and blind people were employed for sensory evaluation with the aim of determining the preferences of consumers toward hard-boiled and scrambled eggs of different species of birds, and whether the appearance of these eggs has an effect on the perception of other sensory impressions. RESULTS: Sighted people differently evaluated the texture of both boiled and scrambled eggs as compared with blind people. This was mainly because blind people largely used their sense of touch for evaluation. All other attributes of boiled eggs were evaluated similarly by both groups of panelists, whereas those of scrambled eggs were evaluated differently. CONCLUSION: The obtained results unequivocally demonstrated that differences in taste of scrambled eggs when served hot are easier to evaluate than those of boiled eggs. On the basis of ranking by the sensory panel, it was established that eggs of birds belonging to the order Galliformes are more preferred by consumers than those of duck and goose. By contrast, eggs of ostrich and emu are characterized by unfavorable sensory profiles; moreover, the albumen of boiled ostrich eggs has an unsightly appearance. © 2019 Society of Chemical Industry.

Sensory evaluation of poultry meat: A comparative survey of results from normal sighted and blind people.

Visual assessment is one of the key criteria in the sensory evaluation of foods. The appearance of food products may affect their perception by other senses, sometimes giving a false picture of their quality. A true assessment of such sensory attributes as aroma, taste, tenderness, and juiciness, which are components of the overall liking of food, without the use of instrumental methods is feasible only by blind people. We have advanced a hypothesis that blindness may modify the impressions perceived through other senses used in food evaluation. To confirm this hypothesis, a sensory testing of cooked breast and leg meat from various poultry species was conducted by normal sighted and blind panelists aged from 18 to 26 years. It has been demonstrated that the lack of sight is compensated by other senses, the intensified perception of which enables a more precise sensory evaluation of food in terms of such parameters as the aroma, tenderness and juiciness. Thus, blind people can be recommended as panelists evaluating the sensory profile of food products. Scores given by the sensory panel allowed the conclusion that the most desirable poultry meat was BM of broiler chicken and capon, followed by Guinea fowl. Lower scores were given by the panelists to meat of water fowl (goose, duck), whereas the lowest ones were assigned to cooked ostrich meat.