Dorota Pietrzak

Early and 24 h post-mortem changes in breast muscle quality traits of two turkey genotypes and their reciprocal crosses raised under semi-confined conditions.

Abstract An experiment was conducted to determine the effect of reciprocal crossing of turkeys on early and 24 h post-mortem changes in quality traits of their breast muscles. The turkeys of slow-growing (SG) and fast-growing (FG) lines as well as SF (SG × FG) and FS crosses (FG × SG) were reared with access to free range. After slaughter turkey breast muscles were examined in the following terms: 5 min, 45 min, 2 h and 24 h post-mortem, for: temperature, pH, glycogen content (G), lactate content (L) and electrical conductivity (EC). Quality attributes of the breast meat were evaluated based on chemical composition, water holding capacity (WHC), cooking loss (%), shear force (N) and colour (L*, a*, b*). Despite differences in the rate of post-mortem changes, the genotype of turkeys had no significant effect upon many quality traits assessed 24 h post-mortem. Meat of lighter birds (SG and SF) was characterised by a lower fat content but a similar protein content compared to meat of FS and FG turkeys. In addition, meat of males from these groups was darker. Meat from the breast muscles of heavier birds (FS and FG) was harder. Significant negative maternal effects were determined for temperature of meat of both male and female turkeys, for pH2 and EC24 of males as well as for L2, L24 and cooking loss of female meat. Positive heterosis was confirmed only for pH2 of female meat and for G2 of male meat. In summary, the direction of fast- and slow-growing turkey crossing may affect the quality of their meat. However, meat of both types of hybrids reared under semi-confined conditions (with the possibility of using free range) was characterised by appropriate quality parameters.

Early and 24 h post-mortem thigh (ilio tibialis) muscle metabolism and meat quality in two genetic types of turkeys and their reciprocal crosses, raised under semi-confined conditions

ABSTRACT 1. The experiment was conducted in order to determine the effect of the direction of turkey crossing on quality traits of their thigh muscle. 2. In total, 1358 turkeys of slow- (SG) and fast-growing (FG) lines as well as SF crosses (SG × FG) and FS crosses (FG × SG) were reared with access to free range to 21 weeks of age in the case of males and 15 weeks of age in the case of hens. 3. After slaughter of 15 males and 15 hens from each genetic line, their thigh muscles were examined and the following traits were measured after 5-min, 45-min, 2-h and 24-h post-mortem: temperature, pH, glycogen content (G), lactate content (L) and electrical conductivity (EC). Quality attributes were evaluated based on chemical composition, water holding capacity, cooking loss (%) and colour. 4. The rate of post-mortem changes in temperature, G, L and pH in muscles differed among the 4 lines of turkeys, with the highest metabolic rate determined for muscles of SG turkeys, followed by muscles of SF, FS and FG birds. A more beneficial muscle water holding capacity of both sexes of turkeys and better results of cooking loss in male muscles were found in SG and SF turkeys. The thigh muscles of the crosses were characterised by a higher content of protein and a lower content of fat compared to the muscles of FG turkeys, and in the case of the males also by a higher protein content compared to the muscles of SG birds. 5. Owing to the faster post-mortem metabolism, better water holding capacity, lower cooking loss and fat content at a similar content of protein, the thigh muscles of SF crosses raised in the free range system represent a better quality of meat for consumers compared to the thigh muscles of FS turkeys.

The effect of pale, soft and exudative meat on the quality of canned pork in gravy

The objective of the study was to evaluate the use of PSE meat in the production of sterilized pork type canned meat in its own gravy. Canned meat products were produced with 50% of PSE meat as well as with 100% PSE meat, and compared with canned meat products of good quality (RFN). It was found that decreased quality of PSE meat had a small impact on the quality of canned meat products. Substitution of both 50% as well as the total quantity of RFN meat with PSE meat did not affect the course of the sterilization process, neither increase the quantity of excreted fat and jelly in canned meat. It also had no effect on the instrumentally-measured parameters of texture and neither did it affect different sensory quality features, including the overall desirability of the product. The PSE canned meat product were characterized by higher values of L* and b* color parameters.

Chemical Composition of Edible Ostrich Offal

The offal (hearts, stomachs, and livers) of 24 African ostriches (Strutio camelus var. domesticus) from Polish farms were used in this study. Offal were taken directly from the production line; they were weighed and their water, fat, protein, ash and total collagen contents were determined. Ostrich hearts and stomachs were found to have high protein (18.1% and 19.0%, respectively) and low fat content (2.0% and 0.9%, respectively), typical of lean meat. Thus, the offal could be used in processed offal products or in pet food. Ostrich livers had slightly lower protein content (16.6%) and significantly higher and diverse fat content (4.4–28.4%). Heavier livers had significantly (P<0.05) higher fat and lower protein, water, and ash content. The utilization of ostrich liver should be preceded by classification of its fat content.

A Potential Use of 3-D Scanning to Evaluate the Chemical Composition of Pork Meat.

UNLABELLED The aim of this study was to determine the possibility of 3-D scanning method in chemical composition evaluation of pork meat. The sampling material comprised neck muscles (1000 g each) obtained from 20 pork carcasses. The volumetric estimation process of the elements was conducted on the basis of point cloud collected using 3-D scanner. Knowing the weight of neck muscles, their density was calculated which was subsequently correlated with the content of basic chemical components of the pork meat (water, protein and fat content, determined by standard methods). The significant correlations (P ≤ 0.05) between meat density and water (r = 0.5213), protein (r = 0.5887), and fat (r = -0.6601) content were obtained. Based on the obtained results it seems likely to employ the 3-D scanning method to compute the meat chemical composition. PRACTICAL APPLICATION The use of the 3-D scanning method in industrial practice will allow to evaluate the chemical composition of meat in online mode on a dressing and fabrication line and in a rapid, noninvasive manner. The control of the raw material using the 3-D scanning will allow to make visual assessment more objective and will enable optimal standardization of meat batches prior to processing stage. It will ensure not only the repeatability of product quality characteristics, but also optimal use of raw material-lean and fat meat. The knowledge of chemical composition of meat is essential due to legal requirements associated with mandatory nutrition facts labels on food products.

Quality changes of chicken breast meat packaged in a normal and in a modified atmosphere

SUMMARY The present paper aimed at the assessment of the changes of quality and shelf life of chicken breast meat (musculus pectoralis) packed in an atmosphere of normal air (on polystyrene trays wrapped in PVC foil) and in a modified atmosphere (MAP) with a mixture of gases: 75% O2 and 25% CO2. Physicochemical (headspace gas composition in MAP packages, drip loss, pH value, color components in L*, a*, b*, thermal drip, and TBARS) and microbiological (total plate count, lactic acid bacteria, and Pseudomonas spp.) parameters were monitored for up to 9 d of storage in a cooling room or display case. Breast meat packaged in MAP was characterized by higher quality and longer shelf life in comparison to PVC‐wrapped meat, which was exhibited by slower and less intensive quality changes. Moreover, storage of the chicken breast meat in the display case resulted in acceleration of negative changes occurring in the quality of the raw material during storage. The shelf life of the tested chicken breast meat wrapped in PVC foil and in MAP and stored in the cooling room was 8 and 9 d, respectively. Meat wrapped in PVC foil was characterized by unacceptable quality as soon as d 7 of storage in the display case, whereas the MAP meat was characterized by acceptable quality until the end of the experiment at 9 days. Thus, MAP packaging allows for the extension of the shelf life of meat in comparison to meat wrapped in PVC foil (in an atmosphere of normal air) by at least one d in the cooling room storage, and more importantly by 2 d for display case storage.

Using Density Measurement on Semispinalis capitis as a Tool to Determinate the Composition of Pork Meat

The aim of the present study was an attempt to utilize density measurements using different methods as 3D scanning, hydrostatic, and pycnometric for the estimation of chemical composition of 20 pork semispinalis capitis. The density determined with direct (hydrostatic, pycnometric) and indirect (3D scanning) methods was correlated with water, protein, fat, and ash content. The highest correlation coefficients (absolute value) between density and water (r = 0.86), protein (r = 0.79), and fat (r = − 0.87) content of pork necks were found for hydrostatic method. Despite the standard error of prediction (SEP) obtained for density determination using 3D scanning method was close to acceptable tolerance range recommended by the EU law, which amounts to 20% mean value on the declaration of calculated fat and protein content in a product, further studies are needed on a larger population of samples.

The Effect of Drying Parameters on the Quality of Pork and Poultry-Pork Kabanosy Produced according to the Traditional Specialties Guaranteed Recipe

The aim of this study was to determine the effect of differentiated air relative humidity during the drying process on selected quality features of TSG (traditional specialties guaranteed) pork and poultry-pork kabanosy. After heat treatment and 24-hour cooling at 4–6°C, the products were placed in three chambers at 15°C with differentiated air relative humidity: 60, 70, and 80%, respectively. The drying process was carried out until all variants of kabanosy achieved the required final yield of the product (<68%). Color components, water activity and shear force, water, protein, fat, and salt content, and the TBARS indicator values were determined. The drying process might be shortened (~50%) by a reduction of humidity in the drying chamber from 80 to 60%. The changes in the content of chemical components in pork kabanosy compared to poultry-pork ones demonstrated the different dynamics of the drying of the two types of kabanosy and the need for the selection of optimum drying conditions relative to raw material composition.

Influence of feed additives used in prevention of coccidiosis on the quality of enteric microflora of fast-growing and slowgrowing chickens / Wpływ wybranych dodatków paszowych stosowanych w profilaktyce kokcydiozy na jakość mikroflory jelit kurcząt szybko i wolno rosnących

Abstract The experiment was conducted on 480 Hubbard Flex chickens (fast-growing) reared to 42 days of age and 480 Hubbard JA 957 chickens (slow-growing) reared to 63 day of age. Day-old chicks were randomly assigned to the three following groups according to the type of coccidiostat: C (control - no coccidiostat in the diet and birds not vaccinated against coccidiosis), A (plant coccidiostat adiCox® AP), and M (monensin coccidiostat). At the end of rearing period the results of the controlled production were presented, the chickens were slaughtered and samples of their intestines were collected for microflora composition analyses. The obtained results show that rearing time influenced the composition of enteric microflora (small intestine and blind gut). Moreover, a higher total count of bacteria was stated in intestinal digesta of the slow-growing chickens that were kept for three weeks longer than the Hubbard Flex chickens. The study also proved a positive influence of the diet on the quantitative composition of enteric microflora. The lowest count of mesophilic bacteria and those from the Enterobacteriaceae family was observed in the chickens receiving adiCox® AP compared to the chickens of the control group and those receiving monensin. Streszczenie Doświadczenie przeprowadzono na 480 kurczętach szybko rosnących Hubbard Flex, które utrzymywano do 42 dnia życia i 480 kurczętach wolno rosnących Hubbard JA 957, odchowywanych do 63 dnia życia. Jednodniowe pisklęta przydzielono losowo do 3 grup żywieniowych w 4 powtórzeniach: K (kontrolna - nie zawierała kokcydiostatyku w diecie i kurczęta nie były szczepione przeciwko kokcydiozie), A (kokcydiostatyk roślinny - adiCox® AP), M (kokcydiostatyk w paszy - monenzyna). Po zakończeniu odchowu, skontrolowano wyniki produkcyjne oraz od kurcząt z każdej grupy pobrano wycinki jelit do dalszych badań mikrobiologicznych. Wykazano wpływ czasu odchowu kurcząt na skład mikroflory treści jelita cienkiego i ślepego; ponadto stwierdzono większą ogólną liczebność bakterii w treści jelit kurcząt wolno rosnących, które utrzymywane były dłużej o 3 tygodnie, w porównaniu z kurczętami Hubbard Flex. Zaobserwowano pozytywny wpływ diety na stan ilościowy mikroflory jelita cienkiego. Najmniejszą liczebność bakterii mezofilnych oraz z rodziny Enterobacteriaceae wykazano w grupie otrzymującej w diecie preparat roślinny, w porównaniu z kurczętami z grupy kontrolnej i otrzymującej monenzynę.