Chemical composition and texture parameters of some selected muscles of the Polish Landrace fatteners slaughtered at different age

Skład chemiczny oraz kruchość mięsa kulinarnego należą do najważniejszych cech decydujących o jego jakości i wartości technologicznej. Parametry te zależą od czynników przedubojowych, takich jak: gatunek, rasa, płeć i wiek zwierzęcia, ponadto podatność na stres, charakter i tempo przemian fizjologicznych zachodzących w mięśniach, stopień umięśnienia i rodzaj mięśnia. Tuczniki rasy polskiej białej zwisłouchej (36 szt.) ubijano w: 60., 90., 120., 150., 180. i 210. dniu życia (po 6 szt. w każdej grupie wiekowej). Mięśnie najdłuższy grzbietu (m. longissimus dorsi) – LD i półbłoniasty szynki (m. semimembranosus) – SM poddano analizie chemicznej, oznaczając zawartość suchej masy, białka, tłuszczu i popiołu. Mięśnie pieczono w 180°C do temperatury wewnętrznej 78°C. Następnie za pomocą teksturometru TA–XT2 firmy Stable Micro Systems oznaczono parametry tekstury oraz siłę cięcia analizowanych mięśni tuczników. W mięśniach starszych tuczników wykazano większą zawartość białka i tłuszczu oraz wzrost wartości siły cięcia i twardości TPA mięśni, w stosunku do osobników młodszych. Poziom białka w mięśniu LD wahał się od 21,0% w 60. dniu życia do 24,9% w 210. dniu życia, a w SM odpowiednio od 20,4 do 23,9%. Zawartość t łuszczu w LD wahała się od 1,2 do 1,8%. Siła cięcia mięśni LD i SM była porównywalna i wahała się od około 3,1 kG/cm2 w 60. dniu życia do około 5,8 kG/cm2 w 210. dniu życia. Natomiast wartość twardości (TPA) wynosiła 54,2 (LD) i 92,5 N (SM) w 60 dniu oraz 129,6 (LD) i 126,0 N (SM) w 210 dniu.Chemical composition and tenderness of the culinary meat are among the most important characteristics determining the quality and technological value of meat. Those parameters depend on the pre-slaughter factors such as: species, race, sex, and age of animal, as well as on its resistance to stress, its character and tempo of physiological changes occurring in its muscles, degree of muscling, and type of muscle. The Polish Landrace fatteners (36 animals) were slaughtered on the 60th, 90th, 120th, 150th, 180th, and 210th day of life (six animals in each age group). The m. longissimus dorsi –LD and m. semimembranosus – SM (from ham) were chemically analyzed and the following parameters were determined: dry matter/water content, protein content, fat content, and ash content. The muscles were roasted at 180°C to reach the inside temperature of 78°C. Then, the two parameters of the fatteners’ muscles were determined: texture profile and Warner-Bratzler force of cut, using a TA-XT2 texture analyzer (manufactured by a Stable Micro Systems Co.). It was found that in the muscles of older fatteners, the content of protein and fat was higher; also, compared with the younger fatteners, the increase in the force of cut and in the TPA hardness of their muscles was found. The protein level in the LD muscle ranged from 21.0% on the 60th day of life to 24.9% on the 210th day of life; whereas in the SM muscle, it was 20.4% and 23.3%, respectively. The fat content in LD ranged from 1.2% to 1.5%. As for LD and SM muscles, the force of cut was comparable and ranged from app. 3.1 kG/cm2 on the 60th day of life to app. 5.8 kG/cm2 on the 210th day of life. The hardness value (TPA) was 54.2 N (LD) and 92.5 N (SM) on the 60th day of life, and 129.6 N (LD) & 126.0 N (SM) on the 210th day

The effect of caponization on bone homeostasis of crossbred roosters. I. Analysis of tibia bone mineralization, densitometric, osteometric, geometric and biomechanical properties

Abstract The presented study focuses on assessing the effect of caponization on the densitometric, osteometric, geometric and biomechanical parameters of tibial bones in crossbred chickens. The study was carried out on 96 hybrids between Yellowleg Partridge hens (Ż-33) and Rhode Island Red cockerels (R-11) aged 16 weeks, 20 weeks and 24 weeks. Birds were randomly assigned to 2 groups-the control group (n = 48; which consisted of intact roosters) and the experimental group (n = 48, which consisted of individuals subjected to caponization at the age of 8 weeks). The caponization had no effect on the densitometric, osteometric and geometric parameters (except the horizontal internal diameter of 16-week-old individuals) of tibia bone, as well as the content of calcium (Ca), phosphorus (P) and the Ca/P ratio in the bone mineral fraction in all analyzed age groups of animals. However, it contributes to a lower percentage of ash in the bones of capons at 20 and 24 weeks of age compared to cockerels. On the contrary, some mechanical and material parameters show the negative effect of caponization. Ultimate load and bending moment decreased in capons in all of the analyzed age groups of animals and yield load, stiffness and ultimate stress also decreased but only in the group of 20-week-old and 24-week-old individuals. This can contribute to the weakening of the capon bones, and in the perspective of prolonged maintenance to their deformation and even fracture

The effect of caponization on tibia bone histomorphometric properties of crossbred roosters

Abstract The negative effect of caponization on the structural, geometric and mechanical parameters of femur and tibia has been shown in a few studies. Nevertheless, its influence on tibia bone microarchitecture is still largely unknown. Therefore, this study aimed to assess the effect of castration on the microstructural parameters of the trabecular and compact bone of tibia bone in crossbred chickens. The experiment involved 96 roosters derived from crossing Yellowleg Partridge hens ( $${\dot{\text{Z}}}$$ Z ˙ -33) and Rhode Island Red cockerels (R-11) fattened until the 16th, 20th and 24th week of life. Animals were randomly divided into 2 groups of 48 each. Group I (control) consisted of intact roosters and group II (experimental) consisted of birds subjected to caponization at the 8th week of age. The castration surgery had no influence on some properties within compact bone such as osteon diameter On.Dm, osteon perimeter On.Pm, osteon area On.Ar, osteocyte lacunar number Ot.Lc.N, osteon bone area On.B.Ar, osteon wall thickness On.W.Th as well as thick-mature collagen content in all analyzed age groups of animals. Nevertheless, our results demonstrate that castration caused a decrease of Haversian canal area Hc.Ar, osteocyte lacunar area Ot.Lc.Ar and osteocyte lacunar porosity Ot.Lc.Po among the 16-week-old birds, decrease of Haversian canal perimeter Hc.Pm and increase of fraction of bone area On.B.Ar/On.Ar among 16- and 24-week-old individuals and also an increase of osteocyte lacunar density Ot.Lc.Dn in the osteons of the oldest roosters. Additionally, some microstructural parameters of trabecular bone show the negative effect of caponization. The youngest 16-week-old capons were characterized by thinnin the trabecular in the epiphysis part of tibia. Moreover, in the case of 24-week-old, there is an increase in the trabecular separation Tb.Sp with simultaneous decrease of trabecular number Tb.N compared to roosters, which may suggest the increase of the bone resorption among the oldest individuals. The increased bone turnover in the epiphysis part of the tibia bone also indicates changes in the collagen fibers distribution, where among 20-week-old animals there is a decrease in the content of immature thin collagen fibers with simultaneous increase in the content of mature thick collagen fibers. Furthermore, among the oldest 24-week-old individuals we can observe the increased thick-to-thin collagen ratio, which may be a sign of slowing down in bone formation

Effects of breed and age of pigs on the properties of model meat batters and sausages

Celem badań było porównanie termostabilności modelowych farszów oraz podstawowego składu chemicznego, tekstury i jakości sensorycznej modelowych kiełbas wytworzonych z mięsa świń ras pbz, wbp, duroc, pietrain i puławska, ubijanych w wieku 120, 150, 180 i 210 dni. Do badań wykorzystywano mięśnie: najdłuższy grzbietu (m. longissimus dorsi - LD) i półbłoniasty (m. semimembranosus - SM). Na podstawie różnicy masy farszów przed i po ogrzewaniu wyliczano wydajność i wyciek cieplny. Podstawowy skład chemiczny kiełbas oznaczano według Polskich Norm. Analizę profilu tekstury (TPA) i pomiary siły cięcia wykonywano przy użyciu teksturometru TA-XT2. Analizę sensoryczną przeprowadzał 5-osobowy przeszkolony zespół o sprawdzonej wrażliwości sensorycznej. Największą stabilnością cieplną charakteryzowały się farsze z mięsa świń pbz i wbp, a najmniejszą z mięsa duroc. Zawartość białka w kiełbasach, niezależnie od rasy i wieku świń, była zbliżona i wynosiła około 13 %. Najmniej wody i najwięcej tłuszczu stwierdzono w wyrobach z mięsa świń pbz i duroc, a najwięcej wody i najmniej tłuszczu z mięsa pietrain. Wraz z wiekiem zwierząt, z których pochodziło mięso, zawartość wody w kiełbasach zmniejszała się, a tłuszczu zwiększała. Twardość TPA kiełbas z mięsa świń ras puławskiej i pietrain była większa niż modelowych produktów z mięsem innych ras. Wartości sprężystości, kohezji, żujności i odbojności kiełbas z mięsa świń duroc były większe w porównaniu z kiełbasami z mięsa innych ras. Najmniejszą sprężystością i kohezją charakteryzowały się kiełbasy z mięsa pietrain i puławskiej. Twardość TPA kiełbas z mięsa zwierząt w grupach wiekowych do 180 dni nie zmieniała się, a zwiększała się w produktach z mięsa świń 210-dniowych, natomiast wartości pozostałych parametrów tekstury były istotnie większe w kiełbasach z mięsa świń 150-dniowych. Wartości siły cięcia były największe w przypadku modelowych kiełbas z mięsa rasy puławskiej i w grupie wiekowej 150 dni, a najmniejsze z mięsa pietrain oraz świń 120-dniowych. Jakość sensoryczna modelowych przetworów była na poziomie dobrym. Najniżej oceniono kiełbasy z mięsa rasy duroc oraz ze zwierząt ubitych w 120. dniu. Optymalną przydatnością do produkcji kiełbas drobno rozdrobnionych parzonych charakteryzowało się mięso świń ras pbz, wbp, puławskiej i pietrain ubitych w 150. dniu chowu. Mniej przydatne do tego rodzaju przetworów było mięso świń duroc.The objective of the investigations was to compare the thermostability of model meat batters and the basic chemical composition, texture, and sensory quality of model sausages from pig meat of the following pig breeds: Polish landrace (pbz), Polish large white (wbp), duroc, pietrain, and puławska. Pigs were 120, 150, 180, and 210 days old when slaughtered. The muscles investigated were m. longissimus dorsi (LD) and m. semimembranosus (SM). The values of yield of batters and cooking losses were calculated based on differences between the masses of batters prior to and after the heating. The basic chemical composition of sausages was determined according to the relevant Polish Standards. The Texture Profile Analysis (TPA) and shearing force measurement were performed using, a TA-XT2 texture analyzer. The sensory analysis was carried out by a team consisting of 5 properly trained persons whose sensory receptiveness levels were proved to be fit. The batters made from the pbz and wpb pig meet were characterized by the highest thermostability level, whereas the batters from the duroc pig meat – by the lowest. The protein contents in sausages were rather similar, they did not depend on the breed and age of pigs, and amounted ca. 13 %. The highest fat and the lowest water contents were found in meat products from meat of the pbz and duroc pigs, whereas the highest water and the lowest fat contents in products from meat of the pietrain pigs. With the advancing age of animals used to manufacture meat sausages from their meat, the water content decreased and the fat content increased. The TPA hardness of sausages made from meat of the puławska and pietrain breeds had a higher value than the TPA hardness of model products made from meat of other breeds. The springiness, cohesiveness, chewiness, and resilience values of sausages made of the duroc pig meat were higher compared to the sausages from meat of other pig breeds. The sausages manufactured from meat of the pietrain and puławska breeds were characterized by the lowest springiness and cohesiveness levels. The TPA hardness values of sausages made from meat of pigs slaughtered at the age not exceeding 180 days did not change, however, they increased in sausages made from meat of 210-day old pigs. The values of other texture parameters were significantly higher in sausages made from meat of 150-day old pigs. The shear force values were the highest in model sausages made from meat of the puławska breed and from meat of 150-day old pigs, and the lowest in sausages from meat of the pietrain breeds and from meat of 120-day old pigs. The sensory quality level of all the model products was good. The sausages made from meat of the duroc breed and of the pigs slaughtered on their 120th day of age were assessed as having the lowest sensory quality. The meat of the pbz, wbp, puławska, and pietrain pig breeds, and slaughtered at the age of 150 days, proved to have the optimal usefulness for manufacturing fine ground, scalded sausages. The meat of the duroc pigs was less useful for manufacturing such products