The Influence of Genotype, Market Live Weight, Transportation, and Holding Conditions Prior to Slaughter on Broiler Breast Meat Color

A study was conducted to determine the influence of genotype, market live weight, transportation time, holding time, and temperature on broiler breast fillet color under commercial processing in Italy. Color was evaluated using a Minolta Chroma Meter (Minolta Chroma Meter CR-300, Minolta Italia S.p.A., Milano, Italy) on a total of 6,997 broiler breast fillets (Pectoralis major muscle) from 79 different flocks chosen at random during a 6-mo period. The flocks were represented by Ross 508 and Cobb 500 genotypes of both genders, processed at different ages, and subjected to different antemortem conditions during transport and holding. Ross 508 broilers exhibited a lower hue angle (H*) than did Cobb 500 (45.12 vs. 48.52; P 3.3 kg) produced a darker breast meat (L* = 51.67) than did the lighter birds (210 km (a* = 3.28 and 3.04, respectively). The shortest holding time (9 h (L* = 52.12 and 52.04, respectively). Furthermore, an increase of both meat a* and saturation (C*) was observed with the advance in holding time. The holding temperature significantly affected the meat color. Breast fillets from birds held at 18°C (L* = 53.11) (P 18°C) also determined a lower breast meat a* (3.77 vs. 3.12 vs. 2.72, respectively; P < 0.001), b* (3.72 vs. 3.41 vs. 3.37, respectively; P < 0.05), C*, and H*. In conclusion, the holding time and temperature exerted the most important effect on broiler breast meat color. However, other factors, such as genotype, live weight, and transportation, may influence breast meat color

Effects of transport and lairage on mortality, live weight loss and carcass quality in broiler chickens.

Influenza del trasporto e della sosta premacellazione sulla mortalit\ue0, sulla perdita di peso e sulla qualit\ue0 della carcassa di pollo. Nel corso della ricerca sono stati esaminati 321 lotti di broilers macellati in condizioni industriali su cui sono stati determinati i seguenti parametri: tasso di mortalit\ue0, perdita di peso vivo, percentuale di carcasse non idonee al consumo, percentuale di ematomi in petto, cosce ed ali. Gli animali trasportati per tempi pi\uf9 brevi (&lt;3,5h) hanno fatto rilevare un tasso di mortalit\ue0 inferiore rispetto a quelli trasportati per tempi medi (3,5-5h) e lunghi (&gt;5h) (0,24 vs. 0,41 e 0,45%; P&lt;0,01). La perdita di peso \ue8 risultata superiore (P&lt;0,01) per tempi di trasporto pi\uf9 lunghi (2,09%) rispetto a quanto osservato per i tempi medi (1,87%) e brevi (1,27%). Negli animali sottoposti ai trasporti pi\uf9 brevi \ue8 stata inoltre rilevata una superiore incidenza di ventrigli con un eccessivo stato di riempimento. La durata della sosta premacellazione non ha influenzato significativamente alcuno dei parametri considerati

The influence of linseed on rabbit meat quality

[EN] A research project was conducted to study the influence of the dietary use of whole linseed on rabbit meat quality. A total of 288 growing rabbits were fed ad libitum (from 55 to 81 d old) with a commercial diet (C) or experimental diets containing 3, 6, or 9% whole linseed (L3, L6 and L9, respectively). After slaughtering, L. lumborum muscles and rabbit meat hamburgers were used to determine pH, colour, cooking loss, total lipid content, fatty acid composition and induced TBARS. Hind leg muscles were analyzed for total lipid content, fatty acid composition and induced TBARS. Finally, a sensory test was carried out to establish the level of acceptability of rabbit meat hamburgers prepared with the meat batters stored for 3 or 6 months at -20°C. The use of linseed determined a lower content of total saturated fatty acid and a higher content of PUFA (P<0.01) in all types of meat. The PUFA n-3 content of the meat increased significantly (P<0.01) with the increasing level of whole linseed in the diet, mainly due to the higher content of alpha-linolenic acid, which also determined a reduction of the n-6/n-3 PUFA ratio. The hamburgers prepared from L6 and L9 groups exhibited higher TBARS values in comparison with L3 and C. Furthermore, the cooking loss of hamburgers was lower in meat from rabbits fed the control diet (C), intermediate in L3 and higher in L6 and L9 (P<0.01). With regard to sensory analysis, the diet did not determine significant differences in the acceptability of the hamburgers produced with frozen meat batters stored for 3 or 6 months. In general, the use of 3% linseed in diets for growing rabbits could be considered suitable for achieving both the enrichment of the meat with alpha-linolenic acid and maintaining good product quality characteristics.The authors are grateful to “F.lli Martini & C. S.p.A.” for technical assistance. Research funded by MIUR - PRIN ex 40%.Bianchi, M.; Petracci, M.; Cavani, C. (2009). The influence of linseed on rabbit meat quality. World Rabbit Science. 17(2):97-107. doi:10.4995/wrs.2009.6639710717

The European perspective on pale, soft, exudative conditions in poultry

ABSTRACT Over the past 15 yr, the European poultry processing industry has gradually increased the availability of poultry meat in a large variety of processed ready meals following what occurred a few years before in North America. This shift toward further processed products has emphasized the necessity for higher standards in poultry meat to improve sensory characteristics and functional properties. In parallel to this market change, the consciousness of the pale, soft, and exudative (PSE)-like meat issue has extensively grown. In poultry, PSE-like meat can be generally considered meat having low ultimate pH, pale color, and poor functional properties (i.e., low water-holding capacity). In the last 10 yr, some studies have been undertaken in Europe to both characterize and evaluate the overall incidence of PSE-like chicken and turkey breast meat. According to these studies, the occurrence of PSE-like meat can be up to 40% within a flock during hot climate. Several key factors have been identified and their effects have been analyzed, including genetics, season, antemortem factors, and slaughtering conditions

In operando XAS investigation of reduction and oxidation processes in cobalt and iron mixed spinels during the chemical loop reforming of ethanol

FeCo2O4 and CoFe2O4 nanoparticles have been studied as oxygen carriers for the Chemical Loop Reforming (CLR) of ethanol. By using in operando X-ray absorption spectroscopy we have followed in real time the chemical and structural changes that take place on the materials as a function of temperature and reactive atmosphere (i.e. ethanol/water streams). During the first step of CLR for both oxides the most active chemical species are the cations in the tetrahedral sites, irrespective of their chemical nature. Quite rapidly the spinel structure is transformed into a mix of wustite-type oxide and metal alloys, but the formation of a metal phase is easier in the case of cobalt, while iron shows a marked preference to form wustite type oxide. Despite the good reducibility of FeCo2O4 imparted by the high amount of cobalt, its performance in the production of hydrogen is quite poor due to an inefficient oxidation by water steam, which is able to oxidize only the outer shell of the nanoparticles. In contrast, CoFe2O4 due to the residual presence of a reducible wustite phase shows a higher hydrogen yield. Moreover, by combining the structural information provided by X-ray absorption spectroscopy with the analysis of the byproducts of ethanol decomposition we could infer that FeCo2O4 is more selective than CoFe2O4 for the selective dehydrogenation of ethanol to acetaldehyde because of the higher amount of Fe(III) ions in tetrahedral sites

Preslaughter risk factors associated with mortality and bruising in rabbits

[EN] The aim of this study was to identify and quantify risk factors associated with the mortality and bruising rate prevalence in 975 commercial batches of growing rabbits delivered for slaughter. The effects of environmental temperature, batch size (number of rabbits delivered per batch), journey and lairage duration on dead on arrival (DOA) and bruising prevalence were investigated and expressed as an odds ratio (OR). This value is equivalent to the relative risk, assessing each specific factor relative to its reference category (OR=1). The overall mortality rate of 0.09% was affected by environmental temperature, batch size, journey and lairage duration. A significantly increased DOA risk was associated with very low (=22.6°C; OR=1.85) environmental temperatures. In addition, a significantly higher odds ratio (OR=1.70) was observed in the largest batches (>=3681 rabbits). Both increasing journey and lairage duration dramatically increased the risk of death during the preslaughter period. Rabbits belonging to batches either transported or laired for a long time had a roughly threefold higher risk of death. The overall prevalence of bruise percentage was 2.13% and was affected by environmental temperature, batch size and journey duration. Environmental temperatures ranging from 7.3 to 12.4°C decreased the risk of bruising (OR=0.90), whereas temperatures from 17.5 to 22.6°C and higher than 22.6°C exhibited significantly higher OR values (1.22 and 1.34, respectively). Moreover OR values were higher for small (734 to 1716 rabbits; OR=1.21) and very small (=3681; OR=1.10). As for journey time, transport duration from 308 to 411 min and longer than 411 min duration increased bruising risk (OR= 1.15 and 1.19, respectively), while this risk was slightly decreased (OR=0.96) for medium journey duration (205 to 308 min). In conclusion, even though average DOA and bruising rates were quite low compared with chickens and turkeys, further logistics and planning improvements should be made in batch harvesting to reduce transport and lairage duration as far as possible in conjunction with extremely low and high environmental temperatures.This research was funded by MIUR - PRIN 2005.228Petracci, M.; Bianchi, M.; Biguzzi, G.; Cavani, C. (2010). Preslaughter risk factors associated with mortality and bruising in rabbits. World Rabbit Science. 18(4). doi:10.4995/wrs.2010.78121918

Color variation and characterization of broiler breast meat during processing in Italy

The variation in broiler breast meat color (L*a*b*) which normally occurs during processing was evaluated using a Minolta Chroma Meter on a total of 6,997 broiler breast fillets (P. major muscles) from a total of 79 different flocks. The samples were randomly collected at 3-6 h post-mortem from the deboning line at a single major Italian processing plant. In addition, a total of 216 fillets were selected based on lightness (L*) values as being dark (L*56) and analyzed for ultimate pH, intact and ground meat cooking loss and shear value. The overall range in measured lightness (L*) was considerable and varied from 40 (dark) to 66 (pale) indicating that high breast meat color variation during processing could exist. Broiler breast meat during summer was found to be paler (+1.7 L* unit), less red (-1.0 a* unit) and less yellow (-0.7 b* unit) than breast meat samples collected during the winter confirming that the incidence of pale meat is greater during summer as indicated by non-scientific observations of plant personnel. It was also determined that paler (L*>56) breast meat is associated with lower ultimate pH and poorer water holding capacity, while dark (L*<50) breast meat is associated with higher muscle pH and cooking yield

Incidence of white striping under commercial conditions in medium and heavy broiler chickens in Italy

Abstract Several types of muscle abnormalities are present in the poultry industry as a result of genetic selection, leading to decreased quality of meat and consequent economic loss. The appearance of thin (moderate) to thick (severe) white striping (WS) striations parallel to muscle fibers on the surface of broiler breast fillets is one of the most troubling issues in the poultry industry. White striping also has unfavorable implications on visual acceptance, nutritional value, and processing traits of breast meat. The aim of this survey was to assess the influence of market class (medium and heavy birds) and genotype (standard- and high-breast yield hybrids) on the incidence of WS in broiler chickens raised under commercial conditions in Italy. The incidence of WS for both medium and heavy broilers was high (43.0%), with 6.2% of samples considered severe. Heavy flocks had significantly higher percentages of both moderate (46.9 vs. 25.8%;P ≤ 0.001) and severe (9.5 vs. 2.7%;P ≤ 0.001) WS than medium flocks. Considering the effect of genotype, high-breast yield hybrids exhibited a higher incidence of both moderate (40.2 vs. 33.2%;P ≤ 0.001) and severe WS (7.2 vs. 5.0%;P ≤ 0.001) compared with standard-breast yield birds. In addition, within the medium class, the occurrence of WS reached higher levels in flocks of males. The heavy class consisted of male flocks separated into 2 slaughter weight categories. Birds that reached higher slaughtering weights (3.8–4.2 kg) exhibited higher incidence of WS than flocks slaughtered at lower weights (3.0–3.8 kg) at a similar age. In conclusion, the main broiler genotypes used for commercial production were affected by a high rate of WS; hybrids selected for higher breast yields were more prone to the WS abnormality. In addition, severe cases of WS are even more prevalent at higher slaughter age and weight, although reduced growth rate is associated with a lower incidence and severity of WS

Quantity and functionality of protein fractions in chicken breast fillets affected by white striping

Recently, white striations parallel to muscle fibers direction have been observed on the surface of chicken breast, which could be ascribed to intensive growth selection. The aim of this study was to evaluate the effect of white striping on chemical composition with special emphasis on myofibrillar and sarcoplasmic protein fractions that are relevant to the processing features of chicken breast meat. During this study, a total of 12 pectoralis major muscles from both normal and white striped fillets were used to evaluate chemical composition, protein solubility (sarcoplasmic, myofibrillar, and total protein solubility), protein quantity (sarcoplasmic, myofibrillar, and stromal proteins), water holding capacity, and protein profile by SDS-PAGE analysis. White-striped fillets exhibited a higher percentage of moisture (75.4 vs. 73.8%; P < 0.01), intramuscular fat (2.15 vs. 0.98%; P < 0.01), and collagen (1.36 vs. 1.22%; P < 0.01), and lower content of protein (18.7 vs. 22.8%; P < 0.01) and ash (1.14 vs. 1.34%; P < 0.01), in comparison with normal fillets. There was a great decline in myofibrillar (14.0 vs. 8.7%; P < 0.01) and sarcoplasmic (3.2 vs. 2.6%; P < 0.01) content and solubility as well as an increase in cooking loss (33.7 vs. 27.4%; P < 0.05) due to white striping defects. Moreover, gel electrophoresis showed that the concentration of 3 myofibrillar proteins corresponding to actin (42 kDa); LC1, slow-twitch light chain myosin (27.5 kDa); and LC3, fast-twitch light chain myosin (16 kDa), and almost all sarcoplasmic proteins were lower than normal. In conclusion, the findings of this study revealed that chicken breast meat with white striping defect had different chemical composition (more fat and less protein) and protein quality and quantity (low content of myofibrillar proteins and high content of stromal proteins) with respect to normal meat. Furthermore, white striped fillets had lower protein functionality (higher cooking loss). All the former changes indicate that white striping has great impact on quality characteristics of chicken breast meat