P.J. Shand

Road transport of cattle, swine and poultry in North America and its impact on animal welfare, carcass and meat quality: A review

This paper reviews the effects of road transport on the welfare, carcass and meat quality of cattle, swine and poultry in North America (NA). The main effects of loading density, trailer microclimate, transport duration, animal size and condition, management factors including bedding, ventilation, handling, facilities, and vehicle design are summarized by species. The main effects listed above all have impacts on welfare (stress, health, injury, fatigue, dehydration, core body temperature, mortality and morbidity) and carcass and meat quality (shrink, bruising, pH, color defects and water losses) to varying degrees. It is clear that the effect of road transport is a multi-factorial problem where a combination of stressors rather than a single factor is responsible for the animals well-being and meat quality post transport. Animals least fit for transport suffer the greatest losses in terms of welfare and meat quality while market ready animals (in particular cattle and pigs) in good condition appear to have fewer issues. More research is needed to identify the factors or combination of factors with the greatest negative impacts on welfare and meat quality relative to the species, and their size, age and condition under extreme environmental conditions. Future research needs to focus on controlled scientific assessments, under NA conditions, of varying loading densities, trailer design, microclimate, and handling quality during the transport process. Achieving optimal animal well-being, carcass and meat quality will entirely depend on the quality of the animal transport process.

Protein Oxidation in Processed Meat: Mechanisms and Potential Implications on Human Health

Processed meats represent a large percentage of muscle foods consumed in the western world. Various processing steps affect the physicochemical properties of the meat, compromise its nutritional components, or produce some compounds that are of health concern. Hence, the impact of oxidation on human health and the aging process and the influence of diet on these harmful reactions are of growing interest. Past decades have seen more focus on lipid oxidation, microbial deterioration, and pathogenicity, as well as production of carcinogenic compounds during meat processing. The oxidation of protein, which is a major component in meat systems, has received less attention. Protein oxidation has been defined as a covalent modification of protein induced either directly by reactive species or indirectly by reaction with secondary by-products of oxidative stress. Not only are these modifications critical for technological and sensory properties of muscle foods, they may have implications on human health and safety when consumed. Cooking, for example, has been observed to increase free radical generation while it also decreases the antioxidant protection systems in meat, both of which contribute to protein oxidation. Many other meat processing techniques, as well as other emerging technologies, may significantly affect protein oxidation and protein overall quality. This paper explores the current understanding of meat processing techniques and their possible effects on the status of protein oxidation and nutritional value, as well as their possible implications on human health.

Theory and methodology of antibiotic extraction from biomatrices

A short review on the basic theory and practices of the extraction and clean-up of agricultural antibiotics from biomatrices is presented. For the analysis of residues of ionophores, beta-lactams, macrolides, chloramphenicol, aminoglycosides, tetracyclines and peptide antibiotics, the use of solid-phase extraction has become nearly ubiquitous as part of the basic extraction methodology. The majority of the methodologies for these compounds report recoveries greater than 70%, with relative standard deviations usually less than 15%. Each of the antibiotic classes, as well as antibiotics within each class, have unique chemistries that must be taken into account when developing a viable extraction method.

Effect of blade tenderization and tumbling time on the processing characteristics and tenderness of injected cooked roast beef

The combined effect of blade tenderization (T, NT) and tumbling time (0, 2, 16 h) on quality characteristics of cooked beef roasts processed with 20 or 40% injection level was investigated. Properties of the beef roasts were determined by measuring processing and textural characteristics (shear force, texture profile analysis). Extended tumbling (to 16 h) favorably affected hydration properties and thermal stability, yielding lower cooking loss and purge and higher WHC for beef roasts. It also decreased shear force and hardness of beef samples by 50-60%, but was unable to increase cohesiveness. Blade tenderization prior to injection generally was found to be beneficial for textural characteristics, tended to improve cook yield, but did not influence other hydration properties. An interaction between tenderization and tumbling was observed for shear force. Blade tenderization decreased shear values by 15-20% for roasts tumbled for 0 or 2 h, but did not improve tenderness with extended tumbling.

Effect of lighting treatment on the productivity, health, behaviour and sexual maturity of heavy male Turkeys

1. Turkey poults (1620) were used to compare the effects of three lighting programmes on heavy strain males reared to 188 d: constant light (24L:0D, CON); increasing light (6L:18D at 7 d gradually increasing to 20L:4D by 63 d, INC); a pattern identical to INC followed by a decrease in daylength from 84 d to 10L:14D at 112 d (DID). 2. Lighting affected growth pattern but had no effect on body weight at 118 d or overall food to gain ratio. 3. Both INC and DID lighting reduced overall mortality in comparison to CON light primarily because of a reduction in the incidence of skeletal disease and spontaneous cardiomyopathy. INC and DID lighting increased the incidence of cannibalism. 4. Turkeys given INC or DID lighting had a superior ability to walk in comparison to those birds given CON light. 5. INC and DID males stood, ate and drank more frequently, and sat less often than CON turkeys during behavioural observation. 6. There were no lighting effects on carcase composition except that INC and DID birds had heavier keel bones. The ultimate force per cm2 (stress) required to break femora was greater for turkeys given INC and DID lighting (P = 0.065). 7. Plasma testosterone concentrations at 117 d were 272.5, 115.2 and 29.5 pg/ml for turkeys given CON, INC and DID lighting, respectively (P = 0.072). Testosterone concentration was not related to growth rate.

Effect of microclimate temperature during transportation of broiler chickens on quality of the pectoralis major muscle

This study investigated the effect of microclimate temperature during preslaughter transportation on chicken meat quality. Ninety broilers per load of 2,900 were monitored individually during 3 to 4 h of preslaughter transport in an actively ventilated trailer. Six transport test runs were conducted at average ambient temperatures of -27, -22, -17, -5, +4, and +11 degrees C. Birds were classified into 4 groups based upon the temperatures recorded in their immediate surroundings as follows: -16 to 0, 0 to 10, 10 to 20, and 20 to 30 degrees C. Internal body temperatures of the birds were recorded using Thermocron DS1922L iButtons. Birds were slaughtered in a commercial facility and meat quality of the chilled carcasses was evaluated by determination of pH, color, drip loss, thaw loss, cook loss, shear force, water-binding capacity, and pellet cook yield of the pectoralis major muscle. The breast meat from birds exposed to temperatures below 0 degrees C showed a significantly higher (P < 0.05) ultimate pH. Breast meat from birds exposed to temperatures below 0 degrees C showed significantly higher (P < 0.05) ultimate pH, a* value, water-binding capacity, and pellet cook yield and a significantly lower L* compared with breast meat of birds exposed to temperatures above 0 degrees C. The average core body temperatures were significantly lower (P < 0.05) during transport for birds exposed to temperatures below 0 degrees C compared with those exposed to temperatures between 0 and 10 degrees C. The latter birds had significantly lower (P < 0.05) core body temperatures compared with those exposed to temperatures above 10 degrees C. Thaw loss was significantly higher (P < 0.05) for breast meat of birds exposed to temperatures above 20 degrees C during transportation. There was no significant trend for b* value, drip loss, cook loss, or shear values based on environment temperature immediately surrounding the birds. Exposure to temperatures below 0 degrees C increased the incidence of dark, firm, and dry breast meat and decreased the incidence of pale, soft, and exudative breast meat. These results demonstrate that preslaughter transport may influence breast meat quality characteristics of broiler chicken.

Effects of raw binder system, meat cut and prior freezing on restructured beef ☆

The effect of different meat cuts or previously frozen meat on processing properties of restructured beef bound with alginate or Fibrimex(TM) was investigated. Inside rounds, chuck tenders, chuck clods and tri-tip were used to manufacture restructured logs. Steakettes manufactured with alginate had significantly (P<0.05) higher particle bind in the raw state but Fibrimex had greater bind between meat pieces after cooking. Choice of cut or use of previously frozen meat to manufacture restructured steakettes had no effect on any of the processing parameters measured. Steakettes made with Fibrimex were lighter, redder and yellower than those made with alginate. Redness and yellowness of steakettes decreased with retail storage time. However, the change in redness and yellowness over time was similar for both binders. Use of previously frozen meat resulted in a darker, less red steakette. When alginate was used to manufacture steakettes, cut had no affect on the acceptability of steakettes. However, when Fibrimex was used steakettes made from clod and tip were preferred by a consumer panel to steakettes made from tender and inside round.

Effect of comminution method and raw binder system in restructured beef.

The effect of particle size, method of particle size reduction (grinding, flaking, slicing) and alginate or Fibrimex(™) binding systems on processing properties of restructured beef were investigated. The size of semimembranosus muscles was reduced with a meat slicer, grinder or flaker (Comitrol) through machine openings that were 2, 4 and 8 mm in size. Bind of meat pieces in raw and cooked beef steakettes were measured. Sensory evaluation to determine the effect of method of size reduction on texture of beef steakettes was done only on steakettes manufactured with alginate. Beef steakettes manufactured with the alginate binding system had significantly (p < 0.05) higher raw bind values than did the beef steakettes manufactured with Fibrimex. Slicing meat for the manufacture of restructured beef steakettes resulted in a higher raw bind than did either grinding or flaking the meat. Significant (p < 0.05) interactions were observed for the bind of cooked steakettes between binder and method of size reduction and binder and opening size. When alginates were used to make restructured steakettes the bind of the cooked product was less (p < 0.05) when meat was sliced than when it was ground or flaked. However, when Fibrimex was used, bind was stronger when sliced meat was used. The alginate system resulted in higher binds for cooked product when particle size was smaller but with the Fibrimex system bind was higher when particle sizes were larger. A consumer panel on alginate restructured steakettes showed no preference for the texture produced by the different methods of particle size reduction.

Release of Angiotensin I-Converting Enzyme Inhibitory Peptides from Flaxseed (Linum usitatissimum L.) Protein under Simulated Gastrointestinal Digestion

The scope of this study was to determine the ability of flaxseed (Linum usitatissimum L.) proteins to release angiotensin I-converting enzyme inhibitory (ACEI) peptides during simulated gastrointestinal (GI) digestion using a static (SM; no absorption in the intestinal phase) and a dynamic model (DM; simultaneous absorption of digested products in the intestinal phase via passive diffusion). Gastric and gastric + small intestinal digests of flaxseed proteins of both models possessed ACEI activity. The ACEI activity of the gastric + small intestinal digest in the DM (IC(50) unabsorbed, 0.05 mg N/mL; IC(50) absorbed, 0.04 mg N/mL) was significantly higher (p < 0.05) than that of the SM (IC(50), 0.39 mg N/mL). Two peptides, a pentapeptide (Trp-Asn-Ile/Leu-Asn-Ala) and a hexapeptide (Asn-Ile/Leu-Asp-Thr-Asp-Ile/Leu), were identified in the most active ACEI fraction (0.5-1 kDa) of the absorbable flaxseed protein digest by de novo sequencing.

Effects of mechanical treatments and moisture enhancement on the processing characteristics and tenderness of beef semimembranosus roasts.

The combined effect of blade tenderization (TD,NTD), pre-massaging (0 and 30min), moisture enhancement and post-injection tumbling (2h) on the chemical, binding and textural characteristics of pre-cooked roasts made from beef top round was investigated. Properties of the beef roasts were determined by measuring processing (i.e., cooking yield, expressible moisture (EM)) and textural characteristics (Warner-Bratzler shear, Kramer shear (KS), texture profile analysis). Brine injection helped to improve the cook yield and had the largest effect on tenderness of semimembranosus muscles. Post-injection tumbling did not significantly improve yield and textural properties of roasts; however, combined with the tenderization, it had beneficial effects on water holding and moisture retention. Pre-tumbling and blade tenderization treatments prior to injection generally were found to be beneficial for textural characteristics; pre-tumbling also tended to improve cook yield, but did not influence EM. However, no synergistic effect between these two variables was observed. An interaction between injection/tumbling and pre-tumbling was observed for KS. There was a significant improvement of KS values of roasts due to pre-tumbling observed for either non-injected roasts or those injected but without tumbling. However, no additional reduction in shear force was observed with pre-tumbling when roasts were tumbled after injection. This suggests that pre-tumbling may not be necessary to ensure more tender roasts when post-injection tumbling is applied, but would be beneficial for non-injected roasts or when tumbling is not applied after injection.