Journal of Muscle Foods最新文献

ABSTRACT

Administration of antibiotics or hormones to broiler chickens for therapeutic and performance-enhancing purposes may lead to deposit of residuals in their carcasses. This could be a potential human health hazard upon exposure to these residues. The objective of this study was to detect residue levels of tetracycline, streptomycin, sulfamethazine, chloramphenicol, trenbolon, estradiol-17ß, and testosterone in broiler chicken meat commonly marketed in the Sultanate of Oman. The Enzyme-Linked Immunosorbent Assay technique was used to detect residues in 128 broiler chicken breast muscles, representing various poultry processing companies from six countries representing four continents. Generally, samples contained various levels of residues of different antibiotic and hormones. Tetracycline levels ranged between 35 and 56 ng/kg (mean 45.9); streptomycin ranged between 30 and 155 ng/kg (mean 100.0); sulfamethazine levels ranged between 0.079 and 5.60 ng/kg (mean 1.07); trenbolon ranged between 0.70 and 3.12 ng/kg (mean 1.67); estradiol 17-ß ranged from 0.06 to 2.00 ng/kg (mean 0.70); chloramphenicol ranged from 5.00 to 74.00 ng/kg (mean 14.38); and testosterone ranged from 4 to 70 ng/kg (mean 25.53). There were significant differences in residue levels of antibiotics and hormones between the companies and countries. There were significant differences in antibiotic and anabolic agents' residues with the exception of trenbolon between continents. This study indicated that broiler chicken meat products available in the local market contained various levels of residues of several antibiotic and anabolic agents. Although levels of some of these residues did not exceed the maximum allowable limits, they still poise a human health hazard.

PRACTICAL APPLICATIONS

There has been an increasing awareness of the widespread drug therapy and the possibility of residues in meat and consequently the potential human health hazards associated with exposure to these residues. Many of these are now classified as carcinogenic, toxic and allergenic, which interfere with human natural physiological functions. The Enzyme-linked Immunosorbent Assay (ELISA) is one of the sophisticate techniques to detect residuals based on enzyme-labeled reagents. Therefore, investigations using ELISA technique to monitor residues of various drugs in meat products should be applicable to insure the safety of animal food products for human consumption.

ABSTRACT

A confounded factorial conjoint choice experiment was conducted with 12 University of Nebraska classes (six Animal Science and six Statistics classes) to examine the effects of price, country-of-origin labeling, marbling, tenderness guarantee, traceable-to-the-farm labeling, class discipline and the possibility of receiving a gift on preferences toward beef rib-eye steaks. All factors, except class discipline and the possibility of receiving a gift, had a significant impact on consumer preferences. Based on the odds ratios, the relative importance of these factors were price (1.97), tenderness guarantee (1.92), country-of-origin label (1.68), marbling (1.43) and traceable-to-the-farm labeling (1.30). This relative order of importance was also supported by the willingness-to-pay estimates: tenderness guarantee ($3.03/lb), country-of-origin label ($2.40/lb), marbling ($1.67/lb) and traceable-to-the-farm label ($1.20/lb). Preferences were also affected by a number of interactions. Our results indicated that a tenderness guarantee and country-of-origin label are almost as important as price in student purchase intent, but that the relative importance was dependent upon other factors such as the level of knowledge about beef and marbling level. In addition, the large number of significant interactions indicated and the ability to evaluate these interactions with confounded factorial conjoint experiments demonstrated the importance of using these experimental designs.

PRACTICAL APPLICATIONS

The relative importance of the factors studied was price, tenderness guarantee, country-of-origin label, marbling and traceable-to-the-farm labeling. Interactions among the factors also suggested that consumers knowledgeable about beef placed a high value on marbling when the country-of-origin was known, while the country-of-origin label had little impact on the value of marbling for less knowledgeable consumers. These results are useful in the packaging, placement, marketing and advertising of beef steaks. Also, we used confounded factorial conjoint choice experiments, which are promising new designs useful for assessing the effects of many factors and their interactions on consumer preferences that do not overburden respondents with long survey forms and provide more information than traditional choice experimental plans.

ABSTRACT

The aim of this study was to compare chemical parameters, fatty acid composition and mineral contents of farm animal meats which are marketed in Turkey. Different kinds of meats were purchased from the meat market including beef, lamb, broiler, turkey, ostrich and quail meat, which are mostly preferred for different reasons by consumers. However, little information exists about the composition of meats of different farm animal species. The results of proximate analysis showed that the high level of protein (24.38%) and low level crude fat (1.19 ± 0.13%) were found in turkey meats, while the low level of protein (18.75%) and high level fat (8.79%) were found in lamb meats. The fatty acid compositions of meats were in the range of 22.68–48.37% for saturated, 21.38–42.45% for monounsaturated and 3.75–47.47% for polyunsaturated acids. The highest micro mineral was determined as zinc (5.7417 ppm) in lamb and ostrich (5.0923 ppm).

PRACTICAL APPLICATIONS

Consumers attitudes toward meat “safety” greatly affect their overall choices and the variety of meat types available for sale. Some meats are more likely to cause heart disease – saturated fats and trans fats. These fats are usually found in foods from animals such as meat milk, cheese and butter. The dietary saturated fatty acids elevate serum cholesterol concentrations, whereas polyunsaturated fatty acids reduce serum cholesterol concentrations and monounsaturated fatty acids have little or no effect. Therefore, knowledge concerning the exact fatty acid composition of the meat is extremely important for the consumer and processing sector. This study provides comparative information to consumer and processing sector about proximate and fatty acid compositions and mineral contents of beef, lamb, broiler, turkey, ostrich and quail meats.

ABSTRACT

A mixture design approach was used to evaluate interactions between carrageenan, gellan gum and flaxseed gum and their effect on total expressible fluid, texture and color of starch-free emulsion type sausage. Increase in the content of carrageenan in the mixture lead to higher total expressible fluid, lower cohesiveness and springiness. Gellan gum had a notable effect in reducing total expressible fluid and improving sausage texture, producing better emulsion stability, increasing viscosity and springiness of the product. Flaxseed gum enhanced emulsion stability and hardness and springiness. All the three gums can improve redness of sausage. Interaction between carrageenan, gellan gum and flaxseed gum improved water-holding capacity, texture and color of the sausage. The optimal values of carrageenan, gellan gum and flaxseed gum in the mixture were 11–27%, 67–82%, 0–12%, respectively.

PRACTICAL APPLICATIONS

Starch and nonmeat protein are very important extenders in emulsion-type sausage production. To prevent water and fat loss during cooking processes is very critical for the quality attributes of emulsion-type sausage without starch and nonmeat protein. Results of this study can be applied to this kind of sausage to prevent water and fat loss. By applying the optimal condition, we can obtain the sausages with good water- and fat-holding capacity and desirable texture.

ABSTRACT

The objective of this study was to determine the influence of hydrodynamic pressure processing (HDP) and aging on the overall quality and protein characteristics of pork loins. Boneless pork loins (n = 12) were split into anterior and posterior halves and were assigned to control and HDP treatments. Following treatment on day 0, each half was divided into two portions (0 and 7 days aging). Samples were removed for the determination of Warner–Bratzler shear force (WBSF), centrifugal moisture loss (CML), gravitational drip loss (DL), color, protein solubility and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis of whole muscle protein extracts. WBSF decreased with HDP (P < 0.05) and aging treatments (P < 0.0001). CML decreased (P < 0.0001) with aging. Controls exhibited slightly less DL after 1 day than HDP samples, but the increase in DL between 1 and 7 days was similar for control and HDP samples.

Treatment effects on L*, a* and b* measurements were minimal. Myofibrillar and total protein solubility were higher (P < 0.01) in HDP samples compared with controls at day 0 but not at day 7. Sarcoplasmic protein solubility decreased (P < 0.05) with aging. SDS-PAGE analysis of muscle proteins demonstrated a strong aging effect and only minor HDP differences. With aging, bands corresponding to 30–33 and 135 kDa increased (P < 0.0001), while bands corresponding to 38 and 95 kDa decreased (P < 0.05) in intensity (relative to the actin band). The 60 kDa band intensity increased (P < 0.05) with both aging and HDP treatments. Thus, data from this study suggest that HDP enhances aging tenderization in pork loins through the physical disruption of the muscle ultrastructure while having little detrimental effect on other parameters of pork quality.

PRACTICAL APPLICATIONS

This study demonstrates that hydrodynamic pressure processing is an effective postharvest technology for enhancing aging tenderization in pork loins through the physical disruption of the muscle ultrastructure with minimal impacts on other pork quality parameters such as water-holding capacity and color.

ABSTRACT

The objective of this study was to determine the effects of pre-harvest Mg supplementation and stunning method on longissimus (LM) and semitendinosus (SM) pork muscle quality. Magnesium was supplemented for 2 days in drinking water (300 ppm) before pigs were harvested at a commercial packing plant using either electrical or CO₂ stunning. Magnesium supplementation did not affect (P > 0.10) ultimate pH, initial fluid loss, retail display purge loss or color of the LM and SM. Pork quality was generally improved in LM and SM samples obtained from the plant using CO₂ stunning as evidenced by reduced initial fluid loss (P < 0.001), reduced purge loss (P < 0.05) and lower L* (darker), a* (less red) and b* (less yellow) values (P < 0.05) during an 8-day retail display. Pork quality was improved when using CO₂ stunning technology; however, Mg supplementation did not improve pork quality in either plant.

PRACTICAL APPLICATIONS

Pork quality is one of the main issues for the pork industry to consider in order to remain competitive in a global market. We evaluated the supplementation of Mg through the water in collaboration with a swine production company and two large commercial packing plants. Clear differences in pork quality were evident, with the packing plant using CO₂ stunning having superior pork quality compared with the plant using electrical stunning. Supplementation of Mg through water can be applied on the farm immediately at a very low cost, but was not effective in improving pork quality in two commercial packing plants under practical conditions.

ABSTRACT

The seasonal lipid variation and fatty acids compositions were assessed in white and red muscles, head, viscera, liver and gonads of little tuna Euthynnus alletteratus. Lipid contents showed a significant variation (P < 0.05) throughout the year, the maximum level was found in the liver during winter season (27.28 g/100 g). The lowest fat contents were found in gonads during the winter and spring seasons, with levels of 1.56 and 1.49 g/100 g, respectively. White and red muscle fat levels increased significantly from winter to summer; viscera lipids, however, showed a significant decrease during the same period. Generally, the increase of the polyunsaturated fatty acids percentage in most organs was usually accompanied with a decrease of saturated fatty acids. It was shown that lipid content was higher in the head and liver compared to other compartments, and the fatty acid composition in the different organs of little tuna was significantly influenced by spawning and season. All lipids extracted contained significant amounts of docosahexaenoic acid and eicosapentaeneoic acid, which have various physiological functions.

PRACTICAL APPLICATIONS

Most of the available literature showed little information about biochemical composition of fillets and by-products of some fish species and are, therefore, not complete for industrial purposes as application in food or feed nutriment. The practical application of this study was performed by the determination of fatty acids levels of little tuna fillets (white and red muscles) and by-products (head, viscera, liver and gonads) to further explain the evolution of lipid and fatty acids throughout the year. Finally, this manuscript may provide some valuable information for other scientists working in the field of food technology.

ABSTRACT

A total of 324 swab samples were collected from organized slaughterhouses and retail outlets at various processing steps from poultry carcasses, and the samples were processed for total viable counts (TVCs) and differential counts. The TVCs (log₁₀ cfu/cm² ± standard error) in organized slaughterhouses at different processing steps were found to be 5.18 ± 0.09 after shackling, 5.24 ± 0.15 after bleeding, 3.95 ± 0.14 after scalding and defeathering, 5.26 ± 0.15 after evisceration and 4.98 ± 0.17 after cutting, while the same in retail outlets were 6.63 ± 0.21 before slaughter, 7.29 ± 0.20 after bleeding, 6.53 ± 0.24 after removal of skin with feathers, 7.24 ± 0.26 after evisceration and 7.40 ± 0.22 after cutting, respectively. Analysis of variance for TVC during different steps in both revealed highly significant differences (P < 0.01). Also, the contamination during various steps varied significantly. The differential counts revealed that Escherichia coli was predominant in all processing steps in organized slaughterhouses, whereas Staphylococcus aureus, E. coli and Clostridium spp. were present in all steps in retail outlets. Twenty samples in retail outlets showed the presence of Salmonella spp. The average prevalence of all organisms isolated during various processing steps in organized slaughterhouses and retail outlets are 9.13 and 82.21% S. aureus, 0 and 47.49% Bacillus cereus, 14.99 and 39.23% Clostridium spp., 17.46 and 81.52% E. coli, and 0 and 10.55% Salmonella spp.

PRACTICAL APPLICATIONS

The study concluded that retail outlets showed highest bacterial counts as well as maximum number of isolates as compared with organized slaughterhouses. Bacillus cereus and Salmonella spp. were absent in hygienically processed carcasses. Evisceration, as well as scalding and defeathering, was found to be the critical operations in organized slaughterhouses, while cutting, bleeding, evisceration and removal of skin with feathers were noted as the critical operations in retail outlets. The presence of pathogenic microbes on poultry carcasses in organized slaughterhouses and retail outlets delineates the different hazards to the consumers from such pathogens and the need for a comprehensive quality assurance program especially in small poultry slaughtering and dressing units to ensure safe and wholesome meat to consumers.

ABSTRACT

In an attempt to improve the chemical, physical and sensory properties of beef burgers containing 11.5–13.7% fat, trials were carried out on eight experimental burger formulations containing carrageenan (0.5%), texturized soya (1.5%) and trisodium phosphate (0.5%), either alone or in different combinations, and compared with a control prepared only with the addition of salt and water. The data obtained were analyzed using a complete randomized design to study the effect of treatments on the proximate composition, thiobarbituric acid reactive substances (TBARS) value, percentage cooking loss, percentage diameter loss and sensory evaluation. The significant difference of the mean was determined using the least significant difference method. Although initial weight, cooked weight, initial diameter length and cooked diameter length were analyzed using means ± standard error. Analyses revealed unexpected interactions between some of the ingredients, the nature of which was not investigated. Results showed that the addition of carrageenan alone improved crude protein content, juiciness and overall acceptability of the beef burger, but it affected the appearance negatively, although there was no significant effect on diameter loss and thickness loss when compared with the control.

Beef burger prepared with the addition of texturized soya alone increased moisture binding and protein level, while it lowered flavor score compared with the control. With respect to the oxidative rancidity, TBARS value was found higher for the market sample; this value was significantly lower with the addition of combination of texturized soya and trisodium phosphate.

It has been found that the addition of a combination of carrageenan, texturized soya and trisodium phosphate reduced the cooking loss compared with the control, while there was no significant effect on the diameter loss and thickness loss of all treatments.

It was also found that the combination of carrageenan, texturized soya and trisodium phosphate improved all sensory attributes and improved protein contents compared with the control.

The sensory scores were highly correlated with each other. No significant correlations were found between moisture percentage and cooking loss together and sensory attributes, while there were high correlations between the TBARS and fat percentage with sensory attributes.

PRACTICAL APPLICATIONS

Reducing the fat content of beef burgers can make a significant contribution to human health and ensure the continuing popularity of this type of convenience food around the world. However,