Breeding objectives for a Nellore cattle rearing system

Abstract:The objective of this work was to define the traits that should be included as breeding objectives for Nellore cattle, according to simulations with a bio-economic model for rearing systems. The economic values (EVs) of the traits were calculated as the differences between the profits due to an increased performance of 1% in each trait, with the others traits remaining constant. To determine the impact of each selection on the revenue system, two scenarios were simulated based on the traits being selected. In the first scenario, the adopted selection criteria were: weaning weight (WW), weaning rate (WR), yearling weight (YW), and mature cow weight (MCW). In the second scenario, the cumulative productivity (CP) of dams was used as an indirect evaluation of the performance of calves, with all the other traits included, except WW. In the first scenario, an EV of R$ 1.44 kg-1 was obtained for WW. In the second scenario, an EV of R$ 2.91 kg-1 was obtained for CP. The trait with the highest EV in both scenarios was WR, which enhanced the profits by R$ 3.21 for each 1% increased performance. The meat price paid to the producer is the factor with the greatest impact on the EVs of all examined traits.

Integrated multivariate analysis to evaluate effects of pre-slaughter handling on pork quality

The aim of this study was to investigate the effect of pre-slaughter handling on the occurrence of PSE (Pale, Soft, and Exudative) meat in swine slaughtered at a commercial slaughterhouse located in the metropolitan region of Dourados, Mato Grosso do Sul, Brazil. Based on the database (n=1,832 carcasses), it was possible to apply the integrated multivariate analysis for the purpose of identifying, among the selected variables, those of greatest relevance to this study. Results of the Principal Component Analysis showed that the first five components explained 89.28% of total variance. In the Factor Analysis, the first factor represented the thermal stress and fatiguing conditions for swine during pre-slaughter handling. In general, this study indicated the importance of the pre-slaughter handling stages, evidencing those of greatest stress and threat to animal welfare and pork quality, which are transport time, resting period, lairage time before unloading, unloading time, and ambience.

Influence of secondary packing on the freezing time of chiken meat in air blast freezing tunnels

Freezing of poultry cuts in continuous convective air blast tunnels is normally performed with the products protected by Low Density Polyethylene (LDPE) as a primary packaging and using Corrugated Cardboard Boxes (CCB) as secondary packaging. The objective of this work was to investigate the influence of these secondary packaging on the freezing of poultry cuts in continuous convective air blast tunnels. The study was performed by replacing CCB with Perforated Metal Boxes (PMB) in order to remove the packaging thermal resistance. The assays, performed in a industrial plant, demonstrated that CCB used commercially for meat freezing have a high heat transfer resistance. Their replacement with PMB can lead to shorter freezing times and spatially homogeneous freezing. Reductions of up to 45% in the freezing times were observed using PMB. The plateau of the temperature curve, related to the freezing time of free water, was significantly reduced using PMB, which is accepted to lead to better product quality after thawing. As the products were protected by the LDPE films as primary packaging, their appearance were not affected. The results presented in this work indicate that replacing CBB with PMB can be an excellent alternative to reduce freezing time and improve freezing homogeneity in industrial air blast tunnels, which could also be applied to other products.

Influence of chitosan addition on quality properties of vacuum-packaged pork sausages

The aim of the study was to evaluate the influence of the chitosan addition on the quality of vacuum packaged pork sausages. A variant of the product was elaborated with 1% (w/w) of chitosan in lactic acid solution at 1% (v/v) and it was compared to a control. Sausages were mechanically stuffed and manually conformed and vacuum packaged. Sausages were stored at 4 °C and microbiological evaluations, pH measurements, texture profile analysis and sensorial evaluation were performed. The chitosan addition in the formulation of the sausages did not reduce the microbiological counts. The pH values obtained in all samples were similar, which suggests that the chitosan addition did not influence the pH values of sausages. The added chitosan did not affect significantly (p < 0.05) the results of the texture profile analysis and sensorial attributes and therefore, the overall acceptance of the sausages.

Partial substitution of nitrite by chitosan and the effect on the quality properties of pork sausages

The aim of the study was to evaluate the influence of partial nitrite replacement by chitosan on the quality of Ham Visking (a type of pork sausages). Five Ham Visking formulations were elaborated modifying the sodium nitrite (0.011; 0.016 or 0.0212%) and chitosan concentrations (0.25 or 0.5%) in the products. Sausages were stored at 4 ºC and physicochemical, microbiological, and sensorial evaluations were performed in order to estimate their shelf life. Chitosan can be used in pork sausages without affecting ensory attributes such as color although the panelists detected textural differences among the samples with chitosan, which suggests that there is some influence of deacetylation degree of chitosan on the textural behavior of sausages which still needed to be explained for a successful application of chitosan in meat products. The reduction of residual sodium nitrite did not affect the color and flavor of such products, but the use of chitosan increasedsignificantly the shelf life of sausages.

Effect of genotype, finishing system, and sex on physiochemical characteristics of goat meat

Seventy-eight kids of both sexes and five genotypes were used: Alpine, ½ Boer + ½ Alpine (½ BA), ¾ Boer + ¼ Alpine, ½ Anglo-nubian + ½ Alpine and "tricross" (½ Anglo-nubian + ¼ Boer + ¼ Alpine) with initial average weight of 14.1 ± 2.5. The objective was to evaluate the effect of genotype, finishing system, and sex on the physiochemical characteristics of goat meat. Finishing systems were: ST1 - kid + dam in pasture and ST2 - weaned kid and feedlot. Kids in ST1 were kept in an area with Panicum maximum cv. Tanzania, and after grazing, water and mineral salt/mix were fed ad libitum to the animals. The animals in ST2 were confined in collective pens distributed according to genotypes and received diet with 16% CP and 73% TDN. The values of pH, a* (red content), Cooking Loss (CL), and Ether Extract (EE) percentage were influenced by genotype. Values for red content (a*) and L* (brightness), CL and percentages of moisture, protein, EE, and ash were influenced by the finishing system. Longissimus dorsi muscle from animals ½ BA exhibited better physiochemical characteristics. For greater tenderness and higher percentages of fat, consumers should choose female kid goat meat.

Rosemary extract and celery-based products used as natural quality enhancers for colonial type salami with different ripening times

This study aimed to evaluate the use of rosemary (Rosmarinus officinalis) extract (RE), celery (Apium graveolis), and low levels of NO3 and NO2 as natural agents to enhance the quality of colonial salami. Salami was produced according to three treatments: (A) Control: 0.1% curing salt; (B) Rosemary: 0.05% curing salt + 0.5% RE (rosemary extract); and (C) Rosemary+celery: 0.14% Veg 503 + 0.27% Veg 504 (sea salt plus celery) + 0.5% of RE (rosemary extract). There was no effect (P > 0.05) of the treatments on water activity, Na content, and residual NO3 and NO2. Fatty acids C18:2 and C20:4 were reduced (P < 0.05) during the ripening period in the Control treatment indicating possible oxidation. The use of celery resulted in lower pH values (P < 0.05) in the salami. Reduced addition of NO3 and NO2 resulted in salami lighter in color (higher L* values, P < 0.05) at the 12th day of ripening. In conclusion, celery-based products proved to be an effective source of NO2 and NO3 for color development, but the low pH of the product indicates the need for better evaluation of its use in fermented salami. The RE (rosemary extract) reduced fat oxidation in salami, but this needs further evaluation.

Influence of physical damage and freezing on histamine concentration and microbiological quality of yellowfin tuna during processing

Yellowfin tuna has a high level of free histidine in their muscle, which can lead to histamine formation by microorganisms if temperature abuse occurs during handling and further processing. The objective of this study was to measure levels of histamine in damaged and undamaged thawed muscle to determine the effect of physical damage on the microbial count and histamine formation during the initial steps of canning processing and to isolate and identify the main histamine-forming microorganisms present in the flesh of yellowfin tuna. Total mesophilic and psicrophilic microorganisms were determined using the standard plate method. The presence of histamine-forming microorganisms was determined in a modified Niven's agar. Strains were further identified using the API 20E kit for enterobacteriaceae and Gram-negative bacilli. Physically damaged tuna did not show higher microbiological contamination than that of undamaged muscle tuna. The most active histamine-forming microorganism present in tuna flesh was Morganella morganii. Other decarboxylating microorganisms present were Enterobacter agglomerans and Enterobacter cloacae. Physical damage of tune during catching and handling did not increase the level of histamine or the amount of microorganisms present in tuna meat during frozen transportation, but they showed a higher risk of histamine-forming microorganism growth during processing.

Okara, a soymilk industry by-product, as a non-meat protein source in reduced fat beef burgers

Okara is a by-product generated during the manufacture of soymilk and tofu. Wet okara was added to beef burgers at 0%, 20%, and 25%. The effects of okara on certain physicochemical, textural, and sensory properties of reduced fat beef burgers were investigated. The beef burgers formulated with okara (104.0-106.0 kcal/100 g) had 60% less calories than commercial beef burgers (268.8 kcal/100 g). The texture profile analysis showed that the addition of wet okara led to a significant increase in hardness (p < 0.05) and a concomitant reduction in the values of chewiness, springiness, and cohesiveness. Lower sensory scores (p < 0.05) of flavour were observed in the beef burgers containing 25% wet okara. However, the sensory evaluation results showed that juiciness, appearance, tenderness, and overall acceptability of beef burgers formulated with okara did not differ statistically from that of the control (0% okara). Wet okara (20%) can be used as a non-meat protein source in the production of reduced-fat beef burgers without changing their sensory quality.

Frog meat microbiota (Lithobates catesbeianus) used in infant food

Captive breeding of bullfrog (Lithobates catesbeianus) is of great economic potential, mainly for its thighs and leather. The nutritional quality of frog meat includes properly balanced amino acids with a protein profile of high biological value, low fat and low cholesterol, and high digestibility due to its short chain molecule structure. It is recommended by doctors and nutritionists, especially for protein restricted children or malnourished children. Aiming to aggregate value to the segment and offer a product with nutritional properties that meet the need of children aged six months and above, a meat product based on the composition of frog meat was developed experimentally. To ensure raw material quality after bleaching and deboning, the microbiota present in the frog meat was determined. The analyses were performed according to Brazilian laws. It was observed that the resident and transient microbiota met the standards set by regulations. The results found were: mesophyll 4.5 x 10(4) CFU/g; Staphylococcus coagulase positive 2.0 x 10² CFU/g; negative for Salmonella sp. and Aeromonas spp. The findings indicate that the raw material showed satisfactory sanitation even in terms of family industry.

Safety criteria for the acquisition of meat in Brazilian University restaurants

The present study's objective was to analyze the procedures aimed at guaranteeing sanitary conditions when acquiring meat. The study was conducted with university restaurants of the Federal Institutions of Higher Education (IFES) located in the five regions of Brazil. Data were collected using a questionnaire and an evaluation list, which was available online to restaurant professionals. The results showed that restaurants chose one or two types of meat, the most frequent of which were beef and chicken. In restaurants managed by the IFES, the acquisition of raw material occurred by bidding. For vendor selection, the restaurants required product registration with the Inspection Service and requested regulation of the supplier by the Health Surveillance. Monitoring was carried out through a technical visit to the supplier and a review of the past records of the supplier. A higher percentage of restaurants in the Southeast region met appropriate sanitary and hygienic criteria for the receipt of meat, followed by the South, Midwest, Northeast and North. We conclude that restaurants meet most of the safety criteria set in the legislation. However, some weaknesses are evident in the physical and functional structure, the system of transportation of raw material and the records of control measures at the place of reception.

Prevalence of Listeria monocytogenes in poultry meat

Abstract The objectives of this study were i) to isolate Listeria spp. and Listeria monocytogenes in broiler wing meat samples, ii) to confirm the isolates by PCR, based on prs and hly A gene sequences, iii) to determine the seasonal and monthly distribution of the isolates. A total of 120 broiler wing meat samples (60 packaged pieces wrapped using strech film in styrofoam plates and 60 unpackaged pieces) bought from different markets in Hatay province were analysed. Listeria spp. was isolated from 57 (47.5%) out of 120 samples. Fifty-four, out of 57 Listeria spp. isolates were identified as L. monocytogenes. L. monocytogenes was isolated from the samples collected during the spring, winter, summer, and autumn at the levels of 26.6%, 40%, 53.3%, 60%, respectively. In this study, the isolation rates were found to be the highest in autumn, while the isolation rates were found to be the lowest in spring. As a consequence, high prevalence of Listeria spp. and L. monocytogenes in poultry wing meat samples may pose a risk for human health. We consider that with obeying the rules of good hygiene practices (GHP), good manufacturing practices (GMP) and HACCP can minimize the contamination with Listeria spp.

Effect of chitosan-carvacrol edible coatings on the quality and shelf life of tilapia (Oreochromis niloticus) fillets stored in ice

Abstract Fish consumption has increased in recent years. However, fish meat is highly perishable, which demonstrates the need for technologies to preserve its quality. Edible coatings (EC) might provide an alternative to extend the shelf life of fish. The goal of this study was to evaluate the effect of EC of chitosan (C) in combination with carvacrol (CAR) on the physical and microbiological changes of tilapia fillets. Fillets were submerged for two minutes in different treatments (T1: control; T2: C 2%; T3: C 2% + 0.125% CAR; T 4: C 2% + 0.25% CAR). At the end of storage, T1 and T2 showed the lowest values of total volatile bases (TVB). The color parameters L*, a* and b* varied from each treatment. The texture decreased and the different treatments reduced the microbial population in relation to the control; T3 and T4 were the most effective. These results show that the use of C with CAR might be an alternative method to preserve the quality and safety of tilapia fillets.

Assessing the use of frozen pork meat in the manufacture of cooked ham

This study aimed to evaluate the effects of slow (–18 °C) and fast freezing (liquid nitrogen) of pork meat, and the use of exudate released upon thawing, on the physicochemical, color, rheological, microbiological, histological, and sensory characteristics of cooked ham. The meat samples were frozen at –18 °C and thawed after 22 weeks for the production of cooked ham. No significant difference was observed regarding physicochemical, color and microbiological parameters or in sensory acceptance. The hardness and chewiness parameters showed significant differences when compared to the control sample (ham made from chilled meat). Light microscopy of cooked ham samples showed that changes in the tissues were caused by freezing and thawing the meat. The effect of exudate was significant on the sodium content and compression force parameters, but this difference was not perceived in the sensory analysis, confirming that frozen pork meat can be used to produce cooked ham without loss of quality.

Effects of oil-water mixed frying and pure-oil frying on the quality characteristics of soybean oil and chicken chop

Abstract The effects of oil-water mixed frying (OWF) and pure-oil frying (POF) on changes in quality characteristics of soybean oil and chicken chop during six days of frying were comparatively investigated. The results showed that the changes in specific extinction coefficients, p-anisidine value, carbonyl value, viscosity and color of soybean oil were more pronounced in the case of POF, indicating that oil oxidative and polymeric degradation was retarded by OWF. Concerning fat content of chicken chop, lower (p<0.05) values were observed in the last three days in the case of OWF than POF. Meanwhile, OWF led to lower acrylamide formation in chops during the six days. Sensory evaluation showed that OWF provided chops with five attributes similar to those of chops fried by POF on the first day. As frying days increased, the decreases in scores for color, odor, flavor and overall acceptability were less in the case of OWF. In conclusion, OWF could be a worthwhile alternative for retarding oil deterioration and producing healthier and higher quality fried meat products.