A rapid sample preparation method for the analysis of stable isotope ratios of beef samples from different countries

RATIONALE

The use of multi-isotopic analyses to trace beef is gaining wider acceptance, but no uniform standard for the pretreatment method is available for the determination of stable isotope ratios. Drying and defatting of meat samples are usually applied. Thus, a rapid sample preparation procedure is required to provide a reference for the study of beef using stable isotope methods.

METHODS

Student's t-test (T-test) was used to determine significant differences between the δ¹³ C and δ¹⁵ N values in traditional and rapid beef sample preparation methods. The δ¹³ C, δ¹⁵ N, δ² H, and δ¹⁸ O values of beef samples from six countries were assayed using elemental analyzer-isotope ratio mass spectrometry. Stable isotope data were subjected to principal component analysis, discriminant analysis, and partial least-squares discriminant analysis (PLS-DA).

RESULTS

There was no significant difference (P > 0.05) between the δ¹³ C and δ¹⁵ N values of the two preparation approaches. A classification of satisfactory was obtained with the original-validation rate of 96.6% and the cross-validation rate of 95.9%. The PLS-DA model was correctly validated to differentiate beef samples from six countries.

CONCLUSIONS

We describe a rapid sample preparation method for beef samples. A model combining stable isotope data and chemometric methods correctly assigned the origin of beef samples from different countries. The results demonstrated the successful utilization of rapid pretreatment methods to prepare beef samples when using multiple stable isotope analyses to trace beef samples from different countries.

Impact of high drinking water nitrate levels on the endogenous formation of apparent N-nitroso compounds in combination with meat intake in healthy volunteers

BACKGROUND

Nitrate is converted to nitrite in the human body and subsequently can react with amines and amides in the gastrointestinal tract to form N-nitroso compounds (NOCs), which are known to be carcinogenic in animals. Humans can be exposed to nitrate via consumption of drinking water and diet, especially green leafy vegetables and cured meat. The contribution of nitrate from drinking water in combination with meat intake has not been investigated thoroughly. Therefore, in the present pilot study, we examined the effect of nitrate from drinking water, and its interaction with the consumption of white and processed red meat, on the endogenous formation of NOCs, taking into account the intake of vitamin C, a nitrosation inhibitor.

METHODS

Twenty healthy subjects were randomly assigned to two groups consuming either 3.75 g/kg body weight (maximum 300 g per day) processed red meat or unprocessed white meat per day for two weeks. Drinking water nitrate levels were kept low during the first week (< 1.5 mg/L), whereas in week 2, nitrate levels in drinking water were adjusted to the acceptable daily intake level of 3.7 mg/kg bodyweight. At baseline, after 1 and 2 weeks, faeces and 24 h urine samples were collected for analyses of nitrate, apparent total N-nitroso compounds (ATNC), compliance markers, and genotoxic potential in human colonic Caco-2 cells.

RESULTS

Urinary nitrate excretion was significantly increased during the high drinking water nitrate period for both meat types. Furthermore, levels of compliance markers for meat intake were significantly increased in urine from subjects consuming processed red meat (i.e. 1-Methylhistidine levels), or unprocessed white meat (i.e. 3-Methylhistidine). ATNC levels significantly increased during the high drinking water nitrate period, which was more pronounced in the processed red meat group. Genotoxicity in Caco-2 cells exposed to faecal water resulted in increased genotoxicity after the interventions, but results were only significant in the low drinking water nitrate period in subjects consuming processed red meat. Furthermore, a positive correlation was found between the ratio of nitrate/vitamin C intake (including drinking water) and the level of ATNC in faecal water of subjects in the processed red meat group, but this was not statistically significant.

CONCLUSIONS

Drinking water nitrate significantly contributed to the endogenous formation of NOC, independent of the meat type consumed. This implies that drinking water nitrate levels should be taken into account when evaluating the effect of meat consumption on endogenous formation of NOC.

TRIAL REGISTRATION

Dutch Trialregister: 29707 . Registered 19th of October 2018. Retrospectively registered.

Relative contribution of sensory characteristics for different types of pork loin, assessed by temporal dominance of sensations

BACKGROUND

Sensory perception is a dynamic process occurring sequentially. The dynamic analysis of the perception of sensory characteristics in meat is important to understand complex meat sensory characteristics. Temporal dominance of sensations (TDS) is a dynamic sensory method that captures the 'dominance of sensations' throughout food consumption, and it is possible to calculate the relative contribution of various sensory characteristics by 'dominance rate' over time. The objective of this study was to assess the major sensory characteristics of the dynamic sensory perception of pork loin. Using the TDS, we evaluated pork loins derived from pigs with different genetic and feeding backgrounds. Moreover, we checked the integrity of the TDS by comparing the TDS results with a descriptive sensory analysis and a physico-chemical analysis.

RESULTS

Seven types of pork loin were evaluated by TDS, and 'tender and/or soft,' 'tough and/or hard,' 'juicy,' 'dry,' 'fat melting,' 'smoothness,' 'sourness,' 'umami,' and 'beast odors' became dominant in at least one type of pork loin. The dynamics of the perception of pork sensory characteristics was also depicted by TDS. In addition, TDS and descriptive analysis demonstrated similarity in principal component analysis.

CONCLUSION

TDS demonstrated the major sensory characteristics on the dynamic sensory perception of pork loin. © 2019 Society of Chemical Industry.

Data from the Farmgate-to-Meat Continuum Including Omics-Based Biomarkers to Better Understand the Variability of Beef Tenderness: An Integromics Approach

This study is based on an integromic approach of 71 young bulls' data from the farmgate-to-meat continuum including omics-based biomarkers, to understand beef tenderness variability in two muscle cuts that differ by their contractile and metabolic properties. By the means of chemometrics using partial least-squares (PLS) and principal component regressions (PCR), important variables from a list of 49 that characterize four levels of the continuum (rearing factors-carcass-muscle-meat) were identified to explain tenderness of Longissimus thoracis (LT) and Semitendinosus (ST) muscles evaluated by a sensory panel and instrumental Warner-Bratzler shear force (WBSF). The PLS and PCR analyses validated 16 and 15 variables for LT and 12 and 14 for ST from the whole continuum to explain sensory tenderness and WBSF, respectively. Among the explanatory variables in the four models and in line with the role of apoptosis in tenderness determinism, HSP70-1A/B (a heat shock protein) was retained to explain beef tenderness irrespective of muscle and evaluation method. Similarly, dressing percentage from the carcass level was another robust predictor but in a muscle-dependent direction manner. HSP20, ENO3, and MyHC-I as three muscle protein biomarkers and dry matter intake (DMI) as a rearing factor were involved in three models to explain beef tenderness. This study highlighted also that several variables were muscle-specific irrespective of the evaluation method of tenderness. For LT muscle, six variables including three carcass traits (fatness score, fat carcass %, and muscle carcass %), two muscle biomarkers (HSP70-8 and MyHC-IIx/b), and one meat quality trait (pH_3h) were found. For ST muscle, five variables were validated from two rearing factors (average daily gain and feed efficiency) and three structural protein biomarkers (α-actin, MyBP-H, and CapZ-β). Finally, for WBSF only, lactate dehydrogenase chain B (LDH-B) was retained positively for LT and negatively for ST muscles. Overall, this trial showed that tenderness of LT and ST muscle cuts is influenced by variables belonging to the whole continuum with relationships that depend on both the muscle type and the evaluation method. It further highlighted the potential of integromic/chemometric approaches on the farmgate-to-meat continuum data to better understand the sophisticated biological processes that orchestrate the conversion of muscle into meat and tenderness determinism.

Broad and Inconsistent Muscle Food Classification Is Problematic for Dietary Guidance in the U.S

Dietary recommendations regarding consumption of muscle foods, such as red meat, processed meat, poultry or fish, largely rely on current dietary intake assessment methods. This narrative review summarizes how U.S. intake values for various types of muscle foods are grouped and estimated via methods that include: (1) food frequency questionnaires; (2) food disappearance data from the U.S. Department of Agriculture Economic Research Service; and (3) dietary recall information from the National Health and Nutrition Examination Survey data. These reported methods inconsistently classify muscle foods into groups, such as those previously listed, which creates discrepancies in estimated intakes. Researchers who classify muscle foods into these groups do not consistently considered nutrient content, in turn leading to implications of scientific conclusions and dietary recommendations. Consequentially, these factors demonstrate a need for a more universal muscle food classification system. Further specification to this system would improve accuracy and precision in which researchers can classify muscle foods in nutrition research. Future multidisciplinary collaboration is needed to develop a new classification system via systematic review protocol of current literature.

Multiplex-PCR As a Rapid and Sensitive Method for Identification of Meat Species in Halal-Meat Products

BACKGROUND

Species identification and authentication in meat products are important subjects for ensuring the health of consumers. The multiplex-PCR amplification and species- specific primer set were used for the identification of horse, donkey, pig and other ruminants in raw and processed meat products.

METHODS

Oligonucleotid primers were designed and patented for amplification of species-specific mitochondrial DNA sequences of each species and samples were prepared from binary meat mixtures.

RESULTS

The results showed that meat species were accurately determined in all combinations by multiplex-PCR, and the sensitivity of this method was 0.001 ng, rendering this technique open to and suitable for use in industrial meat products. It is concluded that more fraud is seen in lower percentage industrial meat products than in higher percentage ones. There was also more fraud found in processed products than in raw ones.

CONCLUSION

This rapid and useful test is recommended for quality control firms for applying more rigorous controls over industrial meat products, for the benefit of target consumers.

Changes in Meat/Poultry/Fish Consumption in Australia: From 1995 to 2011-2012

The purpose of the study was to examine temporal changes in meat/poultry/fish consumption patterns between 1995 and 2011-2012 in the Australian population. Meat/poultry/fish consumption from all food sources, including recipes, was analysed by gender, age group, and socio-economic status using 24-h recall data from the 1995 National Nutrition Survey (n = 13,858) and the 2011-2012 National Nutrition and Physical Activity Survey (n = 12,153). The overall proportion of people consuming meat/poultry/fish remained stable (91.7% versus 91.3%, p = 0.55), but a shift in the type of meat consumed was observed. Red meat, including beef and lamb, was consumed by fewer people over the time period (from 56% to 49%), whereas poultry consumption increased (from 29% to 38%). Amounts of all meat/poultry/fish consumed were reportedly higher in 2011-2012 compared with 1995. This resulted in similar (red meat, and processed meat) or slightly higher (poultry, and fish) per-capita intakes in 2011-2012. The magnitude of change of consumption varied between children and adults, and by gender. Monitoring trends in consumption is particularly relevant to policy makers, researchers and other health professionals for the formulation of dietary recommendations and estimation of potential health outcomes.

Evaluation of a Dutch Public-Private Partnership to Promote Healthier Diet

Purpose.

Public-private partnerships may help to promote healthy diets. We assessed customers' exposure to and the acceptability of a Dutch public-private healthy diet campaign in butcher's shops and investigated the effects on the purchase of lean meat and the use of liquid cooking margarine and potential behavioral determinants.

Methods.

The pretest-posttest control group design included 486 customers (242 experimental and 244 control) of butcher shops representing 64% of the original sample. Campaign exposure, acceptability, and behavioral effects were measured by a questionnaire.

Results.

Seventy-one percent of the customers noticed the campaign. Scores on the acceptability were positive to very positive. Regression analysis revealed that customers in the experimental condition evaluated the campaign better (B = .415; p < .05) and felt more encouraged to buy lean meat (B = .252; p < .05) than customers in the control condition. No effects on behavior were found.

Discussion.

Study design limitations included possible campaign exposure of control group participants. The study shows the feasibility and acceptability of a joint health-promoting activity through a public-private partnership, but there were no effects on behavior.

Detection and characterisation of frauds in bovine meat in natura by non-meat ingredient additions using data fusion of chemical parameters and ATR-FTIR spectroscopy

Concerns about meat authenticity are increasing recently, due to great fraud scandals. This paper analysed real samples (43 adulterated and 12 controls) originated from criminal networks dismantled by the Brazilian Police. This fraud consisted of injecting solutions of non-meat ingredients (NaCl, phosphates, carrageenan, maltodextrin) in bovine meat, aiming to increase its water holding capacity. Five physico-chemical variables were determined, protein, ash, chloride, sodium, phosphate. Additionally, infrared spectra were recorded. Supervised classification PLS-DA models were built with each data set individually, but the best model was obtained with data fusion, correctly detecting 91% of the adulterated samples. From this model, a variable selection based on the highest VIPscores was performed and a new data fusion model was built with only one chemical variable, providing slightly lower predictions, but a good cost/performance ratio. Finally, some of the selected infrared bands were specifically associated to the presence of adulterants NaCl, tripolyphosphate and carrageenan.

Consumer palatability scores and volatile beef flavor compounds of five USDA quality grades and four muscles

Proximate data, consumer palatability scores and volatile compounds were investigated for four beef muscles (Longissimus lumborum, Psoas major, Semimembranosus and Gluteus medius) and five USDA quality grades(Prime, Upper 2/3 Choice, Low Choice, Select, and Standard). Quality grade did not directly affect consumer scores or volatiles but interactions (P < 0.05) between muscle and grade were determined. Consumer scores and volatiles differed (P < 0.05) between muscles. Consumers scored Psoas major highest for tenderness, juiciness, flavor liking and overall liking, followed by Longissimus lumborum, Gluteus medius, and Semimembranosus (P < 0.05). Principal component analysis revealed clustering of compound classes, formed by related mechanisms. Volatile n-aldehydes were inversely related to percent fat. Increases in lipid oxidation compounds were associated with Gluteus medius and Semimembranosus, while greater quantities of sulfur-containing compounds were associated with Psoas major. Relationships between palatability scores and volatile compound classes suggest that differences in the pattern of volatile compounds may play a valuable role in explaining consumer liking.

Rapid visual detection of eight meat species using optical thin-film biosensor chips

Adulteration of meat products has become a very serious issue nowadays. To protect consumer rights, food labeling is required in many countries, and efficient and accurate detection methods are essential as well. This paper reports an innovative method for the rapid detection and identification of meat species based on a silicon-based optical thin-film biosensor chip with which color change results can be perceived by the naked eye without any expensive instruments. This biosensor system can simultaneously and specifically detect eight meat species, including deer, rabbit, duck, chicken, beef, horse, sheep, and pork. The absolute detection limit of this method was 0.5 pg of deer/beef DNA, and the practical detection limit was 0.001%. The biosensor detection can be completed within 30 min after PCR amplification. Therefore, this assay permits specific, sensitive, rapid, and simple detection of meat species in raw or cooked meat products.

[Discrimination of donkey meat by NIR and chemometrics]

Donkey meat samples (n = 167) from different parts of donkey body (neck, costalia, rump, and tendon), beef (n = 47), pork (n = 51) and mutton (n = 32) samples were used to establish near-infrared reflectance spectroscopy (NIR) classification models in the spectra range of 4,000~12,500 cm(-1). The accuracies of classification models constructed by Mahalanobis distances analysis, soft independent modeling of class analogy (SIMCA) and least squares-support vector machine (LS-SVM), respectively combined with pretreatment of Savitzky-Golay smooth (5, 15 and 25 points) and derivative (first and second), multiplicative scatter correction and standard normal variate, were compared. The optimal models for intact samples were obtained by Mahalanobis distances analysis with the first 11 principal components (PCs) from original spectra as inputs and by LS-SVM with the first 6 PCs as inputs, and correctly classified 100% of calibration set and 98. 96% of prediction set. For minced samples of 7 mm diameter the optimal result was attained by LS-SVM with the first 5 PCs from original spectra as inputs, which gained an accuracy of 100% for calibration and 97.53% for prediction. For minced diameter of 5 mm SIMCA model with the first 8 PCs from original spectra as inputs correctly classified 100% of calibration and prediction. And for minced diameter of 3 mm Mahalanobis distances analysis and SIMCA models both achieved 100% accuracy for calibration and prediction respectively with the first 7 and 9 PCs from original spectra as inputs. And in these models, donkey meat samples were all correctly classified with 100% either in calibration or prediction. The results show that it is feasible that NIR with chemometrics methods is used to discriminate donkey meat from the else meat.

The hygiene practices of three systems of game meat production in South Africa in terms of animal class and health compliance

Three game meat production systems used on game ranches in South Africa are reported on. System one is applied in the game export market and conforms to the hygiene requirements of the European Union (EU). System two and three entail game meat available on the local market not subjected to any regulation. System 2 however, implemented basic meat hygiene values. Measurements of pH, temperature, Aerobic Plate Count (APC), E. coli, Salmonella and S. aureus were subjected to a 3×2 factorial analysis of variance with factors that involve 3 system compliances in 2 classes of game animals in a completely randomised design. The measured bacteriological and quality differences between the three systems do not justify EU standards application on the local market but results indicated a significant compliance×class interaction.

Predicting beef tenderness using color and multispectral image texture features

The objective of this study was to investigate the usefulness of raw meat surface characteristics (texture) in predicting cooked beef tenderness. Color and multispectral texture features, including 4 different wavelengths and 217 image texture features, were extracted from 2 laboratory-based multispectral camera imaging systems. Steaks were segregated into tough and tender classification groups based on Warner-Bratzler shear force. The texture features were submitted to STEPWISE multiple regression and support vector machine (SVM) analyses to establish prediction models for beef tenderness. A subsample (80%) of tender or tough classified steaks were used to train models which were then validated on the remaining (20%) test steaks. For color images, the SVM model correctly identified tender steaks with 100% accurately while the STEPWISE equation identified 94.9% of the tender steaks correctly. For multispectral images, the SVM model predicted 91% and STEPWISE predicted 87% average accuracy of beef tender.

Identification of biomarkers of meat tenderisation and its use for early classification of Asturian beef into fast and late tenderising meat

BACKGROUND

The objective of this work was to study the post-mortem evolution of potential biomarkers (µ-calpain activity and proteolytic profile) of meat tenderisation in bovine longissimus dorsi (LD) muscle from several biotypes coming from two beef breeds ('Asturiana de los Valles' and 'Asturiana de la Montaña') and showing different levels of muscular hypertrophy (mh/mh, mh/+, + /+).

RESULTS

LD samples were taken at 2, 12, 24 and 48 h and 3, 7, 14 and 21 days post-mortem. The presence of muscular hypertrophy produced a faster rate of pH decline, faster exhaustion of µ-calpain activity and earlier occurrence of proteolytic changes. Changes in the electrophoretic pattern of some peptides from sarcoplasmic (glyceraldehyde-3-phosphate dehydrogenase) and myofibrillar (troponin T and troponin I) muscle extracts within the first 24 h significantly correlated with meat toughness and allowed accurate discrimination of meat products into two groups: (1) fast tenderising meat, coming from mh-biotypes, and (2) late tenderising meat, from normal (+/+) biotypes.

CONCLUSION

Early monitoring (within 24 h after slaughter) of selected biomarkers in LD muscle allowed accurate prediction of ultimate meat toughness and could be used in the meat industry as a tool for early classification of beef into fast and late tenderising meat.

Iberian ham typification by direct infusion electrospray and photospray ionization mass spectrometry fingerprinting

RATIONALE

Iberian ham is a product of high commercial value whose quality mainly depends on breeding and feeding of pigs in an authorized way. Simple, fast, simple, reliable and high-throughput analytical methods are necessary to assure the quality of ham and for fraud prevention. Tandem mass spectrometry (MS/MS) is proposed as an advantageous alternative over other analytical techniques commonly used in this industry for product authentication.

METHODS

The analytical approach is based on direct infusion electrospray mass spectrometry (ESI(+)-MS) of dichloromethane/methanol (60:40) extracts of ham intramuscular fat. Similarly, atmospheric pressure photoionization ionization mass spectrometry (APPI(+)-MS) was used with a flow injection analysis system for sample introduction with methanol/water (50%) as the mobile phase and toluene as the dopant. All experiments were performed on an API QSTAR® XL Hybrid system using both ESI and APPI sources.

RESULTS

The ESI(+)-MS mass spectra present several clusters of peaks attributed to ammonium adducts [M + NH(4) (+) ] of lipid compounds (mono-, di- and triacylglycerols - MGs, DGs, TGs, and free fatty acids - FFAs), that can be identified by MS/MS spectra. On the other hand, the APPI(+)-MS spectra present [M + H(+) ] ions and reflect a higher fragmentation of the sample. Five different types of Iberian ham samples were successfully classified using partial least-squares discriminant analysis (PLS-DA) of data from these samples.

CONCLUSIONS

The application of direct infusion tandem mass spectrometry to dichloromethane/methanol extracts from intramuscular fat ham allows the simple, fast and reliable fingerprinting typification of different Iberian ham samples from pigs with different diets. With the proposed method, sample handling is minimal and chromatographic separation is not necessary, which represents an evident advantage over other analytical procedures usually used for this purpose.

An on-line near-infrared (NIR) transmission method for determining depth profiles of fatty acid composition and iodine value in porcine adipose fat tissue

The present work describes a measurement method using spatially resolved near-infrared (NIR) spectroscopy to determine porcine carcass fat quality as a function of the distance to the skin by estimating its iodine value (IV). The new method is capable of performing on-line carcass grading at full production speed (approximately 1000 carcasses per hour). The method is demonstrated in an experiment where 35 carcasses were sampled at an abattoir, selected from three feeding groups. The NIR transmission instrument was applied on the loin of each carcass, and a parallel reference sample was removed and processed into 1.8 mm thick disks, representing a depth-of-fat profile from the loin. The disks were analyzed for fatty acid composition using gas chromatography (GC) and for IV. A principal component analysis (PCA) of the obtained GC reference values clearly showed that the feeding regimes can be differentiated. Using interval partial least squares (iPLS) regression, a model was produced that can predict the IV of the fat at a given measured depth with a root mean square error of cross-validation (RMSECV) of 1.44. The results show how the IV varies as a function of feeding regime and as a function of fat depth. The maximum variation found within a single depth profile was 10.1 IV from the skin to the innermost part of the fat layers. In the sample material investigated the average span in IV between the average values of the two porcine backfat layers was 6.4 IV (the maximum difference was 8.6 IV). The new method can provide the abattoir with new chemical information about fat quality and production quality that will open new possibilities of meat/carcass grading and product development.

Consistent predictable patterns in the hydrogen and oxygen stable isotope ratios of animal proteins consumed by modern humans in the USA

Published datasets of proteinaceous animal tissues suggest that co-variation between amino acid hydrogen (δ²H) and oxygen (δ¹⁸O) isotope ratios is a common feature in systems where isotopic variation is driven by geographic or temporal variation in the δ²H and δ¹⁸O values of environmental water. This has led to the development of models relating tissue δ²H and δ¹⁸O values to those of water, with potential application in a number of fields. However, the strength and ubiquity of the influence of environmental water on protein isotope ratios across taxonomic groups, and thus the relevance of predictive models, is an open question. Here we report strong co-variation of δ²H and δ¹⁸O values across a suite of terrestrial and aquatic animal meats purchased in American food markets, including beef, poultry (chicken and turkey), chicken eggs, pork, lamb, freshwater fish, and marine fish. Significant isotope co-variation was not found for small collections of marine bivalves and crustaceans. These results imply that isotopic signals from environmental water were propagated similarly through most of the diverse natural and human-managed foodwebs represented by our samples. Freshwater fish had the largest variation in δ²H and δ¹⁸O values, with ranges of 121‰ and 19.2‰, respectively, reflecting the large isotopic variation in environmental freshwaters. In contrast marine animals had the smallest variation for both δ²H (7‰ range, crustaceans) and δ¹⁸O (3.0‰ range, bivalves) values. Known-origin beef samples demonstrated direct relationships between the variance of environmental water isotope ratios and that of collected meats.

How much do soil and water contribute to the composition of meat? A case study: meat from three areas of Argentina

The main goal of this study was to propose a reliable method to verify the geographical origin of meat, establishing the influence of soil and water on its isotopic and elemental composition. Thus, beef meat, soil, and water samples were collected from three major cattle-producing regions of Argentina (Buenos Aires, Córdoba, and Entre Ríos). Multielemental composition was determined on these three matrices by inductively coupled plasma mass spectrometry (ICP-MS), δ(13)C and δ(15)N by isotope-ratio mass spectrometry (IRMS), and the (87)Sr/(86)Sr ratio by thermal ionization mass spectrometry (TIMS). Soil and drinking water samples could be characterized and clearly differentiated by combining the isotopic ratios and elements, demonstrating differences in geology and climatic conditions of three regions. Similarly, meat originating at each sampling area was characterized and differentiated using only five key variables (Rb, Ca/Sr, δ(13)C, δ(15)N, and (87)Sr/(86)Sr). Generalized procrustes analysis (GPA), using the three studied matrices (soil, water, and meat) shows consensus between them and clear differences between studied areas. Furthermore, canonical correlation analysis (CCA) demonstrates significant correlation between the chemical-isotopic profile of meat with those corresponding to both soil and water (r(2) = 0.93, p < 0.001; and r(2) = 0.83, p < 0.001, respectively). So far, there are clear coincidences between the meat fingerprint and those from soil/water where cattle grew, presenting a good method to establish beef provenance. To the authors' knowledge this is the first report linking the influence of soil and water all together on the composition of beef, presenting the basis for the authentication of Argentinean beef, which could be extended to meat from different provenances.

Multielement isotope analysis of bovine muscle for determination of international geographical origin of meat

Multielemental (C, N, H, S) stable isotope ratio analysis was used as an analytical tool to verify the geographical origin of beef from several European and non-European countries. Beef samples were collected from nine different countries, and the (13)C/(12)C, (15)N/(14)N, (2)H/(1)H, and (34)S/(32)S ratios of defatted beef were measured using isotope ratio mass spectrometry (IRMS). There were highly significant differences in the mean isotopic values of the beef from different countries. The results of discriminant analysis showed that the four isotope ratios were significant for the discrimination of geographical origin and that 84.9% of the samples were correctly assigned to the country of origin (82.2% when cross-validated). Beef was also classified according to geographical origin when additional information on different feeding regimens used in Ireland was included, with 85.0% of the samples correctly allocated and 82.9% cross-validated using the isotopic signatures. All of the Irish beef samples verifiable as pasture-fed beef were correctly classified and then cross-validated.

Beef authentication and retrospective dietary verification using stable isotope ratio analysis of bovine muscle and tail hair

Stable isotope ratio analysis (SIRA) was used as an analytical tool to verify the preslaughter diet of beef cattle. Muscle and tail hair samples were collected from animals fed either pasture (P), a barley-based concentrate (C), silage followed by pasture (SiP), or silage followed by pasture with concentrate (SiPC) for 1 year (n = 25 animals per treatment). The (13)C/(12)C, (15)N/(14)N, (2)H/(1)H, and (34)S/(32)S isotope ratios in muscle clearly reflected those of the diets consumed by the animals. By applying a stepwise canonical discriminant analysis, a good discrimination of bovine meat according to dietary regimen was obtained. On the basis of the classification success rate, the (13)C/(12)C and (34)S/(32)S ratios in muscle were the best indicators for authentication of beef from animals consuming the different diets. Analysis of (13)C/(12)C and (15)N/(14)N in tail hair sections provided an archival record of changes to the diet of the cattle for periods of over 1 year preslaughter.

Discrimination of the geographical origin of beef by (1)H NMR-based metabolomics

The geographical origin of beef is of increasing interest to consumers and producers due to "mad cow" disease and the implementation of the Free Trade Agreement (FTA). In this study, (1)H NMR spectroscopy coupled with multivariate statistical analyses was used to differentiate the geographical origin of beef samples. Principal component analysis (PCA) and orthogonal projection to latent structure-discriminant analysis (OPLS-DA) showed significant separation between extracts of beef originating from four countries: Australia, Korea, New Zealand, and the United States. The major metabolites responsible for differentiation in OPLS-DA loading plots were succinate and various amino acids including isoleucine, leucine, methionine, tyrosine, and valine. A one-way ANOVA was performed to statistically certify the difference in metabolite levels. The data suggest that NMR-based metabolomics is an efficient method to distinguish fingerprinting difference between raw beef samples, and several metabolites including various amino acids and succinate can be possible biomarkers for discriminating the geographical origin of beef.

Tracing the geographical origin of beefs being circulated in Korean markets based on stable isotopes

We have examined the carbon, nitrogen and oxygen isotopic compositions of American, Mexican, Australian, New Zealand and Korean beefs, which are currently being circulated in Korean markets, to check whether stable isotope ratios can identify their country of origin. Each beef exhibited statistically distinct isotopic compositions, especially in oxygen and carbon, because of the different isotopic compositions of their water and cattle feeds. Nevertheless, their isotopic compositions still showed some overlap, especially among USA, Australian, and Korean beefs, which sometimes resulted in significant misidentification when a single isotope was considered. However, the discrimination was generally successful when both the carbon and the oxygen isotopes were used.

Phospholipase A2 and antioxidant enzyme activities in normal and PSE pork

In order to reveal the relationship between phospholipase A(2) and antioxidant enzymes and drip loss in pork, the study was designed to examine the effects of phospholipase A(2) and antioxidant enzymes on the water-holding capacity of pork during postmortem chilling. Six PSE and RFN samples (longissimus muscle) were used to determine the activities of phospholipase A(2) (tPLA(2,) cPLA(2)+sPLA(2) and iPLA(2)), superoxide dismutase (SOD) and GSH-Px, and acid phospholipase. The results showed that pH(1 h) and pH(24 h) from PSE pork were lower (p<0.01) than for normal pork (RFN), but the L* value at 1h and 24h postmortem, TBARS content, drip loss at 48 h and 96 h, cooking loss, tPLA(2) activity and iPLA(2) were higher (p<0.01) than of normal pork. Correlation analysis indicated that drip loss at 48 h was negatively related to pH(1 h) (p<0.01) and pH(24 h) (p<0.01) but positively to T(1 h) (p<0.01) and the activities of total phospholipase A(2) (p<0.05) and calcium-independent phospholipases A(2) (p<0.01). The tPLA(2) and GSH-Px play important roles in drip loss.

[Determination of geographical origin of beef based on FTIR spectroscopy analysis]

The aim of the present study was to investigate the feasibility of tracing the geographical origin of beef with FT-NIR spectroscopy, set up the model for identifying the beef geographical origin, and validate the rate of discrimination. Fifty eight defatted beef samples from Jilin, Guizhou, Ningxia, and Hebei in China were dried and milled. Based on the NIR spectra of the pre-processing beef, the samples were subjected to principal component analysis (PCA), cluster analysis (CA), discriminant analysis (DA), and a qualitative model was established to do discriminant analysis and validated. The results showed that there were some differences in NIR spectra from different geographical origins, and the element contents in the beef samples were different from different locations. According to the Euclidean distance of NIR spectra, the geographical origin can be identified by cluster analysis. The distance of spectra is the shortest between the samples from Guizhou and Hebei province. Meanwhile there is a certain crossover. This model calibrated by 40 samples was used to predict the varieties of 18 unknown beef samples. The recognition rate of 100% was achieved. So applying FT-NIR fingerprint spectroscopy to trace geographical origin of beef is accurate, rapid and low-cost.

Identification of gadoid species in fish meat by polymerase chain reaction (PCR) on genomic DNA

Identification of fish species is significant due to the increasing interest of consumers in the meat of sea fish. Methods focusing on fish species identification help to reveal fraudulent substitution among economically important gadoid species in commercial seafood products. The objective of this work was to develop a conventional PCR method for the differentiation of the following gadoid fish species in fish products: Alaska pollack ( Theragra chalcogramma), blue whiting ( Micromesistius poutassou), hake spp. ( Merluccius spp.), Atlantic cod ( Gadus morhua), saithe ( Pollachius virens), and whiting ( Merlangius merlangus). The species-specific primer pairs for gadoid species determination were based on the partial pantophysin I ( PanI) genomic sequence. Sequence identification was confirmed by cloning and sequencing of the PCR products obtained from the species considered. For the simultaneous detection of Alaska pollack, blue whiting, and hake spp., a quadruplex PCR system was constructed. Other gadoid species were detected in separate PCR reactions. After optimization of the reactions, the developed PCR systems were used for the analysis of codfish samples obtained from the Czech market and the customs' laboratories. This method represents an alternative approach in the use of genomic DNA for the identification of fish species. This method is rapid, simple, and reliable without the need for further confirmative methods. Furthermore, the identification of a mixture of more than one species is possible. The PCR system has been optimized for routine diagnostic purposes.

Evaluation of the efficacy and cost-effectiveness of melengestrol acetate in feedlot heifer calves in western Canada

The purpose of this study was to evaluate the relative efficacy and cost-effectiveness of feeding melengestrol acetate (MGA) to feedlot heifer calves in western Canada. Heifers fed MGA had significantly (P less than .05) improved average daily gain, feed conversion, and carcass quality grade and lower rates of initial undifferentiated fever treatment and bovine respiratory disease mortality. However, heifers fed MGA had less desirable (P less than .05) carcass yield grade. There was a net economic advantage of Can $11.31/animal in favor of heifers fed MGA. Based on these results, it is efficacious and cost-effective to feed MGA to heifer calves raised in standard large-pen commercial feedlots in western Canada.

Benchmarking carcass characteristics and muscles from commercially identified beef and dairy cull cow carcasses for Warner-Bratzler shear force and sensory attributes1

The objective of this study was to benchmark carcasses and muscles from commercially identified fed (animals that were perceived to have been fed an increased plane of nutrition before slaughter) and nonfed cull beef and dairy cows and A-maturity, USDA Select steers, so that the muscles could be identified from cull cow carcasses that may be used to fill a void of intermediately priced beef steaks. Carcass characteristics were measured at 24 h postmortem for 75 carcasses from 5 populations consisting of cull beef cows commercially identified as fed (B-F, n = 15); cull beef cows commercially identified as nonfed (B-NF, n = 15); cull dairy cows commercially identified as fed (D-F, n = 15); cull dairy cows commercially identified as nonfed (D-NF, n = 15); and A-maturity, USDA Select grade steers (SEL, n = 15). Nine muscles were excised from each carcass [m. infraspinatus, m. triceps brachii (lateral and long heads), m. teres major, m. longissimus dorsi (also termed LM), m. psoas major, m. gluteus medius, m. rectus femoris, and m. tensor fasciae latae] and subjected to Warner-Bratzler shear force testing and objective sensory panel evaluation after 14 d of postmortem aging. Carcass characteristics differed (P < 0.05) among the 5 commercially identified slaughter groups for the traits of lean maturity, bone maturity, muscle score, HCW, fat color, subjective lean color, marbling, ribeye area, 12th-rib fat thickness, and preliminary yield grade. Carcasses from commercially identified, fed cull cows exhibited more (P < 0.01) weight in carcass lean than did commercially identified, nonfed cull cows. There was a group x muscle interaction (P = 0.02) for Warner-Bratzler shear force. Warner-Bratzler shear force and sensory overall tenderness values demonstrates that muscles from the SEL group were the most tender (P < 0.01), whereas muscles from the B-NF group were the least tender (P < 0.01). Sensory, beef flavor intensity was similar (P > 0.20) among cull cow carcass groups and more intense (P < 0.01) than the SEL carcass group. Muscles from the SEL group exhibited less (P < 0.01) detectable off-flavor than the cull cow carcass groups, whereas the B-NF group exhibited the most (P < 0.01) detectable off-flavor. Although carcass and muscle quality from commercially identified, fed, cull beef and dairy cows was not similar to A-maturity, USDA Select beef, they did show improvements when compared with nonfed, cull, beef and dairy cow carcasses and muscles.

Effects of alpha-tocopheryl acetate supplementation in preslaughter diet on antioxidant enzyme activities and fillet quality of commercial-size Sparus macrocephalus

This study examined the effects of dietary alpha-tocopheryl acetate supplementation on antioxidant enzyme activities and fillet quality in commercial-size Sparus macrocephalus. Three hundred fish [main initial weight (350+/-12) g] were divided into three groups (E250, E500 and E1000) and reared in 9 cages. The fish were fed for 8 weeks with three diets containing different levels of dietary alpha-tocopheryl acetate (289, 553, 1 069 mg/kg). Over the experimental period, fish were fed to satiation and reached a final mean weight of (465+/-28) g without significant body weight difference and proximate composition difference. Fillet alpha-tocopherol was significantly (P<0.05) different between groups, reaching levels of 14.2, 22.1, 30.9 microg/mg fillet for groups E250, E500 and E1000, respectively. Total serum superoxide dismutase (SOD) activity increased significantly (P<0.05) in fish fed the diets high in alpha-tocopheryl acetate, but serum glutathione peroxidase (GPX) activity was unaffected. In storage on ice, fillets of fish fed the diets high in alpha-tocopheryl acetate exhibited significantly lower (P<0.05) levels of oxidation. These results suggested that increased dietary alpha-tocopheryl acetate could increase its flesh deposition, increase the activity of SOD and prevent lipid peroxidation of Sparus macrocephalus fillets in retail storage on ice.

Classification of adipose tissue species using Raman spectroscopy

In this study multivariate analysis of Raman spectra has been used to classify adipose tissue from four different species (chicken, beef, lamb and pork). The adipose samples were dissected from the carcass and their spectra recorded without further preparation. 102 samples were used to create and compare a range of statistical models, which were then tested on 153 independent samples. Of the classical multivariate methods employed, Partial Least Squares Discriminant Analysis (PLSDA) performed best with 99.6% correct classification of species in the test set compared with 96.7% for Principal Component Linear Discrimination Analysis (PCLDA). Kohenen and Feed-forward artificial neural networks compared well with the PLSDA, giving 98.4 and 99.2% correct classification, respectively.

The Influence of the Season and Market Class of Broiler Chickens on Breast Meat Quality Traits

The influence of the season and market class of broiler chickens on breast meat quality traits was determined on a total of 18 flocks reared and processed under commercial conditions. According to the Italian poultry production system the following classes of birds were considered: light size (1.2 kg of carcass weight; n = 90) and medium size (1.8 kg of carcass weight; n = 90), represented by females slaughtered at 40 and 52 d old, respectively, whereas heavy size were 57-d-old male broilers (2.4 kg of carcass weight; n = 90). After slaughter, 15 carcasses per flock (n = 270) were randomly collected during winter (n = 135) and summer (n = 135) seasons and used at 24 h postmortem to determine breast (pectoralis major) meat color (lightness, redness, and yellowness), pH, drip and cook loss, as well as Allo-Kramer (AK) shear values. Furthermore, pectoralis minor muscles were used to determine lipid, protein, moisture, and ash content. Finally, because the flocks included white- and yellow-skinned broilers, the color of the carcass skin was measured to assess the relationship between skin and raw breast meat color. With regard to the season, breast meat from birds slaughtered during summer exhibited a paler and less red color, lower pH, higher drip and cook losses, lower AK-shear, and a higher content of moisture and a lower content of protein and ash. In respect to medium and heavy birds, light broilers produced breast meat with higher values of redness, lower pH and cook loss, higher AK-shear values, and a higher content of moisture and ash. Finally, a positive correlation (r = +0.92; P < or = 0.001) between skin and breast meat yellowness was found. These results indicate that during summer, broiler breast meat undergoes a depression of its functionality and quality. Moreover, the market class of birds also determined some differences in breast meat quality attributes.

Polymerase Chain Reaction–Restriction Fragment Length Polymorphism of Mitochondrial 12S rRNA Gene: A Simple Method for Identification of Poultry Meat Species

Chicken (Gallus gallus), duck (Anas platyrhynchos), turkey (Meleagris gallopavo), guinea fowl (Numida meleagris) and quail (Coturnix japonica) are the common poultry species consumed as meat throughout the world. In this work, a molecular technique has been developed for identification and differentiation of meat originating from these species. This tool helps in detection of misrepresentation of different poultry meats. The technique involves the extraction of DNA from the given sample, polymerase chain reaction (PCR) amplification of mitochondrial 12S rRNA gene using universal primers, restriction analysis with selected restriction enzymes, followed by identification of meat species based on restriction fragment length polymorphism (RFLP) pattern. In this study, we used HinfI, Mph1 103I, MvaI, and Eco47I to identify and differentiate to poultry species referred to above. This species identification technique has also been applied successfully to processed meat products including those cooked at 120 degrees C for 30 min. Simplicity of interpretation of results combined with versatility makes this a convenient and appropriate technique in the hands of meat analysts for identifying poultry meat species.

A simple carbon isotope model for reconstructing prehistoric human diet

A compilation of experimental animal data shows that neither delta13C(collagen) nor delta13C(apatite) nor Delta13C(CO-AP) indicate diagnostic reconstructions of diet, diet energy and diet protein. In contrast, plots of delta13C(collagen) against delta13C(apatite) provide a model of three regression lines (C3, C4, and marine diet protein) where position on each line indicates the energy source (C3, C4, or mixed). Neither body size nor trophic position appears to affect these relationships. Modern free-ranging, terrestrial fauna do not fit the model perhaps because they, unlike the experimental fauna, mainly use fermentation rather than digestion during energy metabolism. Archaeological humans fall as expected based on associated floral and faunal evidence. Foraging people plot at positions expected from associated C3 fauna and plants. Those from Cahokia plot, as expected, from associated deer, nuts, and maize whereas people from nearby smaller sites plot in positions consistent with eating more fish. Agriculturists from Ontario and Grasshopper Pueblo plot consistent with dependence on fish by the former and on turkeys by the latter. In Tierra del Fuego, people from interior regions ate more terrestrial fauna, as suggested by ethnohistoric reports, than did people from the coast. In the Southwestern Cape in South Africa individuals late in the sequence have pure C3 diets whereas ones early in the sequence ate marine protein as suggested by independent archaeological evidence. People on San Nicolas Island depended on C4 plants in contrast to other islands off California's coast. This simple model provides more detailed and precise dietary information than do individual isotopic measures.

Evaluation of post-polymerase chain reaction melting temperature analysis for meat species identification in mixed DNA samples

Real-time uniplex and duplex polymerase chain reaction (PCR) assays with a SYBR Green I post-PCR melting curve analysis were evaluated for the identification and quantification of bovine, porcine, horse, and wallaroo DNA in food products. Quantitative values were derived from threshold-cycle (C(t)) data obtained from serial dilutions of purified DNA. The limits of detection in uniplex reactions were 0.04 pg for porcine and wallaroo DNA and 0.4 pg for cattle and horse DNA. Species specificity of the PCR products was tested by the identification of peaks in DNA melting curves, measured as the decrease of SYBR Green I fluorescence at the dissociation temperature. The peaks could be distinguished above the background even at the lowest amount of template DNA detected by the C(t) method. The system was also tested in duplex reactions, by use of either single-species DNA or DNA admixtures containing different shares of two species. The minimum proportions of each DNA species allowing the resolution of T(m) peaks in the duplex reactions were 5% (cattle or wallaroo) in cattle/wallaroo mixtures, 5% porcine and 1% horse in porcine/horse mixtures, 60% porcine and 1% wallaroo in porcine/wallaroo mixtures, and 1% cattle and 5% horse in cattle/horse mixtures. A loss in the sensitivity of the method was observed for some DNA combinations in the duplex assay. In contrast, the results obtained from SYBR Green I uniplex and duplex reactions with single-species DNA were largely comparable to those obtained previously with species-specific TaqMan probes, showing the suitability of that simpler experimental approach for large-scale analytical applications.

Fluorescence characteristics of wholesome and unwholesome chicken carcasses

Each chicken carcass intended for U.S. consumers is mandated to be inspected by Food Safety and Inspection Service (FSIS) inspectors for its wholesomeness at the processing plants. Fluorescence responses of wholesome and unwholesome chicken carcasses were characterized and further evaluated for potential on-line applications for detection and classification of wholesome and unwholesome chicken carcasses. For this study, unwholesome chicken carcasses included cadaver and those with disease conditions such as airsacculitis and septicemia. Fluorescence characteristics from the epidermal layers in the breast areas of chicken carcasses were dynamic in nature. Emission peaks and ridges (maxima) were observed at 386, 444, 472, 512, and 554 nm and valleys (minima) were observed at 410, 460, 484, and 538 nm. One of the major factors affecting the line shapes of fluorescence responses from chicken carcass skin layers was absorption by hemoglobin. With the use of the normalized ratio spectra (NRS) approach, oxyhemoglobin was shown to be a major constituent in chicken carcasses affecting the fluorescence emission line shapes. Subtle line shape changes in the NRS also provided a qualitative means by which to assess the minute differences in oxy- and deoxyhemoglobin compositions perturbed by poultry diseases such as septicemia and airsacculitis. With the use of simple fluorescence band ratios as a multivariate model, wholesome and unwholesome chicken carcasses were correctly classified with 97.1% and 94.8% accuracies, respectively. On-line implementation of fluorescence techniques for the assessment of chicken carcass wholesomeness appears promising.

Flavor relationships among muscles from the beef chuck and round1

This research compared off-flavor notes and the relationship of pH and heme-iron content to off-flavor for different beef muscles. After grading, knuckles and shoulder clods were removed from 16 USDA Choice and 14 USDA Select beef carcasses, vacuum-packaged, and aged for 7 d. The rectus femoris (REC), vastus medalis (VAM), vastus lateralis (VAL), teres major (TER), infraspinatus (INF), and triceps brachii-long head (TRI) were separated, cut into steaks, and frozen (-16 degrees C). Sensory analysis was conducted using a trained taste panel, with steaks grilled to an internal temperature of 65 degrees C. Heme-iron concentration and pH were determined. The INF had lower (P < 0.05) off-flavor intensity ratings and less frequent sour flavor than the other muscles, and the VAL had the most intense (P < 0.05) off-flavor ratings and among the greatest frequency of sour, charred, and oxidized flavors. The frequencies of liver-like, bloody, and rancid flavors were not affected by muscle type. Heme-iron concentration did not differ among muscles. Three USDA Select carcasses had intense off-flavor in the muscles. Liver-like flavor was highly negatively correlated with off-flavor intensity for each of the muscles tested. Muscles rated a 5 or below (on an 8-point rating scale, where 1 = extremely intense off-flavor and 8 = no off-flavor) in off-flavor intensity and identified as liver-like by 30% or more of the panelists were grouped together and compared to normal muscles. Those in the liver-flavored group were less frequently identified as charred, probably because the liver-like flavor was so intense. There were no differences between the 2 groups for sour, metallic, bloody, oxidized, or fatty off-flavor notes. Regression equations containing the linear and quadratic functions of heme-iron concentration, muscle pH, and their interaction were established for the frequency of off-flavor notes within each muscle. The REC, TER, VAL, and VAM showed a relationship between pH, heme iron, and off-flavor intensity (P < 0.05). Liver-like flavor was explained partially by pH and heme iron in the REC, VAM, and VAL (R2 = 0.45 to 0.55; P < 0.05). Few other significant relationships were found. Heme iron and pH were unrelated to metallic, oxidized, or rancid flavors for any of the muscles tested. These data suggest that liver-like off-flavors are specific to individual animals, and that pH and heme iron are not strongly related to off-flavor notes.

Relationship among GeneSTAR marbling marker, intramuscular fat deposition, and expected progeny differences in early weaned Simmental steers

Research has demonstrated that triiodothyronine and thyroxin are correlated with marbling (MARB) deposition in Wagyu cattle. Polymorphisms in the 5' region of the thyroglobulin gene have been associated with an improvement in overall fattening and could be used as a gene marker for MARB. The commercially available GeneSTAR MARB test measures the specific thyroglobulin gene polymorphism and identifies cattle as having 0, 1, or 2 copies of the allele; these are identified as 0-STAR, 1-STAR, or 2-STAR, respectfully. Early weaned Simmental steers (n = 192) of known genetics were individually fed over a repeated 4-yr trial period to determine the correlations between GeneSTAR MARB test [Genetic Solutions/Bovigen Pty. Ltd. (Australia) in conjunction with Frontier Beef Systems, LLC (Louisville, CO)] results and intramuscular fat (IMF) deposition. Yearling weight, MARB, percent retail cuts, and carcass weight EPD were calculated for each steer. Steers were weaned at 88.0 +/- 1.1 d, pen-fed a high-concentrate diet for 84.5 +/- 0.4 d before allotment, and subsequently individually fed a 90% concentrate diet composed primarily of cracked corn and corn silage for 249.7 +/- 0.7 d. Steers were slaughtered at 423.3 +/- 1.4 d. Deoxyribonucleic acid samples were used by Genetic Solutions/Bovigen (Australia) for GeneSTAR MARB analysis. Steers with allele types of 0-STAR (n = 47), 1-STAR (n = 95), and 2-STAR (n = 33) had no effect (P > 0.10) on MARB score, chemically determined IMF percentage, quality grade, or percent low Choice and better. There were no differences (P > 0.10) in performance or other carcass parameters among the allele types. GeneSTAR results were not associated with MARB (P > 0.10). Conversely, MARB EPD was correlated (P < 0.01) with MARB score (r = 0.44) and IMF percentage (r = 0.27). Thus, in this management system, MARB EPD is an accurate predictor of IMF deposition. These data suggest that the GeneSTAR MARB marker was not an efficacious predictor of IMF deposition in early weaned Simmental steers fed a high-energy diet.

PCR-RFLP authentication of meats from red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus), cattle (Bos taurus), sheep (Ovis aries), and goat (Capra hircus)

PCR-RFLP analysis has been applied to the identification of meats from red deer (Cervus elaphus), fallow deer (Dama dama), roe deer (Capreolus capreolus), cattle (Bos taurus), sheep (Ovis aries), and goat (Capra hircus). PCR amplification was carried out using a set of primers flanking a conserved region of approximately 712 base pairs from the mitochondrial 12S rRNA gene. Restriction site analysis based on sequence data from this DNA fragment permitted the selection of MseI, MboII, BslI, and ApoI endonucleases for species identification. The restriction profiles obtained when amplicons were digested with the chosen enzymes allowed the unequivocal identification of all domestic and game meat species analyzed in the present work.

Postweaning growth and carcass traits in crossbred cattle from Hereford, Angus, Norwegian Red, Swedish Red and White, Friesian, and Wagyu maternal grandsires1,2

The objective of this study was to characterize breeds representing diverse biological types for postweaning growth and carcass composition traits in terminal crossbred cattle. Postweaning growth and carcass traits were analyzed on 434 steers and 373 heifers obtained by mating F1 cows to Charolais sires. Maternal grandsires represented Hereford, Angus, and MARC III (1/4 Hereford, 1/4 Angus, 1/4 Pinzgauer, and 1/4 Red Poll) dams to Hereford or Angus (British Breeds), Norwegian Red, Swedish Red and White, Wagyu, or Friesian breeds. Breed groups were slaughtered serially in each of 2 yr (2002 and 2003). Postweaning ADG, slaughter weight, hot carcass weight, dressing percentage, percentage Choice, LM area, marbling score, USDA yield grade, fat thickness, retail product yield (percentage), retail product weight, fat yield (percentage), fat weight, bone yield (percentage), and bone weight were analyzed. Maternal grandsire breed was significant (P < 0.05) for all traits except dressing percentage, percentage Choice, and LM area. Marbling score for animals with Norwegian Red, Wagyu, Swedish Red and White, British Breeds, and Friesian inheritance was 550, 544, 532, 530, and 515, respectively (SEM = 8). Retail product weight for these animals was 224, 211, 227, 223, and 223 kg, respectively (SEM = 2 kg). Maternal granddam breed was not significant for any of the traits analyzed. Grandsire breed effects can be optimized by selection and use of appropriate crossbreeding systems.

Meat and fish consumption, APC gene mutations and hMLH1 expression in colon and rectal cancer: a prospective cohort study (The Netherlands)

OBJECTIVE

The aim of this study was to investigate the associations between meat and fish consumption and APC mutation status and hMLH1 expression in colon and rectal cancer.

METHODS

The associations were investigated in the Netherlands Cohort Study, and included 434 colon and 154 rectal cancer patients on whom case-cohort analyses (subcohort n = 2948) were performed.

RESULTS

Total meat consumption was not associated with the endpoints studied. Meat product (i.e. processed meat) consumption showed a positive association with colon tumours harbouring a truncating APC mutation, whereas beef consumption was associated with an increased risk of colon tumours without a truncating APC mutation (incidence rate ratio (RR) highest versus lowest quartile of intake 1.61, 95% confidence interval (CI) 0.96-2.71, p-trend = 0.04 and 1.58, 95% CI 1.10-2.25, p-trend = 0.01, respectively). Consumption of other meat (horsemeat, lamb, mutton, frankfurters and deep-fried meat rolls) was associated with an increased risk of rectal cancer without a truncating APC mutation (RR intake versus no intake 1.79, 95% CI 1.10-2.90). No associations were observed for meat consumption and tumours lacking hMLH1 expression.

CONCLUSIONS

Our data indicate that several types of meat may contribute differently to the aetiology of colon and rectal cancer, depending on APC mutation status but not hMLH1 expression of the tumour.

Intramuscular tenderness variation within four muscles of the beef chuck1

The i.m. tenderness variation was examined within four beef chuck muscles, the infraspinatus (IF), supraspinatus (SS), triceps brachii (TB), and serratus ventralis (SV). The IF, SS, TB, and SV muscles were cut into 2.5 cm thick steaks perpendicular to the long axis of the muscle. An identification tag was placed on each steak, consisting of a muscle identification number, steak number, and orientation of the steak. Steaks were vacuum-packaged and stored at -22 degrees C until subsequent analysis. Steaks were thawed at 1 degrees C and cooked on electric broilers to an internal temperature of 71 degrees C. One core was removed from each 2.5-cm x 2.5-cm section parallel to the muscle fiber and sheared once to determine Warner-Bratzler shear force (WBSF). The SS had an overall WBSF mean of 5.43 kg (SD = 2.20 kg) with no tenderness difference (P = 0.43) among steak locations. The IF had an overall WBSF mean of 3.16 kg (SD = 1.01 kg) with no tenderness difference (P = 0.51) among steak locations. The SV had a mean WBSF value of 4.37 kg (SD = 1.27 kg) with tenderness variation (P < 0.05) among steak locations; however, tenderness variations were not dispersed in a discernible pattern. The TB had a mean WBSF value of 4.12 kg (SD = 1.26 kg) with lower (P < 0.05) shear force in the middle region of the TB, and the distal and proximal ends were tougher (P < 0.05). Results of this study provided a reasonably detailed mapping of the tenderness regions within the IF, SS, TB, and SV muscles, and this information could be used to add value to the beef chuck by cutting and marketing consistently tender regions.

French multi-agency outbreak investigation team. Outbreak of E. coli 0157:H7 infections associated with a brand of beefburgers in France

On 24 and 25 October 2005, 5 cases of haemolytic uraemic syndrome (HUS)

Sociodemographic, knowledge, and attitudinal factors related to meat consumption in the United States

OBJECTIVE

To provide information about meat consumption and factors that explain differences among subpopulations, and to evaluate how knowledge and attitudes about nutrition and awareness of diet and health influence meat consumption.

DESIGN

The 1994-1996 Continuing Survey of Food Intakes by Individuals provided two nonconsecutive 24-hour recalls. The Diet and Health Knowledge Survey was administered at least 1 week after the last 24-hour recall. Meat subgroups (chicken, beef, pork, and processed pork products) were calculated from Food Guide Pyramid meat groups by using recipe ingredients.

SUBJECTS

The study sample included 4,802 children and 9,460 adults from the Continuing Survey of Food Intakes by Individuals and 5,649 adults from the Diet and Health Knowledge Survey.

STATISTICS

Weighted percentages and means described the food intake and self-assessed dietary characteristics. Relationships among types of meat intake, dietary characteristics, and demographics were evaluated using a two-stage, multivariate regression model.

RESULTS

Individuals in higher income households consumed relatively more chicken; those in low-income households consumed more processed pork products. Those consuming no beef and smaller amounts of chicken had the lowest discretionary fat intakes. Beef and pork consumers were more likely to think that their diets were too high in fat, but less likely to believe it is important to eat a low-fat diet. Region of residence affected the probability of consuming most meats. Having a high level of education was associated with a lower likelihood of consuming beef and pork.

CONCLUSIONS

Sociodemographic factors are strong predictors of the probability of choosing particular types of meat and of the amounts eaten. Knowledge and attitudes about diet and meat products also influence choices.

Two-wave-band color-mixing binoculars for the detection of wholesome and unwholesome chicken carcasses: a simulation

Visual inspection of wholesome and unwholesome chicken carcasses with a novel two-narrowband color-mixing technique for optically enhanced binoculars is simulated. From mean spectra of wholesome, airsacculitis (air-sac), cadaver, inflammatory process (IP), septicemia-toxemia (septox), and tumor chicken samples, 10 nm wave-band pairs are selected using color difference and chromaticness difference indices for simulation of multitarget and single-target detection. The color appearance simulation uses the CIECAM97s color appearance model. Results show that for multitarget detection, the wave-band pair of (454 nm, 578 nm) is able to differentiate all six chicken conditions. For single-target detection of wholesome, air-sac, cadaver, and tumor, the wave-band pairs of (449 nm, 571 nm), (441 nm, 576 nm), (458 nm, 576 nm), and (431 nm, 501 nm), respectively, easily distinguish the target condition from the other five conditions. For single-target detection of IP and septox, the wave-band pairs of (454 nm, 591 nm) and (454 nm, 590 nm), respectively, are able to differentiate the target conditions from wholesome and tumor conditions but have difficulty with the other chicken conditions. The two-color-mixing technique shows promise for use in small-scale processing plant environments to improve the visual inspection process.

Association of single nucleotide polymorphisms in the leptin gene with carcass and meat quality traits of beef cattle1

Studies with different populations are required to properly characterize the robustness of associations of polymorphisms in candidate genes with economically important traits across beef cattle populations before this sort of genetic information can be used efficiently in breeding and management decisions. The objective of this study was to evaluate the association of previously reported SNP in the bovine leptin gene with carcass and meat quality traits from a large sample of crossbred beef cattle. Five SNP (UASMS1, UASMS2, UASMS3, E2JW, and E2FB) were genotyped on 1,111 crossbred bulls, heifers, and steers. The measured traits included fat, lean, and bone yield (%) by partial rib dissection, grade fat, LM area, HCW, quality grade, LM i.m. fat, and tenderness evaluation of LM and semitendinosus muscle. Only four SNP were analyzed (UASMS1, UASMS2, E2JW, and E2FB), because UASMS1 and UASMS3 were completely linked. A uni-variate mixed-inheritance animal model was used to evaluate the association of either genotypes or haplo-types with the traits. The two leptin exon 2 SNP were associated with fat and lean yield and grade fat (E2JW, P < 0.01; E2FB, P < 0.05), and they interacted in their effect on LM tenderness (P < 0.01). The leptin promoter SNP were either not associated with any of the traits (UASMS2) or with fat yield only (UASMS1). Three haplotypes (TCAC, CCAT, TTAC) were at high frequency in the population (88%) and had similar effects on all the traits. Compared with the common haplotypes, one haplotype (CCTT) showed a significantly different effect on fat and lean yield and grade fat (P < 0.01), and one haplotype (TTTT) had a different effect on LM tenderness (P < 0.03). Therefore, important associations between SNP within the leptin gene with lean yield, fatness (fat yield and subcutaneous fat), and tenderness were detected. Results confirm some of the previously reported associations, but diverge with respect to others, showing that further efforts are required to validate some prospective associations.

Effects of crude protein concentration and degradability on performance, carcass characteristics, and serum urea nitrogen concentrations in finishing beef steers

Two experiments were conducted at two locations to determine the effects of dietary CP concentration and source on performance, carcass characteristics, and serum urea nitrogen (SUN) concentrations of finishing beef steers. British x Continental steers were blocked by BW (357 +/- 28 and 305 +/- 25 kg initial BW; n = 360 and 225; four and five pens per treatment in Exp. 1 and 2, respectively). Steam-flaked corn-based diets were arranged in a 3 x 3 factorial with three CP concentrations (11.5, 13, or 14.5% of DM) and three sources of supplemental CP (N basis): 100% urea; 50:50 blend of urea and cottonseed meal; or 100% cottonseed meal. Steers in both experiments were initially implanted with Ralgro and reimplanted with Revalor-S on d 56. Performance and carcass data were pooled across locations. Crude protein concentration x source interactions were not observed (P = 0.22 to 0.93) for performance and carcass data. Crude protein concentration affected ADG (P = 0.02) and carcass-adjusted (to a common dressing percent within location) ADG quadratically (P = 0.06). Increasing the concentration of supplemental urea linearly increased carcass-adjusted ADG and G:F (P < 0.05) and carcass-adjusted G:F (P < 0.001). Dry matter intake was not affected (P = 0.93) by either CP concentration or source. Hot carcass weight (HCW; P = 0.02), LM area (P = 0.05), and dressing percent (P = 0.03) increased linearly with increasing urea concentration, whereas increasing CP concentration quadratically affected HCW (P = 0.02), with a maximum at 13% CP. Differences in backfat thickness and yield grade were negligible across treatments. Neither marbling score nor percentage of carcasses grading USDA Choice was affected by CP concentration or source. At all times measured, SUN concentrations increased (P < 0.05) with increasing CP concentration, but effects of CP source were small and variable across time. Results indicate that increasing CP concentrations from 11.5 to 13% slightly increased ADG and carcass-adjusted ADG, whereas increasing the proportion of supplemental urea increased carcass-adjusted ADG, G:F, and carcass-adjusted G:F and increased HCW, LM area, and dressing percent. A CP concentration above 13% seemed detrimental to ADG and HCW. Serum urea N increased over time, with CP concentration having a greater effect than CP source.

Effects of marbling and shear force on consumers' willingness to pay for beef strip loin steaks

Experimental economic procedures were used to measure the effects of changes in marbling score and Warner-Bratzler shear force (WBSF) value on consumer purchasing behavior and willingness to pay for beef strip loin steaks (n = 541). Consumers were more likely to bid on a steak during the experimental auction if the steak had a high marbling score or low WBSF value. Averaging across all consumers in the study (n = 489), the predicted odds that consumers would submit a nonzero bid were favorable for steaks with a marbling score greater than Modest(50) or a WBSF value less than 3.9 kg. Bid prices for steaks were analyzed with respect to changes in steak marbling score, WBSF value, quality grade marketing category classification (Select, Low Choice, Premium Choice, and Prime), and WBSF marketing category classification (very tender, <or= 3.4 kg; slightly tender, 3.41 to 4.40 kg; slightly tough, 4.41 to 5.40 kg; or very tough, > 5.40 kg). The percentage of bids that were zero was highest (P < 0.05) for Select steaks, intermediate (P < 0.05) for Low Choice steaks, and lower (P <0.05) for Premium Choice or Prime steaks. Steaks in the very tender category had the lowest (P < 0.05) percentage of zero bids, and steaks in the slightly tough and very tough categories had the highest (P < 0.05) percentage of zero bids submitted from "buyers" in the auction. Premium Choice and Prime steaks were valued higher (P < 0.05) than Select steaks by consumers. On average, Premium Choice steaks received a 0.89 dollars/kg premium, and Prime steaks received a 2.47 dollars/kg premium over the mean bid price for Select steaks. Predicted mean bid prices for steaks decreased by 1.02 dollars/kg for each 1 kg increase in WBSF value. On average, steaks in the very tender marketing category received a higher (P < 0.05) bid price than the bid price for steaks in the slightly tender, slightly tough, and very tough categories (+0.83 dollars/kg, +2.09 dollars/kg, and +2.55 dollars/kg, respectively). Mean bid prices for steaks from the slightly tough and very tough categories did not differ (P = 0.184). Compared with the mean bid price for steaks in the slightly tender category, steaks from the slightly tough and very tough categories were discounted (P < 0.05) by 1.26 dollars/kg and 1.72 dollars/kg, respectively. Results suggest that marbling score and WBSF influence both the probability that consumers will purchase and the price they are willing to pay for strip loin steaks.