431 research outputs found
Enhancement of pigmeat quality by altering pre-slaughter management
End of project reportThe studies presented in this report were conducted to investigate the effect of breed, slaughter weight, castration of male pigs and strategic feeding strategies on the performance of pigs to slaughter and on
their carcass quality.
The effect of breed, gender and feeding regimen on the performance of pigs and their carcass quality was examined in the first study (Section 3). From weaning to slaughter Landrace-sired pigs grew at a similar rate but had a better feed conversion efficiency compared with Duroc-sired pigs.
Landrace-sired pigs also had a higher carcass lean and greater muscle depth than Duroc-sired pigs.
Entire male pigs grew more efficiently, had lower lean content in their carcasses and had a reduced kill out yield when compared with gilts. The eye muscle depth was greater for gilts than entire males.
Diluting the diet with grass-meal (GM) reduced growth rate, caused a deterioration in feed conversion efficiency, reduced back fat thickness, reduced eye muscle thickness and reduced kill out yield compared to the control feeding regimen of a cereal based diet. Compensatory growth was observed
during a re-alimentation period following a period of diet dilution with grass-meal. However,
where it did occur, in most cases it was only partial. Adding 5% rapeseed oil instead of lard to the finisher diet increased nitrogen utilization efficiency and phosphorous utilization efficiency.
The effect of gender (boar, castrate, gilt) and slaughter weight (80 to 120kg) on pig performance, carcass quality, meat quality, and nitrogen excretion was investigated in the second study (Section 4).
Boars grew faster than gilts and more efficiently than castrates or gilts. Castrates had a higher kill out
yield than boars. Nitrogen excretion from castrates was similar to gilts which were both higher than that from boars. The processing value of carcasses from castrates may be higher than that of boars and
gilts. In particular castrates had heavier loins and bellies than either boars or gilts. Carcasses from castrates and gilts had a higher temperature (recorded 24 hours post slaughter) than boars. However,
pH24 was not affected by gender. The intramuscular fat content of the l. dorsi in castrates was higher than that of boars or gilts, however at 1.65% this was well below the level (2.0%) above which any
noticeable sensory attributes might be detected.
Feed intake increased with increasing slaughter weight and feed conversion efficiency deteriorated. N
excretion also increased with each increment in weight. Carcass lean content increased up to 90kg live EOP 4939.doc 4 25/10/2005
weight then reached a plateau and declined after 110kg live weight. Heavier carcasses yielded more product for approximately the same slaughtering cost and the associated larger muscles could make it
easier to use seam butchery techniques that result in lean, well-trimmed, attractive cuts and joints. The pH45 and pH24 were reduced with increasing slaughter weight and drip loss increased. Heavier pigs
may be more prone to the development of PSE than lighter pigs as their carcass temperature remains higher for longer than that of lighter pigs
Consumer attitudes on salt and fat reduced foods in the Republic of Ireland
Public health campaigns are continually promoting healthier foods and in parallel many food manufacturers are working on recipes low in fat and salt. The following survey investigates how well consumers (n = 1045) in Ireland have assimilated the message of consuming healthier foods, including salt and fat reduced foods, into their diet. It seems that campaigns regarding the importance of a balanced diet have generally been adopted by respondents, as only a minority of the participants did not take care of their diet, independent of age, gender and level of education. More than half of the participants carefully maintained a balanced diet. Furthermore, an increase in purchasing salt reduced food was observed, though fat reduced food products were already better accepted. In general, men, young adults (<30 years) and lower educated people purchased less salt and fat reduced foods and took less care in maintaining a balanced diet. No conflict was observed for traditional foods reduced in salt and fat content when their intrinsic sensory character is maintained. The majority of the participants were aware of the health risks of a diet rich in salt and fat, though less participants transferred this knowledge into their diet. A very high demand for more salt and fat reduced foods on the market was observed although the smaller range of salt and fat reduced products and their higher prices might diminish the level of consumer acceptance. Launching taxation and subsidies in tandem might counteract this and furthermore, user-friendly product labelling schemes are required
Rapid descriptive consumer analysis using simultaneous and monadic sample presentation for coffee
The objective of this study was to investigate how rapid descriptive consumer analysis using simultaneous presentation of samples compared with monadic presentation of samples, using both affective and descriptive sensory evaluation methods. Simultaneous presentation of coffee samples for sensory acceptance testing, using ranking analysis, was conducted using naĂŻve assessors. In a separate session, assessors evaluated the same coffee samples, using monadic presentation and employing the same scales. Similarly, descriptive consumer analysis, using simultaneous and monadic sample presentation, was conducted using descriptive attributes chosen by the panel. For RDA (Ranking descriptive analysis), coffee samples were presented simultaneously (randomised) to assessors and subsequently ranked. The process was then repeated using the same assessors; however, samples were presented in monadic and randomised presentation order. Data accumulated from the study were analysed by Analysis of Variance (APLSR-ANOVA Partial Least Squares Regression). Results obtained indicate that simultaneous presentation of samples was more effective than monadic presentation, as a larger amount of attributes with significant (P < 0.05) intensity differences were observed using RDA. Thus, simultaneous presentation of samples also allows ranking in SAT evaluation and proved a useful tool in establishing the hedonic attributes of products. We propose to call this method Ranking Acceptance Analysis (RAA)
Investigating the influence of ultrasound pre-treatment on drying kinetics and moisture migration measurement in Lactobacillus sakei cultured and uncultured beef jerky
Low Frequency-Nuclear Magnetic Resonance (LF-NMR) was employed to elucidate changes in water distribution in cultured (Lactobacillus sakei) and uncultured beef jerky samples subjected to ultrasound pre-treatment. Ultrasound pre-treatment at frequencies of 25, 33 and 45 kHz for 30 min, followed by marination (18 h) was carried out for both cultured and uncultured jerky samples. Among the various kinetic models assessed, the Wang and Singh model provided the closest fit to the drying experimental data, with high R2 (âĽ0.994), low RMSE (â¤0.023) and low AICc (100 ms (T22), respectively. Results presented in this study demonstrates that the ultrasound effect on drying behaviour was frequency dependent and that LF-NMR can be employed to evaluate moisture mobility and drying degree of beef jerky
An investigation of the effect of rapid slurry chilling on blown pack spoilage of vacuum-packaged beef primals
The aim of this study was to investigate if rapid slurry chilling would retard or prevent blown pack spoilage (BPS) of vacuum-packaged beef primals. Beef primals were inoculated with Clostridium estertheticum subspp. estertheticum (DSMZ 8809), C. estertheticum subspp. laramenise (DSMZ 14864) and C. gasigenes (DSMZ 12272), and vacuum-packaged with and without heat shrinkage (90°C for 3 s). These packs were then subjected to immediate chilling in an ice slurry or using conventional blast chilling systems and stored at 2°C for up to 100 days. The onset and progress of BPS was monitored using the following scale; 0-no gas bubbles in drip; 1-gas bubbles in drip; 2-loss of vacuum; 3-âblownâ; 4-presence of sufficient gas inside the packs to produce pack distension and 5-tightly stretched, âoverblownâ packs/packs leaking. Rapid slurry chilling (as compared to conventional chilling) did not significantly affect (P > 0.05) the time to the onset or progress of BPS. It was therefore concluded that rapid chilling of vacuum-packaged beef primals, using an ice slurry system, may not be used as a control intervention to prevent or retard blown pack spoilage. Significance and Impact of the Study: This study adds to our growing understanding of blown pack spoilage of vacuum-packaged beef primals and suggests that rapid chilling of vacuum-packaged beef primals is not a control option for the beef industry. The results suggest that neither eliminating the heat shrinkage step nor rapid chilling of vacuum-packaged beef retard the time to blown pack spoilage
The eating quality of beef from young dairy bulls derived from two breed types at three ages from two different production systems
peer-reviewedExpansion of the Irish dairy herd has led to more dairy breed male calves being available for beef production. This study investigated the physico-chemical and sensory characteristics of beef from Holstein-Friesian (HF) and Jersey Ă HF (JEX) young bulls fed pasture grass only or pasture grass plus 2 kg concentrate during their first grazing season and slaughtered at 15, 19 or 22 mo of age. Longissimus thoracis (LT) muscles were collected from 67 carcasses. Postmortem pH, ultimate pH (pHu), meat colour, chemical composition, collagen content and solubility were evaluated. After ageing for 21 d, Warner-Bratzler shear force and cooking loss were determined, and assessments by a trained sensory panel were conducted. Meat from older animals was darker. The pHu, moisture and ash contents decreased, while residual roast beef flavour length increased with age. However, increasing age to slaughter did not negatively influence tenderness. JEX beef had lower cooking loss, was darker and redder, in addition to having higher sensory scores for initial tenderness and fattiness than HF beef. Warner-Bratzler variables were positively correlated with cooking loss and chewiness and were negatively correlated with intramuscular fat (IMF) content, soluble collagen and initial tenderness. In summary, most young dairy bull beef samples were acceptably tender after 21 d of ageing and half of them had acceptable IMF content. Slaughter age affected beef colour, pHu, chemical composition and flavour length. The eating quality of meat from the JEX breed type was considered to be superior to that of the HF breed type. Diet during the first season had no effect on meat quality traits
Impact on the physicochemical and sensory properties of salt reduced corned beef formulated with and without the use of salt replacers
peer-reviewedThe aim of this study was to investigate physicochemical and microbiological properties as well as a sensory (affective and descriptive) driven sodium reduction (0.2âŻg/100âŻg - 1.0âŻg/100âŻg product) strategy for a cured meat product (corned beef). A second aim was to use the same methodology to further reduce salt, using salt replacers. Significant differences in colour, hardness and cooking loss were measured. Corned beef samples low in sodium (0.2âŻg/100âŻg, 0.4âŻg/100âŻg) showed reduced (PâŻâŻ0.05) to liking of flavour and overall acceptability. Samples formulated with CaCl2, MgCl2 and KCl scored higher (PâŻâŻ0.05) to liking of flavour and overall acceptability. However, a sodium reduction in corned beef was determined to be achievable as assessors liked (PâŻ<âŻ0.05) the flavour of the sodium reduced corned beef containing 0.4âŻg/100âŻg sodium and formulated with potassium lactate and glycine (KLG), even with the noticeable lower salty taste. Sodium reduction in corned beef (packaged under modified atmosphere) did not negatively impact on the microbiological shelf-life.This study was funded by the Irish Food Industry Research Measure (FIRM) as part of the project titled âPROSSLOW; Development of assessor accepted low salt and low fat Irish traditional processed meat (Ref: 11 F 026)â
Variation in the quality of meat from Irish steers at the time of slaughter.
End of Project ReportThere is no information on the variation in quality, in particular
tenderness, that exists in Irish Beef nor is there information on the
variation that would remain if optimum practices were imposed at
all stages of the beef production chain. Evaluation of the success of
measures to improve beef consistency requires information on
existing variation and the minimum variation achievable.The objectives
of this project were (i) to establish the variation that exists in
the quality of meat from Irish cattle, (ii) to quantify the minimum
variation in meat quality that can be achieved in a practical beef production
system, (iii) to determine the effects and mechanisms of
additional sources of variation.
The conclusions from this project are:
⢠The M. longissimus dorsi (loin) was found to be more variable
than the M. semimembranosus (topside) for most quality
attributes examined (tenderness, sarcomere length and pH).
The scale of variation within the loin was similar to that
reported by the other research groups within the EU and US.
Heifers were more variable than steers for most attributes,
while there was no consistent classification effect on the
variability of meat quality attributes.
⢠Tenderness was equally variable in meat from genetically similar
steers, managed similarly, compared to commercial steers
randomly selected from a factory lairage but matched for
weight and grade.This was likely a result of both groups being
crossbred beef cattle of similar age, fat score, carcass weight
and managed identically post-mortem. However, variation in
tenderness of both groups was less than that observed in
a survey of commercial throughput (experiment 1). This
decrease is attributed to better pre-and-post-slaughter handling
practices.
⢠The data suggest that selection of sires (within a breed) with
better than average conformation has no deleterious effect on the eating quality of beef of their progeny.A more comprehensive
comparison of sires within a breed and between
breeds is required to confirm the generality of this conclusion.
⢠In a comparison of genotypes, gender and slaughter weights,
there was no evidence that variation around the mean value
for tenderness differed between breeds or liveweights after
14 days ageing. Bulls were more variable than steers for some
quality traits but the variation in tenderness was similar for
bulls and steers after 14 days ageing.
⢠While optimising the management of animals during the pre
and post-slaughter period reduced variation in tenderness,
some residual variation remained. A large percentage of the
residual variation in tenderness (Warner Bratzler shear force)
after 2 and 7 days post-mortem was explained by proteolysis
(breakdown of myofibrillar proteins).Variation in tenderness
(Warner Bratzler shear force) after 2 days post-mortem was
largely explained by phosphates (energy) and proteolysis,
while sensory tenderness was largely explained by phosphates
and glycolytic potential.
⢠Further work is required to reduce residual variation in Irish
beef and to determine the causes of this variation
Ultrasound-Assisted Marination: Role of Frequencies and Treatment Time on the Quality of Sodium-Reduced Poultry Meat
peer-reviewedThe objective of this study was to evaluate the influence of high-power ultrasound (US)
to accelerate marination of chicken breast; the effect of ultrasonic frequencies and marination times
were investigated on samples containing full sodium levels (FS) or 25% sodium reduction, either by
reducing NaCl (R50) or by its partial substitution with KCl (SR). Chicken breasts were marinated
in plastic bags immersed in an ultrasonic bath operating with a frequency of 25, 45 or 130 kHz for
1, 3 or 6 h at a temperature of 2.5 Âą 0.5 âŚC. Chicken marinated using US had a significantly higher
uptake (p < 0.05) of sodium compared to control samples (no US) marinated for the same amount of
time. No significant changes were observed in the quality parameters of sonicated chicken samples
compared to controls. However, significant decreases (p < 0.05) in lipid oxidation were observed in
SR samples when treated by US. These results suggest the use of ultrasound in the meat processing
industry as a novel technology for enhancing marination processes and formulation of reduced
sodium meat products
Correlating Volatile Lipid Oxidation Compounds with Consumer Sensory Data in Dairy Based Powders during Storage
peer-reviewedLipid oxidation (LO) is a recognised problem in dairy powders due to the formation of volatile odour compounds that can negatively impact sensory perception. Three commercial dairy powders, fat-filled whole milk powder (FFWMP), skim milk powder (SMP), and infant milk formula (IMF), stored under different conditions (21 °C, 37 °C, or 25 °C with 50% humidity), were evaluated by consumer acceptance studies, ranked descriptive sensory analysis, and LO volatile profiling using headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME GCMS) over 16 weeks. Significant (p = 0.001) differences in the concentration of LO compounds and sensory perception were evident between sample types in the different storage conditions. The sensory acceptance scores for FFWMP and SMP remained stable throughout storage in all conditions, despite the increased perception of some LO products. The IMF sample was perceived negatively in each storage condition and at each time point. Overall increases in hexanal, heptanal, and pentanal correlated with âpaintyâ, âoxidisedâ, âcookedâ, and âcaramelisedâ attributes in all samples. The concentration of some LO volatiles in the IMF was far in excess of those in FFWMP and SMP. High levels of LO volatiles in IMF were presumably due to the addition of polyunsaturated fatty acids (PUFA) in the formulation
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