Fresh Meat

Palatability Assurance Critical Control Point (PACCP)

Palatability of beef constitutes three main characteristics; flavour, juiciness and most important of all, tenderness. It represents important criteria that influence the decision by the consumer to purchase beef. The palatability of beef is dependent on production, processing, and cooking methods used to prepare the beef for consumption. In the USA, recent surveys have identified that consumers have difficulty in selecting beef because they are unsure of its quality particularly its tenderness.

In order to overcome this problem the Australian beef industry has pioneered a key initiative called Meat Standards Australia (MSA). This programme developed consumer taste panels as a measure to evaluate the effectiveness of a grading system and as a tool to develop a detailed understanding of factors which interact to determine the eating quality of individual beef cuts. In the UK, the Meat and Livestock Commission (MLC) has produced publications on best practice. In the Republic, Bord Bia have a beef quality mark in place and there has been a lot of progress with this system within the Irish beef industry.

Quantification of variation in beef at processor, retailer, consumer level and within certain beef markets to achieve a full palatability assured critical control points (PACCP) system

The objective of this project is to develop a Palatability Assurance Critical Control Point (PACCP) plan for the Irish beef industry taking on board what is already known, testing some emerging issues and embracing new technologies which may contribute to the development of an Irish PACCP system. Overall a set of guidelines will be established for the processing industry to ensure that beef products will be highly palatable. This will be achieved by the establishment of a grading system similar to the PACCP system in Australia.

The Australian model was developed using a multiple regression approach whereby input variables from the production, processing and value adding sectors were included in a model to predict palatability of individual muscles for a range of cooking techniques. This approach allowed changes in palatability to reflect the estimated effects of the input variables rather than using the approach of non-negotiable cut-offs (fixed range of values for measured parameters). However ultimate pH, fat depth and ossification (age of animal) all have cut-offs.

The current model was developed using production, processing and sensory data for 12,700 samples contained in the MSA database. The database now contains 400,000 samples and 60,000 consumers have contributed to its building through assessment of these samples. The Meat Technology Department in conjunction with the Marketing Group will lead the setting up of the Better Beef consumer taste panels at Ashtown Food Research Centre’s new state of the art training and conference centre.

It is envisaged that over 3,000 consumers will participate in the Better Beef taste panels over the next three years.

The Australian model is now available through agreement with the MSA and will be applied within the Irish context. Its ability to predict beef palatability under Irish conditions will be evaluated. Parameters of importance within the Irish beef production and processing industries will be inputted. Sensory trials of a large number of consumers will be used to test the model. The experimental design will be similar to the MSA protocols. The initial work will create a baseline of the palatability of Irish beef under normal processing conditions. Further CCPs will be introduced as the project proceeds. Parallel to this, research at pilot scale level, will investigate different aspects of technology, which may be included in the final PACCP plan. Consumer science and statistical experts will compliment the experienced team of meat researchers and their Australian consultants (i.e. the MSA staff). karen.brandon@teagasc.ie or paul.allen@teagasc.ie

Variation in the eating quality of Irish beef

There are three aims of this research: to quantify existing variation in the eating quality of Irish beef, to identify factors contributing to this variation and to apply measures to reduce it. In general, the main quality attributes that were focused on were tenderness (measured both instrumentally (Warner Bratzler shear force) and by sensory analysis), colour (Hunter L, a, b) cooking loss, drip loss, chemical composition and the degree to which the muscle was contracted or stretched (sarcomere length). In the live animal gender, heifers and young bulls, were main contributors to eating quality variation, with steer beef being the least variable. Liveweight, classification grade, breed or sire had no significant level of contribution. The striploin (M. longissimus dorsi) was more variable compared to the topside (M. semimembranosus) for most attributes with the exception of colour. A significant reduction in variation was achieved through the application of “best-practice” pre- and pos-slaughter management. Factors such as using steers, one breed (Belgian Blue cross Holstein Friesian breed) and minimising stress were applied during production. Post-slaughter management incorporated pelvic hanging and a moderate chilling regime. Pelvic hanging in a moderate chill resulted in uniform actomyosin crossover as shown by transmission electron micrographs. However, as unacceptable variation remained in tenderness, biochemical processes within the muscle were studied to identify their level of input to variation in tenderness. At some time points the biochemical make up of the muscle was able to explain a large percentage of the variation tenderness. This research has been successful in reducing variation in the eating quality of beef and in providing some explanation for this variation. Further research may focus on the contribution of enzymatic degradation and also on variation introduced at the retail and consumer level, (See more..) anne.mullen@teagasc.ie or aidan.moloney@teagasc.ie

Introducing technical innovations in processing plants

While various intervention techniques have been introduced at industry level such as electrical stimulation and aitchbone hanging in an attempt to improve tenderness, research has found that these techniques do not affect all muscles throughout the carcass equally. The approach to this research is to examine the beef carcass as a set of individual muscles and cuts by removing muscles shortly after slaughter (hot-boning) and to establish the optimum treatment early post mortem for these pieces. anne.mullen@teagasc.ie

The application of a novel hot-boning and chilling procedure for the processing of beef cuts

Currently, a novel beef packaging system is being developed with potential benefits to the industry. These benefits include increased meat yield, reduced energy costs resulting from less chiller space and a saving of refrigeration input, quicker throughput of meat in the packaging plant and a reduction in transport costs and labour.

Using this system, the carcass is hot-boned and the hot meat is tightly packaged in elasticated film using a “PI-VAC” machine. This new system overcomes two major disadvantages associated with hot-boning: the toughening which is caused by muscle contraction during chilling of hot-boned meat, and shape distortion of the hot-cut meat. PI-VAC operates by stretching tubes of elastic film to the inside wall of the packaging chamber. The hot muscle is inserted into the chamber, pressure is released and the film returns to its original dimensions. The meat forms into the shape of its constraining pack and the muscle shape is not distorted. The restraining force of the film hinders muscle contraction and thereby prevents toughening. Using this new system hot-boned meat packed in PI-VAC can be chilled quickly producing beef of consistent tender eating quality. Using this system variability of tenderness will be reduced as individual muscles can be treated optimally. anne.mullen@teagasc.ie

Improving pig carcass grading

According to EU regulations, pig carcasses must be graded according to their lean meat content determined by an approved instrumental method. Equipment is authorised if it is shown to be sufficiently accurate based on a sample of 120 carcasses. The lean meat percentage of these carcasses must be determined by a standardised cutting procedure and the dissection of the four main cuts, the ham, loin, belly and shoulder.

Most countries have more than one type of equipment authorised for use. The most common grading equipment are grading probes. These use light reflectance to measure the fat and lean depths at defined points on the carcass. More recently, ultrasound probes and the automated ultrasound scanner AUTOFOM have been authorised in some countries.

The lack of uniformity in the types of equipment used and in the measuring sites in the various national grading regulations has lead to the perception that grading is not standardised across the EU countries. There is also real evidence that carcasses do not achieve the same grading in different countries. The possible sources of the variation are many, including the application of the dissection procedure, variation between different grading equipment, variation between copies of the same equipment, variation between operators and the representative of the calibration sample.

On-going research aims to improve the standardisation of pig carcass grading within the EU, by identifying the main sources of variation, by improving the statistical procedures used in authorisation trials and by identifying objective methods of determining the lean meat content that could be used in place of dissection.

The reference method of determining the lean meat content is slow and costly and requires highly skilled butchers. This may be a major source of variation and may be a barrier to conducting authorisation trials for mew equipment and for checking the calibration of existing equipment.

It is necessary to identify objective methods of determining the lean meat content that are as accurate as the dissection method and would be easier to standardise. The three methods chosen are a vision system, X-ray computed tomography (CT) and nuclear magnetic resonance imaging (NMRI).

Initially, research aims to measure these sources of variation and allow recommendations to be made for the control and monitoring of grading so as to achieve better standardisation in the future.

The accuracy criterion that has to be met for grading equipment to be authorised is that the standard error must be less that 2.5% lean meat. This is a fairly minimalist approach, especially since it is the calibration standard error not the prediction standard error (i.e. it is based on the calibration sample rather than a sample not used to calibrate the equipment). The requirements for selecting a representative sample as also rather basic, especially in relation to subpopulations (different breeds and sexes).

The statistical methods used to evaluate the results of authorisation trials is largely left to the individual national authorities, though there is an assumption that classical regression will be used. With the advent of the AUTOFOM, which generates large amounts of data, these classical methods are not appropriate. The second workpackage addresses these statistical issues and will make recommendations for sampling and statistical analysis procedures to be used, backed up by a manual to help in conducting authorisation trials, (See more...) paul.allen@teagasc.ieor log onto www.eupigclass.org

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