Reports

Testing of Meat Standards Australia's quality system. Comparison of the quality of unfrozen and frozen lamb meat.

Published:

23/03/2023

Authors:

Guðjón Þorkelsson, Aðalheiður Ólafsdóttir and Óli Þór Hilmarsson

Supported by:

Sheep farming development capital

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

Information on the Meat Standards Australia (MSA) quality and marketing system for lamb was compiled and their consumer testing methodology was tested and compared with conventional sensory evaluation of fresh and thawed lamb loin muscles. The fresh meat was both lighter and redder than the thawed meat. This is important in retail when consumers choose meat for cooking. Shrinkage during storage and shrinkage during heating was much greater in the thawed meat. The fresh meat had more softness, tenderness and juiciness than the thawed meat. The frozen/thawed meat was not tenderized like the fresh meat. This shows the importance of wasting before or after freezing. However, there was no difference in consumer ratings of tenderness, juiciness, taste and overall palatability between fresh and thawed lamb. The assurance of taste quality through the management of critical control points, the differentiation of meat carcasses, cuts and muscles and pricing and labeling according to taste quality are fundamental aspects of MSA's activities. The system was established in response to declining sales and consumer dissatisfaction with the taste of the meat, but also to reach new target groups of consumers who are willing to pay a higher price for high quality, thus contributing to increased value in the lamb value chain. There should be opportunities here in the entire value chain of lamb meat in Iceland.


Information on Meat Standards Australia (MSA) cut based lamb classification and marketing scheme were collected and analyzed. MSA consumer testing protocol was tried on fresh and frozen lamb loins and compared with traditional sensory analysis. The fresh loin muscles had a lighter and redder color than the thawed loins. The thawed loins had higher storage and cooking loss. The fresh loins were in sensory analysis softer, more tender, and juicier. The thawed meat was not aged before heating whereas the fresh meat was aged for 6 days. This shows the importance of aging the meat before freezing or after thawing. This was not demonstrated in consumer testing where there was no difference between fresh and thawed meat in tenderness, juiciness, flavor and overall liking.  

The MSA cut and cooking method based scheme was developed through collaboration between industry and research by defining best practices through the identification and monitoring of critical control points for eating quality. It covers all aspects of the supply chain from producers, processors, and retailers to food service operators. This allows product quality to be improved and match customer requirements. The MSA schemes for both beef and lamb were designed to respond to declining sales and consumer complaints about variable and sometimes poor quality of the meat. It is also designed to classify meat based on eating quality and to identify consumer groups willing to pay more for high quality meat and thereby adding value to all links in the supply chain. This approach should also be applicable and create new opportunities to increase value in the lamb supply chain in Iceland. 

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Reports

Grazing on Angelica archangelica and flavor of lamb meat / Grazing on Angelica archangelica and flavor of lamb meat

Published:

01/07/2009

Authors:

Guðjón Þorkelsson, Rósa Jónsdóttir, Aðalheiður Ólafsdóttir, Óli Þór Hilmarsson

Supported by:

National Association of Sheep Farmers

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

Grazing on Angelica archangelica and flavor of lamb meat / Grazing on Angelica archangelica and flavor of lamb meat

The effect of grazing on angelica on volatile substances, fatty acids, odor and taste of heated lamb was studied. 18 lambs were divided into three equal groups. One was on a traditional pasture, another was 3 weeks and a third 6 weeks before slaughter on a pasture where angelica was predominant. The lambs were 120-140 days old at slaughter. A graphical test, Quantitative Descriptive Analysis (QDA) was used to describe the sensory properties of heated vertebral muscle with surface fat. Volatile fragrances were isolated from aggregate vertebral muscle samples with fat from all three groups and measured on a gas mass spectrometer (GC-MS) to obtain the mass spectra of the substances and thus identify them. Gas chromatography olfactometry (GC-O), based on the odor of substances as they emerge from the gas column, was used to identify odoriferous substances which may be in very small quantities but produce characteristic odors. Fatty acids were measured by gas analysis. The statistical method ANOVA (GLM - General Linear Model) and Duncan`s tests were used to analyze whether experimental groups differed in terms of sensory assessment factors and odorants. Experimental group sensory symptoms were examined by Principal Component Analysis (PCA). The partial least square regression analysis (PLSR) was performed. The model had volatile substances and fatty acids as control variables (X-variables) and statistically significant sensory evaluation factors as response variables (Y-variables). Most of the variability in sensory evaluation results could be explained by whether or not the lambs were on angelica. The meat of lamb angelica had a spicy odor and spice flavor associated with high levels of αpinene, β-phellandrene and octanal and C18: 1 and C18: 2 fatty acids but lamb meat on a traditional pasture had a lamb and wool odor and generally stronger odor and flavor associated with 2-butanone, 3-methyl-3-buten-1-ol and 3-hydroxy-2-butanone and saturated fatty acids. The time spent on angelica explained only the 4.6% variability. The results indicate that special terpenoids i.e. β-phellandrene and α-pinene are characteristic of the meat of lambs that have been on angelica. The results of the project strongly suggest that grazing angelica in the last weeks before slaughter changes the taste of lamb. The study confirms that angelica meat is unique. This feature can then be used in the marketing of the meat.

The influence of finishing traditional grazing lambs on fields of Angelica archangelica on volatile compounds, fatty acids and odor and flavor of cooked meat was studied. 18 lambs were divided into 3 equal groups. One grazing on traditional grassland pasture, one grazing for 3 weeks and one grazing for 6 weeks on Angelica pasture. The lambs were slaughtered at the age of 120-140 days. Quantitative Descriptive Analysis (QDA) was used to describe the sensory attributes of cooked loins with subcutaneous fat. Gas chromatography-mass spectrometry (GC-MS) and gas chromatography olfactometry (GC-O) were used to identify volatile compounds and describe their odors. Fatty acids were analyzed by gas chromatography (GC). Analysis of variance was used to study the influence of treatments on sensory attributes. Relationship between sensory attributes, volatiles and fatty acids was studied using principal component analysis (PCA) and Partial Least Square Regression (PLSR). Most part of the variation in sensory data (95.4%) was explained by the grazing or not grazing on Angelica. Meat of lambs that grazed on Angelica had spicy odor and flavor that correlated with high amount of α-pinene, β-phellandrene and octanal and C18: 1 and C18: 2 fatty acids while the meat of the control lambs that continued to graze on pasture had lamb meat and wooly odors and generally stronger odors and taste that correlated with high amounts of 2-butanone, 3-methyl-3-buten-1-ol and 3-hydroxy-2-butanone together with saturated fatty acids. Only small part of the variation (4.6%) was explained by how long the lambs grazed on Angelica. The results indicate that specific terpenoids, eg βphellandrene and α-pinene can be used as indicators of Angelica pasture. The results strongly indicate that grazing traditional grass pasture lambs on Angelica fields changes the flavor of the meat. The study confirms that the Angelica meat is unique and this can be used in the marketing of the meat.

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Reports

Assessment of slaughter in sheep slaughterhouses in the autumn of 2008

Published:

10/02/2009

Authors:

Valur Norðri Gunnlaugsson, Óli Þór Hilmarsson, Ásbjörn Jónsson, Guðjón Þorkelsson

Supported by:

National Association of Sheep Farmers

Contact

Valur Norðri Gunnlaugsson

Research Group Leader

valur.n.gunnlaugsson@matis.is

Assessment of slaughter in sheep slaughterhouses in the autumn of 2008

The Annual General Meeting of the National Association of Sheep Farmers decided in April 2008 that a detailed assessment will be made of the treatment of lamb at slaughter, especially during killing and cooling. An explanatory memorandum to the resolution stated: "The meeting considers it necessary to examine the possible effects of these two factors on the quality of the meat. When the animal is killed by electricity, there is a risk that the carcasses will not be able to bleed sufficiently and there is a risk of cooling hardening with too rapid cooling or freezing. Matís ohf. carried out an assessment of the above factors in the autumn of 2008 where the killing and cooling processes in 6 slaughterhouses were examined, of which one house was visited twice. Monitor the killing of 100 carcasses in each house to see procedures and take out facilities. The acidity and temperature of the carcass were measured regularly as well as the temperature in the slaughterhouses of the slaughterhouses. Carcasses taken in this study followed jogging through the normal process of action in each slaughterhouse, but before freezing, the backbone was removed and frozen. Vertebral muscles were then used in texture measurements to see different gravitational processes between slaughterhouses on the meat of the meat. The results show that the killing method affects the death stiffening process. It was much further in the carcasses of lambs in houses that use the "head-back" method than in houses that had a head clip. Cooling time is clearly too short in some houses. Thus the freezing temperature was highest as it was shortest and well above 6.0 in the house where it was only 4 hours. The viscosity of the meat was lowest in the vertebral carcasses from the slaughterhouse, where the head-back killing method was used, electrical stimulation was used and extensive and long cooling ensured that the meat was almost completely tenderized.

At annual general meeting of sheep farmers association in 2008 was concluded that a general observation ought to take place on treatment of lamb meat at slaughterhouses, particularly at electrocute step and the cooling phase. The aim was to see the influence of these factors on meat quality. Matis ohf. visited 6 slaughterhouses in autumn 2008. The results showed that the electrocution method affected the pH of carcasses. In some slaughterhouses the cooling phase was too short and therefore the pH was too high in carcasses when they were frozen. The tenderest meat came from the slaughterhouse where the meat was electrically stimulated and there was a long cooling paste.

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Reports

Effect of chilling on lamb tenderloin

Published:

01/01/2007

Authors:

Ásbjörn Jónsson, Óli Þór Hilmarsson, Valur Norðri Gunnlaugsson

Supported by:

Agricultural Contracts Executive Committee

Contact

Óli Þór Hilmarsson

Project Manager

oli.th.hilmarsson@matis.is

Effect of chilling on lamb tenderloin

In recent years, cooling in slaughterhouses has increased significantly. Therefore, cooling in meat is faster. The speed of cooling has a great influence on the quality of meat. The refrigeration must follow the process of freezing to death in such a way that the meat quality is as high as possible, and it is therefore important to control the refrigeration process. Too fast cooling or freezing of lamb shortly after slaughter can cause cooling in the meat and the result is stiffer meat. The main objective of the project was to study the texture properties (tenderness) in lamb meat at different refrigeration temperatures and time in the slaughterhouse. Temperature measurements were performed in dilka carcasses in the slaughterhouse of slaughterhouses at different air temperatures. Samples were taken from the vertebral body dilka carcasses after varying lengths of presence in the meat hall, and they were frozen. Texture measurements were then performed on the samples to assess the effect of cooling on the muscle. The results of this study showed that meat stored in a meat hall and frozen the same day (after 4-5 hours) was stiffer than meat that had a longer cooling time in a meat hall. The project was carried out by Matís employees and funded by the Agricultural Contracts Executive Committee.

In recent years chilling in abattoirs has increased significantly and, furthermore, chilling in meat has become more rapid. The chilling rate has great effects on the quality of meat. The chilling has to correlate with rigor mortis to gain the best quality of the meat. A too rapid chilling or freezing of the meat shortly after slaughtering will cause cold shortening in the meat and the result is tough meat. The main object of the project was to study the textural properties of lamb meat at different chilling conditions and time in abattoirs. Samples were taken from the M. longissimus after different storage in the chilling room, and frozen. Measurements of textural properties were performed on the samples to estimate the impact of chilling of the muscle. The results indicated that meat stored for a short time in the chilling room and then frozen the same day (after 4 -5 hours) was tougher than meat stored for longer time in the chilling room. The project was done by employees of Matís and sponsored by the Ministry of agriculture.

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