Reports

The effect of subcategories in the EUROP fat classification of lamb carcasses on meat quality

Published:

20/12/2023

Authors:

Guðjón Þorkelsson, Aðalheiður Ólafsdóttir, Eva Margrét Jónudóttir and Óli Þór Hilmarsson

Supported by:

Sheep farming development capital

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

The aim of this study was to investigate the effect of a 15-point fat evaluation of lamb carcasses on fat in the back muscle and its taste and texture. A small relationship was found between fat categories in the European assessment and fat in spinal muscles and fat explosion by visual assessment. Fat groups had rather little effect on taste and texture. Spinal muscles in fat category 3+ were significantly softer, more tender and juicier than from other categories. Spinal muscles from fat group 2- were the least tender and the least juicy of all the groups in the experiment. It is interesting that out of about 14.5% of carcasses of lambs slaughtered in the second slaughter at the experimental farm LBHÍ went to the European subcategory 3+. There are possibly opportunities to revise the fat classification and process this meat and sell it as a special quality product. Little fat was measured in spinal muscles or in the range 1.1% – 3.6% and on average 1.92%. The reason may be the young age at slaughter, the Icelandic sheep breed and possibly breeding for a lot of muscle and lean meat.
_____

The effects of subclasses of EU fat classification of lamb carcasses on chemical fat, visual marbling scores and eating quality of loin muscle (m. longissimus dorsi) were studied. Correlation coefficients between fat classes, chemical fat content and marbling scores were low. The only effects of fat classes on eating quality were that class 2- had the least tender and juicy loin muscles and class 3+ loin muscles were the softest, most tender and juicy. 14,5% of the 317 carcasses of the lambs slaughtered were classified as 3+ according to the EU guidelines. Maybe there is an opportunity to review the rules in Iceland and separate the carcasses with the higher quality meat and market them as such. Intramuscular fat was low or from 1.1% – 3.9% and averaging 1.92%. The reasons may be young age at slaughter, the Icelandic sheep breed and maybe breeding for leaner meat.

View report

Reports

Ratio of meat, fat and bones in lamb meat – Chemical content of lamb meat and by-products 

Published:

15/12/2023

Authors:

Óli Þór Hilmarsson, Ólafur Reykdal, Guðjón Þorkelsson, Helgi Briem and Hafliði Halldórsson

Supported by:

Icelandic Food Innovation Fund (is. Matvælasjóður)

Contact

Ólafur Reykdal

Project Manager

olafur.reykdal@matis.is

In the project, an assessment was made of the ratio of meat, fat and bones in lamb meat. Carcasses from the meat evaluation categories O-2, R-2, R-3, U-2, U-3, U-3+, and E-3 were selected for the evaluation, nine carcasses from each evaluation category, a total of 63 carcasses. Carcasses from these categories cover the 92% production based on the division into meat food categories in 2021. Carcasses were selected on three different slaughter days, in two slaughterhouses, in the north and the south, in such a way that the head of the meat evaluation department at the Food Agency, selected all carcasses and confirmed that each a carcass would be a traditional carcass in its assessment category and not at the edge of the category. The day after slaughter, the carcasses were split in half. One half was divided into thighs, forequarters, loins and loins according to the traditional division, while the other half was divided into three weight categories, lightweight under 14.5 kg, medium 14.5 - 16.8 kg and heavy 16.9 - 19.0 kg. The halves were then divided in different ways, with parts going into the various products. Precision deboning was applied to both halves of the lamb carcasses to find the division of the various cuts and products into meat, fat, bone and sinew. Atrophy was also found due to loss of ossification. 

Meat utilization (meat ratio) for the lamb carcasses as a whole was 59.0 (50.7-67.3)%, fat ratio was 16.2 (9.7-28.0)%, bone ratio was 17.7 (13.4- 22.1)% and the tendon ratio was 6.3 (4.4-8.1)%. Atrophy during precision boning was 1.1 (0.0-2.5)%. The average meat utilization was highest in the evaluation category U-2, except for the front part, where the utilization was somewhat higher in E-3. Within the flesh filling categories U and R, it was clearly seen how the percentage of fat changes according to the definitions of fat categories. 

The proportion of meat, fat and bones in different quality categories confirms that the meat assessment is realistic and in accordance with the definitions behind the assessment. 

The proportions of meat, fat, bones, tendons and shrinkage were found for 30 lamb products from selected weight classes. High meat percentage was obtained for thigh without rump, hip bone and tail bone from heavy carcasses (74%) and thigh with shank without hip from both light and medium carcasses (69%). 

Measurements were made of nutrients in lamb pieces and lamb products. Heavy metal measurements were made on lamb pieces. These results will be useful for packaging labeling and for providing information to consumers and retailers. The lamb meat was so rich in vitamin B12, vitamin folate, potassium and zinc that it is permissible to label these substances as part of the meat's nutrition label on the packaging. The heavy metals mercury, cadmium, lead and arsenic were not measurable in the meat, i.e. were below the limits that could be safely measured. This limit is very low and therefore the possible concentration of heavy metals is extremely low.  

Sampling of lamb offal and other side products took place in three slaughterhouses, at SS in Selfoss, KS in Sauðárkrók and Norðlenska in Húsavík. Samples were obtained from liver, kidney, heart, lung, testicle, esophagus, pancreas, spleen, and blood. Chemical measurements were made on selected nutrients and heavy metals. The lamb offal and by-products are rich in iron and selenium, but these substances are important nutrients. All samples reach significant levels of selenium. In the case of significant quantities, labeling of food packaging is permitted according to the labeling regulation. Most of the samples reached significant levels of iron. The heavy metal cadmium was detectable in liver and kidney but not in other samples. Mercury, lead and arsenic were not measurable in the samples, although with the exception that mercury in the kidneys was measurable. 

Chemical measurement results call for attention and improvements in labeling and information. 

Meat, fat, and bone ratios of Icelandic lamb – Chemical composition of lamb meat and side-products 

Meat, fat, and bone ratios of Icelandic lamb meat, were studied. Carcasses from the EUROP classes: O-2, R-2, R-3, U-2, U-3, U-3+, and E-3 were selected, nine carcasses from each class, a total of 63 carcasses. Carcasses from these classes represent 92% of the lamb meat production in Iceland as reported for 2021. Carcasses were selected during three slaughtering days, in two slaughterhouses in north and south Iceland. The EUROP classifications of carcasses were confirmed by a specialist from the Icelandic Food and Veterinary Authority.

The carcasses were divided into halves the day after slaughtering. One half was divided into traditional cuts: leg, forequarter, saddle, and flank. The other half was used for the study of various cuts, where each product was made from one of three selected carcass weight ranges: light carcasses below 14.5 kg, medium carcasses 14.5-16.8 kg and heavy carcasses 16.9-19.0 kg. Deboning was carried out on all products and yields were reported (meat, fat, bones, tendons). Wastage due to cutting, and deboning was reported.

Tissue ratios for whole lamb carcasses were on average 59% meat, 16% fat, 18% bones, and 6% tendons. Wastage during cutting and deboning was 1.1%. The meat yields were highest for class U-2, except for forequarter which had a bit higher meat yield for class E-3. For conformation classes U and R, it was clear that fat yields were related to the definitions of fat thickness for fat classes 2, 3 and 3+.

Yields were reported for meat, fat, bones, and tendons in 30 meat products. Highest meat yields were for leg products (74% and 69%).

Selected nutrients were analyzed in legs, forequarters, saddles, flanks, and several products. The results will be used for labeling and dissemination. Lamb meat was rich in vitamin B12, folate, potassium, and zinc. These nutrients can be used for nutrition declarations of the meat. The heavy metals mercury, cadmium, lead, and arsenic were below the quantification limits in lamb meat. The quantification limits were very low.

Sampling of lamb organ foods and side-products was carried out in three slaughterhouses. The following side-products were sampled: Liver, kidneys, heart, lungs, testicles, gullet, sweetbread, spleen, and blood. Selected nutrients and heavy metals were analyzed. These products were generally rich in selenium and iron which can be used for nutrition declarations in most cases. The heavy metal cadmium was reported for liver, and kidneys, cadmium was however below the quantification limit in other products.

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. 

View report

Reports

Air-dried lamb. Final report / Air dried lamb meat. Final report

Published:

01/05/2010

Authors:

Þóra Valsdóttir, Óli Þór Hilmarsson, Guðjón Þorkelsson

Supported by:

Productivity Fund, Professional Council for Sheep Breeding / BÍ Board

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Air-dried lamb. Final report / Air dried lamb meat. Final report

The aim of the project was to develop products from air-dried lamb in collaboration with farmers. The project was also about increasing farmers' skills in processing and processing lamb into air-dried products, ie. make them suitable for the manufacture of such products. A co-operation group of 5 farmers was formed who were interested and have facilities for home processing of such products. The aim was to develop one product with each farmer, and the product must meet all the requirements for safety, quality, finish and presentation that are relevant for products in the consumer market. In the main, it went well. Farmers were able to adopt the production methods necessary for dry processing and they developed new production processes and products, each different from what is on the market today. The results therefore strengthen the farm in question for the development of new products from its own raw materials and thus their working basis.

The aim of the project was to develop products from air dried lamb in cooperation with farmers. The project centered as well on extending farmers' knowledge on processing and curing methods for these products. Group of five farmers was selected to participate in the project. All farmers had an interest and facilities for this kind of processing. The products should fulfill all requirements regarding safety, quality and presentation of consumer products. This succeeded in most cases. The farmers adopted practices needed in producing dry aired products, new processing methods and products were developed. The results will thus strengthen each producer in development of new products from their own raw material, thus boosting their own operation.

View report

Reports

Taste and pastures. Progress report

Published:

01/12/2009

Authors:

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

Supported by:

Agricultural Productivity Fund, Agricultural University of Iceland

Contact

Rósa Jónsdóttir

Research Group Leader

rosa.jonsdottir@matis.is

Taste and pastures. Progress report

The project is about researching and investigating whether there are differences in the characteristics and tastes of lamb meat according to grazing habits and the origin of lambs in them. The purpose is to further strengthen the basis for the processing and sale of lamb directly from the farm based on the specificities of each area. The project is carried out in collaboration with Austurlambur, Búnaðarsamband Austurlands, the towns of Hákonarstaðir and StóraBreiðuvík, Gunnarsstaðir, Matís and the Association of Chefs. It is divided into preparation by farmers, slaughter and sampling, measurements of flavors and aromas, assessment of culinary properties, settlement and presentation at the Agricultural Research Council and preparation of promotional material for the farm / area in question for use in marketing and finally writing a scientific article on the research. The project hopes to be able to describe in detail the taste and characteristics of lamb meat of different grazing types to use when the meat is sold in the local lamb market in online stores, tourism, restaurants and other gourmet markets so that higher prices can be obtained. the meat and higher profitability directly on the farm. The farm in question and Austurlamb will utilize the results in promotions and marketing work, as well as the project being useful to other producers and processors of lamb meat. All preparation, slaughter, sampling and measurements have been completed and the results are being processed. A final report and publication of the results is expected in February at the Agricultural Research Council. At the end of January, a half-day seminar on the effects of grazing on the taste of lamb is planned, held at Matvælaskólinn in Kópavogur with the participation of Matís, Matvælaskólinn, sheep farmers and chefs.

View report

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.

View report

Reports

Air-dried lamb. Forathugun / Air dried products from lamb

Published:

01/03/2009

Authors:

Þóra Valsdóttir, Óli Þór Hilmarsson, Guðjón Þorkelsson

Supported by:

Technology Development Fund

Contact

Þóra Valsdóttir

Project Manager

thora.valsdottir@matis.is

Air-dried lamb. Forathugun / Air dried products from lamb

The aim of the project is to prepare a collaborative project between parties in Iceland, the Faroe Islands and Norway on the development of air-dried lamb products in connection with the establishment of small start-up companies and food tourism.

The report includes a summary and analysis of the state of air drying in Iceland and a survey of market and commercial criteria. The analysis is divided into:

(1) a survey of the status of air-dried lamb in Iceland

(2) the impact of production methods on efficacy, quality and safety: a summary of technical and safety considerations; and

(3) a summary of the criteria for marking the origin and protection of certain products.

Finally, the selection of partners and the formulation of projects related to air drying of lamb are explained.

The aim of the project is to prepare a cooperative project between parties in Iceland, Faroe Islands and Norway on development of new air-dried products from lamb. The product development will be done in relation with establishment of small companies and food tourism.

The report is a summation and analysis on the situation of air drying in Iceland and exploration of market and business-related issues. The analysis is divided into:

(1) exploration on the situation of air dried lamb in Iceland

(2) influence of production methods on curing, quality and safety

(3) summation of criterion for origin-based labeling and protection of specific products.

Finally, established cooperation and creation of projects linked to air dried lamb is listed.

Report closed until 01.04.2012 / Report closed until 01.04.2012

View report

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.

View report

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.

View report
EN