Peer-reviewed articles

A Comparison of Fresh and Frozen Lamb Meat-Differences in Technological Meat Quality and Sensory Attributes

Contact

Guðjón Þorkelsson

Strategic Scientist

gudjon.thorkelsson@matis.is

Technological meat quality and sensory attributes of fresh and frozen lamb meat were compared. Samples were collected from two abattoirs (one small-scale, one large-scale) that use different slaughter methods in terms of chilling regime and electrical stimulation. The fresh and frozen meat samples included products from both slaughter systems. Ten twin pairs of ram lambs were used in the study, with one of each twin slaughtered at each abattoir. Fresh meat was analyzed after chilling and frozen meat was stored frozen for three months and analyzed after thawing. The Musculus longissimus thoracis et lumborum was analyzed for colour, cooking loss, sensory attributes, Warner-Bratzler shear force (WBSF) and distribution of water and lipid within each meat sample. Meat samples analyzed after frozen storage were darker, less red and more yellow than the fresh meat. Freezing and frozen storage increased fluid loss and WBSF compared with the fresh meat, due to protein denaturation. Frozen storage affected sensory attributes by increasing fatty odor, frying flavor, sour flavor, fatty flavor and liver flavor, and by reducing juicy texture and mushy texture.

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
EN