How Colour Changes in Ageing in Vacuum Aged Lamb09 August 2014
The effect of vacuum ageing of lamb steaks from early fattening lambs during aerobic display sees quality changes in the meat that include changes in colour and an increase in the pH values.
The Spanish study Effect of vacuum ageing on quality changes of lamb steaks from early fattening lambs during aerobic display that will appear in the December issue of Meat Science shows that the redness of the vacuum aged meat decreases with age.
In the study by Aída R. Callejas-Cárdenas, Irma Caro, Carolina Blanco, Luz H. Villalobos-Delgado, Nuria Prieto, Raúl Bodas, Francisco J. Giráldez and Javier Mateo, the effects of vacuum ageing on the quality changes of lamb steaks during retail display were assessed.
Biceps femoris and Quadriceps femoris muscles from 30 early fattening lambs fed barley straw and concentrate or alfalfa and concentrate were used.
Half of the muscles were vacuum aged for three weeks (VA), and the other half were not aged (control).
Control and vacuum aged muscles were sliced and aerobically displayed.
Weight loss, pH, aldehyde contents, instrumental colour characteristics and colour acceptance were measured at display days 1, 3, 7 and 14.
The colour stability of vacuum aged vs. fresh lamb (early fattening lambs) was compared.
The colour of vacuum aged lamb was less stable at display in spite of its higher initial redness.
At day one redness was higher in vacuum aged lamb.
However, redness of vacuum aged lamb decreases more rapidly during further storage.
Redness and colour acceptance decreased in vacuum aged lamb from day three, whereas in not-aged lamb the decrease was observed from day seven onwards.
Colour acceptance at display correlated to L* for fresh and L* and a* for aged lamb.
L* and a* values ≥ 42 and 7, respectively, were required for consumers' colour acceptance.
From days seven to 14 a drop of colour acceptance accompanied by an increase in pH and a decrease in lightness was observed in control and vacuum aged lamb.
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