Murdoch University Research Repository

Welcome to the Murdoch University Research Repository

The Murdoch University Research Repository is an open access digital collection of research
created by Murdoch University staff, researchers and postgraduate students.

Learn more

Intramuscular fat as a predictor of eating quality

Moyes, Sonya (2019) Intramuscular fat as a predictor of eating quality. Honours thesis, Murdoch University.

PDF - Whole Thesis
Download (754kB) | Preview


The steady decline in sheepmeat consumption throughout Australia over recent decades has been partly driven by inconsistencies in eating quality. Eating quality, and thus sensory perception (tenderness, juiciness, flavour, overall liking), is a key factor influencing consumer demand of sheepmeat. A strong positive driver of consumer sheepmeat sensory scores is intramuscular fat (IMF), and has therefore been proposed as a required measurement in future grading systems. IMF of the M. longissimus lumborum (loin) has been shown to be moderately correlated with IMF of muscles throughout the lamb carcass, indicating potential to predict eating quality of these muscles based on loin IMF. Thus, there is potential to predict the eating quality of these muscles based on the IMF content of the loin.
Consumer sensory scores of untrained consumers were obtained for the grilled loin, M. semimembranosus (topside), M. gluteus medius (rump), M. biceps femoris (outside) and both the M. rectus femoris and M. vastus lateralis (knuckle) of 918 lambs. IMF was measured in all muscles using a lab-based near-infrared procedure. Linear mixed effects models (SAS Version 9.1) were used to analyse consumer scores for tenderness, juiciness, flavour and overall liking of all individual cuts. Two versions of these models were tested; firstly fitting loin IMF as a covariate, and secondly fitting IMF of each individual cut as a covariate. Both loin IMF and individual cut IMF predicted the eating quality of all cuts for tenderness and flavour. However, in the loin, outside and topside, only juiciness and overall liking scores could be predicted. In almost all cases, loin IMF accounted for more eating quality variation than individual cut IMF, describing between 8%-20% more variance. The results suggest that to predict eating quality, measuring of IMF within each cut is not needed, with only a single measurement of IMF taken from the loin required to predict eating quality. This is an important finding and supports current investment within the Australian sheepmeat industry to develop and implement an online objective measurement of IMF within the loin.

Item Type: Thesis (Honours)
Murdoch Affiliation(s): Agricultural Sciences
Supervisor(s): Pannier, Liselotte, Anderson, Fiona, Gardner, Graham and Pethick, David
Item Control Page Item Control Page


Downloads per month over past year