Technological Quality of Meat for Processing 353 - methylcyclopentanone (Imafi don and
Spanier 1994 ). Methyl - branched compounds
appear to arise from phosphoglycerides
(Werkoff et al. 1993 ; Mottram 1998 ). These
compounds are affected by diet, breed, and
muscle.
Muscles vary in their concentrations of
compounds important to meat fl avor/odor.
Stetzer et al. (2008) reported that beef
Complexus contained twice the concentration
of 2,3 - octanedione, nonanal, and butanoic
acid, and 30% more hexanoic acid than the
Gludeus medius , Rectus femoris , Vastus lat-
eralic , Vastus medialis , Psoas major , and
Longissimus dorsi.
Off - Flavors
Muscle tissue also contains compounds that
contribute to off - fl avors in the fi nished
product as a result of genetics, sex of the
animal, heme content of the muscle tissue,
and diet. Livery fl avor is an objectionable,
off - fl avor in beef that increases as iron
content increases (Campo et al. 1999 ; Calkins
and Cuppett 2006 ; Yancey et al. 2006 ).
Sulfur - containing compounds (thiols, sul-
fi des, thiazoles, sulfur - substituted furans) can
interact with carbonyl compounds to produce
a livery fl avor (Werkhoff et al. 1993 ).
Muscles often exhibiting liver - like fl avor,
such as the Psoas major (loin) and Gluteus
medius (round), have higher levels of heme
iron and/or myoglobin (Yancey et al. 2006 ).
Compared with beef Infraspinatus , Psoas
major , and Rectus femoris , the Gluteus
medius had the highest liver off - fl avor score
(Stetzer et al. 2007 ). Of the Complexus ,
Serratus ventralis , Vastus lateralis , Vastus
medialis , and Longissimus dorsi , the Vastus
lateralis had the highest liver off - fl avor score
and the Longissimus dorsi had the lowest
(Stetzer et al. 2006 ). Stetzer et al. (2008)
reported that livery off - fl avor was positively
correlated with pentanal, hexanal, 3 - hydroxy -
2 - butanone, and hexanoic acid.
Sex and carcass maturity also affect off -
fl avors. Beef from bulls has a more livery,
bloody fl avor than that from heifers, which
appears to be related to higher 2 - propanone
and ethanol contents (Gorraiz et al. 2002 ).
To the extent that carcass maturity affects
iron content, it can increase metallic, rancid,
bloody, salty, and bitter fl avor notes (Calkins
2006 ). Volatile compounds impact these
fl avor notes as well. Higher concentrations of
phospholipids, phosphatidylcholine, and
phosphatidylethanolamine increase livery
and ammonia fl avors in beef (Larick et al.
1989 ). Several muscles ( Triceps brachii ,
Vastus lateralis , and Vastus intermedius )
with livery off - fl avor have more heptanol,
hexanal, hexanol, B - pinene, 1 - octene - 3 - ol,
and nonanal.
Because of their effects on desirable and
undesirable fl avor components, diet, animal
sex, age at slaughter, genetics, and muscle
must be considered when meat tissues are to
be used for specifi c products (fresh, whole
cuts vs. cured, smoked products).Factors Affecting
Tenderness/Texture
In general, consumers rate tenderness as the
major factor that determines the eating
quality of meat (Brewer and Novakofski
2008 ). Tenderness embodies all the mouth
feel characteristics perceived kinesthetically:
those perceived prior to mastication (particle
size, oiliness), during mastication (tender-
ness, juiciness), and after mastication (fi brous
residue, mouth coating; Bourne 1992 ).
Tenderness is composed of mechanical
(hardness, cohesiveness, elasticity), particu-
late (grittiness and fi brousness), and chemi-
cal components (juiciness and oiliness;
Bourne 1992 ). Minimally, meat tenderness is
affected by myofi brillar, connective tissue,
and compositional components. The myofi -
brillar component can be affected by cold
shortening and proteolytic degradation; the