Handbook of Meat Processing

250 Chapter 13

the correct blend of gases that maximizes

initial color, color stability, and shelf life,

while also minimizing microbial growth,

lipid oxidation, and gaseous headspace

(Mancini and Hunt 2005 ). Jakobsen and

Bertelsen (2000) reported that while O 2 levels

higher than 20% were necessary to promote

meat color, package O 2 contents higher than

55% did not result in additional color stabi-

lizing benefi ts.

High O 2 concentrations can cause protein

oxidation, which has been linked to increased

toughness in MAP meat, particularly beef.

Thus, protein oxidation may decrease eating

quality by reducing tenderness and juiciness,

and enhancing fl avor deterioration and dis-

coloration (Xiong 2000 ). Zakrys et al. (2008)

showed that high O 2 concentrations in MAP -

stored beefsteaks were shown to have

increased toughness scores after cooking, as

determined by 134 consumers (Fig. 13.2 ;

Zakrys et al. 2008 ).

oxidation processes, thereby causing the
rapid development of meat rancidity (Renerre
1990 ). The oxidation of polyunsaturated fatty
acids not only causes the rapid development
of meat rancidity, but also affects the color,
the nutritional quality, and the texture of beef
(Kanner 1994 ).
High O 2 - MAP increases lipid oxidation in
meat: beef (Jakobsen and Bertelsen 2000 ;
Zakrys et al. 2008 ; Zakrys et al. 2009 ), pork
(Lund et al. 2007 ), and lamb (Kerry et al.
2000 ). High - oxygen atmospheres (80% O 2 )
also promote pigment oxygenation, and
therefore, prolong the time before metmyo-
globin is visible on the muscle surface. The
drawback to high O 2 MAP is that although it
maintains redness during storage, rancidity
often develops in the meat while color is still
desirable (Jayasingh et al. 2002 ). Because
consumers use meat color as an indicator
of freshness and wholesomeness, recent
advances in MAP have focused on fi nding

Day 12

Carbonyls cont.

TBARS

1.0

0.8

0.6

0.4

0.2

0.0

Principal Component 3

–0.2

–0.4

–0.6

–0.8

–1.0

–1.0

Toughness

L′ value

HI conc.

Day 8

Days

Day 4

O 240

O 270

O 260

O 280

O 250

O 2

OxMb conc.

overall acceptability

JuicinessWBSF

Oxidized flavor

Liking of flavor

a′ value

Day 0

NHI conc.

–0.8 –0.6 –0.4 –0.2 0.0

Principal Component 1

0.2 0.4 0.6 0.8 1.0

b′ value

Figure 13.2. An overview of the variation found in the mean data from the ANOVA - partial least squares
regression (APLSR) correlation loadings plot for each of the 5 MAP treatment groups: 40%, 50%, 60%, 70%,
and 80% oxygen, with all packs containing 20% CO 2 and the make - up gas N 2. Shown are the loadings of the
X and Y variables for the fi rst 3 PCs for raw data. • = days and MAP treatments,  = sensory descriptor and
instrumental variables. The concentric circles represent 100% and 50% explained variance, respectively.
(Adapted from Zakrys et al. 2009 .)