A 2x2 factorial experimental design with 2 replications was
used to study the effects of a combination of electrical stimulation
and delayed chilling of pre-rigor muscle on meat characteristics.
Twenty Standard and Good grade beef cattle were slaughtered and 5
carcasses were assigned to each of the 4 treatments. Meat characteristics
were evaluated subjectively (sensory panel evaluation) and
objectively (W-B shear device). Other relative parameters were also
measured. Electrically stimulated carcasses cooled faster in the
first hr postmortem; thereafter the order of further cooling was reversed.
The 24 hr postmortem weight loss in the electrically stimulated
with delayed chilling did not differ (P > . 05) from those receiving
electrical stimulation plus immediate chilling nor those not
stimulated but chilled immediately. For delayed chill carcasses,
24 hr postmortem weight loss was lower (P < . 05) in electrically
stimulated than in non-stimulated groups. Electrical stimulation
reduced (P < . 05) cooking losses. A further reduction (P < . 05) in
cooking losses was achieved by the electrical stimulation-delayed
chilling treatment. The difference in sarcomere lengths among the 4
treatments was not significant (P > . 05). At the microstructural
level, an open triad and T- system were observed immediately following
electrical stimulation. As early as 24 hr postmortem, considerable
Z-line degradation was observed in the electrically stimulated and
delayed chilled samples.
2. PROTEIN QUALITY OF PRESSURIZED MEAT
The effect of hydrostatic pressurization of pre-rigor beef
round muscle (semitendinosus) on protein quality was biologically and
chemically determined. For biological evaluation rats (Long-Evans
strain) were used. Chemical evaluation was carried out by amino
acid analysis. The biological and chemical protein efficiency ratios
(PER) of pressurized meat were 2.47 and 2. 7 respectively, compared
to 2.60 and 2.84 for the control meat. Pressurization did not
affect the apparent biological value (BV) or net protein utilization
(NPU) of meat but significantly (P <. 05) improved protein digestibility.
Total essential and non-essential amino acid contents of pressurized
samples were not different from that of the control. At the range
tested, the protein quality of meat was not adversely affected by
pressure treatment
