| Summary: | Oxidative rancidity is a major cause of quality deterioration in cooked chicken meat
products stored at refrigeration temperatures. Butylated Hydroxytoluene (BHT), a
synthetic antioxidant normally used to control lipid oxidation in foods has been shown
to have several health issues and is banned in several European countries and Japan.
Two experiments were conducted to evaluate the effectiveness of red palm olein
(RPOo) and BHT to retard lipid oxidation and to determine vitamin E and carotenes
levels in reformed and cooked chicken meat during storage at 0±4°C. In the first
experiment, boneless chicken leg meat was mixed with either chicken fat or with
palm shortening containing varied amounts of palm olein, palm kernel oil, palm
stearin, RPOo (0, 22.5 and 45%) and BHT (0, 50 and 10 ppm). The meat batter was
stuffed in test tubes, cooked to an internal temperature of 75°C and st red for 60 days
at 0±4°C. In a follow-up experiment, the chicken meat batter was prepared with
chicken fat or with palm shortening containing varied amounts of palm olein, palm
kernel oil, palm stearin and RPOo (0, 22.5 and 45%), stuffed in high density
polyethylene (HDPE) plastic casing, cooked to an internal temperature of 75° C and
stored 120 days at 0±4°C. The concentrations of thiobarbituric acid reactive
substances (TBARs), tocopherols, tocotrieonols, alpha- and beta-carotene in the
cooked batter during storage were monitored. In both experiments, the pal
shortening was formulated to achieve slip melting point similar to that of chicken fat.
The results of the first experiment showed that at day 1, TBARs value of the meat
batter were in the range of 0.68 to 0.78 mg MDAlkg. The batter formulated with
chicken fat as the main source of fat had the highest TBARs value (p <0.05). The
TBARs values of the other formulations ranged from 0.68 to 0.73 were not
significantly different. At day 30, the TBARs values of the batter formulated with
chicken fat and palm shortening without RPOo or BHT were 3.32 and 2.42 mg
MDA/kg respectively. Addition of 22.5 and 45% of RPOo in the palm shortening
reduced the TBARs values to 1.84 and 1.57 mg MDAlkg respectively. For the same
storage period, the TBARs values for samples with 50 and 100 ppm BHT were 2.24
and 1.89 mg MDAlkg respectively. In experiment two, the TBARs values at day 30
were 3.71, 2.65, 2.28 and 2.13 mg MDAlkg for meat batters formulated with chicken
fat, palm shortening without RPOo and palm shortening with 22.5 and 45% RPOo
respectively. At the end of the storage period, vitamin E level in the cooked chicken
meat with palm shortening containing 22.5 and 45% RPOo were 269.39 and 298.11
mg/kg respectively compared to 30.58 mg/kg for the batter formulated with chicken
fat. At the same time, total ar t ne level was 77.82 mg/kg in the samples with
22.5% RPOo and 141.67 mg/kg for batter with 45% RPOo; almost 70 percent of
vitamin E and 75 percent of carotenes were retained. Addition of 22.5 and 45% RPOo
in palm shortening has been shown to reduce oxidative rancidity and increased
vitamin E and carotenes levels in cooked chicken meat batter during storage at 0±4°C.
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