The Effect Of Different Physical And Chemical Factors On Pork Myoglobin Stability

Based on domestic and international factors in the study of various physical and chemical effects on meat color, in order to deeply understand the physiological characteristics of all aspects of pork Rongchang pig, the experimental subject chose Rongchang pig meat as raw materials, select physical and chemical factors such as the temperature, salt concentration,sodium nitrite, high pressure and so on. the experimental subject get the sensory score, color design, cured color, rate and determination of myoglobin content, and significance analysis, the experimental subject make Rongchang pig color evaluation to be objective, research stability of Rongchang pig meat myoglobin to promote consumption of Rongchang pig meat. The major findings are as follows:1 The research of sodium nitrite on the color stability of pork Rongchang pork products During Curing process, the sensory score of muscle color increases with the addition of the amount of sodium nitrite.Experimental determination of the value of meat color, The change trend of the L* value of Longissimus dorsi muscle and the L* value of hind leg musclesis is in accord. The L* value of the group which didn't add sodium nitrite changed little; while, the other three groups which added sodium nitrite changed a lot. During 0～48h cured time, the b* value of the groups which didn't add sodium nitrite increased; while, the a* value of the groups which added sodium nitrite decreased obviously.During 0～48 h cured time, growth trends of the b* values for all test groups increased little, the higher sodium nitrite, the more slowly the b* values increased.From the determination of the change of the rate of the color, we can know, the addition of the sodium nitrite in the 0～150 mg/kg range is larger, the color is more obvious.Espeically in the initial stage (0～8h),the rate of cured color is significantly up (Add 50,100 and 150 mg/kg, respectively from 12% to 41%,14% to 47%and 18% to 58%); nitroso-hemoglobin in in the initial stage (0～8h) generated the largest amount (data not shown).During the curing process, the three groups which added sodium nitrite. With cured time is longer, the ratio of the deoxy myoglobin (DeoxyMb) and metmyoglobin (MetMb) in three kinds of myoglobin is lower; while, the ratio of oxymyoglobin (MbO2) increased slightly.2 The research of NaCl concentration on the color stability of Rongchang pork productsThe sample extraction after different NaCl concentrations (pH 6.8 in sodium phosphate buffer), With the increase of NaCl concentration, the absorption spectrum curve of 3% NaCl solution is the maximum; the absorption curve of NaCl concentration of 2% and 4% NaCl solution is similar; the absorption spectrum curve of NaCl concentration of 5% NaCl solution is the minimum.In room temperature, NaCl concentrations of different samples of meat after the extraction (pH 6.8 in sodium phosphate buffer). The ratio of Deoxy myoglobin (DeoxyMb) decreased slightly; metmyoglobin (MetMb) almost didn't changed; the proportion of oxymyoglobin (MbO2) significantly changed:the proportion of oxymyoglobin (MbO2) of 3% NaCl solution is the highest proportion;the proportion of oxymyoglobin (MbO2)of 4% NaCl solution followed, the proportion of oxymyoglobin (MbO2) of 5% NaCl solution is the lowest proportion.The preservation rate of myoglobin is the highest in 3% NaCl solution; 4% NaCl solution just followed by; the preservation rate of myoglobin is the lowest in 5% NaCl solution. In the 20～60℃, the preservation rate of myoglobin were quite different. at different NaCl solution concentrations, myoglobin preservation rates all decreased with the increase of temperature.This subject selected the hind leg muscle as the thinning trial test material of 2%.3% and 4% NaCl concentration. When the NaCl concentration is 3%, the absorbance value of the extraction solution is the highest; when the NaCl concentration is 2%, the absorbance of the meat sample is the lowest.3 The research of temperature on the color stability of Rongchang pork productsThe extraction of the meat sample after different temperatures (pH 6.8 sodium phosphate buffer). As the temperature increases, when the temperature is 20℃,30℃and 40℃. The absorbance values of extraction solution are similar, the wave spectrum did not change significantly; when the temperature is 50℃and 60℃. the meat-like myoglobin was heat denaturation, the wave spectrum changed significantly and the absorbance value decreased obviously.In the temperature treatment experiment, the higher the temperature, the amount of oxygen myoglobin (DeoxyMb) almost didn't change; the ratio of the metmyoglobin (MetMb) in three kinds of myoglobin increased slightly; the ratio of oxymyoglobin (MbO2) decreased significantly.This subject selected the hind leg muscle as the thinning trial test material of 20℃～40℃.when the temperature is 20℃. the absorbance values of extraction solution is maximum; when the temperature is 40℃, the absorbance of the meat sample is minimum. At 20℃-40℃,the characteristic absorption peak of myoglobin is significant; as the temperature increases, the characteristic absorption peaks gradually weakened.4 The research of high pressure on the color stability of Rongchang pork productsWith the increase of high pressure processing value, the sensory score of the hind leg muscles and longissimus dorsi muscle decreased.Through the entire trial.wo know that after high pressure treatment, the change trend of the color of the meat:red value (a*) becomes smaller, the brightness value (L*) increased, yellow value (b*) changed little.Under high pressure, the ratio of oxymyoglobin (bright red) decreases with pressure increases, the ratio of metmyoglobin (brown) was rising, and the proportion of deoxy myoglobin remained unchanged during the the high pressure treatment test (the hind leg muscles in about 40%,44% of longissimus muscle samples or so). In the research of processing time on the color of the meat samples, the L* and a* value of the meat samples which was after high pressure treatment of 400MPa is obviously different from the L* and a* value of the meat samples which was after high pressure treatment of 200MPa. Meat samples after high pressure treatment, brightness value increased and red value decreased, and yellow value changed little. Throughout the experiment, in 0-12-minute, curve changed steeply; in 12-18 minutes, curve changed smoothly.In the test of the influence of the preserved samples after the high pressure process, after the same high pressure, the color of the treated sample were pink. CoMPared with the control of meat, the a* values of the preserved meat sample decreased smaller, and the a* value curve is relatively stable; the b* values of the preserved meat sample decreased relatively largely; the L* values of the preserved meat sample decreased less, and the L* value curve is relatively stable.