| Sika deer is one of China’s traditional medicinal economic animals. With the development of deer farming industry and the improvement of people’s living standard, venison becomes more and more popular in Chinese food. Because of the short history of venison as food in China, information about the quality, storage conditions, and safety of venison is limited. In experiment I, general nutritional components, hormones and correlation related with meat quality of different parts of venison, namely, shoulder, hindquarter, tenderloin and abdominal flesh during antler growing, pre-breeding and over wintering periods were determined. In Experiment II, according to the changes of temperatures in different seasons, meat quality, total colonies number, and the changes of total volatile basic nitrogen(TVB-N)of the fresh venison at temperatures of ﹣20,4, 10, 18 and 25℃ were studied. And based on the national standards for edible meat and above results, the shelf life of fresh sika venison at each temperature was predicted. In Experiment III, effects of glucose infusion on reducing pre-slaughtering stress of deer, to improve the quality of the sika venison were investigated.Experiment I: General nutrirional components, hormones(growth hormone, estrogen, testosterone) and conventional meat quality(p H, meat color, shear force, water loss rate) of different parts of venison, namely, shoulder, hindquarter, tenderloin and abdominal flesh during antler growing, pre-breeding and over wintering periods were determined. The results showed that the moisture content, crude ash, Ca and P element content, hormones(growth hormone, estrogen, testosterone) content, and conventional meat quality(p H, meat color, shear force, water loss rate) did not differ significantly during different periods(P>0.05), crude fat content of meat during pre-breeding period was significantly higher than that of antler growing and over wintering periods(P<0.05); crude protein content of antler growing period was significantly higher than that of pre-breeding and over wintering periods(P<0.05). According to the determination results, fatty acids content of venison was highest in pre-breeding period. And characteristic roots of two fatty acid were λ>1, so there were 2 principal components of fatty acid in venison during different periods, the first principal component was myristic acid and the second principal component was C16:1. Total amino acids content of antler growing period was higher than that of pre-breeding period and over wintering period. And characteristic roots of one amino acid was λ>1, so there were 1 principal component of amino acid in venison during different periods, the first principal component was Glu. Meanwhile, different index of different parts of venison(shoulder, hindquarter, tenderloin and abdominal flesh) did not differ significantly in general nutritional components, hormone content and Ca, P contents(P>0.05), and the conventional meat quality(p H, meat color, shear force, water loss rate) of abdominal flesh was the highest while hindquarter was the poorest, suggesting that abdominal flesh’s color is better, but p H, tenderness, water retention of abdominal flesh is worse than other parts.Experiment II: After slaughtering, p H, shear force, water loss rate, total colonies number, and TVB-N content of fresh venison stored at-20, 4, 10, 18 and 25 ℃ were measured at regular intervals. The results showed that at 4, 10, 18 and 25 ℃, p H value dropped steadily, but at-20 ℃, an upward trend appeared in the later stage. At any temperature, water loss rate increased and shear force declined at first then declined later. At 4, 10, 18 and 25 ℃,TVB-N content surpassed the edible standard(20mg / 100g) at 96, 72 and 24 h. At 10, 18 and 25 ℃, total colonies number were higher than edible standard at 72, 18 and 18 h. The venison stored under-20 ℃ for 90 d was not putrid, suggesting that venison could be stored at-20 ℃ for at least 90 d.Experiment III: Fifteen healthy stags with similar weight were divided into three groups. Animals in groups A and B were injected 10%, 20% glucose solution before slaughter, and Group C was set as control group to test glycogen content, p H48 and color of post-mortem muscle. The results showed that compared with control group, the muscle glycogen content in groups A and B were significantly higher than that of control group(P<0.05), while p H48 in groups A and B decreased significantly comparing with group C(P<0.05), meat color was improved in groups A and B, indicating that pre-slaughter glucose infusion significantly improved meat quality. Correlation between muscle glycogen content and p H48 was analyzed, results indicated that post-mortem muscle glycogen content was negatively related with p H48, y=-2.1041x+16.96, with R being 0.8421. |
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