The Study On The Effects Of Freeze-thaw Cycles, Thawing Methods And Heating Methods On The Quality Of Duck Meat

Duck meat is a kind of nutritious food, it has the characteristics of low fat, rich in vitamins B, and also, duck meat contains all the essential amino acids which needed by human body, duck meat is widely popular with its unique flavor. Freezing method is one of duck meat’s main sales model in our country. In the production and processing of duck meat, due to the faultiness of the cold chain, duck meat is often in freezing-thawing cycle in the transport process and sales, freezing-thawing cycles and thawing methods can impact to some extent on the quality of duck meat. And the same time, there are many different heating methods of cooking on duck meat. Different heating modes have different effects on the duck meat.This paper studied the effect of the number of freeze-thaw cycle(0,1,3,5).different thawing methods (4℃ refrigerator thawing,25℃ air thawing, unpackaged water thawing at 25℃,15℃ water thawing,25℃ water thawing,35℃ water thawing and 45℃ water thawing) and three kinds of heating methods (85℃ water bath heating,85℃ infrared heating, microwave heating) on the quality of frozen duck meat by taking thawing loss, cooking loss, pH value, thiobarbituric acid (TBA) value, color, texture, the protein solubility and muscle SEM(scanning electron microscopy) as indexes.The results showed that freeze-thaw cycles have significant effects on the meat quality changes, thawing loss and cooking loss increased with the increase of the number of freeze-thaw cycles; the TBA value of fresh meat was 0.19mg/kg, and its value was 0.65mg/kg after 5 cycles of freeze-thaw; freeze-thaw cycles had obvious effects on the structure of duck muscle fibers, it could reduce the total protein solubility and destroy the duck muscle structure, which resulted in muscle gap widened and muscle bundles arranged in disorder.Seven kinds of thawing methods influenced on each index of duck meat are different, the duck meat had the lowest thawing loss when it was thawed at 4℃ condition(p<0.05); the TBA value was high(p<0.05) but hardness was low(p<0.05) when duck meat was thawed at unpackaged condition; pH significantly increased with increasing thawing temperature, but the total protein solubility was decline. The experimental results indicated that thawing temperature and whether to package the meat had greater impacts on the quality of duck breast meat; unpackaged thawing method and warm water thawing method both had adverse effects on the quality of duck breast meat. The result of the effect of three kinds of heating methods on the duck meat shows that in the process of heating, duck meat’s cooking loss increased; Microwave heating method and water bath heating method had similar effects on the trend of duck meat color, Compared with microwave heating method and water bath heating method, infrared heating method had significant difference on a* and b*; Heating can increase the sample hardness, in three kinds of heating methods, the sample center temperature rises slowly by infrared heating method but the hardness increasing was the most obvious, and the hardness attach to the highest when heating 30min; different heating methods have little effect on the elasticity of duck meat; for microwave heating, within lmin heating time, duck meat’s chewiness changed significantly; protein solubility decreased gradually during the heating process, the higher sample center temperature is, the lower the solubility; muscle bundles became closed gradually in infrared heating method process, microwave heating will lead to the emergence of a large number of empty in samples.Results:Freeze-thaw cycles have detrimental effects on meat quality, it should be avoided in the processing and consumption; thawing temperature is higher, the duck meat quality is poorer and unpackaged thawing method has great influence on the duck meat; the heating method will directly affect the taste of the duck, different method has different influence on duck meat texture, in the process should pay attention to the influence of various factors; attention should be paid to the influence of various factors in the processing.