The Microbiological Change, Function And Mechanism Of Dried Beef In The Processing

Dried beef is one kind of beef product which is made of beef cuttings, salt nitrite and spices and processed with curing and drying procedure. It has been consumed in fresh and cooked dish for a long time. Since it is produced mainly in traditional style with long processing period and high cost., its production now is situated at small scale and initial standardized stage It is necessary to make systemic research on the aspect of microbiological function and mechanism during the dried beef processing. China is one of largest raw beef production country in the world. It is benefit for the competitive ability of Chinese beef products to make such kind research. The thesis has mainly made studies on the forming law of nutrition and sensory quality traits, volatile compounds, the microbiological change, fuction and its mechannism in the processing of Chinese-made BundnerfleischIn the thesis, the determination of the population change of Micrococucaceae, Lactic acid bacteria, lactobactreim, Staphylococcus in the Chinese-made Bundnerfleisch processing and the separation and the characteristics of the microbiological strains were made. The results are the followings: The population of Micrococucaceae, Staphylococcus mainly increased in the drying stage and the Lactic acid bacteria, Lactobactreium population mainly increased in the fore-part of the curing stage. We separated and got 8 strains of bacteria. Staphylococcus warneri, Staphylococcus sciuri, Staphylococcus auricularis, Staphylococcus xylosus, and Staphylococcus saprophyticus may survive in the salt solution with 12%.The Staphylococcus auricularis and Staphylococcus sciuri has the ability to resist the nitrite in the normal concentration. The Staphylococcus warneri, Staphylococcus saprophyticus and L. plantarum has the lipase activity.The relationship of microbiological population of different species with the value of sensory traits, content of amino acid basic nitrogen, free amino acid, free fatty acid, acidity have been invetigated. The result shows that the correlative relations of microbiological population of different microbe with the sensory traits, physic-chemical character are week in final product. We detect the microbes play little function in the quality formation of Chinese-made Bundnerfleisch in the product state. We also inoculate the 8 separated species of bacteria in the surface sterilized raw meat and made the comparison of the quality and the fermented traits. The results show the increase of the separated bacteria in the raw meat influence the sensory quality of dried beef and its content of free fat acid and .some kinds of free amino acid.We had studied the composition of Bundnerfleisch and the formation of volatile compounds during its processing in the thesis,.The result shows that there are 27 kinds of hydrocarbon, 11 kinds of alcohol, 21 kinds of aldehyde, 17 kinds of phenol, 12 kinds of ketone, 3 kind of acid, 12 kinds of ester and 10 heterocyclic in the Chinese-made Bundnerfleisch.. The flavor compound of hexanal, octanal, 1-nonanal, 2-pentyl- furan which determine the flavor ofdry cured ham have been found in the Chinese-made Bundnerfleisch. There is a great difference of the volatile compounds composition among the beef ,cured beef and Bundnerfleisch. Most of the volatile compounds of beef and cured beef could not be found in the Bundnerfleisch and also there are many kinds of volatile compounds which do not exist in Bundnerfleisch. The difference of the volatile compounds composition among the beef,cured beef and Bundnerfleisch shows that the formation of volatile compounds in Chinese-made Bundnerfleisch mainly formed in the drying process except the aldehyde.We also studied the nutritive, hygienic and sensory quality, the quality difference among different parts and the formation of quality traits of Chinese made Bundnerfleisch in the thesis. The results show that the Chinese-made Bundnerfleisch consumed in high grade hotel is safety according to our country hygienic standard of meat and meat product.It is nutritious and acceptable f...