Study On The Processing Technology Of Liquid Smoked Beef And Changes Of Its Quality During Storage Period

Beef has been among the most popular meat products since a long time ago. This paper used fresh beef as materials and treated it with liquid smoke. As a result, we succeeded in making a new beef products with great liquid smoke taste. Additionally, this paper also studid the the biochemical characteristics change of this new beef products after it was heated at different temperatures and storage at37℃. It can be reviewed as follows:The effects of liquid smoke concentration and liquid smoke time on the beef quality had been studied. The results shown that beef treated with liquid smoke concentration of3%and liquid smoke time of2h was characterized with good smoke taste, either larger concentration or longer time would make the smoke taste unfriendly and the sensory evaluation went down. The TPA result shew that:liquid smoke treatment promoted the Hardness, Springiness and Chewness of beef, and the larger concentration, the more promotation. Liquid smoke was able to bring down the L*value of beef, increased its a*and b*value, which on the whole made beef black and red. The water content of beef after cooked was48.55%and went further up after being treated with liquid smoke, but went up less than ones treated with water, moreover, the more liquid smoke concentration and longer liquid smoke time, the less water increment. Phenols content of beef also increased as the liquid smoke concentration increased.Volatile compounds were identified using GC-MS system to assess the effects of liquid smoke on the flavor of beef. Firstly, the effects of SPME fibre style, extraction time and extraction temperature were studied recpectively. As a result,50/30μm DVB/CAR/PDMS、75μm CAR/PDMS were better than65μm PDMS/DVB and100μm PDMS, and the extraction temperature of50℃and time of40min were the best. There were38volatile compounds identified from the sample without liquid smoke. Liquid smoke was able to dramatially increase the volatile compounds of beef, the volatile compounds of beef with liquid smoke for2h,4h went up to59and89respectively. Among the89compounds, aldehydes and ketone were the most, which suggested carbonyl compounds were probably the most important contribution of liquid smoke to the flavor of beef.Biochemical characteristics (preference sensory evaluation, TBA, TVB-N, pH and total bacterial count) of liquid smoke beef was studied after being heated with boiling water bath,100℃water vapour and110℃water vapour recpectively. The results shown that, the shelf life of control samples was only12d, samples with different heat treatment remained good in quality before the24th day, thereafter, however, they also appeared some badness. The TBA and TVB-N value changed in the same trend for both samples. Since the36th day, TBA and TVB-N value for treated samples begain to go up, beginning from the42nd day, TBA and TVB-N values for100℃steam sample were significantly higher than that of the other two sample groups.During the storage period, pH value for the three sample groups changed slowly. Different heating treatments were all able to inactivate bacteria inside beef, which made TBC went up slowly before the30nd days, since then, samples treated with100℃steam had a larger TBC value than that of the other two sample groups. According to the hygienic standard for cooked meats products<GB2726—2005>, the shelf life of100℃steam group was48d, while the shelf life of both the boiling water group and110℃steam group were60d.