| With the improvement of people's living standards,the requirements on meat quality are getting higher and higher.Therefore,technology research on meat tenderi-zation has become one of the hot spots nowadays.However,there are lots of Meat Tenderizers of different quality in current market,which raises potential security risks.Due to the limited resources of proteases derived from animals and plants,the cost is higher,which fails to meet market needs.Besides,it is hard to standardize production by single protease from microbial sources because the results of tenderizing vary.With the development of meat industry,it requires a safer,more efficient and controllable meat tenderizer to standardize industrialized cuisines,especially for the Chinese traditional cooked meat.Biologically active agent is a proteases compound enzyme preparation through advanced fermentation technology on selected specific microbes.Logically,it can degrade different beef proteins to tenderize beef and improve the flavor as well as processing quality.In order to obtain microbial strain suitable for the tenderization of beef,a total of 22 bacteria of producing proteinase were isolated from traditional lobster sauce and wine song in Guizhou.Through screened with microscopy,analyzed enzyme activity and TPA value of beef with in treatment of fermented broth,a bacteria desiginated as D7 was found to show the optimal strain and the enzyme activity of 71.68 U/mL.The results from molecular bi o l o g i c a l i d e n t i f i c a t i o n s h o w e d t h a t i t w a s v e r y s i m i l a r t o B a c i l l u s amyloliquefaciens(JN700123.1)with similarity of 99% on the basis of the physiological and biochemical identification,by 16 S rDNA sequences analysis and phylogenetic analysis.So the strain was identified as Bacillus amyloliquefaciens.The optimal medium ratio is as follows:Carbon source adding quantity is 1.68 %,Nitrogen source adding quantity is 2 %,pH value is 7.66,Enzyme activity was 111.96 U/mL and the actual Enzyme activity is tested to be 110.37 U/mL and Beef hardness value is decreased by 41 % compared with blank group.While,The optimal culture condition is as follows: the liquid volume is 71 mL,the temperature is 31 ?,the Culture time is 49 h,the enzyme activity was 124.53 U/mL and the actual Enzyme activity is tested to be 125.55 U/mL,Beef hardness value is decreased by 49 % compared with blank group.The process parameters are as follows: The tenderization temperature is 28 C,the tenderization time is 52 min,the sodium chloride content is 2.8 %,and the beef hardness is decreased by about 51 % compared with the blank group.After centrifugation of the fermentation broth of Bacillus amyloliquefaciens and application of clear liquid to beef,the result showed that the content of volatile basic nitrogen of beef was increased,and beef muscle cells got relaxed because of enzymes,which improved its water holding capacity and reduced the cooking loss significantly.Moreover,the determination of total free amino acids of beef was increased from 6.47 g/100 g to 8.06 g/100 g.Therefore,we can come to the conclusion that enzymes can help solution of protein hydrolysis to improve product flavor. |
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