Study On Maturity Indicators And High-efficiency Techniques Of Soaking Fat Pork

Fat pork soaking in liquor（soaking fat pork）is a critical element for the impregnating process of Soybean-flavor liquor（Yubingshao）.The soaking process of soaking fat pork takes over half year.The traditional method depends on experience,and there are not quantitative indicators to judge the maturity of soaking fat pork.Moreover,we can not control the soaking process accurately as we don’t know the changes of soaking fat pork in the soaking process and its mature mechanism,which greatly influences the production efficiency of Soybean-flavor liquor.In this paper,the color,lipid oxidation and fatty acids content of different soaking fat pork in soaking process were detected,and determined the maturity indicators of soaking fat pork.The relationships of component changes of soaking fat pork and its soaking solution were also investigated.The effects of different pre-treatments and soaking conditions to the soaking efficiency were studied.The major results are as follow:（1）During the soaking process,the soaking fat pork’s b*value increased significantly from 2.51±0.08 to 31.07±3.16,acid value increased significantly from 0.59±0.04mg KOH/g to 6.62±0.64 mg KOH/g,and thiobarbituric acid value（TBARS）increased significantly from0.58±0.03 mg MDA/Kg to 4.03±0.13 mg MDA/Kg（p<0.05）.The content of oleic acid(C_18:1)decreased 21.65%significantly,and the content of linoleic acid(C_18:2)increased11.57%significantly after the process（p<0.05）.Moreover,the ratio of saturated fatty acids and unsaturated fatty acids（SFA/UFA）decreased significantly from 1.83 to 1.38.As for the monitoring of dibasic acid ester in the impregnating process of Soybean-flavor liquor,six maturity indicators were determined:b*value,acid value,TBARS value,oleic acid(C_18:1),linoleic acid(C_18:2),and SFA/UFA.Its maturity value were 31.07±3.16,6.62±0.64 mg KOH/g,4.03±0.13 mg MDA/Kg,14.84±1.13 g/100g,4.05±0.84 g/100g,1.38±0.11,respectively.（2）During the soaking process,the change of soaking fat pork and its soaking solution’s acid value and TBARS value revealed a relationship of simultaneous rise,soaking solution’s acid value increased from 0.28±0.00 mg KOH/mL to 0.65±0.04 mg KOH/mL with the rise of soaking fat pork’s acid value,soaking solution’s TBARS value increased from 1.17±0.02 mg MDA/L to 6.24±0.87 mg MDA/L with the rise of soaking fat pork’s TBARS value.The change of soaking fat pork and its soaking solution’s oleic acid(C_18:1)content was showed a complementary trend at first,then synchronously increased,the oleic acid(C_18:1)content of soaking solution increased from 1.69±0.01 mg/100mL to 430.84±48.53 mg/100mL steadily with the oleic acid(C_18:1)content of soaking fat pork decreased firstly and increased later.The change of soaking fat pork and its soaking solution’s linoleic acid(C_18:2)content synchronously increased at first,then showed a complementary trend,the linoleic acid(C_18:2)content of soaking solution increased from 2.65±0.01 mg/100mL to 41.54±0.71 mg/100mL firstly,then decreased to 4.72±1.40 mg/100mL with the rise of linoleic acid(C_18:2)content of soaking fat pork.The change of soaking fat pork and its soaking solution’s SFA/UFA synchronously decreased at first,then showed a complementary trend,the SFA/UFA of soaking solution decreased from 1.98±0.00 to 1.18±0.00 firstly,then increased to 1.84±0.08with the decease of SFA/UFA of soaking fat pork.（3）The soaking efficiency of soaking fat pork was related to pre-treatment methods.Cooked fat pork was the optimal pre-treatment methods,then ultrasonic treated fat pork and fat pork soaked in warm water according to the soaking efficiency,the b*value and acid value of cooked fat pork showed a biggest change,increased 308.91%,81.25%,respectively.And according to the quality of soaking fat pork,ultrasonic treated fat pork was the optimal pre-treatment methods,then cooked fat pork and fat pork soaked in warm water,the TBARS value,oleic acid(C_18:1)content,and linoleic acid(C_18:2)content and SFA/UFA of ultrasonic treated fat pork showed a biggest change,increased 138.26%,41.57%,160.67%,respectively,SFA/UFA decreased 28.09%.Different soaking solutions also affected the soaking efficiency of soaking fat pork greatly.Liquor with oil was better than liquor,and the optimal oil ratio was 5%,the b*value,acid value,TBARS value,oleic acid(C_18:1)content,and linoleic acid(C_18:2)content of fat pork soaking in liquor with 5%oil increased 280.65%,420.83%,117.50%,31.52%,160.14%,respectively,and SFA/UFA decreased 30.11%.Furthermore,50%ethanol with 5%oil was better than 50%vol liquor,the b*value,acid value,TBARS value,oleic acid(C_18:1)content,and linoleic acid(C_18:2)content of fat pork soaking in 50%ethanol with 5%oil increased 254.53%,450.00%,142.50%,23.81%,151.55%,respectively,and SFA/UFA decreased 28.98%.The optimal soaking method was soaking in liquor firstly and then soaking in oil,the b*value,acid value,TBARS value,oleic acid(C_18:1)content,and linoleic acid(C_18:2)content of fat pork soaking in liquor firstly and then soaking in oil increased 70.87%,701.61%,15.08%,19.35%,12.48%,respectively,and SFA/UFA increased0.80%.This study provides scientific basis for setting the quality standard of soaking fat pork,renders technical supports to optimize the production techniques of soaking fat pork and improves the productivity of mature soaking fat pork,which showed a promising application.