Effect Of Ultra High Pressure Treatment On The Quality Of Traditional Hurood

In this paper,the ultra-high pressure treatment conditions are selected by taking the pressure level and holding time as variables,the colony forming unit and texture of hurood as detection indexes.With untreated hurood as a comparison,the effect of ultra-high pressure treatment on the quality of hurood has evaluated,and the quality changes in hurood stored under different temperature conditions have monitored and discussed.The main findings are as follows.(1)Taking the pressure level and holding time of ultra-high pressure as variables,and the colony forming unit and texture of hurood as detection indexes,the appropriate ultra-high pressure treatment condition was finally selected as 500 MPa and 10 min.After processing with this condition,the colony forming unit of hurood was less than 10 CFU/mL,the hardness was 4292.52±206.11 g,the elasticity was 0.84±0.04,the viscosity was 0.78±0.01,the chewiness was 2815.70±180.76,the texture of hurood was significantly improved.(2)After the hurood was treated with ultra-high pressure,the content of free amino acids and free fatty acids increased,the total amount of free amino acids was 4.82 mg/g,which was 32.57%higher than before the ultra-high pressure treatment,and the content of glutamate and glycine increased significantly,increasing by 45.50%and 2.43 times respectively.The total content of free fatty acids was 1.42 mg/g,which was 27.93%higher than before treatment.(3)After the hurood was treated with ultra-high pressure,the activity of DPPH·and·OH free radical removal was significantly enhanced,from 18.33±0.96%and 40.22±0.38%before treatment,increased to 21.53±1.15%and 41.58±0.40%,there was no significant change in the reductive activity.The microstructure of hurood before and after ultra-high pressure treatment was observed by scanning electric mirror.After treatment,the structure of hurood's protein was relatively loose,the formation of uneven protein clusters,protein system appears in different sizeholes.(4)The storage test results of hurood at 10? and 4? before and after treatment shows,on the 28th day,the colony forming unit in the ultra-high pressure treatment group hurood was 8.92×103 CFU/mL and 85 CFU/mL,respectively.compared with the<10 CFU/mL in first day,increased only by<8.92×102 CFU/mL and<75 CFU/mL.After ultra-high pressure treatment,pH value and acidity were basically unchanged and relatively stable;proteolysis capacity was significantly higher during storage than that of untreated group,reached 1148.46±3.18(?g/mL Tyr)and 674.40±76.71(?g/mL Tyr)on day 28,respectively.(5)After ultra-high pressure treatment,the whiteness and reddness of hurood were reduced,and the light transmittance and yellowness were enhanced.The hardness and chewability were significantly decreased,elasticity and cohesion were increased,color and texture were improved,and remained stable during storage.(6)After ultra-high pressure treatment,the umami,abundance,saltiness and sweetness values of hurood increased,while the sour,astringent,bitter and bitter aftertaste values decreased.The response values of aromatic components,alcohols,aldehydes and ketones increased,while those of nitrogen oxides,sulfides and terpenes decreased.and remain stable during the storage period,and the lower the storage temperature,the better.This shows that ultra-high pressure treatment has an optimized effect on the smell of hurood,and combines with low temperature storage to help the formation and protection of the smell.