| Free radical, highly related to the aging, inflammation and autoimmune diseases of human body, is key point to the research and development of antioxidant foods aiming at preventing disease and aging which possess significant importance.Selenium-enriched preserved beef is accepted by the public which could be considered as healthy food with essential trace elements selenium and highly safety.Selenium-enriched preserved beef can eliminate some of the free radical and exhibit anti-oxidation ability. In addition, process parameters of selenium-enriched preserved beef production were determined by orthogonal optimization in this essay. With extension of storage time, selenium-enriched preserved beef gradually deteriorated by oxidative rancidity or hydrolysis cooperate with oxygen, water, light, heat and microorganisms, resulting in stench, odor and changes in residual amount of nitrite, the number of microorganisms and fat oxidation. In order to slow down fat rancidity,addition of a certain amount of natural antioxidants to prolong the shelf life of selenium-enriched preserved beef is necessary. Therefore, this work uses basil leaf to extract rosemary acid and explores the best extraction method. Simultaneously, the free radical scavenging ability of rosemary acid were measured. Furthermore, the study focused on the change of POV value and acid value in storage after adding rosemary acid to selenium-enriched preserved beef, which is compared with sample adding Vc,Ve and TBHQ. This study illustrates how rosemary acid and selenium synergistic effect on the quality change of preserved beef, and the main contents and conclusions are listed in the following:Extracting rosemary acid using ultrasonic method can associate with enzyme by using Response Surface Optimization. In this work, the optimum conditions contain:cellulase enzyme dosage 0.03 g, ultrasonic power 480 W, ultrasonic time 10 min,solid-liquid ratio 1:40. In such condition, rosemary acid extraction amount can reach to1.083mg/g, which is 1.76 times higher than enzymatic extraction method that was only0.617mg/g. In addition, Rosemary acid shows free radical inhibition, DPPH radical inhibition rate reached 69.28%, superoxide anion inhibition rate reached 61.37%,hydroxyl radical inhibition rate reached 78.25%. And under the same conditions,rosemary acid exhibits greater radical scavenging capacity on this three free radical than VE.This study analyses the influence of concentration of sodium selenite, acidilactici inoculum and fermentation temperature on the quality of preserved beef using orthogonal analysis. According to the results of visual analysis and variance analysis,the fermentation temperature and the concentration of sodium selenite, compared with other factors influencing sensory evaluation and POV value of selenium-enriched preserved beef, have a significant impact on the quality of selenium-enriched preserved beef. Based on the result of experiment, the optimum parameters of various factors were shown as: A2B2C2, which represented inoculation of 16(μ g / ml), the fermentation temperature is 30 ℃ and the concentration of sodium selenite is 9%. In the meanwhile,the selenium in the content of selenium-enriched preserved beef reached 110μg / kg,and the vast majority of it is organic selenium, which preserved beef with higher selenium content and quality, as well as more conducive to human health.This essay utilize rosemary acid,extracted using the optimum parameters, and selenium as antioxidant to estimate antioxidant property for preserved beef. By comparison of different added amount of rosemary acid, 0.025% shows the relatively low peroxide value, acid value and thiobarbituric acid value for selenium-enriched preserved beef, whereas the antioxidant effect turns out to be the best. Compared with VC, VE and TBHQ through quantitative analysis, adding rosemary acid and selenium exhibits lower POV values in the condition of 35 ℃ incubator storage which means that synergies of rosemary acid and selenium has greater antioxidant property. Working through the shelf life prediction of preserved beef, collaboration of rosemary acid and selenium extends the shelf life to 256 days in 20 ℃, which is much longer than singleusage of VC, VE and TBHQ. Furthermore, selenium was found having a synergistic effect on the rosemary acid. However, only a speculation of synergy mechanism of rosemary acid and selenium has been made, the specific mechanism and priority mechanism remains unknow.By studying the Perilla frutescens rosemary acid in the leaves and antioxidation of selenium-rich dried beef, using selenium and rosemary acid synergistic antioxidant effect, not only the preparation of the selenium-rich food, also can improve the antioxidant effect of dried beef, the results of selenium and rosemary acid synergistic antioxidant research has academic value, to improve the shelf life of the dried beef has practical guiding significance. |
PDF Full Text Request