Effects Of High Pressure Treatment On Enzyme In Peony Seed And Research Of Peony Seed Oil Stability

(1)Effects of high pressure on lipoxygensae in peony seedThe expertment studied the effects of high pressure,presusure-holding time and pH on lipoxygenase in peony seed.The optimal treating condition was obtained by BBD and studied its effects on the stability of peony seed.The study showed that it was negative correlation between the high pressure and the activity of lipoxygenase,the same was between the pressure-holding time and the activity of lipoxygenase.Then,the relationship between pH and the activity of lipoxygenase was not simply linear.Integrated single factor and BBD,the optimal treatment condition was high pressure 307 Mpa,pressure holding-time 26.8min,pH7.2.Under those conditions,the activity of lipoxygenase was 40U/g,compared with normal pressure,it decreased by 95%.The stability of peony seed oil was greatedly improved.(2)Extraction of peony oil by supercritical carbon dioxideThe experiment studied the effects of the pressure,temperature and fluid flow on the extraction rate of peony oil.Firstly,the single factor experiment was carried out to find the effects of pressure,temperature and fluid flow.It showed that the extraction rate of peony oil almost increased with the increase of the pressure,temperature and fluid flow.But the cost increased,and the pressure affected the activity of enzyme.Based on the results of single factor experiment,the orthogonal experiment was carried out to determine the optimum process conditions of the extraction rate of peony oil by supercritical carbon dioxide.The orthogonal experiment showed that the effects of pressure and temperature were significant on the extraction rate of peony oil,but the effect of the fluid flow was not significant.The obtained optimal operation conditions were the pressure 30 MPa,temperature 35℃,the fluid flow 1.2L/h.To ensure the accurate of the experiment,the extraction rate of peony oil was 31.41% at the optimal operation condition.(3)Effects of ultrahigh pressure processing on stability of the peony seed oilThe oxidation speed of peony seed oil by the ultrahigh pressure processing would be slow,The peroxide value was low compared with the peony seed oil without the ultrahigh pressure processing.So the stability of the peony seed oil was higher after ultra-high pressure treatment.(4)Effects of high pressure on lipase in peony seedThe expertment studied effects of high pressure,presusure-holding time and pH on lipase in peony seed.The optimal treating condition was obtained by BBD.Integrated single factor and BBD,the optimal treatment condition was 306.5MPa,pressure holding-time 26.8min,pH6.92.(5)Influence of ultra-high pressure processing of peony seed oil compositionThe kinds of fatty acids in different pressure were also a great gap.Through study,the quality of peony seed oil was the highest under the pressure of 500 MPa.The quantity of linolenic acid was also the most.