Study On Preparation Process And Stability Of Peony Seed Oil

Paeonia seed is mature seed of peony which belongs to perennial, deciduous shrubs.As a by-product of the production of Tree Peony Bark, Paeonia seed riches in crude fat.In order to further exploit and develop the paeonia seed oil, we researched thepreparation and the quality of the oil. The main results are as follows:Paeonia seed oil was extracted by supercritical CO2extraction method. Using thePaeonia seed oil yield as the evaluation criteria, different factors were considered, suchas the extraction temperature, pressure, time and CO2flow rate. Based on the singlefactor experiment, the best optimization technology was obtained by using theorthogonal experiment. The optimal process conditions were obtained as follows:extraction pressure35MPa, extraction temperature45℃, extraction time2.5h and CO2flow rate30L·h-1. The yield of the paeonia oil was23.85%in such circumstance. Themain fatty acid constitutes and relative contents of Paeonia seed oil were linolenic acid(56.778%), linoleic acid (31.113%), palmitic acid (8.996%) and stearic acid (2.52%),respectively.Paeonia seed oil was extracted by subcritical fluid extraction method. Using thePaeonia seed oil yield as the evaluation criteria, different factors were considered, suchas the extraction temperature, pressure, time and extraction times. Based on the singlefactor experiment, the best optimization technology was obtained by using theorthogonal experiment. The optimal process conditions were obtained as follows: theextraction temperature50℃, pressure0.5MPa, time30min and extraction times three.The yield of the paeonia oil was24.16%in such circumstance. The main fatty acidconstitutes and relative contents of Paeonia seed oil were linolenic acid (45.412%),linoleic acid (38.119%), palmitic acid (11.125%) and stearic acid (3.649%),respectively.Paeonia seed oil was extracted by aqueous enzymatic extraction method. Using thePaeonia seed oil yield as the evaluation criteria, different factors were considered, suchas enzyme type, the extraction temperature, time, enzyme dosage, solid/liquid ratios andenzyme PH. Based on the single factor experiment, the best optimization technologywas obtained by Response surface methodology. The optimal process conditions wereobtained as follows: the extraction temperature52℃, time4h, enzyme dosage556U/g,solid/liquid ratios1:5.4and enzyme pH10.3. The yield of the paeonia oil was23.25%in such circumstance. The main fatty acid constitutes and relative contents of Paeoniaseed oil were linolenic acid (58.163%), linoleic acid (24.055%), palmitic acid (12.33%)and stearic acid (3.555%), respectively.The properties of oils extracted by different methods were analyzed and compared.It can be concluded that three different oils have the same infrared spectra absorption.The UV absorption intensity of oils followed by supercriticalCO2＞subcritical＞ aqueous enzymatic in the200nm-250nm and260nm-315nm. The four main fatty acidswere detected by GC-MS and they were linolenic acid, linoleic acid, palmitic acid andstearic acid, respectively. The refractive index, saponification and iodine value have nosignificant differences in three oils. The acid value and peroxide value of Paeonia seedoil extracted by subcritical fluid slightly higher than the other two extracted methodsand it also have a deeper color.Taking the POV as evaluation index, the effects of temperature, light and air on theoxidative stability were studied. The results showed that three factors promoted theoxidation of peony seed oil. So the oil should be kept in low temperature, evaded thelight and sealed.The effects of several anti-oxidants and synergists on the oxidative stability of thePaeonia seed oil extracted by supercritical CO2were studied by Schaal experiment.Using the POV and TBA value as the evaluation index, the results showed that with theexception of VE, the oxidative stability of oil was increased by the other threeanti-oxidants. And it depended on the added amount of anti-oxidants. Under theconcentration of0.02%, the anti-oxidation ability of several anti-oxidants in the peonyseed oil listed descending as TBHQ＞TP＞DMY＞Rosemary＞VE.When TP and DMY compound by3:1synergistic, the anti-oxidative effect is betterthan that of single TP. VC and CA had great synergistic effect with regard to the twokinds of anti-oxidants and the effect of VC is superior to that of CA.