水酶法提取牡丹籽油的研究 GC-MS . Aqueous enzymatic extraction of Paeonia suffruticosa seed oil

Abstract

The Paeonia suffruticosa seed oil was extracted by aqueous enzymatic method.According to comparative experiments,the three-step enzymolysis combined with twice demulsification was chose as the optimal process.The results showed that the extraction conditions of Paeonia suffruticosa seed oil by three-step enzymolysis combined with twice demulsification were optimized as follows: 5 g Paeonia suffruticosa seed powder,ratio of material to water 1∶ 5,dosage of cell wall polysaccharides hydrolysis enzyme(ratio of Cellelase to Pectinase 2∶ 1) 1.5 mL,enzymolysis time 2.5 h; α-amylase dosage 0.6 mL,enzymolysis time 45 min; alkaline protease dosage 0.18 g,enzymolysis time 2 h; using freezing and thawing demulsification method,freezing temperature-20 ℃,freezing time 18 h,thawing temperature 50 ℃,thawing time 2 h.When extracting oil from 200 g of Paeonia suffruticosa seed powder under the optimal conditions,the free oil yield was 17.6% and the total oil yield was 25.4%.The Paeonia suffruticosa seed oil obtained had good quality in terms of undetected peroxide,the acid value 3.5 mgKOH/g,iodine value 177.09 gI/100 g and saponification value 173.07 mgKOH/g.The unsaturated fatty acids content of Paeonia suffruticosa seed oil was up to 92.77%,in which the contents of linolenic acid,linoleic acid and oleic acid were 37.33%,31.13% and 24.31% respectively.The aqueous enzymatic extraction of Paeonia suffruticosa seed oil had the items of the seed powder without drying and the extraction temperature below 70 ℃ during the whole process,which could reduce the chances of oil oxidation.