Extraction, Component Analysis And Antioxidant Activity

This paper aimed at studying the reason of poor oxidation stability of pine nut oil. Pine nut kernel was used as the raw material. The physical and chemical indicators of pine seed oil extracted with the ultrasonic assisted solvent extraction were determined. The components of pine seed oil, including VE, fatty acids, sterols and flavor compounds were qualitatively and quantitatively analysis by high performance liquid chromatography and gas chromatography. The polar compounds of pine seed oil extracts were analysis by high performance liquid chromatography-mass spectrometry. Otherwise, the oxidative stability of pine seed oil and antioxidant activity of polar pine seed oil extracts were studied, resulting provide a basis for improving the storage period of pine seed oil.Pine seed oil was extracted by ultrasonic assisted solvent extraction, through the orthogonal experimental design, with the oil rate as the study index, to determine the optimal process conditions were:ultrasonic power 0.41 W/cm2, extraction time 25min, and ratio of liquid to solid 1:9 (g:ml). The biggest oil rate was 98.85%. At this time, the acid value and peroxide value of pine seed oil were 1.08 and 0.66, respectively. They were in the range of GB.Pine seed oil obtained under the optimum extraction process conditions was used as raw material. The contents of VE were determined by high performance liquid chromatography. The compositions and contents of the fatty acids, sterols and flavor substances of pine seed oil were determined by gas chromatography. The results showed:the contents of oleic acid and linoleic acid among pine seed oil were 31.33% and 44.39%, respectively; the contents of unsaturated fatty acid was up to 91.6%; the contents of VEwas 73.27mg/100 g oil, the alpha-TOC was about 14.43 mg/100 g oil; the contents of total sterol was 2076.62mg/kg, including squalene. sesamin, campesterol, sitosterol,16-alpha-hydroxypregnenolone and astaxanthin; flavor compounds were mainly included alkenes and alkynes compounds.The stability of pine seed oil was inspected. The polar group of pine seed oil extracts was analysised by HPLC-MS. The antioxidant activity of polar pine seed oil extracts were studied by the DPPH radical scavenging assay, ABTS radical scavenging assay,β-carotene bleaching test and iron reduction experiments, respectively. The results showed:the stability of pine nut oil was poor, only higher than that of peanut oil; nineteen compounds were detected in the polar pine seed oil extracts, including kaempferol, epicatechin gallate, quercetin, chlorogenic acid acid, coffee acid, terpineol and so on. The antioxidant capacity of polar pine seed oil extracts was poorer than those of olive oil and sesame oil, which could explain the poor oxidation stability of pine seed oil. Complex antioxidants (tea polyphenols-VC-citric acid) would play an important role in the oxidative stability of pine nut oil.In this paper, the extraction processing of pine seed oil, the composition of pine seed oil and polar groups, the oxidation stability of pine seed oil and the antioxidant activity of polar pine seed oil extracts were studied, which could provide the basic data and the basis theory for improving the storage stability of pine seed oil.