Extraction Process And Oxidation Stability Of OkraSeed Oil

Okra[Abelmoschusesculentus(Linnaeus)Moench] is along with the flowers, vegetables and medicinal of functions, and it can be used in many ways. However, the mature time of Okra is very short so that fruit quality could rapidly aging, fiber increased, food value reducingif you picked late and this phenomenon restricts the development of the Okra industry.To achieve sustainable development and make full use of resources for the okra, the high oil content varieties was screened by compared the main components and physicochemical properties of difference, the preparation process of aqueous enzymatic oil was optimized, and fatty acid composition and oxidative stability were compared for the samples prepared by different processes.The results are as follows:(1)There are significant differences for different varieties of okra in the main chemical composition. All about, with the highest ash content is Taiwan wufu, with the highest flavonoids content is Lv wuxing, with the highestprotein and total sugar content are Liuyang native species.(2) The oil content difference for different varieties of okra seeds in the order: Wu-jiao>Lv wuxing>Taiwan wufu>Liuyang native species>Hibiscus coccineus. There are significant differences to different varieties of okra on the physical and chemical properties. All about, the highest saponification value is Lv wuxing; The highest iodine value is Taiwan wufu that is far less than the prescribed standards for soybean oil; Refractive index is similar in different varieties of okra seeds, it has no significant difference (P< 0.05).(3) Alcalase (55 ℃, pH8.5) is the most suitable for aqueous enzymaticextraction of okra seed oil, it is regression equation:Y= 13.913 88+0.754 00X1+0.483 44X2+0.253 15X3-0.898 62X12-0.606 94X22-0.375 36X32+0.402 50X1X2 (Y represent yield, X1representratio of solid to liquid, X2represent time, X3represent the enzyme dosage).(4)The best process conditions for aqueous enzymatic extraction of okra seed oil is: ratio of solid to liquid 1:5.5 (g/mL), enzymolystime 4.2 h, enzyme dosage 3% (in the substrate quality meter).Under the condition, the yield is 14.25 ±0.06%(n=5),it and 14.32% (predict peak) between was no significant difference (P> 0.05).(5)13 kinds of fatty acids were detected from okra seed oil, and the composition and the content is not affected by the preparation process. Besides, the proportion (SFA:MUFA:PUFA) is very balanced, close to 1:1 : 1 from the United Nations Food and Agriculture Organizationand the World Health Organization recommends an ideal model.(6)With the increase of oxidation induction temperature (X/℃), the induction period is shorten for different process (ethanol extraction, squeezing water method and enzymatic) preparation of okra seed oil. When the room temperature, the shelf life of okra seed oil by aqueous enzymatic method(230 d), shorter than solvent leaching method(281 d), longer than the cold press method(164 d), which reflects the potential advantages in normal temperature storage of aqueous enzymatic extraction of okra seed oil.