Studies On Preparation Of Nervonic Acid From Malania Oleifera

Nervonic acid is the core natural ingredients of nerve cells and nerve fibers in the brain. The lack of nervonic acid will cause stroke sequelae, senile dementia, cerebral palsy, brain atrophy, memory loss, insomnia, forgetfulness and other brain diseases. However, nervonic acid is difficult for the body itself to generate, which can be supplemented in vitro. With the development of oil chemistry, certain plant rich in nervonic acid is founded by scientists, and a new path for the sustainable use and development of nervonic acid is created by this discovery. Malania oil is richer in nervonic acid than any other plant.In this paper, the extraction process of Malania oil, the saponification process for nervonic acid and the separation and purification process of nervonic acid were systematically studied based on Malania oleifera. It aims to establish a suitable preparation process of nervonic acid for industrial production. Thus, the contents and achievements of this paper are as follows:1. Study on extraction process of Malania oilThree different extraction techniques of solvent extraction, ultrasonic-assisted extraction and supercritical CO₂ extraction were studied. The sensory evaluation, oil yield, physical and chemical properties were used as indicators to evaluate these techniques. It showed little difference in sensory evaluation among three kinds of Malania oil from different techniques, though oil from supercritical CO₂ extraction was with better clarity. In the aspect of oil yield:ultrasonic-assisted extraction ?58.00%?> solvent extraction ?54.51%?> supercritical CO₂ extraction ?30.70%?; In the aspect of physical and chemical properties:the content of moisture and volatile matter ?0.82%-0.85%?, relative density ?0.8949-0.8955?, refractive index (n²⁰) ?1.4691-1.4695?, the saponification value ?161.0-167.0? and peroxide value ?0.010-0.013 g/100g? were similar. The acid value ?solvent extraction 2.4 mg/g< ultrasonic-assisted extraction 3.1 mg/g< supercritical CO₂ extraction 18.3 mg/g?, and the iodine value ?ultrasonic-assisted extraction 56.71 g/100g< solvent extraction 58.47 g/100g< supercritical CO₂ extraction 77.44 g/100g? were significantly different. Thus, Ultrasonic-assisted extraction is suitable for Malania oil with low acid value ?3.1 mg/g?, low peroxide value ?0.011 g/100g? and low iodine value ?56.71 g/100g?. In addition, under the temperature of 60 ? extracted for 25 min, the extraction yield was 58.00%, and the extraction transfer rate was 89.64%. Furthermore, the fatty acid of Malania oil extracted from this method was analyzed by GC-MS. The results showed that the main components were oleic acid 26.0%, erucic acid 14.1% and nervonic acid 43.4%.2. Study on saponification process for nervonic acidA method for the determination of free nervonic acid in process control was established, and the saponification process for nervonic acid was optimized. The single factor experiments and the response surface design were used to optimize the saponification process. Choosing content of nervonic acid and yield of mixed fatty acid as indicators, the effects of solvent type, alkali type, saponification time, alkali-material ratio, liquid-solid ratio and saponification temperature were investigated. The model for the content of nervonic acid was established by the Design-Expert 8.0.6 software: Y=-1168.4+171.9A+1975.1B-325.1C+25.9D-424.1AB+17.0AC+2.6CD-14.0A²-0.2D². The indicators of R ?0.9294? and SNR ?17.012> 4?, means that the model was reliable. In addition, the saponification parameters were optimized according to the response surface map and contour map:saponification time of 4 h, alkali-material ratio of 0.25 g/g, liquid-solid ratio of 1 mL/g, saponification temperature of 90 ?. Under these conditions, the content of free nervonic acid increasing from 59.32 mg/g to 396.19 mg/g, which is in good fitting with the predicted value 412.99 mg/g, and the saponification rate of nervonic acid was 85.65%. The present situation with low degree of saponification or unreasonable saponification time is changed by the optimization of the saponification process and raw material for separation and purification of nervonic acid is provided.3. Study on separation and purification process of nervonic acidThe mixed fatty acids obtained by saponification were further purified by low-temperature crystallization and molecular distillation technology. Firstly, choosing alcoholas the crystallization type, the effects of alcohol concentration, solid-liquid ratio, crystallization time and crystallization temperature on the enrichment of nervonic acid were investigated by single-factor experiment and orthogonal experiment design. According to the two-index evaluation of content and yield of nervonic acid, the optimal experimental conditions were A₂B₂C₂, namely solid-liquid ratio of 1:4, crystallization temperature of 4 ? and crystallization time of 6 h. Under these conditions, the content of nervonic acid reached 789.79 mg/g, the yield reached 27.86%, and the recovery rate of nervonic acid reached 58.63%. Secondly, the single-factor experiment and variance analysis were used to optimize the appropriate parameters for molecular distillation, and the method of separation and purification from free fatty acids was established. The effects of distillation temperature, charging rate and wiper rolling speed on molecular distillation were studied. The optimum conditions were as follows:distillation temperature of 160 ?, charging rate of 2 d/s, wiper rolling speed of 300 r/min. Under these conditions, the content of nervonic acid was 561.21 mg/g, the yield was 54.09%, and the recovery rate of nervonic acid was 85.67%. Thirdly, molecular distillation-solvent crystallization technology was established to purify nervonic acid. The content of nervonic acid of final product was 717.02 mg/g, the yield was 37.77% and the recovery rate of nervonic acid was 76.47%. The separation and purification process is simplified by molecular distillation-solvent crystallization technology which is of significance for industrialized production. In addition, the final product with high purity and high yield is safe and harmless to health.In this paper, the preparation of nervonic acid from Malania Oleifera kernel was studied systemly. The method has many advantages, such as, simple operation, few steps, short production time, high purification efficiency and environment friendly. The yield of final product was 20%, the purity of nervonic acid was 70%, and the transfer rate of nervonic acid was 58%.