Extraction And Application Of Bitter Almond Oil In Insecticide

Bitter almond contains amygdalin and almond oil, amygdalin can be decomposed to benzaldehyde under acidic condition, benzaldehyde is one of the most widely used flavor in fragrance industry. Almond oil contains high contents of unsaturated fatty acids and VE, it is an advanced edible oil, also can be used in cosmetics materials. At present, production and processing of amygdalin in China domestic market is limited to a single product, and discarded other products. In particular, amygdalin is discarded as toxic substances. This is not only wasted the resources but also caused environmental pollution. Therefore, it's necessary to study the comprehensive extracting technique of bitter almond. This article through the comprehensive research of extraction method and technique of Almond oil and bitter almond oil, provide theoretical basis and technological information for the processing and utilization of bitter almond. On the other hand, the best habitat of bitter almond is selected with the oil contents and fatty acid constituents and VE of almond oil, also with oil and the benzaldehyde content of bitter almond oil. There are a lot of researches show that essential have the control effect on agriculture pest, but there have not been reported the biological activity of bitter almond oil on pest. Our researches on the biological activity of bitter almond oil on four pests provide the theoretical basis for the feasibility of bitter almond oil as plant-based pesticides. The results were showed as follows:1. The optimized technological parameters of almond oil with supercritical CO₂ were as follows: extraction pressure 35Mpa,extraction temperature 50℃,CO₂ flow rate 24 L·h^-1, granular size 60mu and extraction time 2h. Under the optimum conditions, the yield of bitter almond oil was 52.98%.2. The optimized technological parameters of bitter almond oil yield extracted by wet distillation were as follows: time in hydrolysis 1h,temperature 40℃,distilling time 60min,ratio of water to material 10:1 and pH of hydrolysis 5. Under the optimum conditions, the yield of bitter almond oil was 7.25‰.3.To consider the yield of almond oil, content of unsaturated fatty acid and VE of almond oil, the yield and constitutes of bitter almond oil, extract almond oil with supercritical CO₂, and extract bitter almond oil with wet distillation is the best technology line of utilization of bitter almond. To reduced the cost, combined with the content of benzaldehyde in bitter almond oil, extract almond oil with press and extract bitter almond oil with wet distillation is the best echnology line.4.Choice out the best habitat of bitter almond is selected with the oil contents and fatty acid constituents and VE of almond oil, also with oil and the benzaldehyde content of bitter almond oil. The best habitat of bitter almond is LinYou.5.The fumigation effect of the essential oil with and without HCN of bitter almond on insects was studied. The results show that the two kinds of bitter almond oil have strong fumigation activity against Musca domestica vicina, Aedes albopictus and Mythirmna separata. It is have the characteristic of low effective concentration and quick response. In addition, the research on fumigation activity against Sitophilus zeamais in vacuity warehouse and warehouse is showed that the fumigation toxicity is lower in warehouse than in vacuity warehouse.6.The contact toxicity of two kinds of bitter almond on Musca domestica vicina, Mythirmna separata and Sitophilus zeamais was studied. The result showed that the contact toxicity of bitter almond oil is stronger with the increase of concentration. On the other hand, the contact toxicity order of bitter almind oil on three pests is Musca domestica vicina, Mythimna separata Walke and Sitophilus zeamais Mots.7.The research of antifeedant toxicity of bitter almond oil against 3th instar larve of Mythimna separata Walke showed that under the higher concentration, the antifeedant rates are above 95.78% at the test time, but under the lower concentration, the antifeedant rates are decreased with prolonging the treatment time.8. Deterrent effect of bitter almond oil on the adult of Sitophilus zeamais Mots. was tested. The result showed that the deterrent effect is decreased with prolonging the treatment time. On the other hand, the mortality rate of Sitophilus zeamais Mots increased in accordance with prolonging the treatment time, eventually achieve the 100% mortality.9. Bioassay method on the skin were employed to assess the effective protection time and the repellency of bitter almond oil and floral water against Aedes albopictus. The result showed that the repellent rate of two kinds of bitter almond oils after 8 hours are above 96.76%,but the repellent rate of floral water at 8 hours is 58.28%.On the other hands, the effective protection time of two kinds of bitter almond oil is 6h and 8h respectively, it's significantly higher than floral water.10. Growth and development activity of two kinds of bitter almond oil against Musca domestica vicina and Mythirmna separata.is studied. The result showed that the time of larvae and pupal stage is shortened 1 to 2 days, and caused some malformed pupas (permanent pupa or died pupae in Musca domestica vicina) in the treatment of different concentration. 11. Populations inhibitory effect of two kinds of bitter almond oil against Sitophilus zeamais Mots showed that the populations inhibitory effect of F1 and F′is decreased with the decrease of concentration, the populations inhibitory rate of F1 and F′is between 30% and 100%, 29.39% and 58.19% respectively.12.The study of insecticidal activity against four pests of two kinds of bitter almond oils showed that insecticidal activity of the oil without HCN is higher then the oil with HCN.