Studies On The Extraction And Antioxidant Activities Of Phytic Acid From Rapeseed Cake

Phytic acid is a natural compound which can be widely found in coms, legumes andoil-seeds. It has attracted great attention by its application in food industry, environmentprotection and medical treatment depending on its unique chelation with metals and naturalanti-oxidization. Therefore, the exploitation of phytic acid using our abundant plantresources has a broad prospect.The technics of phytic acid extraction from protein-extracted rapeseed cake wasstudied and the extraction conditions of acidic solution were optimized. 704^# weak alkalineion-exchange resin was chose and the parameters of ion-exchange process were studied bystatic and dynamic method respectively. The antioxidant activities of phytic acid was alsostudied. The main conclusions of the experiments were as follows:(1) The process of extraction was optimized by orthogonal experiment on the basis ofunifactor experiments with phytic acid extraction rate as the index. The optimal conditionswere: HC1 concentration 0.Smol/L, temperature 60℃, time 30min, rapeseed—HC1 cakeratio 1:5, under which the extraction rate of phytic acid was 95.8ï¼…. The content of organicphosphor in obtained phytin was 31ï¼….(2) 704^# weak alkaline ion-exchange resin was chose in comparison with 717^#. Theabsorption equilibrium could be reached when the time was 2h, pH3 and temperature20～30℃at static state. The 1.0 mol/L NaOH had the best effect as the static washingsolvent.(3) The absorption and washing effect of 704^# weak alkaline ion-exchange resin onphytic acid were studied by dynamic method. The results revealed that choosing 7.4mg/mland 1.5ml/min as the concentration of samples and the velocity of the flow respectively hadbetter effect on phytic acid absorption. The efficiency of the resin was better with a higherratio of column diameter to height in a certain scope. It was found that the solvent of1.0mol/L NaOH had a better washing effect with the velocity of flow 1.0ml/L. The qualityof phytic acid obtained met the GB.(4) The antioxidant activities of phytic acid were studied. The results showed that theaxunge peroxidation reaction could be slowed down by phytic acid with a better effect thanBHT. An obvious scavenging effect of phytic acid on OH and O2 was also observed inthe two radical systems which was in proportion to its quantity. The IC₅₀ of phytic acid onscavenging OH and O^2- were 2.54mg/ml and 9.28mg/ml respectively.