Study On The Extraction Of Pineapple Polysaccharide And Its Biological Activity

Pineapple peel that was grown in Fujian province was used as raw material to prepare pineapple polysaccharide. After separating and purifying, the decoloring technology, the anti-oxidation activity, and the multipication effects to bacillus bifidus of pineapple polysaccharide were studied. This study opened up a new way for the comprehensive utilization of pineapple byproducts and promoted the value of pineapple.(1) Hot water extraction was used to extract pineapple polysaccharide. Using the pineapple polysaccharide extraction efficiency as an index, the effects of the factors such as different solid-liquid ratio, temperature and time were studied. Results showed that the relative importance of these factors was as follows:temperature> time> solid-liquid ratio. Under the optimal conditions for the hot water extraction technology of 100℃, three hours and 1:20 as solid-liquid ratio, the pineapple polysaccharide extraction efficiency reached 5.2%.(2) Acticarbon and chitosan were used to decolor pineapple polysaccharide. Based on the results from orthogonal experiments, the optimal conditions for acticarbon decoloring were that pH value was 3, the amount of acticarbon was 1% of pineapple polysaccharide, and the time was 30 minutes. The rate of decoloring was 86.5% and the retention rate of polysaccharide was 93.09% under the above conditions. While the optimal conditions for chitosan decoloring were that the amount of chitosan was 5%, time was 45 minutes, and temperature was 45℃. The rate of decoloring using chitosan was 74.3% and the retention rate of polysaccharide was 95.23% under the latter conditions. Both of the two methods could decolor pineapple polysaccharide efficiently.(3) The ability of pineapple polysaccharide to scavenge free radicals was studied by using hydroxyl radicals system, superoxide anion system and polysaccharide reductive ability system. Results show that, when the concentration of pineapple polysaccharide was 12 mg mL-1, the scavenging rate of hydroxyl radicals reached 90% measured by the salicylic acid colorimetry. When the concentration was 6 mg mL-1, the scavenging rate of superoxide anions reached 80% measured by the pyrogallol autoxidation method. The reductive ability of pineapple polysaccharide enhanced with its concentration, and there was a good concentration-response relationship between the concentration and the reductive ability.(4) The method of plate culture count was used to study the multipication effects of pineapple polysaccharide on active bacillus bifidus. Results show that differences existed in the multipication effects between matched groups under experimental concentration of pineapple polysaccharide. It explained the effects of pineapple on adjusting intestinal flora and improving intestinal environment.