| In 1998, Mexico Milpa ALta edible cactus was introduced to China by Agriculture Ministry. Many people like Milpa ALta cactus for its individual flavour and taste when it appeare in market.In the study, the nutritional ingredients of edible cactus were analyzed, the cactus candy was exploited, the antimicrobial activity of extracts of edible cactus were studied, SOD from edible cactus was separated and purified, its nature was studjed. This experiment aims at estabilishing basis for exploiting edible cactus.The results showed that it was low in carbohydrate, crude protein and fat. Glu was the major part of the amino acids. The contents of malate ,tartrate, oxalate and peotin were high, it was rich in Ca, Mg, Fe, Zn.It was shown that extrats of edible cactus extrated by using water and ethanol had an inhibiting activity to E.coli etc, and are not effective to Penicillium sp etc. In short, water extracts of edible cactus has a stronger inhibiting activity than ethanol extracts. The MIC for every kind of microorganism is respedtively as follows: E.coli 0.25%, Staphylococcus aureus 0.125%, Bacillus cereus 2%, In addition, extracts of edible cactus were excellent in heat stability, it still showed a strong antiseptic power after a treatment of 121℃,20min.SOD from edible cactus was separated and purified through ammonium sulfate precipitation and column chromatography with Sephadex G-75 gel filtration. The specific activity is 7158U/mg, 50.93% of the SOD activity was recovered, the molecular weight of SOD subnit is about 16000 daltons. the enzyme is Cu,Zn-SOD. Its maximum UV absorption is at 275nm. The SOD from edible cactus has good heat(80℃,120min) and acid-base stability in pH 3.0-9.0(25℃,60min), in which the activity of SOD do not decline. The quantity of SOD in edible cactus is high (110U/g). |
