Study of Enzyme Activity and Stability to pH and Temperature of Bromelain Extracted from Curaua (Ananas erectifolius L. B. SMITH) Purple and White

Ananas erectifolius (curaua) is a fibrous vegetable that can be found in North region of Brazil. It has physico-chemical features that provide great potential in the automobile industry as a source of fibers. In addition, from the same plant, the development of new extraction and purification processes for bromelain have been studied. To optimise this process, it is necessary to investigate  enzyme stability, so that bromelain retains its biological activity when stored, isolated, purified or subjected to any other manipulation, such as autodigestion, proteolytic enzymes and heating. This study aimed to evaluate the activity of the enzyme bromelain extracted from the leaves of curaua, white and purple, and study its stability. The proteolytic activity was measured for each of the tests by the azocasein method. The stability study to pH and temperature was accomplished by the enzyme activity after storage at 4°C and -18°C, compared with the lyophilized crude extract, over a period of 30 days. The samples were subjected to different conditions for a period of 60 minutes and then the remaining bromelain activity was measured. Results showed that bromelain extracted from lyophilized curaua provided better stability and a higher enzymatic activity, and was also more stable at 20°C, losing only 5% of its activity