(P04-072-24) Heat Stability of Myrosinase Activity in Plants of Family Brassicales

Objectives: The myrosinase enzyme, present in cruciferous and related vegetables, converts glucosinolate precursors also present in the plants to the highly antioxidant isothiocyanates (ITC). ITCs like sulforaphane are known for their health advantages, including cancer prevention and enhanced cognitive function. As many plants in the Brassicales Family thrive in extreme temperatures, this study aims to test myrosinase activity in 20 plants living in various climates from around the world when exposed to high temperatures. The isolation of a high heat stable myrosinase would allow for various applications in the food and supplement industries.

Methods: Myrosinase activity was assessed in aqueous extracts of desiccated leaf samples at three different temperatures (20°C, 70°C, and 85°C), with 30 minutes’ incubation using a chromogenic enzyme assay.

Results: Overall, plants in Moringaceae Family have higher activities at all temperatures. Myrosinase activity ranged from 0 to 30.634 I.U./g dry weight at room temperature. As the temperature rose, the activity of myrosinase decreased in all the leaf samples. Plants grown in cool areas showed a lower activity at room temperature, as well as when exposed to higher temperatures, and at 85°C, the activity of myrosinase dropped to zero. In comparison, plants grown in hotter climates tended to have a more stable myrosinase activity when incubated at higher temperatures, especially in M. peregrina that still maintained 10% myrosinase activity at 85°C.

Conclusions: Myrosinase activity in the plants tested varied at room temperature and at high temperatures. Plants living in hotter climates exhibited more stable myrosinase activity at higher temperatures compared to those from cooler climates. The implications of these findings will allow for extraction and purification and further study of the gene for the myrosinase enzyme from M. peregrina and allow for countless applications in basic science and health-related research as well as industry.

Funding Sources: N/A