Enzymatic improvement of date quality. Use of invertase to improve texture and appearance of “sugar wall” dates

Abstract “Sugar wall” dates, which have crystalline sucrose present in the tissue, were improved in quality and market value by treating the fruits with food grade invertase. Enzyme concentration, temperature, time, and the degree of sucrose hydrolysis necessary to prevent recrystallisation during subsequent storage were studied in Deglet Noor dates. Native invertase activity, which can be reactivated by spraying or vacuum hydration was not sufficient to bring the ratio of sucrose: reducing sugar to a level low enough to prevent subsequent sucrose recrystallisation.