Uptake kinetics and absorption of calcium in apple matrices.

摘要

Kinetics of Ca uptake by blanched and unblanched apple tissue during impregnation treatments under vacuum or/and at atmospheric pressure were investigated. The relative absorption of Ca in rats, with calcium carbonate as reference substance, was also analysed as a first approach. Apple impregnation was conducted (with and without previous blanching in saturated vapour) in isotonic glucose aqueous solutions containing calcium gluconate and lactate. A 50 mm Hg vacuum pressure was applied for a time t1 (0-180 min) or atmospheric pressure was used for a process time t2 (0-7.5 h). Ca uptake by apple tissue was influenced by system pressure, blanching and impregnation time, reaching 500-4600 mug Ca/g, depending on process variables. True Ca absorption ranged between 74 and 86%.