Effects of high hydrostatic pressure (HHP) on bioaccessibility, as well as antioxidant activity, mineral and starch contents in Granny Smith apple

The aim of this work was to study the effect of high hydrostatic pressure on the bioaccessibility of specific nutrients (antioxidant, minerals and starch) in apple and to establish processing conditions that maximise the health benefits. The apple was pressurised at 500 MPa during 2, 4, 8 and 10 min. The antioxidant activity, mineral and starch content and bioaccessibility of apple samples were significantly affected by the processing and digestion conditions. Therefore, these results indicated that in vitro digestion has a noticeable effect on the antioxidant concentration, IC50, with much lower values (a smaller IC50 value corresponds to a higher antioxidant activity) of apple samples compared with those untreated and non-digestion. Apple has the highest calcium content (30.33 +/- 1.94 mg/100 g), iron (14.46 +/- 3.49 mg/100 g) and zinc (6.22 +/- 0.91 mg/100 g). High hydrostatic pressure increased the mineral contents availability by 2.11-303.00% for calcium, 4.63-10.93% for iron and 8.68-28.93% for zinc. The dialysability and solubility of calcium, iron and zinc with respect to the values for the untreated sample were reduced by this high pressure technique. Consumption of apple under high hydrostatic pressure may supply substantial antioxidants, mineral and starch, which may provide health promoting and disease preventing effects. (C) 2011 Elsevier Ltd. All rights reserved.