Enhanced polyphenol content and antioxidant capacity in the edible portion of avocado dried with superheated-steam

In order toevaluatethe effects of drying methods on assay, this present study investigated the effect of superheated-steam drying at three different temperatures (130°C, 150°C and 170°C), in comparison with freeze drying on phenolic and flavonoid contents as well as antioxidant capacities in avocado (Persea americanaMill) pulp. The results showed that superheated-steam dried (SHSD) avocado pulp gave significantly higher total phenolic and total flavonoid contents compared to its freeze dried (FD) counterpart. The IC50 values from the DPPH assay were significantly lower (higher antioxidant activity)in SHSD pulp at all the temperatures used (6.69 – 12.16 mg/ml) compared to FD (35.02 mg/ml). The ORAC values also showed significantly higher radical absorbing capacitywhen SHSD at 170°C (26.58 µmol TE/1g)compared to FD (15.18 µmol TE/1g).The results showed that the drying methods significantly increased antioxidant capacity of SHSD avocado pulp in comparison with the FD.Superheated-steam drying at 170°C is proposed as an appropriate drying technique and condition to preserve pulp in avocado.