Total phenolics
Drying methods affected phenolics content, ranging from
963.2 mg GAE/100 g db in VD samples to 1725.2 GAE/100 g db in FD
samples (Fig. 1a). The highest content observed in FD samples
might be due to no heat used in this method. Statistical analysis
revealed that CD and VD samples contained significantly (p 0.05)
lower phenolic content as compared to FD and IRD. Ice crystals,
formed within the tissue matrix during freeze drying, rupture the
cell structure facilitating solvent extraction and consequently high
extraction of phenolic compounds (Shih, Kuo, & Chiang, 2009).
Infrared dried sample had high phenolic content which might be
due to non-enzymatic conversion of phenolic precursors to new
phenolic compounds as in case of microwave drying (Soong &
Barlow, 2004). Total phenolic content of freeze dried powder
from Tommy Atkins mangoes has been reported to be 825 mg GAE/
100 g (Hung, 2012). Our results showed higher values of phenolic
content of mango powder than reported by these researchers,
which might be attributed differences in fruit maturity or horticultural
practices.