Starch was estimated in PPW (2.5 g in 0.02 M citrate/
Na2HPO4 solution, 97.5 mL, pH 5), after gelatinization (placed in
boiling water for 30 min), by enzymatic treatment (2.6 U a-amylase
and 4.9 U glucoamylase (Sigma, USA)) for 240 min at 50 C,
deactivated in boiling water for 10 min, filtered (0.45 lm), and
analyzed by HPLC for glucose using mannitol as an internal standard.
PPW (5.0 g) was extracted using a Soxhlet apparatus with
CH2Cl2 (150 mL) for 16 h, the lipid extract was concentrated to dryness,
and the yield was determined gravimetrically according to
ASTM D1108-96.