WAI and WSI were determined according to Anderson et␣al.
(1969). The ground sample (2.5 g) was suspended in 30 mL of
distilled water at room temperature. After standing for 30 min
(with intermittent shaking every 5 min), the sample was centrifuged
at 3000 rpm for 15 min. The supernatant was decanted into
an evaporating dish of known weight and dried at 105 C until
constant weight. The remaining gel in the centrifuge tube was
weighed, andWAI andWSI were calculated as following equations: