The molecular weight of the EPS was determined
The water BIX 02565 and retention properties of the EPS were observed according to the method of Chen, Siu, Cheung, and Wu (2014) with modification. The EPS sample was ground into fine powder, over-dried at 95 °C for 5 h, and weighted (noted as W0). For measurement of water absorption, the EPS was placed in a sealed humidity chamber maintained by saturated K2CO3 at 43% relative humidity (RH) at 25 °C for 24 h then weighted (noted as Wt). The water-absorption rate (Ra) was represented by the following formula: Ra (%) = 100 × (Wt − W0)/W0.
For evaluating the properties of water retention, the sample (noted as W0) was first placed in a peroxisomes humidification chamber containing pure water at 25 °C for 24 h and weighted (noted as W1), then transferred to a humidity chamber containing saturated K2CO3 (43% RH) to dehydrate at 25 °C for 24 h and weighted (noted as W2). The water retention rate (Rr) was obtained by: Rr (%) = 100 × (W2 − W0)/(W1 − W0).