SUMMARY
Dried sandfish (Holothuria scabra) is often poorly dried by artisanal fishers in the Philippines, resulting in downgrading of the product. To establish recommended moisture content (MC) for a stable product, this study aimed to develop moisture sorption isotherms (MSI) at 30, 45 and 60°C at ten levels of water activity (aw) using an isopiestic method based on saturated salt solutions. MSI data was fitted to six mathematical models by non-linear regression analysis. Water vapor transmission rate (WVTR) of low-density polyethylene (PE) and polypropylene (OPP) film was measured at 30 and 35oC. A mass-balance model was used to predict shelf life and moisture content during storage based on MSI and WVTR data. MSI of H. scabra followed a Type III curve, which was best fitted to a Peleg model. For a stable product, the recommended range for MC during storage was 0.12-0.18 g g-1 dry matter to avoid over- or under-drying; this corresponded to aw of 04-0.6. Predicted shelf life for PE and OPP film packs at 30oC reached 114 d and 372 d, respectively; at 35oC, predicted shelf life was 83 d and 141 d, respectively.