Moisture sorption isotherm and shelf-life estimation of freeze-dried surimi powder

¹ Department of Aquatic Product Technology, Faculty of Fisheries and Marine Sciences, IPB University, 16680 Bogor, West Java, Indonesia
² Center of Coastal and Marine Resources Studies (PKSPL), IPB University, 16127 Bogor, Indonesia

^* Corresponding author: wahyu.ramadhan@apps.ipb.ac.id

Abstract

Due to the fact that commercial wet surimi must be frozen, the adoption of dried surimi or surimi powder has emerged as the favored choice in the surimi industry to reduce costs. However, as surimi experiences the transition to its dried form, changes in moisture content can potentially influence quality and shelf life. To determine the optimal storage conditions for surimi powder, moisture sorption isotherms were evaluated over a range of water activity from 0.069 to 0.970. Five sorption models were then applied to the data. The water vapor permeability of three different packaging materials was also determined and the Labuza mathematical model was used to predict the shelf life of the product. This study attempted to assess the changes in the quality of surimi powder and predict its shelf life. The moisture sorption isotherm curve for dried surimi revealed a smooth sigmoid pattern, signifying equilibrium moisture content. The chosen sorption isotherm model, the Hasley formula (Me = log(log(ln(1/aw)) + 1.893) /-2.209), generated the mean relative determination value of 2.31. The Labuza model estimated the shelf life of dried surimi, revealing a predicted shelf life of 22.6, 4.5, and 6.1 months with retort pouch, HDPE, and OPP packaging, respectively.