Phase change material‐assisted freezing of tuna: Impact on freezing process and thawing loss

Abstract

Due to slow freezing, freezing fresh fish in a chest freezer often leads to deterioration while products are thawed. Many approaches have been conducted to deal with it. One of them is the application of Phase Change Material (PCM) in refrigeration systems. This study aims to investigate the ability of PCM to accelerate the freezing of fish in the household freezers. The tuna used was stored in the freezer with PCM, which was put on a surface wall cabinet then compared with storage in the freezer without PCM. Besides, the door of the freezer was also opened frequently (three times a day, 1 hr each time) to find out the effect of fluctuating temperatures and freezing operations for 60 hr. The parameters observed include the evolution temperature of the air cabinet and fish, energy consumption of the freezer, and thawing loss. Results showed that PCM accelerated the cooling rate of air cabinets and fish but could not suppress the fluctuation temperature. The quality of the frozen tuna improved, which was indicated by a decreased thawing loss parameter from 3.10% to 1.76%. Overall, this finding revealed PCM has significant potential to improve the fish freezing process. Practical Applications The household chest freezer is widely used to freeze fish by small and medium‐sized enterprises (SMEs). The most important factors in freezer preferences are simple operations and low energy consumption. But, the freezer worked at slow freezing, which caused higher thawing losses of the product. Hence, the application of PCM to the household freezer potentially improves the freezing process of the fish. So, sellers and retailers of fish could maintain their products without replacing the freezer with an advanced one.